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CT 06-13; Tabata 10; Geotechnical Review; 2013-08-30
GEOTECHNICAL INVESTIGATION TABATA DEVELOPMENT CARLSBAD, CALIFORNIA Prepared for: LENNAR HOMES 25 Enterprise, Suite 300 Aliso Viejo, CA 92656 Prepared by: GROUP DELTA CONSULTANTS 9245 Activity Road, Suite 103 San Diego, California 92126 GDC Project No. SD365 Document No. 13-0339 March 4, 2014 March 4, 2014 Lennar Homes 25 Enterprise, Suite 300 Aliso Viejo, California 92656 Attention: Mr. Tom Lee SUBJECT: GEOTECHNICAL INVESTIGATION Tabata Development Carlsbad, California Mr. Lee: Group Delta Consultants (GDC) is pleased to submit this geotechnical investigation for the Tabata residential development in Carlsbad, California. The project will include the construction of 26 two-story wood framed residential buildings founded on post- tensioned slabs. Specific conclusions regarding the potential geotechnical constraints at the site, and preliminary geotechnical recommendations for grading, foundation, retaining wall and pavement design are provided in the following report. We appreciate this opportunity to be of continued professional service. Feel free to contact the office with any questions or comments, or if you need anything else. GROUP DELTA CONSULTANTS Matthew A. Fagan, G.E. 2569 James C. Sanders, C.E.G. 2258 Senior Geotechnical Engineer Senior Engineering Geologist Distribution: (1) Addressee, Mr. Tom Lee (tom.lee@lennar.com) (1) Addressee, Ms. Roberta Correia (robcorreia@cox.net) N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc GEOTECHNICAL INVESTIGATION TABATA DEVELOPMENT CARLSBAD, CALIFORNIA TABLE OF CONTENTS 1.0 INTRODUCTION .......................................................................................... 6 1.1 Scope of Services ................................................................................ 6 1.2 Site Description ................................................................................... 7 1.3 Proposed Development ....................................................................... 7 2.0 FIELD AND LABORATORY INVESTIGATION ............................................. 8 3.0 GEOLOGY AND SUBSURFACE CONDITIONS .......................................... 8 3.1 Santiago Formation ............................................................................. 9 3.2 Old Alluvium ........................................................................................ 9 3.3 Fill ..................................................................................................... 10 3.4 Groundwater ...................................................................................... 10 4.0 GEOLOGIC HAZARDS ............................................................................... 11 4.1 Ground Rupture ................................................................................. 11 4.2 Seismicity .......................................................................................... 11 4.3 Liquefaction and Dynamic Settlement ............................................... 11 4.4 Landslides and Lateral Spreads ......................................................... 12 4.5 Tsunamis, Seiches and Flooding ....................................................... 14 5.0 CONCLUSIONS .......................................................................................... 15 6.0 RECOMMENDATIONS ............................................................................... 17 6.1 Plan Review ....................................................................................... 17 6.2 Excavation and Grading Observation ................................................. 17 6.3 Earthwork .......................................................................................... 17 6.3.1 Site Preparation ................................................................... 18 6.3.2 Compressible Soils .............................................................. 18 6.3.3 Building Areas ..................................................................... 18 6.3.4 Fill Compaction ................................................................... 20 6.3.5 Subgrade Stabilization ......................................................... 20 6.3.6 Surface Drainage ................................................................. 20 6.3.7 Slope Stability ...................................................................... 21 6.3.8 Temporary Excavations ....................................................... 21 6.3.9 Bulk/Shrink Characteristics .................................................. 22 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc GEOTECHNICAL INVESTIGATION TABATA DEVELOPMENT CARLSBAD, CALIFORNIA TABLE OF CONTENTS (Continued) 6.4 Preliminary Foundation Recommendations ....................................... 22 6.4.1 Post-Tension Slabs (Category I) ........................................... 22 6.4.2 Post Tensioned Slabs (Category II) ...................................... 23 6.4.3 Post Tensioned Slabs (Category III) ..................................... 24 6.4.4 Settlement ........................................................................... 24 6.4.5 Lateral Resistance ................................................................ 24 6.4.6 Slope Setback ..................................................................... 24 6.4.7 Seismic Design .................................................................... 25 6.5 On-Grade Slabs ................................................................................. 25 6.5.1 Moisture Protection for Slabs ............................................... 25 6.5.2 Exterior Slabs ...................................................................... 27 6.5.3 Expansive Soils .................................................................... 27 6.5.4 Reactive Soils ...................................................................... 28 6.6 Earth Retaining Structures ................................................................. 28 6.7 Preliminary Pavement Design ............................................................ 29 6.7.1 Asphalt Concrete ................................................................. 30 6.7.2 Portland Cement Concrete .................................................. 30 6.8 Pipelines ............................................................................................ 31 6.8.1 Thrust Blocks ...................................................................... 31 6.8.2 Modulus of Soil Reaction ..................................................... 31 6.8.3 Pipe Bedding ....................................................................... 31 7.0 LIMITATIONS ............................................................................................. 31 8.0 REFERENCES ............................................................................................ 32 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc GEOTECHNICAL INVESTIGATION TABATA DEVELOPMENT CARLSBAD, CALIFORNIA TABLE OF CONTENTS (Continued) LIST OF TABLES Table 1 – 2013 CBC Acceleration Response Spectra ........................................... 36 Table 2 – Summary of Remedial Excavations ...................................................... 37 LIST OF FIGURES Figure 1A – Site Location Map ............................................................................. 39 Figure 1B – Site Vicinity Plan ............................................................................... 40 Figure 2A – Exploration Plan ............................................................................... 41 Figure 2B – Geotechnical Map ............................................................................ 42 Figure 2C – Tentative Grading Plan ..................................................................... 43 Figure 2D – Revised Grading Plan ....................................................................... 44 Figure 2E – Proposed Development .................................................................... 45 Figure 3A – Regional Geologic Map ..................................................................... 46 Figure 3B – Regional Topography ....................................................................... 47 Figure 3C – 100-Year Floodplain ......................................................................... 48 Figure 3D – Tsunami Inundation Map ................................................................. 49 Figure 4 – Regional Fault Map ............................................................................. 50 Figure 5 – Wall Drainage Details .......................................................................... 51 LIST OF APPENDICES Appendix A – Field Exploration ............................................................................ 52 Appendix B – Laboratory Testing ......................................................................... 86 Appendix C – Dynamic Settlement Analyses ...................................................... 118 Appendix D – Slope Stability Analyses ............................................................... 125 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc GEOTECHNICAL INVESTIGATION TABATA DEVELOPMENT CARLSBAD, CALIFORNIA 1.0 INTRODUCTION This report provides geotechnical recommendations for the proposed Tabata residential development in Carlsbad, California. The approximate location of the site is shown in Figures 1A and 1B. The site vicinity is shown in more detail in Figures 2A and 2B. The residential complex will include 26 wood frame buildings and an access road, as shown in Figures 2C through 2E. The objective of this study was to provide site-specific geotechnical recommendations for remedial grading and the design and construction of the proposed structures, pavements and associated surface improvements. The recommendations presented herein are based on our subsurface exploration, laboratory testing, engineering and geologic analyses, and previous experience with similar geologic conditions. 1.1 Scope of Services This report was prepared in general accordance with the provisions of the referenced proposal (GDC, 2013b). In order to develop geotechnical recommendations for the development, the following services were provided. ● A geologic reconnaissance of the surface characteristics of the site, and a review of the pertinent reports referenced in Section 8.0. ● A subsurface exploration of the site including ten hollow stem auger borings and five cone penetrometer test (CPT) soundings. The approximate locations of the explorations are shown on the Exploration Plan. Logs of the explorations are presented in Appendix A. ● Laboratory testing of samples collected during the field explorations. The laboratory test results are summarized in Appendix B. ● Engineering analysis of the field and laboratory data to help develop recommendations for site preparation, remedial earthwork, foundation design, soil reactivity, and site drainage and moisture protection. Our analyses are summarized in Appendices C and D. ● Preparation of this report summarizing our findings, conclusions and geotechnical recommendations. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 7 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 1.2 Site Description The subject site consists of the proposed Tabata residential development in the City of Carlsbad, California. The site is located immediately southeast of the intersection between El Camino Real and Camino Hills Drive, which form the northern and western property boundaries, respectively. Existing single- family residential developments bound the southern and eastern edges of the property. The approximate location of the site is shown on the Site Location Map, Figure 1A. The site vicinity is shown in more detail in Figure 1B. The site slopes moderately down to the north. The elevation at the toe of the fill slope at the southeast corner of the parcel is roughly 120 feet above mean sea level (MSL). The elevation along El Camino Real in the northeast portion of the parcel is about 82 feet MSL. The surface of the site has been repeatedly graded over the years, and used for agricultural purposes. Most of the site is now covered with a light growth of weeds and grass. A landscaped 2:1 (horizontal to vertical) fill slope ascends as much as 40 feet up to the residential lots along the southern and eastern edges of the site. A few trees and shrubs are also scattered across Parcel 2 (see Figures 2A and 2B). A northwesterly trending ridgeline once crossed through the southwest corner of the property. Remnants of the ridge may remain in the previously demolished residential area (Parcel 2 in Figure 2B). However, topographic indications of the ridgeline have been mostly obliterated by the previous grading activities on site. Various cuts and fills appear to have been conducted throughout Parcel 2. The slopes that now border the perimeter of Parcel 2 appear to be graded fill slopes, as indicated by Boring B-5. 1.3 Proposed Development Site development will include 26 two-story residential buildings supported by post-tension slab foundations. Other site improvements will include a new asphalt concrete paved residential street, Portland cement concrete sidewalks, and various associated subsurface utilities. A bio-swale and detention basin is proposed along the northern edge of the site. A preliminary layout of the planned development is shown in Figures 2D and 2E. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 8 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 2.0 FIELD AND LABORATORY INVESTIGATION Ten hollow stem auger borings and five cone penetrometer test (CPT) soundings were advanced at the site between January 30th and February 5th, 2014. The maximum depth of exploration was approximately 65 feet below surrounding grades. The approximate locations of the explorations are shown in Figures 2A through 2E. Logs describing the geologic conditions encountered are presented in Appendix A. Soil samples were collected from the borings for laboratory testing and analysis. The testing program included gradation, hydrometer analysis and Atterberg Limits to aid in material classification using the Unified Soil Classification System (USCS). Expansion Index tests were conducted on remolded samples to aid in post-tension slab design. Tests were conducted on relatively undisturbed ring samples to help estimate the in-situ dry density and moisture content of the various geologic materials we encountered on site. Direct shear tests were also conducted on the ring samples to aid in strength characterization for the slope stability analyses. Corrosivity tests were conducted on bulk soil samples to evaluate the pH, resistivity, chloride and sulfate content of the on-site soils. Maximum density tests were conducted on the bulk samples to help estimate shrinkage of the compacted alluvial soil. R-Value tests were also conducted on the bulk samples to aid in preliminary pavement section design. The laboratory test results are presented in Appendix B. 3.0 GEOLOGY AND SUBSURFACE CONDITIONS The site is located within the coastal plain section of the Peninsular Ranges geomorphic province of California, which consists of subdued landforms underlain by marine sedimentary formations. As observed in our subsurface investigation, the entire site is underlain at depth by the Eocene-age Santiago Formation, which is covered with alluvial flood plain deposits associated with Agua Hedionda Creek. The approximate locations of the explorations conducted for this investigation are shown on Geotechnical Map, Figure 2B. The general geology in the site vicinity is shown on the Regional Geologic Map, Figure 3A. The regional topography is also shown in Figure 3B. Logs describing the subsurface conditions encountered in the explorations are presented in Appendix A. The soils encountered in our subsurface explorations are described in more detail below. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 9 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 3.1 Santiago Formation Sedimentary materials associated with the Eocene-age Santiago Formation were encountered in all of our borings at depth. As observed on site, the Santiago Formation (Map symbol Tsa) most commonly consists of sandy lean or fat claystone (Unified Soil Classification CL or CH) with lesser amounts of siltstone (ML). The formation varies widely in color from olive or bluish gray to light gray and orange brown. The claystone is typically high in plasticity (the average Liquid Limit of the samples we tested was 55, with an average Plasticity Index of 33). Laboratory tests also indicate that the formational materials have a high expansion potential (an Expansion Index of 120 to 123), and are very corrosive with a severe soluble sulfate content. Our tests indicate that the Santiago Formation has an average in-situ dry density of about 105 lb/ft3, with an average moisture content of 21 percent. The corrected standard penetration test (SPT) blow counts (N60) within the formation generally ranged from 20 to 64 and averaged 46. This indicates that the claystone is typically very stiff to hard in consistency. Pocket Penetrometer readings and CPT interpretations indicate that the formation typically has an undrained strength well above 4,000 lb/ft2. Direct shear testing suggests that the formational materials also have a drained shear strength exceeding 23º with 200 lb/ft2 cohesion, as shown in Figure B-5.6. 3.2 Old Alluvium Quaternary-age alluvial sediments associated with the Agua Hedionda Creek and Letterbox Canyon drainages were encountered in most of the explorations conducted at the site (map symbol Qoa). Up to 65 feet of alluvium was encountered in the northwest corner of the site, with lesser alluvial depths to both the south and east. The Old Alluvium most commonly consists of sandy lean clay (CL) or clayey sand (SC). In several borings, the alluvium graded into clean sand (SP or SW) near the contact with the underlying Santiago Formation. The upper 10 to 15 of the alluvium was typically stiff in consistency, whereas the deeper clays were very stiff to hard. Laboratory tests indicate that the alluvium is moderately expansive (an Expansion Index ranging from 66 to 91), and very corrosive with a severe soluble sulfate content. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 10 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The alluvium has an in-situ dry density ranging from about 105 to 125 lb/ft3, with an average dry density of 105 lb/ft3 and an average moisture content of 14 percent. The corrected standard penetration test (SPT) blow counts (N60) within the alluvium ranged from 9 to 64 and averaged 31. In general, the SPT and CPT data indicate that the upper 10 to 15 feet of alluvium may be moderately compressible under the new fill and foundation loads, whereas the deeper alluvial deposits appear to be older and better consolidated. An average shear wave velocity of 288 m/s was measured in the upper 47 feet of the soil profile in CPT-3 (see Figure A-13c). This shear wave velocity (VsD) was then extrapolated to a depth of 30 meters (Vs30) using a common formula (Vs30~[1.45–(0.015*D)]*VsD), where D is the depth measured in meters. The average shear wave velocity for the upper 30 meters (Vs30) estimated in this manner was 356 m/s (corresponding to a 2013 CBC Site Class D). 3.3 Fill Shallow undocumented fill (2 to 7 feet deep) was encountered in all of the borings. The fill generally appears to be similar to the underlying alluvium from which it was likely derived. The fill typically consists of clayey sand (SC) with lesser amounts of sandy lean clay (CL). Approximately 15 feet of fill was also encountered at the old home site in Boring B-5. This fill included some gravel and demolition debris. The fill stockpile recently placed in the northwest corner of the site is generally composed of silty sand (SM). The existing fill is loose to medium dense, and considered potentially compressible. 3.4 Groundwater Groundwater was encountered in CPT-1 and CPT-2 at depths ranging from about 34 to 36 feet below grade (or an elevation of about 49 feet MSL). This corresponds to an ultimate groundwater depth ranging from 50 to 65 feet below the planned building pad elevations shown in Figure 2D. It should be noted that groundwater levels may fluctuate over time throughout the site due to changes in the water surface elevation and flow rate within Agua Hedionda Creek, as well as variations in rainfall, irrigation, or site drainage conditions. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 11 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 4.0 GEOLOGIC HAZARDS The subject site is not located within an area previously known for significant geologic hazards. Potential geologic hazards will generally be the result of moderate ground shaking on relatively distant active faults (the Rose Canyon fault zone is located about 11 km west of the site). Each potential geologic hazard is discussed below. 4.1 Ground Rupture Ground rupture is the result of movement on an active fault reaching the surface. Known faults within 100 km of the site are shown in the Regional Fault Map, Figure 4. The site is not located within an Alquist-Priolo Earthquake Fault Zone, and no evidence of active or potentially active faulting was found during our site investigation or literature review. Consequently, ground rupture is not considered a significant geologic hazard at the site. 4.2 Seismicity The site is located at latitude 33.1439° north and longitude 117.2865° west. The United States Geologic Survey has developed an interactive website that provides Next Generation Attenuation (NGA) probabilistic seismic analyses based on the site location and average shear wave velocity (USGS, 2009). An average shear wave velocity (Vs30) of 356 m/s was estimated from CPT-3, as discussed in Section 3.2. The peak ground accelerations (PGA) with a 2, 5 and 10 percent probability of being exceeded in a 50 year period are estimated at 0.45, 0.33g and 0.26g, respectively. These levels of risk are often referred to as the Maximum Considered, Upper Bound and Design Basis Earthquakes, respectively. By comparison, the design level PGA from the 2013 CBC Design Response Spectrum shown in Table 1 is 0.31g. 4.3 Liquefaction and Dynamic Settlement Liquefaction is a process in which soil grains in a saturated deposit lose contact due to earthquakes or other sources of ground shaking. Liquefiable soils typically consist of cohesionless sands and silts that are loose to medium dense, and saturated. To liquefy, these soils must be subjected to ground shaking of sufficient magnitude and duration. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 12 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The alluvial soils are primarily clays, which are not considered susceptible to liquefaction. In addition, groundwater was only encountered in soundings CPT-1 and CPT-2, at depths of 34 to 36 feet below existing grades (more than 50 feet below proposed finish grades). The other borings and CPT soundings did not encounter groundwater. Therefore, if soil liquefaction were to occur during a large earthquake, the occurrence would be located deep below the ground surface and proposed improvements. Liquefaction at such depths would not be expected to produce surface manifestations (SCEC, 1999). Although liquefaction is not considered a significant hazard to the proposed improvements, dynamic settlement may still occur in areas where medium dense granular alluvial soils are subjected to earthquake shaking of sufficient magnitude and duration. Dynamic settlement analyses were conducted for the site using a design level PGA of 0.31g associated with the 2013 CBC Design Response Spectrum. The estimated dynamic settlements at the five CPT locations are presented in detail in the figures of Appendix C. The total dynamic settlement (including dry soil settlement above groundwater and liquefaction below) is estimated at less than 1 inch at the site. According to state guidelines, a differential settlement equal to one-half the anticipated total dynamic settlement may be conservatively assumed for structural design (SCEC, 1999). Therefore, we estimate that the dynamic differential settlement for the proposed structures will not exceed ½ inch in 40 feet. Dynamic differential settlements of this magnitude are not expected to result in significant damage to the proposed improvements. 4.4 Landslides and Lateral Spreads Regional geologic maps suggest the presence of an ancient landslide within the subdivision southeast of the subject site, as shown in Figure 3A. This area was previously graded, and fill slopes up to 40-feet in height were constructed over the mapped location of the landslide. No documents describing the as- graded conditions for the adjacent subdivision were found in our literature review. However, in accordance with the standards of engineering practice, measures should have been taken during mass grading of that subdivision to remove the landslide debris and stabilize the existing fill slopes. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 13 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc No indications of slope failure were observed in our geologic reconnaissance. Roughly 10 feet of new fill is proposed for Lots 1 through 3 along the eastern edge of the site. This new fill will ultimately buttress the existing fill slope in that area, increasing the overall slope stability. However, temporary 1:1 cut slopes up to about 20-feet high will be needed to complete the remedial earthwork and construct the proposed retaining walls along the southern and eastern portions of the site. Group Delta should observe the geology exposed in the temporary 1:1 cuts to confirm the anticipated geotechnical conditions. The Revised Grading Plan indicates that a 2:1 (horizontal to vertical) fill slope up to about 12-feet in height will separate the lower Lots 21 to 26 from the upper Lots 14 to 20 (see Figure 2D). Roughly 6-foot high 2:1 fill slopes will also separate Lots 1, 2 and 3. Fill slope inclinations of 1½:1 are proposed for other minor slopes (less than 2 feet high) which will separate several lots. Stability analyses were conducted using SLOPE/W with Spencer's Method of Slices, based on the geologic conditions observed in the explorations. Lower bound shear strengths were estimated for each geologic unit (see Appendix B). Our stability analyses indicate that the proposed 2:1 fill slopes will possess an adequate factor of safety against deep-seated static failure (FS>1.5), assuming that our remedial grading recommendations are implemented during construction. Our analyses also indicate that the 1:1 cut slopes will possess an adequate safety factor for a temporary condition (FS>1.2). The results of our slope stability analyses are presented in Appendix D. Seismic slope stability was also analyzed using simplified methods. For the seismic analyses, estimates of Modal Magnitude (M), Distance (r) and Maximum Horizontal Acceleration (MHA) were developed. The Significant Duration of Shaking (D5-95) and Mean Period of Input Acceleration (Tm) were estimated in general accordance with the referenced guidelines (SCEC, 2002). SEISMIC PARAMETER ASSUMED VALUES Magnitude (M) 7.2 (Rose Canyon) Distance (r) 11 km (Rose Canyon) Acceleration (MHA) 0.31g (Design Level PGA) Duration (D5-95) 17 seconds Mean Period (Tm) 0.5 seconds Shear Wave Velocity (vs) 356 m/s Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 14 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The seismic stability analyses indicate that the proposed slopes will have yield accelerations (Ky) that exceed 0.24g. Given a peak ground acceleration of 0.31g, the seismic slope deformation is estimated at less than 1 inch. Seismic deformation of this magnitude is generally deemed tolerable. 4.5 Tsunamis, Seiches and Flooding The site is located about 2½ miles from the Pacific Ocean, as shown on the Site Location Map, Figure 1A. The proximity to the ocean suggests that the potential may exist for damage in the event of an earthquake induced tsunami. However, the existence of the offshore barrier islands, and the configuration of the continental shelf in San Diego County have historically provided relief from tsunamis. The five greatest tsunamis that occurred within the Pacific Ocean in the last 100 years did not significantly impact San Diego County. Studies have indicated that a 500-year tsunami within the Pacific Ocean may result in a water surface runup of about 11 feet above tidal elevations along the coast of Carlsbad (U.S. Army, 1974). Assuming a high tide of 9 feet at the time of the tsunami, the inundation zone is estimated to include areas with an elevation of about 20 feet or less. Available topographic data indicates that the subject site is located more than 80 feet above mean sea level. Given the elevation of the site, the potential for damage due to tsunamis is considered remote. The California Geologic Survey’s Tsunami Inundation Map for this area suggests that the water surface runup from a tsunami would not extend beyond the eastern end of the Agua Hedionda lagoon (see Figure 3D). The site is not located within a FEMA 100-year flood zone or a dam inundation zone, as shown in Figure 3C. The 100-year floodplain is shown in more detail on the Site Vicinity Plan, Figure 1B. The site is not located below any lakes or confined bodies of water. Consequently, the potential for earthquake induced flooding due to seiches or dam failures is considered low. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 15 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 5.0 CONCLUSIONS The proposed development appears feasible from a geotechnical standpoint, provided that the following recommendations are implemented. However, there are several geotechnical constraints which will impact site development. ● Many of the structures will be underlain by relatively deep alluvium. We have recommended that the upper 10 or 15 feet of alluvium be excavated and compacted, which should remove the more compressible soil. With the addition of the planned fills, most of the lots will ultimately be underlain by 20 to 30 feet of compacted fill. However, up to about 20 feet of old alluvium may be left in place beneath Lots 21 to 26. We recommend that construction of settlement sensitive surface improvements be delayed for at least 4 weeks after rough grading of the site is completed, in order to allow for settlement of the remaining alluvium. Settlement monuments should be installed during grading in Lots 21 and 26 in order to confirm that settlement is completed prior to construction. The remedial grading is summarized in Table 2. ● Several of the proposed structures along the southern edge of the site would be directly underlain by highly expansive claystone of the Santiago Formation. We do not recommend constructing the proposed improvements directly on the highly expansive clays. For Lots 4 through 11, we recommend that the cut portions of the building pads be over-excavated at least 4-feet below finish pad grade. The over-excavation should be backfilled with low expansion imported sand (EI<20). Preliminary post-tension (PT) slab design parameters are provided for these conditions in Section 6.4.3 (Category III). ● The remaining lots will be underlain by fill derived from the existing alluvium. Laboratory tests indicate that the alluvial soils at the site generally have a medium potential for expansion (an Expansion Index of 66 to 91). Preliminary PT slab design parameters are provided for moderately expansive (Category II) conditions in Section 6.4.2. As an alternative, the remaining lots may also be capped with 3-feet of low expansion sand (EI<20) to reduce the potential for heave and cracking to the proposed concrete sidewalks and driveways. Preliminary PT slab design parameters are also provided for Category I (low expansion) conditions in Section 6.4.1. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 16 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc ● The existing fill soil throughout the site is considered to be compressible, and should be excavated and replaced as compacted fill prior to site development. Existing fills include most of Parcel 2, as well as the new fill stockpile recently placed in the northwest corner of the site. Note that the new fill stockpile appears to primarily be composed of low expansion silty sand, and may be suitable for use as a select low expansion fill on the surface of the lots. ● The temporary 1:1 cut slopes that will be needed to complete the remedial earthwork along the eastern and southern edges of the site should be observed by Group Delta to verify the anticipated geologic conditions. If adverse geology is observed, additional remedial grading recommendations for a stabilization fill or buttress may be provided during grading. ● Laboratory tests indicate that the on-site soils present a severe potential for sulfate attack. The sulfate hazard is typically mitigated by the use of Type V cement for new on-grade concrete, with a maximum water to cement ratio of 0.45 and a minimum 28-day compressive strength of 4,500 psi. ● Laboratory tests indicate that the on-site soils are also very corrosive to metals. Typical corrosion control measures should be incorporated into the design, such as providing adequate concrete cover or protective coatings for steel reinforcement, and providing sacrificial anodes as needed for buried metal pipes. A corrosion consultant may be contacted for specific recommendations. ● Shallow groundwater was not encountered during our site investigation. Groundwater was only encountered in soundings CPT-1 and CPT-2 at an elevation of about 49 feet MSL. This corresponds to a groundwater depth of about 50 to 65 feet below planned finish grades. Groundwater seepage is not anticipated within the proposed remedial excavations. However, wet soils may be generated by the proposed remedial excavations that may require extra effort to dry back to a moisture content suitable for compaction. ● The potential for active faults, seismic settlement or floods to impact the site is remote. Other geologic hazards that may impact development include strong ground shaking from an earthquake on an active fault. This hazard may be mitigated by structural design in accordance with the applicable building code. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 17 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.0 RECOMMENDATIONS The remainder of this report presents recommendations regarding earthwork construction and design of the proposed structures. If these recommendations do not cover a specific feature of the project, please contact our office for amendments. 6.1 Plan Review We recommend that the foundation and grading plans be reviewed by Group Delta Consultants prior to construction. We anticipate that substantial changes in the development may occur from the preliminary design concepts used for our investigation. Such changes may require additional evaluation, which could result in modifications to the recommendations provided herein. 6.2 Excavation and Grading Observation Foundation and grading should be observed by Group Delta. During grading, Group Delta should provide observation and testing services continuously. Such observations are considered essential to identify field conditions that differ from those anticipated by this investigation, to adjust designs to the actual field conditions, and to determine that the grading is accomplished in general accordance with the recommendations presented in this report. Our recommendations are contingent upon Group Delta Consultants performing such services. Our personnel should perform sufficient testing of fill and backfill during grading and improvement operations to support our professional opinion as to compliance with the compaction recommendations. 6.3 Earthwork Grading and earthwork should be conducted in general accordance with the applicable local grading ordinance and the requirements of the current California Building Code. The following recommendations are provided regarding specific aspects of the proposed earthwork construction. These recommendations should be considered subject to revision based on the conditions observed by our personnel during grading. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 18 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.3.1 Site Preparation: General site preparation should begin with the removal of the deleterious materials from the site. Deleterious materials include existing structures, improvements, trees, vegetation, trash, contaminated soil and demolition debris. Existing subsurface utilities that are to be abandoned should be removed and the excavations backfilled and compacted as described in Section 6.3.4. Alternatively, abandoned pipes may be grouted with a two-sack sand- cement slurry under the observation of Group Delta Consultants. 6.3.2 Compressible Soils: The undocumented fill, stockpiled fill and surficial deposits of alluvium throughout the site are considered poorly consolidated and compressible. By comparison, the deeper deposits of Old Alluvium and the Santiago Formation are hard, and are considered much less susceptible to settlement under the new fill loads. Compressible fill and the surficial alluvial soils should be excavated and replaced as compacted fill prior to development. In general, over- excavation depths are anticipated to vary from about 10 to 15 feet across the site, as summarized in Table 2. In all areas of proposed fill placement or surface improvements such as pavements, sidewalks, exterior flatwork and buildings, the compressible soils should be excavated under our geologic observation. The actual remedial excavation depths may vary depending upon the conditions observed by our geologist during grading. Once the compressible soils have been excavated, the bottom of the excavation should be scarified, brought to slightly above optimum moisture content, and then compacted as described in Section 6.3.4. The stockpiled soils may then be replaced as a uniformly compacted fill to the plan finish grades. 6.3.3 Building Areas: In addition to remedial grading to remove and compact compressible soils throughout the building and improvement areas, many of the residential lots will be underlain by transitions between fill and formational materials. Remedial grading should be conducted so that the building foundations do not cross cut/fill transitions, due to the potential for adverse differential movement. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 19 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The surficial soils throughout the site are moderate to highly expansive (see Figure B-2). The use of post-tension slab foundations will help mitigate the potential for damage to the residential structures associated with moderate soil heave. However, we do not recommend constructing buildings directly on the highly expansive fat claystone of the Santiago Formation. Our site investigation indicates that Lots 4 through 11 as shown on the Revised Grading Plan may be underlain directly by the highly expansive claystone, or a transition between claystone and fill (these are the Category III lots described in Section 6.4). The remaining lots will be underlain by relatively deep fill. For Lots 4 through 11 (Category III), the building pads should be over- excavated to a minimum depth of 4-feet below finish pad grade in order to mitigate the presence of both the cut/fill transitions and the highly expansive fat claystone. The highly expansive clay generated by this excavation may be buried in the deeper fills in the bio-retention basin along the northern edge of the site, or removed from the property. The over-excavated areas should extend at least 5 feet horizontally beyond the heave sensitive improvements. The over-excavated areas should then be brought back to plan grades with a uniformly compacted low expansion (EI<20) imported material, as discussed in Section 6.3.4. The alluvium is relatively deep throughout the remaining building pad areas (Lots 1 to 3, and 12 through 26). The removal and compaction of the compressible surficial soils as recommended in Section 6.3.2 is anticipated to result in a relatively uniform depth of moderately expansive soil beneath these 18 lots. Additional remedial grading is not necessary (these are Category II Lots). A summary of the anticipated remedial over-excavation depths for each lot is presented in Table 2. Although post-tension slab foundations may be used to mitigate the potential for damage to buildings associated with moderately expansive soil heave (Category II), the surrounding sidewalks and driveways may still heave and crack over time. In order to reduce the potential for such distress, these residential lots may be capped with three feet of low expansion imported soil (Category I lots), at Lennar’s discretion. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 20 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.3.4 Fill Compaction: All fill and backfill should be placed at slightly above optimum moisture content using equipment that is capable of producing a uniformly compacted product. The minimum recommended relative compaction is 90 percent of the maximum dry density based on ASTM D1557. Sufficient observation and testing should be performed by Group Delta so that an opinion can be rendered as to the compaction achieved. Rocks or concrete fragments greater than 6 inches in dimension should not be used in structural fill. Imported fill sources should be observed prior to hauling onto the site to determine the suitability for use. Imported fill materials should consist of granular soil with less than 35 percent passing the No. 200 sieve based on ASTM C136 and an Expansion Index less than 20 based on ASTM D4829. Samples of the proposed import should be tested by Group Delta in order to evaluate the suitability of these soils for their proposed use. During grading operations, soil types may be encountered by the contractor that do not appear to conform to those discussed within this report. Group Delta should be notified in order to evaluate the suitability of these soils for their proposed use. 6.3.5 Subgrade Stabilization: All excavations should be firm and unyielding prior to placing fill. In areas of yielding or “pumping” subgrade, a layer of geogrid such as Tensar BX-1200 or Terragrid RX1200 may be placed directly on the excavation bottom. The geogrid should then be covered with at least 12 inches of minus ¾-inch aggregate base. Once the excavation is firm enough to attain the required compaction within the base, the remainder of the excavation may be backfilled using either compacted soil or aggregate base. 6.3.6 Surface Drainage: Foundation and slab performance depends greatly on how well surface runoff drains from the site. This is true both during construction and over the entire life of the structures. The ground surface should be graded so that water flows away from structures without ponding. Consideration should also be given to providing a continuous subdrain along the toe of the southern fill slope in order to intercept nuisance seepage from the back lots. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 21 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.3.7 Slope Stability: Various new cut and fill slopes will be constructed throughout the site. We recommend that permanent fill slopes up to 20-feet high be inclined no steeper than 2:1 (horizontal to vertical). Minor fill slopes up to 2-feet high may be inclined at 1½:1. Our analyses indicate that the proposed slopes will have a Safety Factor above 1.5 with respect to deep-seated failure (see Appendix D). All slopes may be susceptible to surficial slope instability and erosion given substantial wetting of the slope face. Surficial slope stability may be enhanced by providing proper site drainage. The site should be graded so that water from the surrounding areas is not able to flow over the top of slopes. Diversion structures should be provided where necessary. Slopes should be planted with vegetation that will increase the surficial stability. Ice plant is generally not recommended. Vegetation should include woody plants, along with ground cover. Irrigation should be limited to the minimum needed to support the landscaping. Plants may be adapted for growth in semi-arid climates with little or no irrigation. A landscape architect should be consulted to develop a planting palate suitable for stabilization. Where fill is to be placed on surfaces inclined steeper than 5:1 (such as up against existing slopes), these surfaces should be benched to provide a relatively level surface for fill placement. The benches should extend through the compressible materials to expose competent material as evaluated by Group Delta. The bench width should generally be adequate to expose 3 to 5 feet of competent material in the vertical wall of the bench. The exposed bench bottoms should be scarified and compacted prior to placing compacted fills. 6.3.8 Temporary Excavations: Temporary excavations will be needed at the site in order to accomplish the planned remedial excavations. All excavations should conform to Cal-OSHA guidelines. Temporary excavations should be inclined no steeper than 1:1 (horizontal to vertical) for heights up to 20 feet. Deeper excavations, or any excavations that encounter seepage should be evaluated by Group Delta Consultants on a case-by-case basis, or shored. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 22 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.3.9 Bulk/Shrink Characteristics: The in-situ density of the alluvium varies from about 105 to 125 lb/ft3, as shown in Appendix A. The maximum density of the fill derived from the alluvium is estimated at 125 to 126 lb/ft3, as shown in Figure B-4. Assuming that the fills are compacted to at least 90 percent of the maximum density as recommended, we estimate that the alluvium will shrink up 10 percent when excavated and placed as fill (5 percent average). Shrinkage may vary considerably based on variations in the alluvium density. 6.4 Preliminary Foundation Recommendations The following recommendations are considered appropriate for post-tensioned slab foundations that bear entirely on compacted fill placed in accordance with our recommendations. These foundation recommendations should be considered preliminary, and subject to revision based on the conditions encountered during grading. The ultimate foundation design should incorporate the geotechnical design parameters provided in the as-graded geotechnical report. The following recommendations are considered generally consistent with methods typically used in southern California. Other alternatives may be available. They are only minimum criteria and should not be considered a structural design, or to preclude more restrictive criteria of governing agencies or the structural engineer. 6.4.1 Post-Tension Slabs (Category I): Category I foundation design conditions are applicable to lots with a low expansion potential. For Category I conditions to apply, the compressible and moderately expansive surficial soils will first need to be excavated and replaced as compacted fill, as described in Section 6.3.2. In addition, the Category I lots will also need to be capped with at least three feet of low expansion imported soil (EI<20), as discussed in Section 6.3.3. Category I conditions may apply to Lots 1 to 3, and 12 through 26. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 23 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The following design parameters were developed in general accordance with the procedures described in the referenced guidelines (PTI, 2007). Post-tension slab design may be conducted by the structural engineer using the following preliminary geotechnical parameters. Moisture Variation, em: Center Lift: 9.0 feet Edge Lift: 5.0 feet Differential Swell, ym: Center Lift: 0.5 inches Edge Lift: 0.7 inches Differential Settlement: ¾ inch in 40 feet Allowable Bearing: 2,000 psf at slab subgrade 6.4.2 Post Tensioned Slabs (Category II): Category II lots will apply to areas underlain by moderately expansive fill soil. Category II conditions are anticipated for Lots 1 to 3, and 12 through 26 (unless selective grading is chosen by the developer to cap these lots with 3-feet of low expansion soil and produce Category I conditions). The following preliminary foundation design parameters were also developed in general accordance with the 2013 CBC and the procedures described in the referenced guidelines (PTI, 2007). Moisture Variation, em: Center Lift: 9.0 feet Edge Lift: 4.6 feet Differential Swell, ym: Center Lift: 1.2 inches Edge Lift: 1.8 inches Differential Settlement: ¾ inch in 40 feet Allowable Bearing: 2,000 psf at slab subgrade Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 24 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.4.3 Post Tensioned Slabs (Category III): Lots 4 through 11 will be underlain by highly expansive claystone of the Santiago Formation (Category III). As described in Section 6.3.3, we recommend that these lots be over-excavated at least 4-feet below finish grade, and capped with 4 or more feet of low expansion import (EI<20). The following preliminary design parameters would apply to these conditions. These parameters were also developed in general accordance with the procedures described in the referenced guidelines (PTI, 2007). Moisture Variation, em: Center Lift: 9.0 feet Edge Lift: 4.8 feet Differential Swell, ym: Center Lift: 1.0 inches Edge Lift: 1.5 inches Differential Settlement: ¾ inch in 40 feet Allowable Bearing: 2,000 psf at slab subgrade 6.4.4 Settlement: Provided that remedial grading is conducted within the building areas as recommended in Section 6.3, total and differential settlement of the proposed structures is not expected to exceed one inch and ¾-inch in 40 feet, respectively. In addition, dynamic settlement of up to ½-inch in 40 feet may occur (see Section 4.3). 6.4.5 Lateral Resistance: Lateral loads against the structures may be resisted by friction between the bottoms of footings and slabs and the soil, as well as passive pressure from the portion of vertical foundation members embedded into compacted fill. A coefficient of friction of 0.25 and a passive pressure of 250 psf per foot of depth may be used. 6.4.6 Slope Setback: As a minimum, all foundations should be setback from any descending slope at least 10 feet. The setback should be measured horizontally from the outside bottom edge of the footing to the slope face. The horizontal setback can be reduced by deepening the foundation to achieve the recommended setback distance projected from the footing bottom to the face of the slope. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 25 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc It should be recognized that the outer few feet of all slopes are susceptible to gradual down-slope movements due to slope creep. This will affect hardscape such as concrete slabs. We recommend that settlement sensitive structures not be constructed within 5 feet of the slope top without specific review by Group Delta Consultants. 6.4.7 Seismic Design: The proposed structures should be designed in general accordance with the seismic provisions of the 2013 California Building Code (CBC) for Seismic Zone 4. An average shear wave velocity (Vsd) of 944 ft/s was measured within the upper 47 feet of the soil profile in CPT-3, as described in Appendix A. This corresponds to an estimated value of 1,168 ft/s (356 m/s) for the upper 100 feet (Vs30), as described previously. Therefore, it is our opinion that a 2013 CBC Site Class D is most applicable to the general site conditions. The USGS mapped spectral ordinates SS and S1 equal 1.070 and 0.413, respectively. For Site Class D, the acceleration and velocity coefficients Fa and Fv equal 1.072 and 1.586, respectively. The spectral design parameters SDS and SD1 equal 0.765 and 0.437. The peak ground acceleration from the design spectrum may be taken as 40 percent of SDS or 0.31g. The recommended 2013 CBC Design Spectrum for Site Class D is shown in the attached Table 1. 6.5 On-Grade Slabs On-grade slabs should be designed by the project structural engineer. Building slabs should be at least 5½ inches thick, and should be reinforced with at least No. 3 bars on 18-inch centers, each way. 6.5.1 Moisture Protection for Slabs: Concrete slabs constructed on grade ultimately cause the moisture content to rise in the underlying soil. This results from continued capillary rise and the termination of normal evapotranspiration. Because normal concrete is permeable, the moisture will eventually penetrate the slab. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 26 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc Excessive moisture may cause mildewed carpets, lifting or discoloration of floor tiles, or similar problems. To decrease the likelihood of problems related to damp slabs, suitable moisture protection measures should be used where moisture sensitive floor coverings, moisture sensitive equipment, or other factors warrant. The most common moisture barriers in southern California consist of two inches of clean sand covered by 'visqueen' plastic sheeting. Two inches of sand are placed over the plastic to decrease concrete curing problems. It has been our experience that such systems will transmit approximately 6 to 12 pounds of moisture per 1000 square feet per day. The architect should review the estimated moisture transmission rates, since these values may be excessive for some applications, such as sheet vinyl, wood flooring, vinyl tiles, or carpeting with impermeable backings that use water soluble adhesives. Sheet vinyl may develop discoloration or adhesive degradation due to excessive moisture. Wood flooring may swell and dome if exposed to excessive moisture. The architect should specify an appropriate moisture barrier based on the allowable moisture transmission rate for the flooring. This may require a “vapor barrier” rather than a “vapor retarder”. The American Concrete Institute provides detailed recommendations for moisture protection systems (ACI 302.1R-04). ACI defines a “vapor retarder” as having a minimum thickness of 10-mil, and a water transmission rate of less than 0.3 perms when tested per ASTM E96. ACI defines a “vapor barrier” as having a water transmission rate of 0.01 perms or less (such as a 15 mil StegoWrap). The vapor membrane should be constructed in accordance with ASTM E1643 and E1745 guidelines. All laps or seams should be overlapped at least 6 inches or per the manufacturer recommendations. Joints and penetrations should be sealed with pressure sensitive tape, or the manufacturer’s adhesive. The vapor membrane should be protected from puncture, and repaired per the manufacturer’s recommendations if damaged. The architect should review ACI 302.1R-04 along with the moisture requirements of the proposed flooring system, and incorporate an appropriate level of moisture protection into the design. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 27 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The vapor membrane is often placed over 4 inches of granular material. The materials should be a clean, fine graded sandy soil with roughly 10 to 30 percent passing the No. 100 sieve. The sand should not be contaminated with clay, silt, or organic material. The sand should be proof-rolled prior to placing the vapor membrane. Based on current ACI recommendations, concrete should be placed directly over the vapor membrane. The common practice of placing sand over the vapor membrane may increase moisture transmission through the slab, because it provides a reservoir for bleed water from the concrete to collect. The sand placed over the vapor membrane may also move prior to concrete placement, resulting in an irregular slab thickness. When placing concrete directly on an impervious membrane, it should be noted that finishing delays may occur. Care should be taken to assure that a low water to cement ratio is used and that the concrete is moist cured in accordance with ACI guidelines. 6.5.2 Exterior Slabs: Exterior slabs and sidewalks should be at least 4 inches thick. Crack control joints should be placed on a maximum spacing of 10 foot centers, each way, for slabs, and on 5 foot centers for sidewalks. The potential for differential movements across the control joints may be reduced by using steel reinforcement. Typical reinforcement for exterior slabs would consist of 6x6 W2.9/W2.9 welded wire fabric placed securely at mid-height of the slab. 6.5.3 Expansive Soils: The near surface soils observed during our field investigation primarily consisted of sandy lean or fat clay (CL and CH) and clayey sand (SC) with a medium to high expansion potential based on common criteria. The Expansion Index (EI) test results are shown in Figure B-2. In general, the alluvium has a medium expansion potential, whereas the Santiago Formation is highly expansive. Due to the presence of expansive soils throughout the site, differential heave of exterior flatwork and sidewalks should be anticipated. One inch of differential heave is not considered unusual, and more may occur where highly expansive soils are present. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 28 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc Post-tension slab foundations will be used to help reduce the potential for distress to new buildings founded over the moderately expansive clays, as discussed in Section 6.4. In order to reduce the potential for differential heave and cracking of other concrete improvements such as driveways and sidewalks, the upper two feet of on-site clayey fill may be replaced with a low expansion sand (EI<20), as a minimum. 6.5.4 Reactive Soils: In order to assess the sulfate exposure of concrete in contact with the site soils, samples were tested for water soluble sulfate content (see Figure B-3). Based on these test results, some of the on-site soils appear to have a severe potential for sulfate attack based on commonly accepted criteria. It should be noted that the use of fertilizer or the presence of sulfate in the irrigation water may cause the sulfate content in the soil to increase over time. The sulfate hazard is typically mitigated by the use of Type V cement for new concrete structures, with a maximum water to cement ratio of 0.45 and a minimum 28-day compressive strength of 4,500 psi. In order to assess the reactivity of the site soils with respect to buried metals, the pH, resistivity and soluble chloride contents of selected soil samples were also determined. These test results are also shown in Figure B-3. The tests suggest that the on-site soils are very corrosive to buried metals. Typical corrosion control measures should be incorporated in the project design. These measures include providing the minimum clearances between reinforcing steel and soil as recommended in the building code, and providing sacrificial anodes (where needed) for buried metal pipes or structures. A corrosion consultant may be contacted for more specific recommendations. 6.6 Earth-Retaining Structures Backfilling retaining walls with expansive soil can increase lateral pressures well beyond normal active pressures. We recommend that retaining walls be backfilled with soil that has an Expansion Index of 20 or less. The on-site soils do not meet this criterion. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 29 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc Retaining wall backfill should be compacted to at least 90 percent relative compaction based on ASTM D1557. Backfill should not be placed until walls have achieved adequate strength. Heavy compaction equipment, which could cause distress to the walls, should not be used. For general retaining wall design, an allowable bearing capacity of 2,000 lbs/ft2, a coefficient of friction of 0.25, and a passive pressure of 250 psf per foot of depth is recommended. Cantilever retaining walls with level granular (imported) backfill may be designed using an active earth pressure approximated by an equivalent fluid pressure of 35 lbs/ft3. The active pressure should be used for walls free to yield at the top at least ½ percent of the wall height. Walls that are restrained so that such movement is not permitted, or walls with 2:1 sloping backfill should be designed for an at-rest earth pressure approximated by an equivalent fluid pressure of 55 lbs/ft3. These pressures do not include seepage forces or surcharge loads. Surcharges within a 1:1 plane extending back and up from the base of the wall should be accounted for in the wall design. All retaining walls should contain adequate backdrains to relieve hydrostatic pressures. Typical wall drain alternatives are presented in Figure 5. 6.7 Preliminary Pavement Design Alternatives are provided below for asphalt concrete and Portland cement concrete pavements. In each case, we recommend that the upper 12 inches of pavement subgrade be scarified immediately prior to constructing the pavement section, brought to about optimum moisture, and compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. Aggregate base should also be compacted to 95 percent of the maximum dry density. Aggregate base should conform to the Standard Specifications for Public Works Construction (SSPWC), Section 200-2. Asphalt concrete should conform to Section 400-4 of the SSPWC and should be compacted to at least 95 percent relative compaction based on the Hveem unit weight. R-Value tests were conducted on bulk samples of the on-site soil collected during the site investigation, in general accordance with CTM 301. The test results are presented in Figures B-6.1 through B-6.4 of Appendix B. The tests indicated subgrade R-Values ranging from 14 to 19. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 30 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.7.1 Asphalt Concrete: Asphalt concrete pavement design was conducted in general accordance with the Caltrans Design Method (Topic 608.4). Traffic Indices of 5.0, 6.0 and 7.0 were assumed for preliminary design purposes. The project civil engineer should review the assumed traffic levels to determine if and where they are appropriate. Based on the minimum R-Value of 14 determined by our laboratory tests, the following pavement sections are recommended. PAVEMENT TYPE TRAFFIC INDEX ASPHALT SECTION BASE SECTION Passenger Car Areas 5.0 3 Inches 8 Inches Truck Traffic Areas 6.0 4 Inches 10 Inches Heavy Traffic Areas 7.0 4 Inches 14 Inches 6.7.2 Portland Cement Concrete: Concrete pavement design was conducted in general accordance with the simplified design procedure of the Portland Cement Association. This methodology is based on a 20-year design life. For design, it was assumed that aggregate interlock would be used for load transfer across control joints. The subgrade materials were assumed to provide “low” subgrade support based on the minimum R-Value of 14. Based on these assumptions, and using the same traffic indices presented previously, we recommend that the PCC pavement sections at the site consist of at least 6 inches of concrete placed over 6 inches of compacted aggregate base. For heavy truck traffic areas, 7 inches of concrete is recommended over 6 inches of aggregate base. Crack control joints should be constructed for all PCC pavements on a maximum spacing of 10 feet, each way. Concentrated truck traffic areas, such as trash truck aprons and loading docks, should be reinforced with number 4 bars on 18-inch centers, each way. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 31 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc 6.8 Pipelines It is our understanding that the development may include a variety of pipelines such as water, storm drain and sewer. Geotechnical aspects of pipeline design include lateral earth pressures for thrust blocks, modulus of soil reaction, and pipe bedding. Each of these parameters is discussed separately below. 6.8.1 Thrust Blocks: Lateral resistance for thrust blocks may be determined by a passive pressure value of 250 lbs/ft2 per foot of embedment, assuming a triangular distribution. This value may be used for thrust blocks embedded into fill soils as well as Old Alluvium. 6.8.2 Modulus of Soil Reaction: The modulus of soil reaction (E’) is used to characterize the stiffness of soil backfill placed along the sides of buried flexible pipelines. For the purpose of evaluating deflection due to the load associated with trench backfill over the pipe, a value of 1,500 lbs/in2 is recommended for the general site conditions, assuming granular bedding material is placed around the pipe. 6.8.3 Pipe Bedding: Typical pipe bedding as specified in the Standard Specifications for Public Works Construction may be used. As a minimum, we recommend that pipes be supported on at least 4 inches of granular bedding material such as minus 3/4-inch crushed rock or disintegrated granite. Where pipeline or trench excavations exceed a 15 percent gradient, we do not recommend that open graded rock be used for bedding or backfill because of the potential for piping and internal erosion. For sloping utilities, we recommend that coarse sand or sand-cement slurry be used for the bedding and pipe zone. 7.0 LIMITATIONS This report was prepared using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No warranty, express or implied, is made as to the conclusions and professional opinions included in this report. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 32 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc The findings of this report are valid as of the present date. However, changes in the condition of a property can occur with the passage of time, whether due to natural processes or the work of man on this or adjacent properties. In addition, changes in applicable or appropriate standards of practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. 8.0 REFERENCES American Society for Testing and Materials (2006). Annual Book of ASTM Standards, Section 4, Construction, Volume 04.08 Soil and Rock (I); Volume 04.09 Soil and Rock (II); Geosynthetics, ASTM, West Conshohocken, PA, Compact Disk. Anderson, J. G. , Rockwell, T. K., Agnew, D. C. (1989). Past and Possible Future Earthquakes of Significance to the San Diego Region: Earthquake Spectra, Vol. 5, No. 2. pp 299-335. APWA (2006). Standard Specifications for Public Works Construction, Section 200- 2.2, Untreated Base Materials, Section 400-4, Asphalt Concrete: BNI, 761 p. Boore, D.M. and G.M. Atkinson (2008). Ground-Motion Prediction Equations for the Average Horizontal Component of PGA, PGV & 5% Damped PSA at Spectral Periods between 0.01s and 10.0s, Earthquake Spectra, V.24, pp. 99-138. Bowles, J. E. (1996). Foundation Analysis and Design, 5th ed.: McGraw Hill 1175 p. California Department of Conservation, Division of Mines and Geology (1992). Fault Rupture Hazard Zones in California, Alquist-Priolo Special Studies Zone Act of 1972: California Division of Mines and Geology, Special Publication 42. California Department of Transportation (2008). Caltrans ARS Online (V1.0.4), Based on the Average of (2) NGA Attenuation Relationships, Campbell & Bozorgnia (2008) & Chiou & Youngs (2008) from http://dap3.dot.ca.gov/shake_stable/ Campbell, K.W. and Y. Bozorgnia (2008). NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV and PGD and 5% Damped Linear Elastic Response Spectra for Periods Ranging from 0.01s and 10s, Earthquake Spectra, V.24, pp. 139-172. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 33 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc Chiou, B. and R. Youngs (2008). An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra, Earthquake Spectra, V.24, pp. 173-216. Group Delta Consultants (2013a). Geotechnical Review, Tabata 10 Subdivision, Carlsbad, CA, Project IR596, August 30. Group Delta Consultants (2013b). Proposal for Geotechnical Services, Tabata Residential Development, Carlsbad, CA, Proposal SD13-108, September 6. International Conference of Building Officials (2010). 2010 California Building Code. Jennings, C. W. (1994). Fault Activity Map of California and Adjacent Areas with Locations and Ages of Recent Volcanic Eruptions: California Division of Mines and Geology, Geologic Data Map Series, Map No. 6. Kennedy, M. P., and Tan, S. S. (2005). Geologic Map of the Oceanside 30’x60’ Quadrangle, California: California Geologic Survey, Scale 1:100,000. Post-Tensioning Institute (2007). Standard Requirements for Analysis of Shallow Concrete Foundations on Expansive Soils and Addendum No. 1 to the 3rd Edition of the Design of Post-Tensioned Slabs-on-Ground, Phoenix Arizona, May, www.post-tensioning.org. Pradel, D. (1998). Procedure to Evaluate Earthquake Induced Settlements in Dry Soils, Geotechnical Journal, Vol. 124, No. 4, pp. 364 to 368. Robertson, P.K. and Campanella, R.G. (1988). Design Manual for use of CPT and CPTu, Pennsylvania Department of Transportation, 200 p. Robertson, P.K. and Wride, C.E. (1990). Soil Classification using the CPT, Canadian Geotechnical Journal, Vol. 27, No. 1, February, pp. 151 to 158. Southern California Earthquake Center (1999). Recommended Procedures for Implementation of DMG SP 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California, University of Southern California, 60 p. Southern California Earthquake Center (2002). Recommended Procedures for Implementation of DMG SP117, Guidelines for Analyzing and Mitigating Landslide Hazards in California, University of Southern California, 110 p. United States Army Engineer Waterways Experiment Station (1974). Tsunami Prediction for Pacific Coastal Communities, Hydraulics Laboratory, Vicksburg. Geotechnical Investigation GDC Project No. SD365 Tabata Development March 4, 2014 Lennar Homes Page 34 N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc United Stated Geological Survey (2009). Earthquake Hazards Program, Based on Three NGA Relationships, Boore & Atkinson (2008), Campbell & Bozorgnia (2008) & Chiou & Youngs (2008) from http://eqint.cr.usgs.gov/deaggint/2008. Vinje & Middleton Engineering, Inc. (2006). Preliminary Geotechnical Investigation, Proposed 26-Lot Subdivision, Camino Hills Drive, Carlsbad, CA (APN 212- 050-32 & 33), Job No. 06-210-P, June 23. Vinje & Middleton Engineering, Inc. (2011). Geotechnical Plan Review Update, Proposed 26-Lot (Tabata 10) Subdivision, Camino Hills Drive, Carlsbad, CA (APN 212-050-32 & 33), Job No. 11-210-P, December 13. Wesnousky, S. G. (1986). Earthquakes, Quaternary Faults, and Seismic Hazard in California: Journal of Geophysical Research, v. 91, no. B12, p. 12587-12631. Youd, T.L. et al. (2001). Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 4, April. Youngs, R.R. and Coopersmith, K.J. (1985). Implications of Fault Slip Rates and Earthquake Recurrence Models to Probabilistic Seismic Hazard Estimates, Bulletin of the Seismological Society of America, vol. 75, no. 4, pp. 939-964. TABLES LotNumber1234567891011121314151617181920212223242526NOTES: 1) As a minimum, compressible soils should be excavated and compacted throught the site as described in Section 6.3.2. Estimated over-excavation depths are below natural alluvial grades.2) For Category II lots, if 3' of non-expansive fill is used to cap the lots as discussed in Section 6.3.3, Category I conditions will apply (otherwise use Category II).3) Category III foundations will generally be founded on 4 feet of low expansion fill (EI < 20) overlying claystone of the Santiago Formation (see Section 6.4.3).4) Represents the estimated depth of Old Alluvium that will remain below the compacted fill once the surficial soil is excavated and compacted.> 91> 91> 92> 92ReferenceElevation [FT]> 90> 97> 105> 112> 117> 115> 114> 114> 113> 113> 112> 111> 109> 103> 102> 101> 101> 102> 102> 102> 92> 92~ 96~ 90~ 86~ 82~ 85~ 88~ 113~ 114~ 114~ 111~ 101~ 91~ 86~ 96~ 108~ 118~ 113~ 113102.0 15 ~ 5 ~ 25 Medium Severe~ 72101.5 15 ~ 11 ~ 25 Medium Severe~ 66100.5 15 ~ 14 ~ 25 Medium Severe~ 6299.7 15 ~ 16 ~ 24 Medium Severe~ 6099.0 15 ~ 18 ~ 22 Medium Severe~ 5998.4 15 ~ 19 ~ 21 Medium Severe~ 58107.8 10 ~ ~ 16 Medium Severe~ 921010 ~ 9~ 201010~ 7~ 4~ 5~ 19108.51010Medium1010~ ~ 8~ ~ 2~ ~ 4High Severe109.144~ ~ ~ 4Category IITotal CompactedFill Depth [FT]113.8~ ~ 4Finish PadElevation [FT]Category IIExpansionPotentialSulfateExposure4~ 4~ 4HighOver-ExcavationDepth [FT]1Category IICategory IICategory IICategory IICategory IICategory2, 3ResidentialResidentialResidentialResidentialResidentialResidentialResidentialResidentialResidentialResidentialTABLE 2SUMMARY OF REMEDIAL EXCAVATIONSGDC PROJECT NO. SD365, Lennar Tabata DevelopmentFoundation108.0102.0BuildingOccupancy TypeRemainingAlluvium [FT]4Residential Category II15Elevation ofFormation [FT]~ 77Residential Category IIResidential Category IIResidential Category III115.0Residential Category III115.0Residential Category III114.7Residential Category III114.0Residential Category III112.3Residential Category III109.7Category III110.8Residential Category II108.0Category IIICategory IIResidential Category II114.0Residential Category II112.0Residential Category II110.5Residential Category II109.5Residential Category II108.5Residential Category II108.412104444~ ~ ~ ~ ~ ~ ~ 27~ 23~ 19~ 7~ 4~ 4~ 4~ 8~ 9~ 21~ 20~ 17~ 16Medium SevereMedium SevereMedium SevereHigh SevereHigh SevereHigh SevereHigh SevereSevereHigh SevereHigh SevereMedium SevereSevereMedium SevereMedium SevereMedium SevereMedium SevereMedium SevereMedium Severe FIGURES 1A SITE LOCATION MAP Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 SITE NO SCALE PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1B SITE VICINITY PLAN Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 SITE ?? AGUA HEDIONDA CREEK FEMA 100-YEAR FLOOD PLAIN (FLOOD ELEVATIONS SHOWN) NO SCALE767472716968Reference: Federal Emergency Management Agency (1997). Flood Insurance Rate Map, San Diego County, Number 060285, Panel 0768G. PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2A EXPLORATION PLAN Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 B-5 B-1 B-2 B-7 B-4 B-10 B-6 B-8 B-9 CPT-1 CPT-4 EL CAMINO REAL CAMINO HILLS DRIVECPT-2 CPT-3 CPT-5 EXPLANATION: Approximate location of exploratory boring. Approximate location of exploratory cone penetration test. B-10 CPT-5 B-3 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2B GEOTECHNICAL MAP Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 B-5 (DF~25’) B-2 (DF~15’) B-7 (DF~17’) B-4 (DF~20’) ?? ?? ?? ?? ?? B-10 (DF~2’) B-6 (DF~13’) B-8 (DF~2’) B-9 (DF~7’) CPT-4 (DF~28’) CPT-2 (DF~55’) STOCKPILE FILL QoaQoa Qoa Qoa Qoa Qoa Qoa Qoa Qoa Qoa FILL FILL FILL FILL FILL CPT-3 (DF~24’) CPT-5 (DF~12’) Reference: Hunsaker & Associates (2013). Grading Plans for Tabata 10 Stockpile (Uncompacted Fill), Drawing No. 472-7B, August 29. B-3 (DF~15’) EXPLANATION: Approximate location of exploratory boring. (DF~ Depth to Formation) Approximate location of geologic contact (dotted where buried by fill). Approximate location of previously placed fill. Approximate location of old alluvial flood deposits (circled where buried). Approximate location of exploratory cone penetration test. B-10 CPT-5 CPT-1 (DF~65’) B-1 (DF~36’) PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2C TENTATIVE GRADING PLAN Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 B-5 B-1 B-2 B-7 B-4 B-10 B-6 B-8 B-9 CPT-1 CPT-4 CPT-2 CPT-3 CPT-5 Reference: Hunsaker & Associates (2013). Grading Plans for Tabata 10, Drawing No. 472-7A, June 20. B-3 EXPLANATION: Approximate location of exploratory boring. Approximate location of exploratory cone penetration test. B-10 CPT-5 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2D REVISED GRADING PLAN Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 B-5 B-1 B-2 B-7 B-4 B-10 B-6 B-8 B-9 CPT-1 CPT-4 CPT-2 CPT-3 CPT-5 Reference: Hunsaker & Associates (2013). Consistency Determination Exhibit, Approved TM Overlay, Tabata 10, Sheet 1, September 24. B-3 EXPLANATION: Approximate location of exploratory boring. Approximate location of exploratory cone penetration test. Approximate location of slope stability cross sections in Appendix D. B-10 A A’ C’ D’ C D CPT-5 B’ B PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2E PROPOSED DEVELOPMENT Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 B-5 B-1 B-2 B-3 B-7 B-4 B-10 B-6 B-8 B-9 CPT-1 CPT-4 CPT-2 CPT-3 CPT-5 Reference: Hunsaker & Associates (2013). Consistency Determination Exhibit, Preliminary Plotting, Tabata 10, Sheet 2, September 24. EXPLANATION: Approximate location of exploratory boring. Approximate location of exploratory cone penetration test. B-10 CPT-5 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 3A REGIONAL GEOLOGIC MAP Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 NO SCALE EXPLANATION: Qls Qls Qoa Tsa Qa SITE Reference: Kennedy and Tan (2005). Geologic Map of the Oceanside 30’ x 60’ Quadrangle, California, Scale 1:100,000. PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 3B REGIONAL TOPOGRAPHY Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 NO SCALE SITE PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 3CTabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 NO SCALE SITE REFERENCE: California Emergency Management Agency (2013). County of San Diego, Encinitas Quadrangle, FEMA Flood Plains and California Specific Flood Areas. EXPLANATION: Approximate location of the FEMA/DWR 100-Year Floodplain 100-YEAR FLOODPLAIN PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 3DTabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 NO SCALE SITE REFERENCE: California Emergency Management Agency (2013). County of San Diego, Encinitas Quadrangle, CEMATsunami Response Emergency Planning Zone. EXPLANATION: Approximate location of the recommended CEMA Tsunami Evacuation Area TSUNAMI INUNDATION MAP PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS United States Mexico 33° 32° Ag u a B l a n c a F a u l t Z o n e L a g u n a S a l a d a F a u l t C e r r o P r i e t o F a u l t Z o n e Sierra Juarez Fau lt Zone S a n M i g u e l F a u l t Z o n e Valle c i t o s F a u l t Z o n e Cala b a s a s F a u l t Z o n eLa Nac ion Fau l t Sa n I s i d ro F a u l t Zon e S a n D ie g o T rou g h -Ba h i a So le d a d F a u l t Z o n e S a n C l e m e n t e F a u l t Z o n ePalo s Ve r d es Fau l t Rose Can yon Fau l t ZoneNe w p o r t - I n g l ew o o d F a u l t Cor o n ado B a n k F au l t Zone El s i n o r e Co y o t e M o u n t a i n S e g m e n t Jul i a n S e g m e n t Ear t h q u a k e V a l l e y Fau l t Z o n e S u p e r s t i t i o n M o u n t a i n S e gm e n t Bo r r e g o M o u n t a i n Se g m e n t C o y o t e C r e e k S e g m e n t Ca s a L o m a - C l a r k S e g m e n t Z o n e Zo n e Fa u l t Su p e r s t i t i o n H i l l s F a u l t Z o n e F a u l t J a c i n t o Im p e r i a l F a u l t Z o n e Brawley Seismic Zone Elmore Ranch Fault Zone C o a c h e l l a V a l l e y S e g m e n t Z o n e Faul t Sa n Cali c o - H i d a l g o F a u l t Z o n e Pinto Mountain Fault Z o n e Me s q u i t e L a k e F a u l t Z o n e B u l l i o n F a u l t San Gorgonio - Banning Fault Zone Gl e n H e l e n S e g m e n t San B e r n a r d i n o S e g m e n t Andr e a s San North Fro n t a l F a u l t Z o n e Gl e n I v y S e g m e n t Whitti e r F a u l t Z o n e Cucamonga Fault Zone Hollywood Fault Z o n e San G a b r i e l F a u l t Z o n e Santa Monica Ventura-Pitas Point Fault San Cayetano Fault Zone NOTATIONS Holocene fault displacement (during past 10,000 years) without historic record. Geomorphic evidence for Holocene faulting includes sag ponds, scarps showing little erosion, or the following features in Holocene age deposits: offset stream courses, linear scarps, shutter ridges, and triangular faceted spurs. Recency of faulting offshore is based on the interpreted age of the youngest strata displaced by faulting. Late Quaternary fault displacement (during past 700,000 years). Geomorphic evidence similar to that described for Holocene faults except features are less distinct. Faulting may be younger, but lack of younger overlying deposits precludes more accurate age classification. Quaternary fault (age undifferentiated). Most faults of this category show evidence of displacement sometime during the past 1.6 million years; possible exceptions are faults that displace rocks of undifferentiated Plio-Pleistocene age. See Bulletin 201, Appendix D for source data. Late Cenozoic faults within the Sierra Nevada including, but not restricted to, the Foothills fault system. Faults show stratigraphic and/or geomorphic evidence for displacement of late Miocene and Pliocene deposits. By analogy, late Cenozoic faults in this system that have been investigated in detail may have been active in Quaternary time (Data from PG&.E, l993.) Pre-Quaternary fault (older than 1.6 million years) or fault without recognized Quaternary displacement. Some faults are shown in this category because the source of mapping used was of reconnaissance nature, or was not done with the object of dating fault displacements. Faults in this category are not necessarily inactive. 4 REGIONAL FAULT MAP 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 100 k m SITE 13-0339 SD365 NO SCALE Tabata Development Lennar Homes PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 5 WALL DRAINAGE DETAILS 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 1) Perforated pipe should outlet through a solid pipe to a free gravity outfall. Perforated pipe and outlet pipe should have a fall of at least 1%. 2) As an alternative to the perforated pipe and outlet, weep-holes may be constructed. Weep-holes should be at least 2 inches in diameter, spaced no greater than 8 feet, and be located just above grade at the bottom of wall. 3) Filter fabric should consist of Mirafi 140N, Supac 5NP, Amoco 4599, or similar approved fabric. Filter fabric should be overlapped at least 6-inches. 4) Geocomposite panel drain should consist of Miradrain 6000, J-DRain 400, Supac DS-15, or approved similar product. NOTES ROCK AND FABRIC ALTERNATIVE PANEL DRAIN ALTERNATIVE 12”12” COMPACTED BACKFILL COMPACTED BACKFILL DAMP-PROOFING OR WATER- PROOFING AS REQUIRED DAMP-PROOFING OR WATER- PROOFING AS REQUIRED 12-INCH MINIMUM MINUS 3/4-INCH CRUSHED ROCK ENVELOPED IN FILTER FABRIC (MIRAFI 140NL, SUPAC 4NP, OR APPROVED SIMILAR) 4-INCH DIAM. PVC PERFORATED PIPE 4-INCH DIAM. PVC PERFORATED PIPE GEOCOMPOSITE PANEL DRAIN 1 CU. FT. PER LINEAR FOOT OF MINUS 3/4-INCH CRUSHED ROCK ENVELOPED IN FILTER FABRIC WEEP-HOLE ALTERNATIVEWEEP-HOLE ALTERNATIVE SD365 13-0339 Tabata Development Lennar Homes PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS APPENDIX A FIELD EXPLORATION N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX A FIELD EXPLORATION Field exploration included a visual and geologic reconnaissance of the site, the drilling of 10 exploratory borings, and the advancement of 5 cone penetrometer test (CPT) soundings. The subsurface investigation was conducted by Group Delta Consultants personnel between January 30th and February 5th, 2014. The maximum depth of exploration was about 65 feet. The approximate locations of the borings and CPT soundings conducted at the site are shown on the Exploration Plan. Logs describing the subsurface conditions encountered in the borings and CPT soundings are shown in Figures A-1 through A-15, immediately following the Boring Record Legends. The 10 exploratory borings were drilled by Pacific Drilling using a 6-inch diameter, continuous flight, hollow stem, truck mounted drill rig. Drive samples were collected from the borings using an automatic hammer with an Energy Transfer Ratio (ETR) of roughly 87 percent. Disturbed samples were collected from the borings using a 2- inch outside diameter Standard Penetration Test (SPT) sampler. Less disturbed samples were collected using a 3-inch outside diameter ring lined sampler (a modified California sampler). These samples were sealed in plastic bags, labeled, and returned to the laboratory for testing. For each sample, the number of blows needed to drive the sampler 12 inches was recorded on the attached logs. The field blow counts (N) were normalized to approximate the standard 60 percent ETR as shown on the logs (N60). Bulk samples were collected from the borings at selected intervals for testing. The borings logs are presented in Figures A-1 through A-10. The five cone penetrometer (CPT) soundings were advanced by Kehoe Testing and Engineering in general accordance with ASTM D5778. The CPT soundings were advanced using a 30-ton truck mounted rig with a 15 cm2 cone. Integrated electronic circuitry was used to measure the tip resistance (Qc) and skin friction (Fs) at 2.5 cm (1 inch) intervals while the CPT was advanced into the soil with hydraulic down pressure. A piezometer located behind the cone tip also measured transient pore pressure (u). The CPT data is presented in Figures A-11 through A-15. N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX A FIELD EXPLORATION (Continued) The first figure for each CPT sounding presents the raw CPT data (Figures A-11a through A-15a). The interpreted soil profile is shown in a color-coded log in Figures A-11b through A-15b. The soil interpretations are a function of the normalized cone resistance and friction ratio (Robertson, 1988, 1990). The interpreted Soil Behavior Type Index (Ic), and the estimated undrained shear strength (Su) for each soil profile are also shown in Figures A-11c through A-15c. At the location of the third CPT sounding (CPT-3), shear wave velocity measurements were taken at 5 foot depth intervals using an air actuated hammer located inside the front jack of the CPT rig. The interval shear wave velocities are shown in Figure A- 13c. The average shear wave velocity for the upper 46.7 feet (Vsd) at the location of sounding CPT-3 was measured as 944 ft/s (288 m/s). Note that the CPT was unable to advance through the dense materials below that depth. However, a common extrapolation method would estimate an average shear wave velocity in the upper 100 feet (Vs30) of 356 m/s based on the following formula (Boore, 2004): Vs30 ~ [1.45 – (0.015*d)] * Vsd ~ [1.45 – (0.015*46.7/3.28)] * 288 m/s ~ 356 m/s. The boring and CPT locations were determined by visually estimating, pacing and taping distances from landmarks shown on the Exploration Plan. The locations shown should not be considered more accurate than is implied by the method of measurement used and the scale of the map. The lines designating the interface between differing soil materials on the logs may be abrupt or gradational. Further, soil conditions at locations between the excavations may be substantially different from those at the specific locations we explored. It should be noted that the passage of time may also result in changes in the soil conditions reported in the logs. Project No. SD365 Tabata Development Lennar Homes BORING RECORD LEGEND #1 HOLE IDENTIFICATION Holes are identified using the following convention: H – YY – NNN Where: H: Hole Type Code YY: 2-digit year NNN: 3-digit number (001-999) SOIL IDENTIFICATION AND DESCRIPTION SEQUENCE Describe the soil using descriptive terms in the order shown Minimum Required Sequence: USCS Group Name (Group Symbol); Consistency or Density; Color; Moisture; Percent or Proportion of Soil; Particle Size; Plasticity (optional). = optional for non-Caltrans projects Where applicable: Cementation; % cobbles & boulders; Description of cobbles & boulders; Consistency field test result Description Sequence Examples: SANDY lean CLAY (CL); very stiff; yellowish brown; moist; mostly fines; some SAND, from fine to medium; few gravels; medium plasticity; PP=2.75. Well-graded SAND with SILT and GRAVEL and COBBLES (SW-SM); dense; brown; moist; mostly SAND, from fine to coarse; some fine GRAVEL; few fines; weak cementation; 10% GRANITE COBBLES; 3 to 6 inches; hard; subrounded. Clayey SAND (SC); medium dense, light brown; wet; mostly fine sand,; little fines; low plasticity. REFERENCE: Caltrans Soil and Rock Logging, Classification, and Presentation Manual (2010). Project No. SD365 Tabata Development Lennar Homes BORING RECORD LEGEND #2 REFERENCE: Caltrans Soil and Rock Logging, Classification, and Presentation Manual (2010). (2.4” ID, 3” OD) (after drilling, date) Project No. SD365 Tabata Development Lennar Homes BORING RECORD LEGEND #3 REFERENCE: Caltrans Soil and Rock Logging, Classification, and Presentation Manual (2010), with the exception of consistency of cohesive soils vs. N60. 26 44 26 39 23 PA PI CR CP EI R UW M UW M 121 114 1299 12 2026 68 10 13 1921 4610 FILL: Silty sand (SM), dense, orangish brown, moist,fine to coarse grained sand, nonplastic. OLD ALLUVIUM: Sandy lean clay (CL), very stiff tohard, dark brown, moist, fine to medium grained sand, low plasticity. (0% Gravel: 48% Sand: 52% Fines) LL~37, PL~14, PI~23 Hard, orangish brown, fine grained sand, low plasticity. Very stiff, increase in fine grained sand, low plasticity. Hard, increase in fines towards bottom of sample. Lean clay (CL), reddish brown and brown, very stiff,moist, medium plasticity. PP~3½ TSF B-1 S-2 R-3 S-4 R-5 S-6 12.6 9.4 18 46 18 40 16 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 41.5 NGRAPHICLOGLOGGED BY 1 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-1 a THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 94 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/5/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.90 85 80 75 70 B-1 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/5/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 64 44 55 132 UW M UW M 123 109 1430 36 16 1614 161839 18 3160 OLD ALLUVIUM: Clayey sand (SC), reddish brown tobrown, very dense, moist, medium to fine grained sand, low plasticity. Well-graded sand with gravel (SW), dense, orangishbrown, moist, coarse to fine grained sand (mostlymedium grained sand), nonplastic, 10% gravel up to 1-inch in maximum dimension. SANTIAGO FORMATION: Claystone (CL), light blueish gray, moist, low plasticity, strongly indurated. Total Depth: 41½ feetNo groundwater encountered R-7 S-8 R-9 S-10 12.1 18.7 66 30 57 91 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 41.5 NGRAPHICLOGLOGGED BY 2 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-1 b THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 30 35 40 45 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 94 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/5/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.65 60 55 50 45 B-1 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 30 35 40 45 2/5/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 18 19 42 64 51 PA PI CP R UW M UW M 115 111 7910 5 67 111627 11 1826 152231 FILL: Clayey sand (SC), medium dense, light brown, dry to moist, fine to coarse grained sand, low plasticity. OLD ALLUVIUM: Clayey sand (SC), medium dense,dark brown, moist, coarse to fine grained sand, low plasticity. (3% Gravel: 52% Sand: 45% Fines) LL~36, PL~16, PI~20 Orangish brown, fine grained sand, low plasticity. Poorly-graded sand (SP), dense, orangish brown, fine tomedium grained sand, nonplastic. SANTIAGO FORMATION: Claystone (CL), light gray, moist, low plasticity, strongly indurated, hard. PP>4½ TSF Total Depth: 21½ feetNo groundwater encountered B-1 R-2 S-3 R-4 S-5 R-6 12.6 9.6 19 13 43 44 53 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-2 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 91 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/5/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.90 85 80 75 70 B-2 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/5/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 23 9 27 32 PA PI CR EI DS DS 106 102 91014 3 33 7 1216 5715 FILL: Clayey sand (SC), medium dense, light brown, dry to moist, fine to coarse grained sand, low plasticity. OLD ALLUVIUM: Sandy lean clay (CL), stiff to verystiff, mottled light gray, blueish gray, purple, moist, medium plasticity. PP~4½ TSF (2% Gravel: 36% Sand: 62% Fines) LL~48, PL~18, PI~30 Lean clay (CL), stiff, dark brown, moist, fine to mediumgrained sand, low plasticity. PP~1½ TSF Clayey sand (SC), dense, orangish brown, moist, fine tomedium grained sand, low plasticity. SANTIAGO FORMATION: Claystone (CL), orangish brown and light gray, moist, low plasticity, moderatelyweathered, very stiff. PP~3½ TSF Siltstone (ML), light gray, most, low plasticity, hard. Total Depth: 21½ feetNo groundwater encountered B-1 R-2 S-3 SH-4 R-5 S-6 18.0 23.4 24 6 28 22 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-3 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 92 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.90 85 80 75 70 B-3 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 22 43 25 64 38 PA PI CR EI UW M UW M 121 122 1087 16 2519 78 9 17 2541 61016 FILL: Clayey sand (SC), medium dense, brown, dry to moist, fine to coarse grained sand, low plasticity. (1% Gravel: 60% Sand: 39% Fines) LL~28, PL~14, PI~14 OLD ALLUVIUM: Clayey sand (SC), medium dense to dense, brown, moist, fine to coarse grained sand, lowplasticity. Medium dense, orangish brown, fine to coarse grainedsand (mostly medium grained), trace gravel up to 1-inchin maximum dimension. Clayey sand with gravel (SC), very dense, increasedmoisture, increase in coarse grained sand, gravel up to 2½-inches in maximum dimension. SANTIAGO FORMATION: Claystone (CL), light gray,orange stains, moist, low plasticity, indurated. Total Depth: 21½ feetNo groundwater encountered B-1 S-2 R-3 S-4 R-5 S-6 8.7 10.0 15 44 17 66 26 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-4 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 102 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.100 95 90 85 80 B-4 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 20 38 22 42 35 PA PI CP R UW M PA PI UW M 110 114 777 10 1425 77 8 11 1726 8915 FILL: Clayey sand (SC), medium dense, orangishbrown, moist, fine to coarse grained sand, low plasticity, few gravel up to 1-inch in maximum dimension. (5% Gravel: 59% Sand: 36% Fines) LL~32, PL~14, PI~18 Sandy lean clay (CL), very stiff to hard, light orangishbrown, dry-moist, fine grained sand, low plasticity. PP~4 TSF (0% Gravel: 38% Sand: 62% Fines) LL~36, PL~15, PI~21 OLD ALLUVIUM: Clayey sand (SC), dense, reddish brown, moist, fine to medium grained sand, lowplasticity. Sandy clay (CL), hard, dark orangish brown and grayishbrown, fine grained sand, moist, low plasticity. PP~4½ TSF B-1 S-2 R-3 S-4 B-5 R-6 S-7 18.0 16.2 14 39 15 43 24 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 36.5 NGRAPHICLOGLOGGED BY 1 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-5 a THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 117 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.115 110 105 100 95 B-5 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 52 44 35 UW M UW M 114 97 920 34 7 1218 91422 SANTIAGO FORMATION: Lean claystone (CL), lightgray with orange staining, moist, low plasticity, strongly indurated, hard. PP>4½ TSF Siltstone (ML), light gray with orange staining, moist, lowplasticity, strongly indurated, hard. Total Depth: 36½ feetNo groundwater encountered R-8 S-9 R-10 17.4 26.1 54 30 36 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 36.5 NGRAPHICLOGLOGGED BY 2 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-5 b THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 30 35 40 45 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 117 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.90 85 80 75 70 B-5 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 30 35 40 45 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 16 16 30 20 51 PA PI EI R UW M UW M UW M 108 118 120 689 4 56 71318 4 68 112033 FILL: Clayey sand (SC), loose to medium dense,moderately brown, dry to moist, fine to coarse grained sand, low plasticity. OLD ALLUVIUM: Sandy lean clay (CL), very stiff, lightgray, dry to moist, low plasticity. PP~4½ TSF (0% Gravel: 47% Sand: 53% Fines) LL~44, PL~18, PI~26 Lean clay (CL), very stiff, dark brown, moist, fine tomedium grained sand, low plasticity. PP~4½ TSF Trace coarse to fine sand, low plasticity. SANTIAGO FORMATION: Lean claystone (CL), lightblueish gray, moist, low plasticity, moderately weathered, very stiff to hard. PP~2½ to 4½ TSF Orange and light gray, dry to moist, strongly indurated, hard. Total Depth: 21½ feetNo groundwater encountered B-1 R-2 S-3 R-4 S-5 R-6 15.6 14.4 13.5 17 11 31 14 53 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-6 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 109 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.105 100 95 90 85 B-6 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 15 15 19 31 20 PA PI CR EI UW M UW M 110 111 555 6 88 45 8 8 1220 459 FILL: Clayey sand (SC), loose to medium dense,brown, moist, fine to coarse grained sand, low plasticity. OLD ALLUVIUM: Sandy lean clay (CL), stiff to verystiff, brown, moist, fine to coarse grained, low plasticity. (0% Gravel: 42% Sand: 58% Fines) LL~46, PL~16, PI~30 Orangish brown, few cobbles. Lean clay (CL), very stiff, dark brown, moist, lowplasticity. PP~1½ to 3 TSF Lean clay with sand (CL), hard, orangish brown, moist,trace fine to coarse grained sand, low plasticity. SANTIAGO FORMATION: Claystone (CL), light grayand orangish brown, moist, low plasticity, weakly to moderately indurated, very stiff. B-1 S-2 R-3 S-4 R-5 S-6 10.3 18.7 10 16 13 32 14 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 31.5 NGRAPHICLOGLOGGED BY 1 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-7 a THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 108 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.105 100 95 90 85 B-7 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 37 51 UW M981218 20 7 1322 SANTIAGO FORMATION: Claystone (CL), light grayand orangish brown, moist, low plasticity, moderately indurated, hard. PP~4 TSF Strongly indurated. Total Depth: 31½ feet No groundwater encountered R-7 S-8 26.138 35 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 31.5 NGRAPHICLOGLOGGED BY 2 of 2 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-7 b THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 30 35 40 45 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 108 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.80 75 70 65 60 B-7 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 30 35 40 45 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 23 31 23 39 94 PA PI EI DS UW M 98 102 579 8 1418 57 9 11 1822 182639 FILL: Sandy lean clay (CL), stiff, brown, moist, lowplasticity. SANTIAGO FORMATION: Sandy fat claystone (CH),gray and orangish brown, moist, few fine grained sand,high plasticity, weathered. PP~2½ TSF (0% Gravel: 32% Sand: 68% Fines) LL~55, PL~20, PI~35 Interbedded with clayey sandstone (SC), dark orange brown, moist, very fine grained, low plasticity. Blueish gray and orange lean claystone (CL), mediumplasticity, slightly indurated, very stiff to hard. PP~2½ TSF Blueish gray, strongly indurated, hard. PP>4½ TSF Total Depth: 21½ feetNo groundwater encountered B-1 S-2 R-3 S-4 R-5 S-6 23.5 23.8 16 32 16 40 65 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-8 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 116 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.115 110 105 100 95 B-8 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 21 17 41 16 27 PA PI EI UW M PA PI DS 110 113 101012 6 66 111923 3 56 81315 FILL: Sandy lean clay (CL), stiff, brown, moist, lowplasticity. (0% Gravel: 45% Sand: 55% Fines) LL~45, PL~18, PI~27 Clayey sand (SC), medium dense, brown and reddishbrown, coarse to fine grained sand, mostly medium grained, low plasticity. SANTIAGO FORMATION: Sandy fat claystone (CH),light gray, moist, high plasticity, slightly weathered. (0% Gravel: 32% Sand: 68% Fines) LL~51, PL~20, PI~31 PP>4½ TSF Sandy lean claystone (CL), brown, moist, trace mediumto fine grained sand, low plasticity, very stiff. PP~2 to 3 TSF Total Depth: 21½ feetNo groundwater encountered B-1 R-2 S-3 B-4 R-5 S-6 R-7 14.1 14.0 22 12 42 11 28 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-9 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 120 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/4/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.115 110 105 100 B-9 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/4/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 20 38 35 63 77 PA PI CR EI DS UW M 103 105 568 10 1722 810 14 14 2540 142330 FILL: Clayey sand (SC), loose to medium dense, lightbrown, moist, fine to coarse grained sand, low plasticity. SANTIAGO FORMATION: Sandy fat claystone (CH),light blueish gray, moist, high plasticity, weathered. (0% Gravel: 30% Sand: 70% Fines) LL~59, PL~25, PI~34 Purple/blueish gray, strongly indurated, hard. PP>4½ TSF Pink/greenish gray, hard. Darker blueish gray, hard. Lean claystone (CL), light gray with orange stains,moist, medium plasticity, hard. Total Depth: 21½ feetNo groundwater encountered B-1 S-2 R-3 S-4 R-5 S-6 19.9 22.2 14 39 24 65 53 Hammer: 140 lbs., Drop: 30 in. (Automatic) TOTAL DEPTH (ft) BORING SAMPLE TYPEGROUP DELTA CONSULTANTS, INC. 21.5 NGRAPHICLOGLOGGED BY 1 of 1 DESCRIPTION AND CLASSIFICATION PROJECT NAME ELEVATION(feet)60PROJECT NUMBER Tabata Development, Carlsbad, CA SITE LOCATION FIGURE A-10 THIS SUMMARY APPLIES ONLY AT THE LOCATIONOF THIS BORING AND AT THE TIME OF DRILLING.SUBSURFACE CONDITIONS MAY DIFFER AT OTHERLOCATIONS AND MAY CHANGE AT THIS LOCATIONWITH THE PASSAGE OF TIME. THE DATAPRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. SHEET NO. 5 10 15 20 GROUND ELEV (ft)BLOW/FT "N"DRY DENSITY(pcf)DRILLING METHOD DEPTH (feet)San Diego, CA 92126 120 N/A / na TSL PENETRATION RESISTANCE(BLOWS / 6 IN)OTHERTESTSNOTES 9245 Activity Road, Suite 103 BORING RECORD 6 DRILLING EQUIPMENT 2/5/2014 CME 75 SAMPLING METHOD DEPTH/ELEV. GROUND WATER (ft) Pacific Drilling Hollow Stem Auger DEPTH (feet)FINISH SAMPLE NO.115 110 105 100 B-10 START MOISTURE(%)MAF Lennar Homes CHECKED BY BORING DIA. (in) SD365 ETR ~ 87%, N60 ~ 87/60 * N ~ 1.45 * N DRILLING COMPANY 5 10 15 20 2/5/2014 GDC_LOG_BORING_MMX_SOIL_SD SD365 LOGS.GPJ GDCLOG.GDT 3/3/14 DEPTH [FEET]Document No. 13-0339CONE PENETOMETER DATA (CPT-1)Project No. SD365FIGURE A-11a050100150200250300Tip Resistance (Qc) [TSF]051015202530354045505560657002468Skin Friction (Fs) [TSF]051015202530354045505560657002468Friction Ratio (FR) [%] Document No. 13-0339SOIL CLASSIFICATION (CPT-1)Project No. SD365FIGURE A-11b05101520253035404550556065700246810Soil Type (SBT)1101001,0000.1 1 10Normalized Cone Resistance, QNormalized Friction Ratio, F(1) Sensitive, fine grained(7) Gravelly sand to dense sand(2) Organic ‐peats(6) Clean to silty sand(5) Silty sand to sandy silt(4) Silt Mix(3) Clay(8) VS Sands(9) VS Fine DEPTH [FEET]Document No. 13-0339ESTIMATED STRENGTH (CPT-1)Project No. SD365FIGURE A-11c050100150200250300Tip Resistance (Qc) [TSF]05101520253035404550556065700 2000 4000 6000 8000Strength (Su) [PSF]051015202530354045505560657001234Soil Type [Ic] DEPTH [FEET]Document No. 13-0339CONE PENETOMETER DATA (CPT-2)Project No. SD365FIGURE A-12a050100150200250300Tip Resistance (Qc) [TSF]051015202530354045505502468Skin Friction (Fs) [TSF]051015202530354045505502468Friction Ratio (FR) [%] Document No. 13-0339SOIL CLASSIFICATION (CPT-2)Project No. SD365FIGURE A-12b05101520253035404550550246810Soil Type (SBT)1101001,0000.1 1 10Normalized Cone Resistance, QNormalized Friction Ratio, F(1) Sensitive, fine grained(7) Gravelly sand to dense sand(2) Organic ‐peats(6) Clean to silty sand(5) Silty sand to sandy silt(4) Silt Mix(3) Clay(8) VS Sands(9) VS Fine DEPTH [FEET]Document No. 13-0339ESTIMATED STRENGTH (CPT-2)Project No. SD365FIGURE A-12c050100150200250300Tip Resistance (Qc) [TSF]05101520253035404550550 2000 4000 6000 8000Strength (Su) [PSF]051015202530354045505501234Soil Type [Ic] DEPTH [FEET]Document No. 13-0339CONE PENETOMETER DATA (CPT-3)Project No. SD365FIGURE A-13a050100150200250300Tip Resistance (Qc) [TSF]0510152025303540455002468Skin Friction (Fs) [TSF]0510152025303540455002468Friction Ratio (FR) [%] Document No. 13-0339SOIL CLASSIFICATION (CPT-3)Project No. SD365FIGURE A-13b051015202530354045500246810Soil Type (SBT)1101001,0000.1 1 10Normalized Cone Resistance, QNormalized Friction Ratio, F(1) Sensitive, fine grained(7) Gravelly sand to dense sand(2) Organic ‐peats(6) Clean to silty sand(5) Silty sand to sandy silt(4) Silt Mix(3) Clay(8) VS Sands(9) VS Fine DEPTH [FEET]Document No. 13-0339SHEAR WAVE VELOCITY DATA (CPT-3)Project No. SD365FIGURE A-13c050100150200250300Tip Resistance (Qc) [TSF]Vs30~ 1,168 ft/s ~ 356 m/s → 2013 CBC Site Class D70177662710001116934909117515511956051015202530354045500 500 1000 1500 2000Velocity (Vs) [FPS]0510152025303540455001234Soil Type [Ic]Vsd~ 944 ft/s DEPTH [FEET]Document No. 13-0339CONE PENETOMETER DATA (CPT-4)Project No. SD365FIGURE A-14a050100150200250300Tip Resistance (Qc) [TSF]05101520253035404550550481216Skin Friction (Fs) [TSF]051015202530354045505502468Friction Ratio (FR) [%] Document No. 13-0339SOIL CLASSIFICATION (CPT-4)Project No. SD365FIGURE A-14b05101520253035404550550246810Soil Type (SBT)1101001,0000.1 1 10Normalized Cone Resistance, QNormalized Friction Ratio, F(1) Sensitive, fine grained(7) Gravelly sand to dense sand(2) Organic ‐peats(6) Clean to silty sand(5) Silty sand to sandy silt(4) Silt Mix(3) Clay(8) VS Sands(9) VS Fine DEPTH [FEET]Document No. 13-0339ESTIMATED STRENGTH (CPT-4)Project No. SD365FIGURE A-14c050100150200250300Tip Resistance (Qc) [TSF]05101520253035404550550 2000 4000 6000 8000Strength (Su) [PSF]051015202530354045505501234Soil Type [Ic] DEPTH [FEET]Document No. 13-0339CONE PENETOMETER DATA (CPT-5)Project No. SD365FIGURE A-15a050100150200250300Tip Resistance (Qc) [TSF]051015202530354045500481216Skin Friction (Fs) [TSF]0510152025303540455002468Friction Ratio (FR) [%] Document No. 13-0339SOIL CLASSIFICATION (CPT-5)Project No. SD365FIGURE A-15b051015202530354045500246810Soil Type (SBT)1101001,0000.1 1 10Normalized Cone Resistance, QNormalized Friction Ratio, F(1) Sensitive, fine grained(7) Gravelly sand to dense sand(2) Organic ‐peats(6) Clean to silty sand(5) Silty sand to sandy silt(4) Silt Mix(3) Clay(8) VS Sands(9) VS Fine DEPTH [FEET]Document No. 13-0339ESTIMATED STRENGTH (CPT-5)Project No. SD365FIGURE A-15c050100150200250300Tip Resistance (Qc) [TSF]051015202530354045500 2000 4000 6000 8000Strength (Su) [PSF]0510152025303540455001234Soil Type [Ic] APPENDIX B LABORATORY TESTING N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX B LABORATORY TESTING Laboratory testing was conducted in a manner consistent with the level of care and skill ordinarily exercised by members of the profession currently practicing under similar conditions and in the same locality. No warranty, express or implied, is made as to the correctness or serviceability of the test results, or the conclusions derived from these tests. Where a specific laboratory test method has been referenced, such as ASTM or Caltrans, the reference only applies to the specified laboratory test method, which has been used only as a guidance document for the general performance of the test and not as a “Test Standard”. A brief description of the various tests performed for this project follows. Classification: Soils were classified visually according to the Unified Soil Classification System as established by the American Society of Civil Engineers. Visual classification was supplemented by laboratory testing and classification using ASTM D2487. The soil classifications are shown on the boring logs in Appendix A. Particle Size Analysis: Particle size analyses were performed in general accordance with ASTM D422, and were used to supplement visual soil classifications. The test results are summarized in Figures B-1.1 through B-1.12. Atterberg Limits: ASTM D4318 was also used to determine the liquid limit and plasticity index of selected soil samples. The Atterberg Limits were used to refine the soil classifications as shown in Figures B-1.1 through B-1.12. Expansion Index: The expansion potential of selected soil samples was estimated in general accordance with the laboratory procedures outlined in ASTM test method D4829. The test results are summarized in Figure B-2. Figure B-2 also presents common criteria for evaluating the expansion potential based on the expansion index. Sulfate Content: To assess the potential for reactivity with concrete, selected soil samples were tested for water soluble sulfate. The sulfate was extracted from the soil under vacuum using a 10:1 (water to dry soil) dilution ratio. The extracted solution was tested for water soluble sulfate in general accordance with ASTM D516. The test results are presented in Figure B-3. Figure B-3 also presents common criteria for evaluating soluble sulfate content. N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX B LABORATORY TESTING (Continued) pH and Resistivity: To assess the potential for reactivity with metal, selected samples were tested for pH and resistivity using Caltrans method 643. The test results are also shown in Figure B-3. Chloride Content: Soil samples were also tested for water soluble chloride. The chloride was extracted from the soil under vacuum using a 10:1 (water to dry soil) dilution ratio. The extracted solution was then tested for water soluble chloride using a calibrated ion specific electronic probe. The test results are shown in Figure B-3. Maximum Density/Optimum Moisture: The maximum density and optimum moisture content of selected soil samples were determined using ASTM D1557 (modified Proctor). The results were corrected for over-size material using ASTM D4718 as a guideline. The test results are summarized in Figure B-4. Direct Shear: The shear strengths of selected samples of the on-site soils were assessed using direct shear testing performed in general accordance with ASTM D3080. These test results are shown in Figures B-5.1 through B-5.5. The shear test results are summarized in Figure B-5.6. R-Value: R-Value tests were performed on a sample of the on-site soils in general accordance with CTM 301. The results are shown in Figures B-6.1 through B-6.4. COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-1LIQUID LIMIT: 37SAMPLE LOCATION: 1' - 5'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 14PLASTICITY INDEX: 23Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.1100999789766352444035333128263'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer52% Fines→←0% Gravel48% Sand ↔2701020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: SCATTERBERG LIMITSSAMPLE ID: B-2LIQUID LIMIT: 36SAMPLE LOCATION: 0' - 5'DESCRIPTION:CLAYEY SANDPLASTIC LIMIT: 16PLASTICITY INDEX: 20Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.21009997959183715745363330282725233'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer45% Fines→←3% Gravel52% Sand ↔2401020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-3LIQUID LIMIT: 48SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 18PLASTICITY INDEX: 30Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.31009898989590817162545045434138333'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer62% Fines→←2% Gravel36% Sand ↔3601020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: SCATTERBERG LIMITSSAMPLE ID: B-4LIQUID LIMIT: 28SAMPLE LOCATION: 0' - 5'DESCRIPTION:CLAYEY SANDPLASTIC LIMIT: 14PLASTICITY INDEX: 14Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.410099979179655139322825232119173'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer39% Fines→←1% Gravel60% Sand ↔1801020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: SCATTERBERG LIMITSSAMPLE ID: B-5LIQUID LIMIT: 32SAMPLE LOCATION: 0' - 5'DESCRIPTION:CLAYEY SANDPLASTIC LIMIT: 14PLASTICITY INDEX: 18Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.51009796918473604736292623212019173'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer36% Fines→←5% Gravel59% Sand ↔1801020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-5LIQUID LIMIT: 36SAMPLE LOCATION: 10' - 15'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 15PLASTICITY INDEX: 21Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.61009997938162474036343230263'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer62% Fines→←0% Gravel38% Sand ↔2801020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-6LIQUID LIMIT: 44SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 18PLASTICITY INDEX: 26Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.7100999690806753444037353329263'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer53% Fines→←0% Gravel47% Sand ↔2801020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-7LIQUID LIMIT: 46SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 16PLASTICITY INDEX: 30Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.81009791827158504642413936333'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer58% Fines→←0% Gravel42% Sand ↔3501020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CHATTERBERG LIMITSSAMPLE ID: B-8LIQUID LIMIT: 55SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY FAT CLAYPLASTIC LIMIT: 20PLASTICITY INDEX: 35Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.91009996898068595551494843363'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer68% Fines→←0% Gravel32% Sand ↔4001020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CLATTERBERG LIMITSSAMPLE ID: B-9LIQUID LIMIT: 45SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY LEAN CLAYPLASTIC LIMIT: 18PLASTICITY INDEX: 27Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.10100999587786655474340383633283'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer55% Fines→←0% Gravel45% Sand ↔3101020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CHATTERBERG LIMITSSAMPLE ID: B-9LIQUID LIMIT: 51SAMPLE LOCATION: 5' - 10'DESCRIPTION:SANDY FAT CLAYPLASTIC LIMIT: 20PLASTICITY INDEX: 31Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.111009997928168595449474440353'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer68% Fines→←0% Gravel32% Sand ↔3801020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight COARSEFINECOARSEMEDIUMFINESILT ANDGRAVELSANDCLAYSAMPLEUNIFIED SOIL CLASSIFICATION: CHATTERBERG LIMITSSAMPLE ID: B-10LIQUID LIMIT: 59SAMPLE LOCATION: 0' - 5'DESCRIPTION:SANDY FAT CLAYPLASTIC LIMIT: 25PLASTICITY INDEX: 34Document No. 13-0339SOIL CLASSIFICATIONProject No. SD365FIGURE B-1.121009997887670666358555245393'' 1½'' 3/4'' 3/8'' #4#8 #16 #30 #50 #100 #200 Hydrometer70% Fines→←0% Gravel30% Sand ↔4201020304050607080901000.0010.010.1110100Grain Size in MillimetersU.S. Standard Sieve SizesPercent Finer by Weight Document No. 13-0339 Project No. SD365 FIGURE B-2 EXPANSION TEST RESULTS (ASTM D4829) SAMPLE DESCRIPTION EXPANSION INDEX B-1 @ 1’– 5’ Old Alluvium: Dark reddish brown sandy lean clay (CL). 66 B-3 @ 0’– 5’ Old Alluvium: Light olive gray sandy lean clay (CL). 91 B-4 @ 0’– 5’ Fill: Dark yellow brown clayey sand (SC). 16 B-6 @ 0’– 5’ Old Alluvium: Yellow brown sandy lean clay (CL). 77 B-7 @ 0’– 5’ Old Alluvium: Dark yellow brown sandy lean clay (CL). 76 B-8 @ 0’– 5’ Santiago Formation: Olive sandy fat claystone (CH). 120 B-9 @ 0’– 5’ Fill: Light gray sandy lean clay (CL). 78 B-10 @ 0’– 5’ Santiago Formation: Olive sandy fat claystone (CH). 123 EXPANSION INDEX POTENTIAL EXPANSION 0 to 20 Very low 21 to 50 Low 51 to 90 Medium 91 to 130 High Above 130 Very High LABORATORY TEST RESULTS Document No. 13-0339 Project No. SD365 FIGURE B-3 CHEMISTRY TEST RESULTS (ASTM D516, CTM 643) SAMPLE pH RESISTIVITY [OHM-CM] SULFATE CONTENT [%] CHLORIDE CONTENT [%] B-1 @ 1’– 5’ 7.7 560 <0.01 0.06 B-3 @ 0’– 5’ 7.0 350 0.90 0.06 B-4 @ 0’– 5’ 6.5 1,740 <0.01 0.03 B-7 @ 0’– 5’ 6.3 450 0.65 0.04 B-10 @ 0’– 5’ 7.0 320 0.23 0.06 SULFATE CONTENT [%] SULFATE EXPOSURE CEMENT TYPE 0.00 to 0.10 Negligible - 0.10 to 0.20 Moderate II, IP(MS), IS(MS) 0.20 to 2.00 Severe V Above 2.00 Very Severe V plus pozzolan SOIL RESISTIVITY [OHM-CM] GENERAL DEGREE OF CORROSIVITY TO FERROUS METALS 0 to 1,000 Very Corrosive 1,000 to 2,000 Corrosive 2,000 to 5,000 Moderately Corrosive 5,000 to 10,000 Mildly Corrosive Above 10,000 Slightly Corrosive CHLORIDE (Cl) CONTENT [%] GENERAL DEGREE OF CORROSIVITY TO METALS 0.00 to 0.03 Negligible 0.03 to 0.15 Corrosive Above 0.15 Severely Corrosive LABORATORY TEST RESULTS Document No. 13-0339 Project No. SD365 FIGURE B-4 MAXIMUM DENSITY & OPTIMUM MOISTURE (ASTM D1557) SAMPLE ID DESCRIPTION MAXIMUM DENSITY [lb/ft3] OPTIMUM MOISTURE [%] B-1 @ 1’– 5’ Old Alluvium: Yellow brown sandy lean clay (CL). 126 9 B-2 @ 0’– 5’ Old Alluvium: Dark yellow brown clayey sand (SC). 125 10 B-5 @ 0’– 5’ Fill: Dark yellow brown clayey sand (SC). 128½ 8½ LABORATORY TEST RESULTS SAMPLE:B-3 @ 2' - 3½'PEAK ULTIMATE OLD ALLUVIUM (Qoa):'23 o 23 o Yellow brown sandy lean clay (CL).C'250 PSF 200 PSF IN-SITU AS-TESTED STRAIN RATE:0.0007 IN/MIN d 106.3 PCF 106.3 PCF (Sample was consolidated and drained)wc 18.0 %21.7 % Document No. 13-0339 DIRECT SHEAR TEST RESULTS Project No. SD365 FIGURE B-5.1 0 1000 2000 3000 4000 0.0 2.0 4.0 6.0 8.0 10.0SHEAR STRESS [PSF]STRAIN [%] 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Peak Strength Test Results 23 Degrees, 250 PSF Cohesion Ultimate Strength Test Results 23 Degrees, 200 PSF Cohesion SAMPLE:B-3 @ 15' - 16½'PEAK ULTIMATE SANTIAGO FORMATION (Tsa):'25 o 25 o Mottled sandy lean claystone (CL).C'350 PSF 150 PSF IN-SITU AS-TESTED STRAIN RATE:0.0002 IN/MIN d 102.4 PCF 102.4 PCF (Sample was consolidated and drained)wc 23.4 %23.9 % Document No. 13-0339 DIRECT SHEAR TEST RESULTS Project No. SD365 FIGURE B-5.2 0 1000 2000 3000 4000 0.0 2.0 4.0 6.0 8.0 10.0SHEAR STRESS [PSF]STRAIN [%] 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Peak Strength Test Results 25 Degrees, 350 PSF Cohesion Ultimate Strength Test Results 25 Degrees, 150 PSF Cohesion SAMPLE:B-8 @ 5' - 6½'PEAK ULTIMATE SANTIAGO FORMATION (Tsa):'25 o 25 o Light olive sandy fat claystone (CH).C'400 PSF 300 PSF IN-SITU AS-TESTED STRAIN RATE:0.0007 IN/MIN d 98.1 PCF 98.1 PCF (Sample was consolidated and drained)wc 23.5 %26.6 % Document No. 13-0339 DIRECT SHEAR TEST RESULTS Project No. SD365 FIGURE B-5.3 0 1000 2000 3000 4000 0.0 2.0 4.0 6.0 8.0 10.0SHEAR STRESS [PSF]STRAIN [%] 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Peak Strength Test Results 25 Degrees, 400 PSF Cohesion Ultimate Strength Test Results 25 Degrees, 300 PSF Cohesion SAMPLE:B-9 @ 10' - 11½'PEAK ULTIMATE SANTIAGO FORMATION (Tsa):'25 o 25 o Dark brown sandy fat claystone (CH).C'300 PSF 250 PSF IN-SITU AS-TESTED STRAIN RATE:0.0002 IN/MIN d 112.7 PCF 112.7 PCF (Sample was consolidated and drained)wc 14.0 %18.3 % Document No. 13-0339 DIRECT SHEAR TEST RESULTS Project No. SD365 FIGURE B-5.4 0 1000 2000 3000 4000 0.0 2.0 4.0 6.0 8.0 10.0SHEAR STRESS [PSF]STRAIN [%] 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Peak Strength Test Results 25 Degrees, 300 PSF Cohesion Ultimate Strength Test Results 25 Degrees, 250 PSF Cohesion SAMPLE:B-10 @ 5' - 6½'PEAK ULTIMATE SANTIAGO FORMATION (Tsa):'25 o 25 o Olive gray sandy fat claystone (CH).C'300 PSF 200 PSF IN-SITU AS-TESTED STRAIN RATE:0.0002 IN/MIN d 102.8 PCF 102.8 PCF (Sample was consolidated and drained)wc 19.9 %23.7 % Document No. 13-0339 DIRECT SHEAR TEST RESULTS Project No. SD365 FIGURE B-5.5 0 1000 2000 3000 4000 0.0 2.0 4.0 6.0 8.0 10.0SHEAR STRESS [PSF]STRAIN [%] 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Peak Strength Test Results 25 Degrees, 300 PSF Cohesion Ultimate Strength Test Results 25 Degrees, 200 PSF Cohesion ALLUVIUM A summary of 5 direct shear tests on PEAK ULTIMATE samples of the on-site clays (CL & CH). All 5 samples were tested at the in-situ '24 o 23 o density under saturated conditions.C'300 PSF 200 PSF Document No. 13-0339 DIRECT SHEAR TEST SUMMARY Project No. SD365 FIGURE B-5.6 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS [PSF]NORMAL STRESS [PSF] Ultimate Values Peak Values Ultimate Strength Peak Strength BORING NO.: B-1 SAMPLE DATE: 2/5/14 SAMPLE LOCATION: 1' - 5' TEST DATE: 2/10/14 SAMPLE DESCRIPTION: Dark reddish brown sandy lean clay (CL) LABORATORY TEST DATA TEST SPECIMEN 12345 A COMPACTOR PRESSURE 140 100 70 [PSI] B INITIAL MOISTURE 7.3 7.3 7.3 [%] C BATCH SOIL WEIGHT 1200 1200 1200 [G] D WATER ADDED 65 77 89 [ML] E WATER ADDED (D*(100+B)/C) 5.8 6.9 8.0 [%] F COMPACTION MOISTURE (B+E) 13.2 14.2 15.3 [%] G MOLD WEIGHT 2114.6 2113.2 2108.1 [G] H TOTAL BRIQUETTE WEIGHT 3188.8 3185.5 3177.7 [G] I NET BRIQUETTE WEIGHT (H-G) 1074.2 1072.3 1069.6 [G] J BRIQUETTE HEIGHT 2.38 2.41 2.45 [IN] K DRY DENSITY (30.3*I/((100+F)*J)) 120.9 118.0 114.7 [PCF] L EXUDATION LOAD 8424 5208 2248 [LB] M EXUDATION PRESSURE (L/12.54) 672 415 179 [PSI] N STABILOMETER AT 1000 LBS 36 44 54 [PSI] O STABILOMETER AT 2000 LBS 97 112 127 [PSI] P DISPLACEMENT FOR 100 PSI 4.43 4.84 5.10 [Turns] Q R VALUE BY STABILOMETER 27 18 11 R CORRECTED R-VALUE (See Fig. 14) 25 17 11 S EXPANSION DIAL READING 0.0074 0.0040 0.0021 [IN] T EXPANSION PRESSURE (S*43,300) 320 173 91 [PSF] U COVER BY STABILOMETER 0.82 0.91 0.98 [FT] V COVER BY EXPANSION 2.47 1.33 0.70 [FT] TRAFFIC INDEX: 5.0 GRAVEL FACTOR: 1.46 UNIT WEIGHT OF COVER [PCF]: 130 R-VALUE BY EXUDATION: 14 R-VALUE BY EXPANSION: 15 R-VALUE AT EQUILIBRIUM: 14 *Note: Gravel factor estimated from pavement section using CTM 301, Section C, Part b. R-VALUE TEST RESULTS Project No. SD365 FIGURE B-6.1a Document No. 13-0339 Sample: B-1 @ 1' - 5'R-Value at Equilibrium: 14COVER AND EXUDATION CHARTSProject No. SD365Document No. 13-0339FIGURE B-6.1b01020304050607080901000100200300400500600700800R-ValueExudation Pressure [psi]0.00.51.01.52.02.53.00.0 0.5 1.0 1.5 2.0 2.5 3.0Cover Thickness by Stabilometer [FT]Cover Thickness by Expansion [FT] BORING NO.: B-2 SAMPLE DATE: 2/5/14 SAMPLE LOCATION: 0' - 5' TEST DATE: 2/10/14 SAMPLE DESCRIPTION: Dark yellow brown clayey sand (SC) LABORATORY TEST DATA TEST SPECIMEN 12345 A COMPACTOR PRESSURE 120 70 170 [PSI] B INITIAL MOISTURE 3.9 3.9 3.9 [%] C BATCH SOIL WEIGHT 1200 1200 1200 [G] D WATER ADDED 112 120 102 [ML] E WATER ADDED (D*(100+B)/C) 9.7 10.4 8.8 [%] F COMPACTION MOISTURE (B+E) 13.6 14.3 12.7 [%] G MOLD WEIGHT 2113.2 2114.3 2108.3 [G] H TOTAL BRIQUETTE WEIGHT 3207.9 3202.1 3207.5 [G] I NET BRIQUETTE WEIGHT (H-G) 1094.7 1087.8 1099.2 [G] J BRIQUETTE HEIGHT 2.47 2.48 2.46 [IN] K DRY DENSITY (30.3*I/((100+F)*J)) 118.2 116.3 120.1 [PCF] L EXUDATION LOAD 3680 2363 4656 [LB] M EXUDATION PRESSURE (L/12.54) 293 188 371 [PSI] N STABILOMETER AT 1000 LBS 45 55 39 [PSI] O STABILOMETER AT 2000 LBS 112 128 100 [PSI] P DISPLACEMENT FOR 100 PSI 4.54 4.87 4.40 [Turns] Q R VALUE BY STABILOMETER 19 11 25 R CORRECTED R-VALUE (See Fig. 14) 19 11 25 S EXPANSION DIAL READING 0.0022 0.0010 0.0041 [IN] T EXPANSION PRESSURE (S*43,300) 95 43 178 [PSF] U COVER BY STABILOMETER 0.87 0.96 0.81 [FT] V COVER BY EXPANSION 0.73 0.33 1.37 [FT] TRAFFIC INDEX: 5.0 GRAVEL FACTOR: 1.49 UNIT WEIGHT OF COVER [PCF]: 130 R-VALUE BY EXUDATION: 19 R-VALUE BY EXPANSION: 22 R-VALUE AT EQUILIBRIUM: 19 *Note: Gravel factor estimated from pavement section using CTM 301, Section C, Part b. R-VALUE TEST RESULTS Project No. SD365 FIGURE B-6.2a Document No. 13-0339 Sample: B-2 @ 0' - 5'R-Value at Equilibrium: 19COVER AND EXUDATION CHARTSProject No. SD365Document No. 13-0339FIGURE B-6.2b01020304050607080901000100200300400500600700800R-ValueExudation Pressure [psi]0.00.51.01.52.02.53.00.0 0.5 1.0 1.5 2.0 2.5 3.0Cover Thickness by Stabilometer [FT]Cover Thickness by Expansion [FT] BORING NO.: B-5 SAMPLE DATE: 2/4/14 SAMPLE LOCATION: 0' - 5' TEST DATE: 2/12/14 SAMPLE DESCRIPTION: Dark yellow brown clayey sand (SC) LABORATORY TEST DATA TEST SPECIMEN 12345 A COMPACTOR PRESSURE 80 120 170 [PSI] B INITIAL MOISTURE 0.9 0.9 0.9 [%] C BATCH SOIL WEIGHT 1200 1200 1200 [G] D WATER ADDED 120 112 104 [ML] E WATER ADDED (D*(100+B)/C) 10.1 9.4 8.7 [%] F COMPACTION MOISTURE (B+E) 10.9 10.3 9.6 [%] G MOLD WEIGHT 2004.6 2017.1 2010.5 [G] H TOTAL BRIQUETTE WEIGHT 3110.2 3118.8 3109.0 [G] I NET BRIQUETTE WEIGHT (H-G) 1105.6 1101.7 1098.5 [G] J BRIQUETTE HEIGHT 2.46 2.44 2.40 [IN] K DRY DENSITY (30.3*I/((100+F)*J)) 122.8 124.1 126.5 [PCF] L EXUDATION LOAD 3016 3955 5522 [LB] M EXUDATION PRESSURE (L/12.54) 241 315 440 [PSI] N STABILOMETER AT 1000 LBS 51 49 46 [PSI] O STABILOMETER AT 2000 LBS 120 113 106 [PSI] P DISPLACEMENT FOR 100 PSI 4.59 4.43 4.37 [Turns] Q R VALUE BY STABILOMETER 15 19 23 R CORRECTED R-VALUE (See Fig. 14) 15 18 22 S EXPANSION DIAL READING 0.0003 0.0009 0.0010 [IN] T EXPANSION PRESSURE (S*43,300) 13 39 43 [PSF] U COVER BY STABILOMETER 0.91 0.88 0.84 [FT] V COVER BY EXPANSION 0.10 0.30 0.33 [FT] TRAFFIC INDEX: 5.0 GRAVEL FACTOR: 1.49 UNIT WEIGHT OF COVER [PCF]: 130 R-VALUE BY EXUDATION: 17 R-VALUE BY EXPANSION: 22 R-VALUE AT EQUILIBRIUM: 17 *Note: Gravel factor estimated from pavement section using CTM 301, Section C, Part b. R-VALUE TEST RESULTS Project No. SD365 FIGURE B-6.3a Document No. 13-0339 Sample: B-5 @ 0' - 5'R-Value at Equilibrium: 17COVER AND EXUDATION CHARTSProject No. SD365Document No. 13-0339FIGURE B-6.3b01020304050607080901000100200300400500600700800R-ValueExudation Pressure [psi]0.00.51.01.52.02.53.00.0 0.5 1.0 1.5 2.0 2.5 3.0Cover Thickness by Stabilometer [FT]Cover Thickness by Expansion [FT] BORING NO.: B-6 SAMPLE DATE: 2/4/14 SAMPLE LOCATION: 0' - 5' TEST DATE: 2/12/14 SAMPLE DESCRIPTION: Dark yellow brown sandy lean clay (CL) LABORATORY TEST DATA TEST SPECIMEN 12345 A COMPACTOR PRESSURE 140 100 70 [PSI] B INITIAL MOISTURE 7.1 7.1 7.1 [%] C BATCH SOIL WEIGHT 1200 1200 1200 [G] D WATER ADDED 102 115 130 [ML] E WATER ADDED (D*(100+B)/C) 9.1 10.3 11.6 [%] F COMPACTION MOISTURE (B+E) 16.2 17.3 18.7 [%] G MOLD WEIGHT 2111.7 2112.5 2100.6 [G] H TOTAL BRIQUETTE WEIGHT 3153.3 3126.2 3133.2 [G] I NET BRIQUETTE WEIGHT (H-G) 1041.6 1013.7 1032.6 [G] J BRIQUETTE HEIGHT 2.40 2.39 2.48 [IN] K DRY DENSITY (30.3*I/((100+F)*J)) 113.2 109.5 106.3 [PCF] L EXUDATION LOAD 8427 5126 2899 [LB] M EXUDATION PRESSURE (L/12.54) 672 409 231 [PSI] N STABILOMETER AT 1000 LBS 38 46 58 [PSI] O STABILOMETER AT 2000 LBS 103 115 131 [PSI] P DISPLACEMENT FOR 100 PSI 4.37 4.60 5.04 [Turns] Q R VALUE BY STABILOMETER 24 18 10 R CORRECTED R-VALUE (See Fig. 14) 22 17 10 S EXPANSION DIAL READING 0.0081 0.0067 0.0027 [IN] T EXPANSION PRESSURE (S*43,300) 351 290 117 [PSF] U COVER BY STABILOMETER 0.84 0.89 0.97 [FT] V COVER BY EXPANSION 2.70 2.23 0.90 [FT] TRAFFIC INDEX: 5.0 GRAVEL FACTOR: 1.49 UNIT WEIGHT OF COVER [PCF]: 130 R-VALUE BY EXUDATION: 14 R-VALUE BY EXPANSION: 14 R-VALUE AT EQUILIBRIUM: 14 *Note: Gravel factor estimated from pavement section using CTM 301, Section C, Part b. R-VALUE TEST RESULTS Project No. SD365 FIGURE B-6.4a Document No. 13-0339 Sample: B-6 @ 0' - 5'R-Value at Equilibrium: 14COVER AND EXUDATION CHARTSProject No. SD365Document No. 13-0339FIGURE B-6.4b01020304050607080901000100200300400500600700800R-ValueExudation Pressure [psi]0.00.51.01.52.02.53.00.0 0.5 1.0 1.5 2.0 2.5 3.0Cover Thickness by Stabilometer [FT]Cover Thickness by Expansion [FT] APPENDIX C DYNAMIC SETTLEMENT ANALYSES N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX C DYNAMIC SETTLEMENT ANALYSES Liquefaction and dynamic settlement analyses were conducted using the data gathered from the CPT soundings. Note that the CPT soundings were conducted within the deepest deposits of the alluvium along the northern edge of the site. The analyses were based on the simplified procedures originally developed by Seed and Idriss, and were conducted in general accordance with the recommended procedures for implementation of DMG special publication 117 (SCEC, 1999). The tip resistance (Qc) was normalized for overburden pressure and corrected for fines content using the procedures described in the referenced document (Youd et al., 2001). The resulting “Normalized Clean Sand Equivalent Tip Resistance” is designated by the symbol Qc1N(CS) in the following figures. Note that the CPT fines correction was based on the Soil Behavior Type Index (Ic). For each sounding, both the Normalized Tip Resistance and Soil Behavior Type Index are plotted as a function of depth for the upper 50 feet of the soil profile. The liquefaction analyses are shown in Figures C-1 through C-5. The central chart for each CPT sounding shows the estimated seismic settlement due to a Peak Ground Acceleration (PGA) of 0.31g from the 2013 CBC Design Spectrum provided in Table 1. The groundwater table was assumed to be at a depth of 35 feet below grade for our analyses, based on the conditions encountered in CPT-1 and CPT-2. Fine-grained soils with an Ic value greater than 2.6 were considered to be too clayey to liquefy. Similarly, granular soils with a normalized clean sand equivalent tip resistance (Qc1N(CS)) greater than 160 were considered too dense to liquefy. Only those soil zones that were both loose enough and sandy enough to liquefy contributed to the estimated post-liquefaction settlement. Seismic settlement was also estimated for dry soils above the groundwater table using the referenced procedure (Pradel, 1998). Our dynamic settlement analyses suggest that the deeper alluvial deposits along the northern edge of the site may experience total dynamic settlements of up to about 1 inch due to the Design Basis earthquake. According to state guidelines, a differential settlement equal to about one-half of the anticipated total liquefaction settlement may be conservatively assumed for structural design (SCEC, 1999). Consequently, we estimate that differential seismic settlement in some portions of the site may approach ½ inch in 40 feet. Seismic settlement of this magnitude is generally deemed tolerable for structures founded on post-tension slabs. DEPTH [FEET]Document No. 13-0339DYNAMIC SETTLEMENT (CPT-1)Project No. SD365FIGURE C-10.01.02.03.04.05.06.0Total Seismic Settlement [IN]Total Settlement = 0.6 [IN]051015202530354045500 100 200 300 400Qc1N(CS)0510152025303540455001234Soil Type (Ic) DEPTH [FEET]Document No. 13-0339DYNAMIC SETTLEMENT (CPT-2)Project No. SD365FIGURE C-20.01.02.03.04.05.06.0Total Seismic Settlement [IN]Total Settlement = 0.7 [IN]051015202530354045500 100 200 300 400Qc1N(CS)0510152025303540455001234Soil Type (Ic) DEPTH [FEET]Document No. 13-0339DYNAMIC SETTLEMENT (CPT-3)Project No. SD365FIGURE C-30.01.02.03.04.05.06.0Total Seismic Settlement [IN]Total Settlement = 0.1 [IN]051015202530354045500 100 200 300 400Qc1N(CS)0510152025303540455001234Soil Type (Ic) DEPTH [FEET]Document No. 13-0339DYNAMIC SETTLEMENT (CPT-4)Project No. SD365FIGURE C-40.01.02.03.04.05.06.0Total Seismic Settlement [IN]Total Settlement = 0.2 [IN]051015202530354045500 100 200 300 400Qc1N(CS)0510152025303540455001234Soil Type (Ic) DEPTH [FEET]Document No. 13-0339DYNAMIC SETTLEMENT (CPT-5)Project No. SD365FIGURE C-50.01.02.03.04.05.06.0Total Seismic Settlement [IN]Total Settlement = 0.1 [IN]051015202530354045500 100 200 300 400Qc1N(CS)0510152025303540455001234Soil Type (Ic) APPENDIX D SLOPE STABILITY ANALYSES N:\Projects\SD\SD365 Lennar, Tabata Development\13-0339\13-0339.doc APPENDIX D SLOPE STABILITY ANALYSES Slope stability analyses were conducted using the program SLOPE/W for the four cross section locations shown on the Revised Grading Plan, Figure 2D. Spencer's Method of Slices was used for all of the analyses. Spencer’s method satisfies both force and moment equilibrium. All of the critical failure surfaces were optimized. The geology of each section was characterized using the general geotechnical conditions encountered in nearby subsurface explorations, as well as our previous experience with similar conditions. Our slope stability analyses for Cross Sections A-A’ through D-D’ are summarized in Figures D-1 through D-4, respectively. Laboratory tests were used to approximate the lower bound shear strengths of the various geologic materials encountered at the site. Direct shear tests were conducted on relatively undisturbed samples of the on-site soils in general accordance with ASTM D3080. The test results were summarized in Appendix B (see Figure B-5.6). Based on these test results and our experience with similar soils, the Santiago Formation and Old Alluvium were both estimated to have shear strengths that generally exceed 23° with 200 lb/ft2 cohesion. A shear strength of 34° with 100 lb/ft2 was assumed for the imported select fill soil. The existing compacted fill within the slope along the southern and eastern edges of the property was assumed to have a shear strength exceeding 30° with 200 lb/ft2 for the stability analyses. Three cases were evaluated for each cross section: temporary, static and seismic stability. Our temporary stability analyses (Case 1) indicate that the temporary 1:1 cut slopes that will be needed to complete the recommended remedial earthwork and construct the proposed retaining walls will possess an adequate factor of safety for a temporary sloping condition (FS>1.2) as shown in Figures D-1.1 through D-3.1. Our static stability analyses (Case 2) indicate that the proposed 2:1 slopes and retaining walls will possess an adequate factor of safety against long-term deep-seated failure (FS>1.5) as shown in Figures D-1.2 through D-3.2. Our seismic stability analyses (Case 3) indicate that the proposed slopes may experience up to about 1 inch of lateral deformation given the design level peak ground acceleration of 0.31g presented in Table 1. Seismic slope deformations of this magnitude would generally be considered tolerable. The seismic stability analyses are summarized in Figures D- 1.3 through D-3.3. For Cross Section D-D’, our analyses indicate that the proposed minor 1½:1 fill slopes (up to about 2-feet high) will possess an adequate factor of safety against long-term failure (FS>1.5), as shown in Figure D-4. 1.81 Existing Fill (30°, 200 PSF) EXISTING CONDITIONS Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-1 CROSS SECTION A-A’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.30 Existing Fill (30°, 200 PSF) Case 1 - Temporary Stability (FS > 1.2) Santiago Formation (23°, 200 PSF) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]90 100 110 120 130 140 150 160 170 D-1.1 CROSS SECTION A-A’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.92 Import Fill (34°, 100 PSF) Existing Fill (30°, 200 PSF) Case 2 - Static Stability (FS > 1.5) Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-1.2 CROSS SECTION A-A’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.00 Import Fill (34°, 100 PSF) Existing Fill (30°, 200 PSF) Case 3 - Seismic Stability (Ky ~ 0.34g) Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-1.3 CROSS SECTION A-A’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.74 Existing Fill (30°, 200 PSF) EXISTING CONDITIONS Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 1.74 D-2 CROSS SECTION B-B’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.54 Existing Fill (30°, 200 PSF) Case 1 - Temporary Stability (FS > 1.2) Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 1.54 D-2.1 CROSS SECTION B-B’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.70 Existing Fill (30°, 200 PSF) Case 2 - Static Stability (FS > 1.5) Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-2.2 CROSS SECTION B-B’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 1.70 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.00 Existing Fill (30°, 200 PSF) Case 3 - Seismic Stability (Ky~0.24g) Santiago Formation (23°, 200 PSF) (-15, 55) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-2.3 CROSS SECTION B-B’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 8.26 Old Alluvium (23°, 200 PSF) EXISTING CONDITIONS Santiago Formation (23°, 200 PSF) (-15, 15) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]20 30 40 50 60 70 80 90 100 110 120 130 D-3 CROSS SECTION C-C’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 4.13 Old Alluvium (23°, 200 PSF) Case 1 - Temporary Stability (FS > 1.2) Santiago Formation (23°, 200 PSF) (-15, 15) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]20 30 40 50 60 70 80 90 100 110 120 130 D-3.1 CROSS SECTION C-C’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 2.46 Old Alluvium (23°, 200 PSF) Fill (30°, 200 PSF) Case 2 - Static Stability (FS > 1.5) Santiago Formation (23°, 200 PSF) (-15, 15) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]20 30 40 50 60 70 80 90 100 110 120 130 D-3.2 CROSS SECTION C-C’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 1.00 Old Alluvium (23°, 200 PSF) Fill (30°, 200 PSF) Case 3 - Seismic Stability (Ky ~ 0.57g) Santiago Formation (23°, 200 PSF) (-15, 15) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]20 30 40 50 60 70 80 90 100 110 120 130 D-3.3 CROSS SECTION C-C’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS 5.46Select Fill (34°, 100 PSF) Static Stability (FS > 1.5) Santiago Formation (23°, 200 PSF) (-15, 55) Minor 1½:1 Fill Slope 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Elevation [FT]60 70 80 90 100 110 120 130 140 150 160 170 D-4 CROSS SECTION D-D’ Tabata Development Lennar Homes 13-0339 9245 ACTIVITY ROAD, SUITE 103 SAN DIEGO, CA 92126 (858) 536-1000 SD365 PROJECT NAME PROJECT NUMBER DOCUMENT NUMBER FIGURE NUMBER GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTSGROUP DELTA CONSULTANTS GROUP DELTA CO.VSULTANT.S Geotechnical Engineering Geology Hydrogeology Earthquake Engineering Materiah Testing A Inspection Forensic Services Proj. No. / Name: Prepared for: Prepared by: Date: Subject: TECHNICAL MEMORANDUM IR-596 / Tabata 10 Subdivision, Carlsbad, CA Lester Tucker / Lennar Curt Scheyhing, PE, GE August 30, 2013 Geotechnical Review INTRODUCTION Group Delta Consultants, Inc. (Group Delta) is pleased to present the results of a review of existing geotechnical information ("paper study") performed for the proposed residential development located on an undeveloped parcel southwest of El Camino Real between Camino Hills Drive and Bryant Drive in the City of Carlsbad, California (see Figures lA through IF). Lennar is considering purchasing and developing the property. Based on our review of existing information, no adverse site or geologic conditions that would preclude development of the site were identified, provided that appropriate geotechnical recommendations are incorporated in the design and construction. Purpose The purpose of our study was to review available information and provide geotechnical input to Lennar as part of their due diligence review for purchase of the property. A geotechnical investigation and report and grading plan prepared by others were provided to Lennar by the seller. These documents were the primary focus of Group Delta's geotechnical review. Pertinent Investigations and Reports The following geotechnical reports provided by the seller were reviewed: • Vinje & Middleton Engineering, Inc., December 13, 2011, "Geotechnical Plan Revieiu Update, Proposed 26-Lot (Tabata 10) Subdivision, Camino Hills Drive, Carlsbad, (A.P.li.'S 212-050-32 & -33)P Job #11-210-P, Prepared For: Tabata Family Trust. • Vinje & Middleton Engineering, Inc., June 23, 2006, "Preliminary Geotechnical Investigation, Proposed 26-Lot Subdivision, Camino Hills Drive, Carlsbad, Califomia, (A.P.H.'s 212-050-32 & -33)P Job #06-210-PP Prepared For: Tabata Family Trust. The existing reports are included as Appendix A. m 32 Mauchly, Suite B • Irvine, California 92618-2336 • (949) 450-3100 voice • (949) 450-21OS fax Tormnee (310)330-5100 A Ontario (909) 605-6500 A .San Diego (SSS) 536-1000 Sacramento (Sl6) 302-2330 A Viclorville (760) 881-3224 tvww.GroupDelta.com a: Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. lR-596 August 30, 2013 Page 2 In addition. Group Delta performed a Phase 1 Environmental Site Assessment (ESA), which was provided to Lennar under separate cover. Scope of Work Group Delta's geotechnical scope of work included the following: • Site visit and photographic documentation; • Review of existing published geotechnical information including: o Aerial Photographs; o Topographic Maps; o Geologic Maps; o Fault Maps and Seismicity Data; o Existing geotechnical reports and grading plan; • Performing an Independent geotechnical assessment based on the data reviewed, commenting on the existing geotechnical report and recommendations, and summarizing our conclusions and comments in this memorandum. Group Delta did not perform additional subsurface investigations or geotechnical laboratory testing for this study. Additional geotechnical field investigation and testing of site soils should be performed during the final design phase of the project. PROJECT DESCRIPTION The site consists of Assessor's Parcel Numbers (APN) 212-050-32 and 212-050-33 and is currently undeveloped. The proposed project consists of rough grading and development of the 10.38 acre site with one or two story wood framed homes with no basements on 26 individual lots. Building pads will be created by cut-fill mass grading. Due to presence of undocumented fill and alluvial soils significant remedial grading (removal and recompaction) is required in portions of the site. Finish grade is generally near the existing grade, with cuts and fills generally within 10 feet of the existing grade, except on the southwest side (Lots 19-22) where excavations up to about 20 to 25 feet below existing grade will be required to remove a small hill. We understand that grading will require import soil. Development will include improvements to Camino Hills Drive, a new "G"-shaped residential street connecting to Camino Hills Drive, retaining walls along Camino Hills Drive, an earthen sound berm adjacent to El. Camino Real, and a bioretention area adjacent to the sound berm. N:\Projects\_AV\l50CNR596 Tabata Site\Gecitech\Tabata Development Oeotech Letter Report revl.doc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. lR-596 August 30, 2013 Page 3 The approximate site latitude/longitude is 33.1439N/ -117.2866W. The project location, topographic map, aerial photographs, and street views of the site are presented in Figures lA through IF, respectively. The tentative tract map is shown in Figure 2. SITE AND SUBSURFACE CONDITIONS Site Conditions GROUP DELTA The site is currently unpaved and undeveloped, and is bounded by El Camino Real on the northeast and by local streets and residential structures on the northwest, southwest, and southeast sides, as shown in Figures lA through IF and Figure 2. Most of the interior of the site is a grassy field gently descending northeasterly toward El Camino Real. The southeast and southwest boundaries ofthe site are ascending 2h: lv graded slopes heavily vegetated with trees and with a maximum height of about 45 feet. A natural hill vegetated with grass and scattered trees is present near the northwest site boundary with a height of up to about 33 feet above the gently sloping portion of the site with slopes of 2h: lv or flatter. A single residential structure formerly occupied this hill (see Figures ICandZ); this structure has been removed. Surrounding streets are paved with asphalt concrete (AC) and have sidewalks, light poles, telephone poles, trees, buried utilities, and associated improvements. Street views of the site are shown in Figures ID through IF. Geology Most of western San Diego County, including the project area, lies within the Peninsular Ranges Geomorphic Province of California. The subject site is located in the coastal plain, in a broad transition zone between older Mesozoic granitic and metavolcanic bedrock (to the east) and the younger, terraced coastal sedimentary rock of Quaternary to Tertiary age (to the west). The sedimentary deposits of the coastal plain generally extend between the coastline and the coastal range foothills and mountains to the east. These formational deposits are overlain locally by Holocene (Recent) overburden soils such as alluvium, colluvium, slopewash, and man-placed fill. Erosion of the coastal plain sediments has resulted in topography characterized by mesas, hills, and ridges dissected by a network of alluvial canyon drainages. The primaiy drainage in the site area is Agua Hedionda Creek located north of the site (Figure IB). The regional geologic setting is shown in Figure 3A. The generalized natural site geology is shown by an overlay of the regional geologic map onto Google Earth imagery in Figure 3B. The project site is at an interface between Tertiary-age (Eocene) soft bedrock of the Santiago Formation (Tsa), Old (late to middle Pleistocene) Alluvial Flood Plain Deposits (Qoa), also referred to as Terrace Deposits (Qt), and young Holocene Alluvium (Qa). Exposures of older Mesozoic granitic rock (Kp, Kl, Kt) and metamorphic rock (Mzu) are not present within the project site but are exposed to the south and east as shown in Figure 3B, and these units form the basement rock underlying N:\Projects\_A\M50(NR596 Tabata Site\Geotech\Tabata Development Qeotech Letter Report revLdoc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 4 the project site at unknown depth. The natural soils at the project site are overlain locally by man placed fill soils, including compacted fills (Qcaf) and undocumented fills (Qaf). A site geologic map presented in the project geotechnical report is shown in Figure 3C, which is generally consistent with the regional mapping and indicates the location of existing compacted and undocumented fill materials. GROUP Seismicity The site is in a seismically active area. At the general latitude of San Diego County, the interaction between the North American and Pacific tectonic plates is considered to take place across a wide area extending from the San Andreas fault in the Imperial Valley, to nearly 100 km offshore to the west (see Figure 4). The main fault zones west of the San Andreas include the San Jacinto and Elsinore fault zones, the Newport Inglewood Rose Canyon fault zone, and a complex system of northwest trending offshore faults include the Coronado Bank, San Diego Trough, and San Clemente faults. A regional fault map is shown in Figure 4. No active faults are known to cross the project site. Major active faults that contribute to the seismic hazard at the site, and calculated deterministic site accelerations are summarized as follows: Mote: Based on Caltrans ARS Online. Fault Name Fault Type Site-Fault Distance (km) Maximum Magnitude, Mmax Deterministic PGA (g's) Rose Canyon Fault Zone (Oceanside section) Strike Slip 11.0 6.8 0.26 Newport-Inglewood Fault Zone (offshore) Strike Slip 13,5 6.9 0.23 Rose Canyon Fault Zone (Del Mar section) strike Slip 14.4 6.8 0.22 Rose Canyon Fault Zone (San Diego section) Strike Slip 31.7 6.8 0.11 Elsinore Fault Zone (Julian Section) Strike Slip 33.8 7.7 0.16 Elsinore Fault Zone (Temecula Section) Strike Slip 33.8 7.7 0.16 Coronado Bank (alt2) Strike Slip 36.3 7.4 0,13 San Diego Trough (north altl) Strike Slip 51.0 7.3 0.10 Elsinore (Qlen Ivy) rev Strike Slip 53.2 7.7 0.11 San Jacinto Fault Zone (Anza section) Strike Slip 73.5 7.7 0.09 DELTA N:\Proiects\_AV\I50CMR596 Tabata SiteXQeotechVTabata Development Geotech Letter Report revl.doc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 5 Probabilistic acceleration versus return period (https://geohazards.usqs.qov/deaqqint/2008/) is estimated as follows: Exceedance Probability 1%/50 years 2% 150 years 5% / 50 years 10% / 50 years 20% / 50 years 50% / 50 years Average Return Period (years) 4975 2475 975 475 224 72 Peak Ground Acceleration, PGA (g's) 0.56 0,46 0,35 0.27 0.20 0.12 Subsurface Soil Conditions Vinje and Middleton Engineering investigated site conditions by drilling four hollow-stem auger borings to depths of 19.5 to 40.5 feet and excavated 10 test pits to depths of 8 to 16.5 feet below existing grades. Standard Penetration Test (SPT) and California (C/\L) Split Barrel Sampler penetration resistances were measured in the borings. Bulk and drive samples collected from the test pits and borings were visually classified in the field and selected samples were tested in the laboratory for in-situ moisture content and dry density, laboratory maximum dry density and optimum moisture content, grain size distribution, Atterberg limits. Expansion Index, direct shear, corrosion (pH, sulfate, chloride, minimum resistivity), and R-value. Field and laboratory data are included in Vinje and Middleton's report in Appendix A. Based on the field investigation Vinje and Middleton prepared a geologic map of the site (see Figure 3Q. Geologic cross-sections from their report are reproduced in Figures 5A through 5D, and the cross-section locations are shown in Figure 3C. They classified the site soils sampled into 3 geologic units, listed below in order of increasing age: • Undifferentiated undocumented fill and Holocene alluvium (Qaf / Qal) • Pleistocene Terrace Deposits (Qt) [same as Old /Mluvium in Figure 3B] • Eocene Formational Rock (Ts) [same as Santiago Formation (Tsa) in Fig. 3B] /Ml 3 units have variable soil types that can be grouped into broad categories based on color, grain size distribution, and plasticity. The site soils were classified by Vinje & Middleton into 5 general types: • Soil Type 1: Pale brown to red brown lean to fat clay to sandy clay (SC/CL/CH) • Soil Type 2: Pale to dark brown to red brown silty and clayey sand (SAVSC) N:\Projects\_A\Ai50CMR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 6 • Soil Type 3: Tan to red-brown clayey to silty sand with gravel (SC/SM)g • Soil Type 4: Pale to dark gray lean to fat clay and silt (CI7CH/MH) • Soil Type 5: Tan to yellow-tan to off-white-grey silty and clayey sand (SM/SC) Available data for the different geologic units were tabulated and analyzed as shown in Table 1 and summarized as follows: GROUP o o • Qaf / Qal: Undocumented Fill and Holocene Alluvium o Covers approximately the eastern 2/3 of the project site Overlies Qt in northeastern part of site, directly overlies Ts in southeastern part of site Depth over Qt or Ts mostly ranges from about 1 to 13 feet, but is shown as deep as 24 to 39 feet (Borings B-2 and B-3) toward the north end of site In boring B-3 undifferentiated Fill / /Mluvium is indicated to bottom of borehole at depth 39 feet. However, drilling problems were experienced below groundwater (below 32 feet), and based on other geologic data it seems unlikely alluvium extends this deep. Loose material is indicated on the log below the groundwater. Based on this boring, the bottom of the alluvium and the liquefaction potential cannot be conclusively determined. Contains soil types 1-5 (SP, SC, C17CH, MH) Coarse grained soils are loose to medium dense (average medium dense) Fine grained soils are soft to stiff Limited testing indicates 64 to 70% passing No. 200 sieve Limited testing indicates Liquid Limit of 45-49 and Plasticity Index of 21-22 Relative compaction is generally estimated at less than 90% Existing moisture is generally wet of optimum Expansion Index is medium to high (measured values are 103-112, "High") Measured R-Value is 5 (which is very low) Corrosivity data: • pH=6.2-6.5 • Soluble sulfate=520-600 ppm • Soluble chloride=60-70 ppm • Minimum resistivity=381-504 ohm-cm Material is generally unsuitable to receive fill or support foundations, requires remedial grading (removal and recompaction) of 6 to 1 O-F feet Wet of optimum moisture may require processing during grading o o o o o o o o o o DELTA namuiuasiiBi N:\Proiects\_AVJ500\IR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 7 o Bottom of overexcavation may require stabilization in some areas with geogrid and rock Qt (Qoa): Pleistocene Alluvial Terrace o Exposed at the surface in roughly the western 1/3 of the site o Underlies fill in the northeastern portion of site o Where present, overlies Ts o Contains all soil types 1-5 (SM, SC, GC, CL/CH) o Coarse grained soils are medium dense to dense (average dense) o Fine grained soils are stiff to very stiff o Limited testing indicates 41% passing No. 200 sieve o Limited testing indicates Liquid Limit of 32 and Plasticity Index of 16 o Existing moisture ranges from wet to dry of optimum (average 3% wet) o Expansion Index is medium (measured value 59) o No R-Value or corrosion data are available o Material is generally suitable to receive fill or support foundations, more weathered portions may require removal and recompaction o Wet of optimum moisture may require processing during grading Ts: Eocene Formational Bedrock, a.k.a. Santiago Formation o Exposed at the surface in a small area on the west side of the site o Underiies Qt in the western and northeastern portions of site o Directly underlies Qaf / Qal in the southeastern portion of site o Contains soil types 2, 4, and 5 (SM, SC, MH/CH) o Ranges from tan-off white-yellow tan silty / clayey sandstone to pale gray-gray siltstone / claystone o When classified as soil, sandstone is dense to very dense and claystone is hard o Limited testing indicates 32% passing No. 200 sieve o Limited testing indicates Liquid Limit of 36 and Plasticity Index of 11 o Existing moisture is generally wet of optimum (average 4% wet) o Measured Expansion Index is low (measured value 46 in sandstone materials), claystone / siltstone portions were not tested but may be highly expansive o No R-Value or corrosion data are available o Material is generally suitable to receive fill or support foundations, more weathered portions may require removal and recompaction or undercutting o Wet of optimum moisture may require processing during grading N;\Proiects\_AV\l50CNR596 Tabata Slte\Geotech\Tabata Development Geotech Letter Report revl.doc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 8 Site soils data sorted according to soil Types 1 - 5 are presented in Table 2. Generally soil Types 1 and 4 are highly expansive and predominantly fine grained with 50% or more passing No. 200 sieve, while soil Types 2, 3, and 5 are low to medium expansion potential and predominantly coarse grained with less than 50% passing No. 200 sieve. Groundwater Groundwater was encountered only in the two deepest borings (B-2 and B-3) in the northern part of the site. Groundwater was encountered in B-2 at a depth of 33 feet perched in the bedrock materials, and in Boring B-3 was encountered at a depth of 32 feet. Drilling problems in boring B-3 included heaving sand in the auger and caving, so blowcounts and samples in this borehole may not be representative of undisturbed conditions. /Mthough the log suggests this is still in fill / alluvial material, based on the depth and the grain size characteristics of materials indicated on the log and the proximity of the hill comprised of Qt materials, the soils below the groundwater appear that they may be part of the Qt (Qoa) or Ts (Tsa) units. GEOLOGIC AND SEISMIC HAZARDS Ground Rupture The site is not located within or nearby an /Mquist-Priolo (AP) earthquake fault zone. Due to lack of any known active fault crossing the site, fault rupture hazard at the site is considered remote. GROUP DELTA Seismic Shaking Strong shaking should be anticipated during the design life of the project. Nearby active faults and their locations with respect to the site are illustrated in Figure 4. Due to presence of alluvial soils at the site, Site Class D (Stiff Soil Profile) is appropriate for seismic analyses. Seismic shaking estimates based on deterministic and probabilistic methods were presented previously under "Seismicity" section. For facilities designed in accordance with Califomia Building Code (CBC) 2010 and ASCE 7-05, the seismic design recommendations are presented in Table 3. Maximum Considered Earthquake (MCE) horizontal Peak Ground Acceleration (PGA) is 0.48g and design PGA is 2/3 of this value or 0.32g. Note that that the MCE PGA is generally consistent with the value reported for 2500 year return period in the previous "Seismicity" section. Liquefaction and Seismic Compaction Liquefaction involves the sudden loss in strength of a saturated, cohesionless soil (sand and non-plastic silts) caused by the build-up of pore water pressure during cyclic loading, such N:\ProjectsVAViJ50CIMR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 9 as produced by an earthquake. This increase in pore water pressure can temporarily transform the soil into a fluid mass, resulting in vertical settlement and can also cause lateral ground deformations. Typically, liquefaction occurs in areas where there are loose to medium dense sands and silts, and where the depth to groundwater is less than 50 feet from the surface. In summary, three simultaneous conditions are required for liquefaction: • Liquefaction susceptible soils (loose to medium dense cohesionless soils); • Groundwater within 50 feet of the surface; • Strong Shaking, such as caused by an earthquake. Groundwater at the site appears to be within formational materials that are generally dense and not subject to liquefaction. In general the liquefaction potential at the site appears to be low. However, data from Boring B-3 is inconclusive due to drilling problems resulting from use of hollow stem auger below groundwater and the log indicating that groundwater may be within loose fill / young alluvium. This boring represents an isolated condition generally outside the developed lots, so it may not represent a concern. However, it should be further investigated by rotary boring and/or CPT prior to final design. Soil Collapse Potential Loose sands and silty sands with clay binder, low moisture content, and low dry density may be prone to sudden collapse and ground settlement if suddenly saturated. Alluvial soils in certain environments may contain such collapse-prone materials. Based on grains size characteristics, consolidation test results (indicate expansion rather than collapse), and moisture content and dry density test results, the collapse potential at the site appears to be low. Remedial grading will further reduce the collapse potential, if present. Seismic Slope Stability The site to be developed is relatively level and post-construction slopes will be engineered compacted fill planned at no steeper than 2h: lv. Therefore, slope instability is not considered a significant hazard at the site. Flood Hazard Based on review of FEMA Rood Insurance Rate Maps (FIRM) website, the site is not located within a 100 year or 500 year flood zone. GROUP DELTA nmmniMiiiBi N:\Projects\_AVJ50CMR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc Geotechnical Review August 30, 2013 Tabata - 10, Carlsbad, CA Page 10 Lennar Homes of California GDC Project No. IR-596 DISCUSSION AND RECOMMENDATIONS Key Geotechnical Issues Development of the site is generally feasible in general accordance with recommendations in the existing geotechnical reports. The following are considered the key issues for site development: • Remedial Grading: o Removal and recompaction is required to remove and recompact compressible undocumented fill and alluvial soils and to undercut the cut lots, and stabilization fills are required where cutting into existing slopes; o Suggested depth of overexcavation is 6 to 10 feet in the fill area, but final depth is left as a field decision leaving some uncertainty in cost estimation; o Report suggests placing geogrid at the bottom of overex where soft and yielding soils are left in place, but area of stabilization is not clearly enough defined for estimating costs, o Based on boring / trench logs, suggested depth of overexcavation appears to remove all loose / soft undocumented fill and alluvial material to competent native soils except for the following locations: • B-2: 10 ft of removal leaves a total of 14 feet of undifferentiated fill / alluvium in place: 4 ft of soft clay (CiyCH) and 10 feet of loose to medium dense clayey sand (SC) • B-3: 7 ft removal leaves more than 20 ft of undifferentiated fill / alluvium in place, including some material described as loose / firm. o Leaving loose / soft undocumented fill / alluvial materials in place as indicated by Borings B-2 and B-3 may represent a risk; additional investigation by boring and CPT is recommended to better define the required depth of removals and potential for future settlement and need for mitigation. If deeper removals are found to be necessary, an option to reduce removal depths would be surcharging these areas during grading. • Expansive Soil: o Highly expansive soils are present in the site, randomly mixed with low to medium expansion soils o Expansive soils result in high post-tensioned slab requirements and thick pavement and flatwork sections o Selective grading and use of low expansion import may be considered to reduce costs of pavement and slabs • Import Soil: PT?nTTP ° Low expansion soil is recommended for import o This material should be used to cap lots and pavement areas to reduce cost of slabs and pavement DELTA imBHIUMiin N:\Projects\_AV\l50CMR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revl .doc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 11 • Selective Grading: o Report suggests placing expansive soils deeper in the fills, lower expansion soils in the shallower portions; due to random presence of materials in the fill / alluvium selective grading and stockpiling materials generated from fill / alluvium may not be practical o Report suggests using Terrace Deposit materials in upper portions of fill to reduce expansion potential o However, terrace deposits do contain clay soils, and no borings are available in the large hill that will be the source of terrace materials, so the expansion characteristics are not known o Additional borings in this area would help to define the properties of the fill that will be generated in this terrace cut o Import soil should be specified as very low expansion and used to cap lots and pavement areas, since selective grading will be easier to control o Quantities and properties of terrace and import soils used to cap lots should be considered and may be used to realize cost savings. Comments on Existing Geotechnical Reports Site characterization and recommendations presented in the existing geotechnical reports generally appear to be reasonable and development of the site is feasible from a geotechnical standpoint if these recommendations are followed. Comments on specific issues are as follows: Remedial grading: o Removal and recompaction, undercutting of bedrock areas, and stabilization fills should be performed as recommended; o Deeper removals may be warranted in the northeastern part of the site near B-2 and B-3, as existing data show some loose / soft undocumented fill and alluvium may be left in place with the existing removal depths, which may pose a risk of future settlement; o Surcharging these deeper alluvial areas by stockpiling may be considered as an alternate to deeper removals; o CPT testing may be considered as a means of better defining required removal depths and surcharge areas across the site; o Soils removed are wet of optimum and may be difficult to compact and require drying; Expansive Soils and Selective Grading: o Import soils are required, and on-site soils range from low to high expansion potential o Savings in slab, hardscape, and pavement design may be realized by importing low expansion soils, selectively grading low expansion on site soils, N:\Projects\_AVJ500\IR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc Geotechnical Review Tabata - 10, Carlsbad, CA Lennar Homes of California GDC Project No. IR-596 August 30, 2013 Page 12 and placing the low expansion import and on-site soils in the upper part of the subgrade o Final values of expansion potential should be determined on each lot after rough grading is complete; • Detailed investigation should be performed including borings and CPTs to supplement existing data and address the following issues: o Refine required depths of removals across the site and areas where deeper removals or surcharge may be warranted o Define or rule out liquefaction potential in saturated alluvium, if present o Expansion potential of borrow soil from the cut areas within the existing hill Should you have any questions regarding this report, please call us at (949) 450-2100. Sincerely, GROUP DELTA CONSULT/MNTS, INC. Curt Scheyhing, P.E., G.E. /Associate Geotechnical Engineer Kul Bhushan, Ph.D., GE Senior Consulting Principal The following are attached and complete this letter: TABLES Table 1 Table 2 Table 3 Summary of Soils Data Sorted by Geologic Unit Summary of Soils Data Sorted by Soil Types 1-5 CBC 2010 / ASCE 7-05 Acceleration Response Spectra FIGURES Figure lA Figure IB Figure IC Figure 1 (D-FO Figure 2 Figure 3A Figure 3B Figure 3C Figure 4 Figure 5 (A-D) APPENDICES Appendix A Vicinity Map USGS 7.5' Quadrangle / Google Eart:h Overiay Aerial Photograph Street View Tentative Tract Map Regional Geologic Map Geologic Map / Google Earth Overlay Site Geologic Map Regional Fault Map Geologic Cross-Sections A, B, C, D, E, X, and Y Geotechnical Reports by Others N:\Projects\_AV\l50CNR596 Tabata Site\Geotech\Tabata Development Geotech Letter Report revLdoc TABLES Field Lab SPT Wet (+) or Depth Soil Geologic Sample N N60 Yd CO Yd-mu RC Dry (-) of -200 c' *' Min. Res. Exploration (ft) Type Unit USCS Color Type (bpt) (bpf) (pcf) (96) (pcf) (%) 1%) Opt. {%] {%] U PL PI U El (psf) (deg) pH S04 CL (ohm-cm) R-Value T-1 1 1 Qaf/Qal ciycH pale brown 64 45 24 21 112 6,2 520 70 504 5 T-1 2 1 Qaf/Qal CL/CH pale brown 100.8 18.5 T-3 3 4 Qaf/Qal CL/CH dark grey 88 28.6 110.5 19.8 79.6 8.8 WET 70 49 27 22 0,07 103 280 23 6,5 600 60 381 T-3 5 4 Qaf/Qal CL/CH dark grey 88,8 27,8 110,5 19.8 80,4 8 WET T-3 7 5 Qaf/Qal sc off-whIte-grey 100,6 18,4 119,5 12.5 84.2 5,9 WET T-5 1 1 Qaf/Qal CL pale brown T-5 5 2 Qaf/Qal SC dark brown 109 11,9 129,6 10.4 84.1 1.5 WET T-5 7 2 Qaf/Qal sc dark brown T-5 8 2 Qaf/Qal sc dark brown 110.8 13,1 129,6 10.4 85,5 2.7 WET T-7 4 1 Qaf/Qal CL pale brown 88.9 26,1 T-8 5 2 Qaf/Qal sc red-brown 101.6 11,9 129,6 10.4 78,4 1.5 WET T-8 8 2 Qaf/Qal SC dark brown 113.6 12,7 129,6 10.4 87,7 2.3 WET T-8 11 2 Qaf/Qal SC dark brown 104.1 12,2 129,6 10.4 80,3 1.8 WET B-2 4 5 Qaf/Qal MH grey spt 4 5 B-2 9 1 Qaf/Qal CL/CH red-brown spt 12 15 B-2 14 2 Qaf/Qal SC red-brown cal 36 30 110.1 18,3 129,6 10.4 85,0 7.9 WET B-2 19 2 Qaf/Qal SC pale brown spt 10 13 B-3 4 2,3 Qaf/Qal SC brown to red-brown cal 40 34 113.2 9 129,6 10.4 87,3 -1,4 DRY B-3 9 3,5 Qaf/Qal SM/SC tan to red-brown spt 25 31 B-3 14 2,3 Qaf/Qal SC red-brown cal 40 34 113,8 9,7 129.6 10,4 87.8 -0,7 DRY B-3 19 5 Qaf/Qal SC red-brown to tan spt 24 30 B-3 24 5 Qaf/Qal SC red-brown to tan cal 44 37 109.5 16,2 119.5 12,5 91,6 3,7 WET B-3 29 5 Qaf/Qal SC red-brown to tan spt 27 34 B-3 34 3,5 Qaf/Qal SP/GP red brown cal 70 59 110.7 20.3 119.5 12,5 92.6 7.8 WET B-4 4 3 Qaf/Qal SC red-brown spt 13 16 B-4 9 5 Qaf/Qal SP red-brown cal 28 23 106.2 11.7 119.5 12,5 88.9 -0,8 DRY max= 70 59 113.8 28.6 129.6 19.8 92.6 8.8 70 49 27 22 0,07 112 280 23 6,5 600 70 504 5 mln= 4 5 88.0 9.0 110.5 10.4 78.4 -1,4 64 45 24 21 0,07 103 280 23 6.2 520 60 381 5 avg= 29 28 104.4 16.7 124.0 12,3 85,2 3.5 67 47 26 22 0,07 108 280 23 6 560 65 443 5 jOROUP Fl N:\Projem\_AV\l50(l\IR596 Tabata SIU\6eatech\s<]»s summary jdoi Sort by Unit TABLE 1 SUMMARY OF SOILS DATA SORTED BY GEOLOGIC UNIT Page 1 of 2 Field Lab SPT Wet (+) or Depth Soli Geologic Sample N N60 Yd a> Yd-max <Bopt RC Ory (-) of -200 c' Min. Res. Exploration (ft) Type Unit USCS Color Type (bpf) (bpf) (pcf) [%) (pcf) (%) (%) Opt. {%) {%) LL PL Pi U Ei (psf) (deg) pH S04 CL (ohm-cm) R-Vaiue T-1 4 2 Qt SC/CL red-brown 104,1 12.9 129.6 10,4 80.3 2.5 WET 41 32 16 16 -0,19 75 32 T-1 7 2 Qt SC/CL red-brown 103,4 15.4 129.6 10,4 79.8 5 WET T-1 9 2 Qt SM/SC dark brown 112.3 8.2 129.6 10,4 86.7 -2.2 DRY T-1 11 2 Qt SM/SC dark brown 119.3 7.8 129.6 10,4 92.1 -2,6 DRY T-1 13 3 Qt SC/GC red-brown 102.8 9,7 T-1 15 3 Qt SC/GC red-brown 103.5 14.1 T-5 10 2 Qt SC red-brown 106.8 13,9 129.6 10,4 82.4 3,5 WET T-5 14 2 Qt SC red-brown 108.5 13,4 129.6 10.4 83.7 3 WET T-6 7 5 Qt SM/SP yellow-tan 105.5 13,3 119.5 12,5 88.3 0,8 WET 59 T-7 7 5 Qt SM/SC tan 99.3 18.9 119.5 12.5 83.1 6.4 WET T-7 10 5 Qt SM/SC tan 92.8 25.2 119,5 12,5 77.7 12,7 WET T-7 12 1 Qt SC/CL brown 98.3 22.5 T-7 14 1 Qt SC/CL brown 95.7 25.7 T-9 5 5 Qt SC yellow-tan 96,1 18.3 119,5 12.5 80.4 5.8 WET T-9 8 5 Qt SC yellow-tan 110,6 12.2 119.5 12.5 92.6 -0.3 DRY T-9 11 5 Qt SC yellow-tan 110.9 13,1 119.5 12.5 92.8 0.6 WET T-9 13 5 Qt SC yellow-tan 99,1 16,9 119.5 12.5 82.9 4.4 WET T-9 15 4 Qt sc yellow-tan 99,3 17,9 119.5 12.5 83.1 5.4 WET B-l 4 2 Qt SC red-brown cal 40 34 113.8 17.4 129.6 10.4 87.8 7 WET B-l 9 4 Qt CL/CH olive-brown spt 13 16 B-2 24 5 Qt CL/CH dark brown cal 48 40 114.6 16.9 119,5 12.5 95.9 4.4 WET B-4 14 2 Qt SC/GC red-brown spt 24 30 B-4 19 3,5 Qt GP red-brown cal 34 28 109,5 5.8 119,5 12.5 91.6 -6.7 DRY max= 48 40 119,3 25,7 129,6 12.5 95.9 12.7 41 32 16 16 -0,19 59 75 32 min= 13 16 92.8 5.8 119.5 10,4 77,7 -6,7 41 32 16 16 -0.19 59 75 32 avg= 32 30 105,1 15.2 123.7 11,6 85.9 2,9 41 32 16 16 -0,19 59 75 32 T-2 3 5 Ts SM/SC tan 101 16.6 119.5 12,5 84.5 4.1 WET T-2 5 5 Ts SM/SC tan 89,8 23.6 119.5 12.5 75,1 11,1 WET 32 36 25 11 -0.13 46 28 166 T-2 8 5 Ts SM/SC tan 107.8 18,8 119,5 12.5 90.2 6.3 WET T-2 10 5 Ts SM/SC tan 114.3 17.4 119,5 12.5 95.5 4.9 WET T-4 5 4 Ts MH/CH grey 106 22 110,5 19.8 95,9 2.2 WET T-4 8 4 Ts MH/CH grey 108 22.4 110,5 19.8 97,7 2,6 WET T-4 10 4 Ts MH/CH grey 106,9 21,2 110.5 19.8 96.7 1,4 WET T-5 15 2 Ts SC off-white 102.5 16 129.6 10,4 79.1 5,6 WET T-8 12 5 Ts SC grey to yellow-tan 94,9 13.7 119.5 12,5 79,4 1,2 WET T-9 16 4 Ts MH grey 97,3 24.3 110.5 19,8 88,1 4,5 WET B-l 14 4 Ts MH pale grey spt 23 29 B-l 18 4 Ts MH pale grey spt 23 29 B-2 29 4 Ts MH pale grey spt 31 39 B-2 34 4 Ts MH pale grey spt 25 31 B-2 39 4 Ts MH pale grey spt 44 55 max= 44 55 114,3 24,3 129.6 19.8 97.7 11.1 32 36 25 11 -0,13 46 28 166 min= 23 29 89.8 13.7 110,5 10,4 75.1 1,2 32 36 25 11 -0,13 46 28 166 avg= 29 37 102.9 19.6 116,9 15,2 88.2 4,4 32 36 25 11 -0.13 46 28 166 (JHOILI' N:\Praiects\_AVM500VIR596TabaU 5Ke\Geotech\Hilli summarvJdw Sort by Unit TABLE 1 SUMMARY OF SOILS DATA SORTED BY GEOLOGIC UNIT Page 2 of 2 Field Lab SPT Wet (+) or Depth Soil Sample N N60 Yd-max RC Dry (-) of -200 c' *• Min. Res. Exploration (ft) Type Unit USCS Color Type (bpf) (bpf) (pcf) (%) (pcf) (%) (96) Opt. (96) (96) LL PL PI U Ei (psf) (deg) pH S04 CL (ohm-cm) R-Value T-1 1 1 Qaf/Qal CL/CH pale brown 64 45 24 21 -1.14 112 6.2 520 70 504 5 T-1 2 1 Qaf/Qal CL/CH pale brown 100,8 18,5 T-5 1 1 Qaf/Qal CL pale brown T-7 4 1 Qaf/Qal CL pale brown 88,9 26.1 T-7 12 1 Qt SC/CL brown 98,3 22.5 T-7 14 1 Qt SC/CL brown 95,7 25.7 B-2 9 1 Qaf/Qal CL/CH red-brown spt 12 15 max= 12 15 101 26 64 45 24 21 -1.14 112 6.2 520 70 504 5 min= 12 15 89 19 64 45 24 21 -1.14 112 6.2 520 70 504 5 avg= 12 15 96 23 64 45 24 21 -1.14 112 6.2 520 70 504 5 T-1 4 2 Qt SC/CL red-brown 104,1 12.9 129.6 10.4 80,3 2.5 WET 41 32 16 16 -0,19 75 32 T-1 7 2 Qt SC/CL red-brown 103,4 15.4 129.6 10.4 79.8 5 WET T-1 9 2 Qt SM/SC dark brown 112.3 8.2 129,6 10,4 86.7 -2.2 DRY T-1 11 2 Qt SM/SC dark brown 119.3 7.8 129.6 10.4 92,1 -2,6 DRY T-5 5 2 Qaf/Qal SC dark brown 109 11,9 129.6 10.4 84,1 1.5 WET T-5 7 2 Qaf/Qal SC dark brown T-5 8 2 Qaf/Qal SC dark brown 110.8 13.1 129,6 10.4 85,5 2.7 WET T-5 10 2 Qt SC red-brown 106.8 13.9 129,6 10.4 82.4 3,5 WET T-5 14 2 Qt SC red-brown 108.5 13.4 129,6 10,4 83.7 3 WET T-5 16 2 Ts SC off-white 102.5 16 129.6 10.4 79,1 5.6 WET T-8 5 2 Qaf/Qal SC red-brown 101.6 11.9 129.6 10.4 78,4 1.5 WET T-8 8 2 Qaf/Qal SC dark brown 113,6 12.7 129.6 10.4 87,7 2.3 WET T-8 11 2 Qaf/Qal sc dark brown 104,1 12.2 129.6 10,4 80.3 1.8 WET B-l 4 2 Qt SC red-brown cal 40 34 113,8 17.4 129,6 10,4 87.8 7 WET B-2 14 2 Qaf/Qal sc red-brown cal 36 30 110,1 18,3 129,6 10,4 85.0 7.9 WET B-2 19 2 Qaf/Qal sc pale brown spt 10 13 B-4 14 2 Qt SC/GC red-brown spt 24 30 B-3 4 2,3 Qaf/Qal sc brown to red-brown cal 40 34 113.2 9 129,6 10.4 87.3 -1.4 DRY B-3 14 2,3 Qaf/Qal sc red-brown cal 40 34 113.8 9.7 129,6 10.4 87,8 -0,7 DRY max= 40 34 119.3 18,3 129,6 10.4 92.1 7.9 41 32 16 16 -0,19 75 32 min= 10 13 101.6 7,8 129,6 10.4 78,4 -2.6 41 32 16 16 -0,19 75 32 a«g= 32 29 109,2 12,7 129,6 10,4 84.2 2.3 41 32 16 16 -0.19 75 32 T-1 13 3 Qt SC/GC red-brown 102,8 9.7 T-1 15 3 Qt SC/GC red-brown 103,5 14.1 B-4 4 3 Qaf/Qal SC red-brown spt 13 16 B-3 4 2,3 Qaf/Qal SC brown to red-brown cal 40 34 113,2 9 129.6 10.4 87,3 -1,4 DRY B-3 14 2,3 Qaf/Qal sc red-brown cal 40 34 113,8 9,7 129.6 10.4 87,8 -0.7 DRY B-3 9 3,5 Qaf/Qal SM/SC tan to red-brown spt 25 31 B-3 34 3,5 Qaf/Qal SP/GP red brown cal 70 59 110,7 20,3 119,5 12.5 92.6 7.8 WET B-4 19 3,5 Qt GP red-brown cal 34 28 109,5 5.8 119,5 12.5 91.6 -6.7 DRY max= 70 59 113.8 20.3 129.6 12.5 92,6 7.8 min= 13 16 102.8 5.8 119.5 10,4 87,3 -6.7 avg= 37 34 108.9 11.4 124.6 11.5 89,9 -0.3 NAProiects\_AWI500MR596 Tabata 5ne\Geotedi\«ills lummaryjclsx Sort by Soil Type TABLE 2 SUMMARY OF SOILS DATA SORTED BY SOIL TYPES 1 -5 Page 1 of 2 Field Lab Exploration Depth (ft) Soil Type Unit USCS Color Sample Type N (bpf) SPT N60 (bpf) Yd (pcf) 00 (96) Yd-max (pcf) (96) RC (96) Wet (+) or Dry (-) of Opt. (96) -200 (96) LL PL Pi U Ei c' (psf) *• (deg) pH S04 CL Min. Res. (ohm-cm) R-Vaiue T-3 3 4 Qaf/Qal CL/CH dark grey 88 28,6 110.5 19.8 79,6 8.8 WET 70 49 27 22 0,07 103 280 23 6.5 600 60 381 T-3 5 4 Qaf/Qal CL/CH dark grey 88,8 27,8 110.5 19.8 80.4 8 WET T-4 5 4 Ts MH/CH grey 106 22 110.5 19.8 95.9 2.2 WET T-4 8 4 Ts MH/CH grey 108 22,4 110.5 19.8 97.7 2.6 WET T-4 10 4 Ts MH/CH grey 106.9 21,2 110.5 19,8 96.7 1.4 WET T-9 15 4 Qt SC yellow-tan 99.3 17.9 119.5 12,5 83.1 5.4 WET T-9 16 4 Ts MH grey 97.3 24,3 110,5 19,8 88,1 4,5 WET B-l 9 4 Qt CL/CH olive-brown spt 13 16 B-l 14 4 Ts MH pale grey spt 23 29 B-l 18 4 Ts MH pale grey spt 23 29 B-2 29 4 Ts MH pale grey spt 31 39 B-2 34 4 Ts MH pale grey spt 25 31 B-2 39 4 Ts MH pale grey spt 44 55 max= min= a«g= 44 13 27 55 16 33 108,0 28.6 119,5 88.0 17.9 110,5 99.2 23.5 111.8 19,8 12,5 18,8 97.7 8,8 79,6 1,4 88.8 4.7 70 49 27 70 49 27 70 49 27 22 22 22 0,07 0,07 0,07 103 103 103 280 280 280 23 23 23 6,5 600 60 381 6,5 600 60 381 6,5 600 60 381 T-2 3 5 Ts SM/SC tan 101 16,6 119,5 12.5 84.5 4.1 WET T-2 5 5 Ts SM/SC tan 89,8 23.6 119.5 12.5 75.1 11.1 WET 32 36 25 11 -0.13 46 28 166 T-2 8 5 Ts SM/SC tan 107.8 18.8 119,5 12.5 90.2 6.3 WET T-2 10 5 Ts SM/SC tan 114.3 17,4 119,5 12.5 95.6 4,9 WET T-3 7 5 Qaf/Qal SC off-white-grey 100.6 18,4 119.5 12.5 84,2 5.9 WET T-6 7 5 Qt SM/SP yellow-tan 105,5 13,3 119,5 12.5 88,3 0.8 WET 59 T-7 7 5 Qt SM/SC tan 99.3 18,9 119,5 12.5 83,1 6.4 WET T-7 10 5 Qt SM/SC tan 92.8 25,2 119,5 12.5 77.7 12,7 WET T-8 12 5 Ts SC grey to yellow-tan 94.9 13,7 119.5 12.5 79.4 1.2 WET T-9 5 5 Qt SC yellow-tan 96,1 18,3 119.5 12.5 80.4 5,8 WET T-9 8 5 Qt SC yellow-tan 110,6 12.2 119.5 12.5 92.6 -0.3 DRY T-9 11 5 Qt SC yellow-tan 110,9 13.1 119.5 12.5 92.8 0,6 WET T-9 13 5 Qt SC yellow-tan 99,1 16.9 119.5 12.5 82.9 4,4 WET B-2 4 5 Qaf/Qal MH grey spt 4 5 B-2 24 5 Qt CL/CH dark brown cal 48 40 114,6 16.9 119.5 12,5 95.9 4.4 WET B-3 19 5 Qaf/Qal SC red-brown to tan spt 24 30 B-3 24 5 Qaf/Qal SC red-brown to tan cal 44 37 109.5 16,2 119.5 12,5 91,6 3.7 WET B-3 29 5 Qaf/Qal SC red-brown to tan spt 27 34 B-4 9 5 Qaf/Qal SP red-brown cal 28 23 106,2 11,7 119.5 12.5 88.9 -0.8 DRY B-3 9 3,5 Qaf/Qal SM/SC tan to red-brown spt 25 31 B-3 34 3,5 Qaf/Qal SP/GP red brown cal 70 59 110.7 20.3 119.5 12.5 92.6 7.8 WET B-4 19 3,5 Qt GP red-brown cal 34 28 109,5 5,8 119.5 12,5 91.6 -6,7 DRY max= 70 59 114.6 25.2 119,5 12,5 95,9 12.7 32 36 25 11 -0,13 59 28 166 mln= 4 5 89.8 5,8 119,5 12.5 75.1 -6.7 32 36 25 11 -0.13 46 28 166 a«g= 34 32 104.1 16,5 119,5 12.5 87,1 4.0 32 36 25 11 -0.13 53 28 165 [GROUP N:\Projects\_AV\l50(AinS9e Tabata Ste\Geotech\solk surnmiryjdsx Sort by Soil Type TABLE 2 SUMMARY OF SOILS DATA SORTED BY SOIL TYPES 1 -5 Page 2 of 2 TABLE 3 CBC 2010 / ASCE 7-05 Seismic Design Parameters and Response Spectra GDC PROJECT NO. IR-596 Tabata Site, Carisbad Site Latitude: 33.1439 Site Longitude: -117.2865 Ss= s,= Site Class= Fv= TL= SMS" SDS= Sor To= 1.157 1.037 1.562 0.800 0.456 0.570 g = short period (0.2 sec) mapped spectral response acceleration MCE Site Class B (ASCE7-2005-Figure22-1) g = 1.0 sec period mapped spectral response acceleration MGE Site Class B (ASCE7-2005-Flgure22-2) = Site Class definition based on ASCE7-2005 Section 11.4.2 = Site Coefficient applied to 8^ to account for soil type (ASCE7-2005 Section 11.4.3 and Table 11.4-1) = Site Coefficient applied to S, lo account for soil type (ASCE7-2005 Section 11.4.3 and Table 11.4-2) sec = Long Period Transition Period (ASCE7-2005 Section 11.4.5 and Figure 22-15) = site class modified short period (0,2 sec) MCE spectral response acceleration = Fa x Sg (ASCE7-2005 Equation 11.4-1) = site class modified 1.0 sec period MCE spectral response acceleration = x Si (ASCE7-2005 Equation 11.4-2) = site class modified short period (0,2 sec) Design spectral response acceleration = 2/3 x S^s (ASCE7-2005 Equation 11.4-3) = site class modified 1.0 sec period Design spectral response acceleration = 2/3 x SMI (ASCE7-2005 Equation 11.4-4) sec = 0.2 SD,/SOS = Conlrol Period (left end of peak) for ARS Curve (Section 11.4.5 ASCE 7-05) sec = SD,/SDS = Control Period (right end of peak) for ARS Curve (Section 11.4.5 ASCE 7-05) T (seconds) 0.000 0.114 0.700 0.900 1.200 1.400 1,600 1.900 2.000 2,300 2.500 2.800 2.900 3.100 3.400 3.600 3.700 3.800 Design Sa (g) 0.320 0.760 0.652 0.507 0.380 0.326 0.285 0.240 0.228 0.198 0.182 0.169 0.157 0.147 0.143 0.134 0.123 0.120 MCE Sa (g) 0.480 1.140 0,760 0,489 0.428 0,360 0.342 0.297 0.274 0.253 0.236 0.228 0,214 0.201 0.195 0.185 0,180 0.175 3 c o *3 Q) 0) O o < o CD Q. CO 2.0 Period (seconds) N:\Projects\_AV\l500\IR596 Tabata Site\Geotech\2010 CBC Calculation (Tabata).xls FIGURES Ocean HillS Country Clu§ The base maps/photos are from Google Maps GROUP DELTA CONSULTANTS GROUP DELTA CONSULTANTS, INC. ENGINEERS AND GEOLOGISTS 32 MAUCHLY, SUITE B IRVINE, CA 92618 (949)450-2100 PROJECT NAME TABATA-10 Carisbad, Califomia FIGURE NUMBER IA PROJECT NUMBER IR-596 VICINITY MAP Reference: USGS Topographic Map ofthe San Luis Rey 7.5' Quadrangle / Google Earth. GROUP 71 DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California USGS 7.5' Quad / Google Earth Overlay Figure 1B Reference: Bing Maps, GROUP DELTA CONSULT.ANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Aerial Photograph Figure 1C Reference: Google Earth GROUP 71 DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Street View from North Figure 1D Reference: Goosjle Earth GROUP DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Street View from Middle Figure 1E Imagpfy Date: 1/2011 lat 3-3fi;v3-182° 100-117.285776° PIPV 209 ft eye alt 95 ft 0 Reference: Google Earth GROUP DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Street View from South Figure IF Reference: Geologic Map of the Oceanside 30x60' Quadrangle CZD .\ttm*im\ riiMHl plain ilt-pi>M(« lUli- HokHrrm*)—.Vbtc un c»t iiiiOMisi.liiLikd samK. nitly of tljy-Kxirm^ jMm mm Di^; IKI IIKIWV- iilliivhil llui ik-ivKtis .H <li<t.^l iihK »ri.l»,iiHK-U I aii(t«ridr ilrp«i%ll« Hudiiidrd (llHlnrtfBr add Plci*lm-*»c) - Ili^'hh If j|.-iiti'iik-il (n l.ifi'il\ ^.ituTcni l.iitiMiil. ilcr>.>siu I ^mimsoli.UlCtl i.> ni.Hk'.it^K CD Mil MSlJufc |IC|«.V- i-iilirc'K dutuiy Iji i|iitMhjni:U- h;ov i .11 t In ••inw HUM* •«Mqi ^htn»u si|Uitik'ly VC laiiiKli4k'« v*vt*.- rcui'livjiiHl m |v>rl .H ll..l.^c.K- M,^, ..I rl.v l..ii.Mi.kv in (hi- iiiriol Wllhin IIK' r>rtHt|ii|ii>i l'>Mnvili<»i. injiiv Wllhin th.- Mfnii-r^-y v,.ii.iv-.* (Md iillH%ial n.M«l plain depovti* niidUidvU llair l.i nnddli- Mti»i.KToi-»fl.i'ij) s,-ilm'.-m. ,kT..stu'.l <w can>on fl>MWT>. < .wiMMN l.l* nUHkiJli-U »»cll i«n>«>lid^cd. p*».»iK M.IU'II. ivtiiir.il'!.-. >.>niiiKtnl> -.liylilK dl^M.vll^l gimct. tjnd. 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TiKtmichiiui Ilk- txnuiKtn. h.idi \ciih.tll> ami biif,)ll\. ihm* envni>.h-hnmii. in.i.ssi\c .ijs>,h>iK- niicitvdv iiiiUMn-* and k-ii'*"i td nllcu U»»MldlnHi*, IJ^IKMKU il;usit»n.' ami tdiMonc llic limt-t p;iri ol the Siniiap* Intnijii-ui mu-rniitrcts nlilt tlk' Ivlni.ii r>Mni:iiton IHHI Uvu-y SamKionc in ihe rni'iiiiia'> ((iLiibniipk' GROUP DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Regional Geologic Map Figure 3A Reference:: USGS Topographic Map ofthe San Luis Rey 7.5' Quadrangle / Google Earth / Geologic Map of the Oceanside 30x60' Quadrangle CE] CE] (lalf lluUK-rilv»—Acl>v<: aiul akmv c-uiytNi IlfNirs ( )ii'-isi> r tlay-hcurinp altu'.ium. I>i»c*^ ll III-MI ilhl> (d\lnillk'U (llnlnvcnv lar^iirly che . MLHICIJICIV .VllavidI n.HMl plain di(m -avmU .iiiixi- .dhjM.il .k'lv nl"iiih."«»o'iididaicd samK. .>il imlilH UKk-ullm ial fbn'dL'p. 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In HHIK- ati-j* che hisal ntcnihcv i> t<\i.-rliiiii '^s liia* jnd htl•>^*n(^h-^;ra^ (Hail amt p*'ppett I'ei'iral mcmK-t liiji ciinsiM* ni" -nt'i. uk-diuni-L'iaiiiL-d. moikraiv^Ix welt-u.iiei! aiknsk ^HUKIOIK- \n iippiT nvmhcr I'ttnsiHiH nl' sn*). ('i>arsi---!nimi'd ario'it ^.mdstoi".- and jjni TIffniijihn'ii ihc Iniiiiaiion. K.ili \ciin.alU ami laleraily, ihiiv CAW-* (.•iiV!iK'i-hrih\n inassi^f ,!:i\sU'ne liiic'hedv tcii}.'iK-s and knv'. .troiWn In-.-.dircKHi'. lafe-iHtnal elavsinik' and iiliMrtiie The tmu'i pan of ihe '^aniiagn rniiilJliiin )nleilini;ots %MI!I ihc Dclniai Fnmralu.n ;IIKI lines SandsiniK- HI ihe l.ni'Hiiias(]iiailr!ini'le GROUP DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Geologic Map Google Earth Overlay Figure 3B insima w/ua BKHn jtHWN/tjaoinoN PHOPOSED CflOUND pmeouo K' CL a CUHHO KfM. GEOLOGIC CROSS-SECTIONS 2006 Report -| 2011 Report LWf "A" PROFILE SCALE; 7 ''*46'(H,). I * (V.) ron STQitu oftMif m_fuetK_ smp ux luMiovfi^Ts PLAMS n» cr o<-rj GEOTECHNICAL LEGEND ^ - - -Test Trench (4/11/2006) ^ - - - Test Boring (5/25/2006) \^ ^ 1 — Eslimated Geologic Contact — Geologic Cross-Section - - Recommended Removal Depth — Eslimated Geologic Contact — Geologic Cross-Section - - Recommended Removal Depth IB — Eslimated Geologic Contact — Geologic Cross-Section - - Recommended Removal Depth Caf — Compacted Fill Slope af-Qal-- - - Old Fill-Alluvium Qt — Terrace Deposii (Pleistocene) Ts — Formational Rock (Eocene) I I PLATE 3 VfltM JOB »06-2lO-P REVISION DESCRIPHON SH£ET 3 we. DATC R£VICVC0 BY> DATC CITY OF CARLSBAD P^GMECWNC OEPARruCNT SKtTs 3 TABATA 10 *PPfiOVt6. CUM K. VAM PCSKI |0»N Bt: _ CHKD bfl. RVHO ev; PROJtCT WX CT 06-13 OHAtMC NO |472-7A| FIGURE 3C - SITE GEOLOGIC MAP GROUP DELTA CONSULTANTS GDC Project No. IR-596 Tabata -10 Carlsbad, California Regional Fault Map Figure 4 OE©L@©I(D QMOm PLATE 12 EXISTING Sn i^TURE TO BE DMOioilseEB 120 100 -80 -80 lao- lOO- •0 so B-4 %iroj.)> •60 SCALE: 1"=30' V&M JOB #06-210-P FIGURE 5A PLATE 13 ff 160 - 140- 120- 100- — u „ •••-7 r 120 100 120- 100 1^ I SCALIJ: i"=30' V&M JOB #06-2 lO-P Ofifiiiial ground suvl'ace appvoximalcd from County of San Diego Topographic Survey Map No.'« 354-1677 & 354-umi, dcUed 1975. FIGURE 5B PL/iTE 14 iso- B-2 (proj.} 100 - IOO TEMMACE BEmBEf7:\'.:: - so r SCALE: r=50' FIGURE 5C SCALE: 1" = 20' COMPACTED A—.^ Far 130 - 120- 110- PROPOSED GRADE (LOT 4] FORMATIONAL ROCK ^ 130 120-1 110 PROPOSED •GRADE fLOT 7) FORMATIONAL ROCK PLATE 4 V&M JOB #06-210-P FIGURE 5D APPENDIXA GEOTECHNICAiL REPORTS BY OTHERS TABATA 10 CT 06-13 GEOTECHNICAL RgPQRT REC GEOTECHNICAL PLAN REVIEW UPDATE PROPOSED 26-LOT (TABATA 10) SUBDIVISION CAMINO HILLS DRIVE. CARLSBAD (A.P.N.'s 212-050-32 & -33) December 13, 2011 Prepared For: TABATA FAMILY TRUST c/o Mr. Gregg Harrington P.O. Box 679 Carlsbad, California 92018 Prepared By: VINJE & MIDDLETON ENGINEERING, INC. 2450 Auto Park Way Escondido, California 92029 Job #06-210-P GEOTECHNICAL PLAN REVIEW UPDATE PROPOSED 26-LOT (TABATA 10) SUBDIVISION CAMINO HILLS DRIVE, CARLSBAD (A.P.N.'s 212-050-32 & -33) I. INTRODUCTION The most current project Grading Plans prepared by REC Consultants, Inc. (not dated) for the proposed 26-lot residential development referenced above, also known as Tabata 10 subdivision, were provided to us for review and comments. The plans are reproduced herein and enclosed with this transmittal as Plates 1-3. The approximate site coordinates are 33.1452°N latitude and 117.2880"W longitude. The subject property was originally studied with respect to surface and subsurface geotechnical conditions performed by this office with findings, conclusions and recommendations summarized in the following written technical report: Preliminary Geotechnical Investigation Proposed 26-Lot Subdivision Camino Hills Drive, Carisbad, California (A.P.N.'s 212-050-32 & -33) Job #11-210-P. report dated June 23. 2006 The reference report was reviewed in connection with the preparation ofthis update study and a copy is attached herein as Appendix A. The purpose ofthis work was to review the referenced report and confirm compatibility of the project current grading plans with the site indicated geotechnical conditions. Additional updated and/oramended recommendations consistent with current codes and engineering standards are also provided in the following sections and will supplement or supersede those given in the referenced report, where specifically indicated. Our efforts in connection with the preparation of this report included a recent site visit conducted by our Engineering Geologist on December 5, 2011. II. SITE DESCRIPTION Existing topographic conditions and proposed development at the project property are shown the enclosed Plate 3. Based on our recent observations, site conditions primarily have remained substantially the same as discussed in the referenced report. In general, much of the study property consists of gently sloping terrain that descends in a northeasteriy direction to El Camino Real. Previous grading activities for off-site developments have modified the property to include large graded slopes that ascend to residential developments along the southerly and easterly site margins. An anomalous hill VfNii-: & MrDniJMON ENr,iNni;i<iN(;, INC. • 2450 Auto PnikWoy • GsconJiclo, Cilifi>rni.i 92020-1229 • Plmnc (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGE 2 marks the northwest property margin adjacent to Camino Hills Drive. The hill rises nearly 30 feet above surrounding areas with slope gradients that generally approach 2:1 (horizontal to vertical) maximum. The large graded slopes that mark the southerly and easteriy site margins were constructed at 2:1 gradients maximum and range to nearly 50 feet high. Drainage terraces were noted in south and northeast portions of the graded embankments. Available pre-development topography indicate the perimeter slopes are largely fill embankments with some fill-over-cut slopes. The previous residential dwelling located on the hilltop in the northwesteriy area of the property has been removed. Elsewhere, the property is characterized by grass covered gently sloping terrain previously utilized for agricultural purposes. Perimeter graded slopes are well landscaped with large trees, shrubs, and assorted groundcover plants. Site drainage sheetlfows in a northeasterly direction towards El Camino Real. Excessive scouring or erosion is not in evidence. ill. GEOTECHNICAL CONDITIONS Geotechnical conditions at the project property have remained substantially unchanged from those discussed in the details in the referenced report (see Appendix A). In general, previous grading has modified much of the project site and altered the original surtace contours. Old topographic maps of the area indicate that lower, level areas of the site were previously characterized by a natural canyon that drained northward toward El Camino Real. Grading of the area in the late 1960's leveled the site for agricultural purposes. Graded perimeter slopes in the south and east margins were constructed at a later date in support ofthe off-site development above. The project site exposes natural formational and Terrace Deposit units that are mantled by surficial alluvial and fill deposits. Eocene age formational rock units are present at shallow to modest depths in south and east portions of the property and found at depth beneath younger soil deposits in northerly areas. Natural Terrace Deposit soils are present in the north and west portions of the property and thicken northward and pinch out atop formational rocks to the south. Undifferentiated fill and alluvial soils occupy lower elevations of the project site and compacted fill sections mark the south and east perimeter areas of the project site. Groundwater conditions, as encountered during the original site investigation, occur at depths of 32 and 33 feet below ground surfaces in the northwest portions of the property (see Boring Logs B-2 and B-3 in Appendix A). The noted groundwater is sufficiently deep and is not expected to impact the proposed grading orthe future stability of the developed property provided our recommendations are followed. ViNii; ti Muwu-.tON liNC-iNi-KKiNC., INC. • 2450 Auto Park W.iy • Ksconrfido, C.iliroini.i 92029-1229 • Plionc (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 3 Details of project earth materials are given in the Test Trench and Boring Logs included in Appendix A (Plates 3-11). Approximate locations of the Test Trench excavations and Boring explorations are transferred and are shown on the enclosed Plate 3. IV. PROPOSED DEVELOPMENT The project current Grading Plan (Plate 3) proposes a substantially similar development scheme to the eariier reviewed project Preliminary Site Plan used as a basis of our geotechnical study in 2006 (see Plate 2, Appendix A). The grading plans outline the creation of a 26-lot residential subdivision with associated interior public roadways and improvements using minorto relatively significant cut-fill grading. Current plans, however, depict new building pad elevations for some lots. Elevated pad elevations on the order of 4 feet are now proposed for perimeter southeastern lots. Similar grades or minor elevation changes are noted forthe remaining lots. Minor graded slopes provide ground elevation transitions between uneven pad surfaces. Additional Cross-Sections showing the proposed new pad elevations and associated new graded embankments are included as Plate 4. Based on the project plans, neariy 26,000 yards of import soil will be required to complete grading and achieve final design grades. A modest sound earthen berm, incorporating relatively short retaining walls, is proposed along tiie north/northwest margin ofthe property adjacent to El Camino Real. Proposed hydro-modification consists of a self-contained vegetated bio-retention/detention area with impermeable liners on sides and bottom, engineered soils, and perforated and header pipes surrounded with aggregate or crushed rocks, along the northern property margins. The treated stonnwater from the bio- retention/detention area is discharged via a new 24-inch RCP storm drain pipe into the existing 36-inch RCP pipe beneath the El Camino Real. Future residential construction is anticipated to consist of single and/or two story conventional wood-frame buildings with exterior stucco supported on shallow stiff concrete foundations with stem-walls and slab-on-grade floors, slab-on-ground with turned-down footings, or post-tension slab foundations. V. SEISMIC GROUND MOTION VALUES For design purposes, site specific seismic ground motion values were determined as part of this investigation in accordance with the California Building Code (2010 CBC). The following parameters are consistent with the indicated project seismic environment and our experience with similar earth deposits in the vicinity of the project site, and may be utilized for project design work: ViNii; & Mit)i>i.i;TON lENtjiNiii-ttiNC, INC. • 2450 Aiito IVk Wny • Escoiulido. Caliloi ni.! 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGE 4 TABLE 1 Site Class Ss Si Fa Fv SMs SMI SDS SDI D 1.158 0.439 1.037 1.561 1.201 0.685 0.801 0.457 According lo Chapter 16, Section 1613 of the 2010 California Buildinq Code. Explanation: Ss: Mapped MCE, 5% damped, spectral response acceleration parameter at short periods. S1: Mapped MCE. 5% damped, spectral response acceleration parameter at a period of 1-second. Fa: Site coefllcient for mapped spectral response acceleration al short periods. Fv: Site coefficient for mapped spectral response acceleration at 1-second period. SMS: The MCE, 5% damped, spectral response acceleration at short periods adjusted for site class effects (SMS=FaS6). SM1: The MCE, 5% damped, spectral response acceleration at a period of 1-second adiusted for site class effects (SM1=FvS1). SDS: Design, 5% damped, spectral response acceleration parameter at short periods (SDS= %SMS). SD1: Design. 5% damped, spectral response acceleration parameter at a period of 1-second (SD1= VsSMI). Site peak ground accelerations (PGA) based on 2 percent probability of exceedance in 50 years defined as Maximum Considered Earthquake (MCE) with a statistical return period of 2,475 years is also evaluated herein in accordance with the requirements of CBC Section 1613 and ASCE Standard 7-05. Based on our analysis, the site PGAMCE was estimated to be 048.g using the web-based United States Geological Survey (USGS) ground motion calculator. The design PGA determined as two-thirds of the Maximum Considered Earthquake (MCE) was estimated lo be 0.32g. VI. HYDRO-MODIFICATIONS Project stormwater management should be designed and constructed considering the site indicated geotechnical conditions. The implemented management practice(s) should also have no short and long term impacts on the site building pad surfaces, graded slopes and natural embankments, fills and backfills, structures, and onsite and nearby off improvements and properties. Site hydro-modification, as currently proposed consist of a self-contained vegetated bio- retention/detention area with impermeable liners on sides and bottom, engineered soils filter medial and perforated and header pipes surrounded with aggregates or crushed rocks, along the northern property margins. Treated water from the bio-retention/detention area is captured and discharged via a new 24-inch RCP pipe into the existing 36-inch RCP storm drain pipe under El Camino Real. The proposed hydro-modification system represent a feasible design and is considered acceptable from a geotechnical viewpoinL ViN(i: & Mii)ni,i:roN liNi;iNi;i;itiN(;. INC. • 2450 Auro Pmk Way • F.sconctiJo, Cnlifornia 92029-1229 * Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION. CAMINO HILLS DRIVE. CARLSBAD PAGE 5 Vll. CONCLUSIONS AND RECOMMENDATIONS Project most current Grading Plans reproduced herein as Ptates 1 through 3 represent feasible designs and development schemes from a geotechnical viewpoint. The most significant change from the original plans include minor to moderate elevations changes in final pad grades for some lots, the addition of an earthen sound wall adjacent to El Camino Real, and a vegetated bio-retention/detention area as a part ofthe project hydro- modification. The site mostly remains substantially unchanged from conditions presented in the referenced Preliminary Geotechnical Investigation report (Appendix A). All conclusions and recommendations provided in the referenced report (Appendix A) remain valid and should be incorporated into the final plans and implemented during the construction phase except where specifically amended or superseded below. Additional site-specific conclusions and recommendations consistent with the enclosed plans, and current codes, standards and engineering practice are also provided below and should be considered where ever appropriate and as applicable: 1. Landslides, faults or significant shear zones are not present at the project property and are not considered a geotechnical factor in the planned developments. The study site is not located near or within the Alquist - Priolo earthquake fault zone established by the State of Caiifornia. 2. Soil collapse, liquefaction and seismically induced settlements will not be a factor in the development of the project property provided our remedial grading and foundation recommendations are followed. 3. All existing underground wateriines, sewer lines, storm drains, utilities, tanks, structures, and improvements at or nearby the project construction site should be throughly potholed, identified, and marked prior to the initiation of the actual excavations, grading and earthworks. Specific geotechnical engineering recommendations may be required based on the actual field locations, invert elevations, backfill conditions and proposed grades in the event of a grading conflict. Utility lines may need to be temporarily redirected, if necessary, priorto earthwork operations and reinstalled upon completion. Alternatively, permanent relocations may be appropriate as shown on the approved plans. Abandoned lines, irrigation pipes, and conduits should be properly removed, capped or sealed off to prevent any potential for future water infiltrations into the embankments, foundation bearing and subgrade soils. Voids created bythe removals ofthe abandoned underground pipes, tanks and structures should be properly backfilled with compacted fills in accordance with the requirements of this report. ViNli: & MM>ni.i:TON l:Ni;iNi;iLl<rNC., INC. * 2450 Auto P.irk Way • Kscomtido, CaliToroia 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGE 6 4. Remove all existing surface and subsurface improvements, old foundations and concrete slabs, vegetation, trees, roots, stumps, construction debris, and all other unsuitable materials and deleterious matter from all areas of proposed new fills, embankments, improvements, and structures plus 10 feet outside the perimeter, where possible and as approved in the field. Trash, vegetation, and construction debris shall not be allowed to occur or contaminate new site fills and backfills. The prepared grounds should be inspected and approved by the project geotechnical consultant or his designated field representative priorto grading and earthworks, 5. Earthwork and remedial grading operations should be completed as specified in the Remedial Grading and Earthworks section of the referenced report (Page 17 of Appendix A). Site upper fill and alluvium deposits in the areas of planned new fills, embankments, structures, and improvements plus 10 horizontal feet outside the perimeter should be removed (stripped) to the underiying competent natural soils. Terrace Deposits, and Formational IRock as approved in thefield, and recompacted. Ground stabilization techniques using Tensar Geogrid BX-1100 (orgreaterfrom the same series) earth reinforcement may be required at the yielding bottom of removals, and within the compacted fill mass, in the case of unsuitable exposure and should be anticipated as specified and directed in the field. Actual removal depths should be established by the project geotechnical consultant at the time of earthwork operalions based on exposed field conditions. Typical removal depths in the vicinity of the subsurface are given in the referenced report (Table 15, Appendix A) and also depicted on the attached Plate 3. Locally deeper removals may be necessary as directed in the field and should be anticipated. 6. Current plans indicated minor to moderate changes in the final pad elevations. Elevated pad grades are now proposed forthe south/southeastern lots with Lots 3-5 raised up to 4 feet above the prior elevations (see Plate 2, Appendix A). Ground transitioning will be accomplished with new graded cuts on the order of 5-8 feet high. Reconstruction of lower sections of the exposed siope in these areas (Lots 4 and 6-10) with stabilization fills, or a toe retaining wall support, as recommended in a referenced report (see Plate 20, Appendix A) may still be necessary. Final recommendations for slope reconstructions for new graded embankments constructed within or at the toe of existing graded slopes will be provided in the field by the project geotechnical engineer based upon actual developed exposures. ViNii-: & MimJi.ivi ON ENi;iNr.i:KiNC., INC. • 2450 Auto P.nk Wny • Fjicondido. Cililbrnla 92029-1229 • Pivrn- (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 7 7. The project is an unbalanced grading operation and neariy 26,000 yards of import soil will be required to achieve final design grades. Onsite soils may also may be expected to shrink approximately 10% to 20% on a volume basis when compacted as specified herein. Import soils required to complete grading, should be good quality non-corrosive, very low expansive sandy granular D.G. type soils (100% passing 1-inch sieve, more than 50% passing #4 sieve and less than 18% passing #200 sieve with expansion index less than 21), inspected, tested as necessary, and approved by the project geotechnical consultant prior to delivery to the site. Import soils should also meet or exceed the design parameters given in the following sections. Good quality sandy granular D.G. type import soils should be placed within the upper pad grades. Attempts should also be made to bury site potentially expansive clays in deeper fills below the upper 4 feet and place, better quality sandy onsite soils within the upper grades using select grading techniques, as specified in the referenced report. 8. The cut portions of cut-fill transition pads should be undercut to a minimum depth of 3 feet or at least 12 inches below the bottom of the deepest footing(s), whichever is more and reconstructed to design pad grades with compacted fills, as specified. In the roadways, driveway, parking and on-grade slabs/improvement transition areas, there should be a minimum of 12 inches of compacted soils below rough finish subgrade. 9. Fill materials, processing, spreading and placement in thin horizontal lifts (less than 8 inches maximum), moisture conditioning above the optimum levels and compaction procedures, and minimum compaction levels (95% within the upper 3 feet and where specified, and 90% below the upper 3 feet) will remain the same as specified. All grading and earthworks should be completed in accordance with the Chapter 18 and Appendix "J" ofthe California Building Code (CBC). City of Carisbad Grading Ordinances, the Standard Specifications for Public Works Construction, and the requirements ofthe referenced soil report (Appendix ) and this update transmittal. 10. New graded slopes, berms, and embankments constructed in connection with the site development are expected minor features on the order of 10 feet high maximum. Graded slopes and embankments should be programmed for 2:1 gradients and constructed as spiffed in the referenced report (see Appendix A). ViNii; 8d MiniM-inoN I-NI;INI-I:IUNC, IN<:. • 2450 Auro P.iik Way • l:scoridido. CaiiCoinia 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGES 11. Excavations and removals of onsite existing fills and alluvium are expected to predominantly generate marginal quality plastic silty to clay-rich deposits which typically require additional processing, mixing and moisture conditioning efforts in orderto manufacture a uniform homogeneous mixture suitable for reuse as new site fills. Site potentially expansive soils should be buried in deeper fills and better quality sandy soils generated from the excavations of site Terrace Deposits, and good quality sandy import soils place within upper pad grades, as specified. Plastic silty to clayey soils are also not suitable for wall and trench backfills and good quality sandy soils should be used for this purpose. For foundation design purposes, however, sandy clay to silty clayey sand (SC/CL) bearing soils with low to high expansion potential (Expansive Index less than 131) based on ASTM D-4829 classification should be considered. Remedial grading and geotechnical foundation design recommendations specified herein are provided to also mitigate adverse affects of site potentially expansive soils . 12. Soil design parameters, and foundafions and slab designs will remain the same as specified in the referenced report. However, the following revised parameters are appropriate based on the anticipated bearing soils properties and supercede those previously given where specifically applicable: * Design edge moisture variation distance for edge lift (em) 4.9 feet. * Design edge moisture variation distance for center lift (em) 9.0 feet. * Design differential swell occurring at the perimeter of slab for edge lift condition (Ym) 1.32 inches. * Design differential swell occurring at the perimeter of slab for center lift condition (Ym) 2,91 inches. In case of post-tensioned slab foundation system, underslab moisture control should consist of a well-perforrning vapor barrier/moisture retardant (minimum 15- mil Stego) placed mid-height in a minimum of 4 inches of clean sand (SE of 30 or greater). However, interior underslab moisture control requirements per CGC Section 4.505.2.1 consisfing of a minimum 4-inch thick base of 14-inch or larger clean aggregate, provided with a vapor barrier (minimum 15-mil Stego) in direct contact with concrete, and a concrete mix design which address bleeding, shrinkage, and curling may also be considered. 13. Alt exterior concrete slabs and flatwork (walkways, and patios) should also be constructed as specified in the referenced report (Appendix A). Slab subgrade soils should be compacted to minimum 90% compaction levels. Subgrade soils should be tested for proper moisture and specified compaction levels and approved bythe project geotechnical consultant prior to the placement of concrete. ViNji; & MMIDLMTON KNClNhl-liiNt;, INC. • 2450 Auto Park Way • l^jrondido, Calilomia 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGES Slab reinforcements lying on subgrade will be ineffective and shortly corrode due to lack of adequate concrete cover. Reinforcing bars should be correctly placed extending through the construction joints tying the slab panels. In construction practices where the reinforcements are discontinuous or cut the construction joints, slab panels should be tied together with minimum 16 inches long #3 dowels (dowel baskets) at 18 inches on centers placed near the mid-height in the slab (9 inches on either side of the joint). Provide thickened slab edge and "tool joint" or "softcut" contraction/control joints for exterior slabs as specified. The larger dimension of any panel shall not exceed 125% of the smaller dimension. All exterior slab designs should be confirmed in the final as-graded compaction report. 14. Preliminary structural section estimates forthe asphalt and PCC paving will remain the same as specified. The minimum asphalt pavement structural section presented in Table 16 of the referenced report (see Page 32 of Appendix A), or the minimum section required by the City of Carlsbad, whichever is greater, should be considered. Provide "tool joint" or "softcut" contraction/control joints for all PCC paving surfaces also as specified. The larger dimension of any panel shall not exceed 125% of the smaller dimension. Joints shall intersect free edges at a 90" angle and shall extend straight for a minimum of 1/4 feet from the edge. The minimum angle between any two intersecting joints shall be 80". Align joints of adjacent panels. Also, align joints in attached curbs with joints in slab panels. Provide adequate curing using approved methods (curing compound maximum coverage rate = 200 sq. ft./gal,). 15. The proposed bio-retention area within the project development is a self- contained system which incorporates timely removal of the captured water by the perforated subdrain pipe and discharging the treated water into the storm water drainage facilities, without allowing accumulation or saturation of the surrounding soils. The proposed bio-retention system is considered acceptable from a geotechnical point of view and may be inslalled at the designated site locations as shown on the project plans. Added care, however, will be required during the bio-retention constructions to void puncturing the impermeable liner and assure positive outflow of the perforated subdrain pipe. 16. Control of site surface drainage and potential for post construction subsurface water caused by surface water infiltrations is one of the most significant geotechnical factors at the project building sites. Surface flow, run-off drainage and subsurface water should not impact graded surface, saturate wall backfills, bearing and subgrade soils or cause erosion. All retaining walls should be provided with a back drain as specified. Drainage ditches should be provided at the top and toe of slopes and behind site retaining walls with collected water directed to approved disposal Vif-jm & MinJ)i.i;TON liNiWNP.i-itiNi.;, INC. • 2450 Auio P.ark Way • Bicondido, Calirornia 92029-1229 • Phone (760) 743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13, 2011 TABATHA 10 SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 10 location via adequate area inlets. All wall back drains, fight pipes and outlet locations should also be shown on the final plans. 17. Final grading and foundation plans should reflect preliminary recommendations given in this report and reviewed and approved by the project geotechnical consultant. Additional or more specific recommendations may be necessary and should be provided at that fime, as required. VIII. GEOTECHNICAL ENGINEER OF RECORD (GER) Vinje & Middleton Engineering, Inc. is the geotechnical engineer of record (GER) for a specific scope of work or professional service under a contractual agreement unless it is terminated or canceled by either the client or our firm. In the event a new geotechnical consultant or soils engineering flrm is hired to provide added engineering services, professional consultations, engineering observations and compaction tesfing, Vinje & Middleton Engineering, Inc. will no longer be the geotechnical engineer of record. Project transfer should be completed in accordance with the California Geotechnical Engineering Association (CGEA) Recommended Practice for Transfer of Jobs Between Consultants. The new geotechnical consultant or soils engineering firm should review all previous geotechnical documents, conduct an independent study, and provide appropriate confirmations, revisions or design modifications to his own satisfaction. The new geotechnical consultant or soils engineering firm should also notify in writing Vinje & Middleton Engineering. Inc. and submit proper notification to the City of Carisbad for the assumption of responsibility in accordance with the applicable codes and standards (1997 UBC Section 3317.8). IX. LIMITATIONS This geotechnical plan review update is not a "Plan Check Review" and does not relieve the responsibility of the project design consultant(s) and contractor(s) to get completely familiarized with the requirements of the project soil report(s) and fully incorporate its recommendations into the project design, plans and construction works, where appropriate, and as applicable. Our review and comments are for general geotechnical conformance of the project plans with the intent of the project soil report and design recommendations. Review of structural and civil engineering calculations, architectural intent and structural and civil engineering design modeling and basis, verification of set back requirements, easements and right-of-ways, as well as code, city and county compliance are beyond geotechnica! engineering services. It is the owner's or his (her) representative's responsibility to provided copies of all pertinent soil report(s), updates, addendum letters and plan review letters to respective design consultant(s), and general contractor and his (her) subcontractor(s) for full compliance. ViN)i; & MiununoN HNCiNiUiUiNti, INC. • 2450 Auio Park Wiy • lisamdido, C.ilifoinia 92029-1229 • Piione (760)743-1214 GEOTECHNICAL PLAN REVIEW UPDATE DECEMBER 13. 2011 TABATHA 10 SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 11 This opportunity to be of service again is sincerely appreciated. Should any questions arise concerning this report, please do not hesitate to contact this office. VINJE & MIDDLETON ENGINEERING, INC. 3:L ehdi S. Shariat 2885 Steven CEG# Distribution: 3ven Melzer C ^tio CERTIFIED 'f^ ^1 ENSINIERING iJf -A GEOLOGIST ' '>\EXRjig<Aa.^ Addressee (2. e-mail) ' REC Consultants Inc., Atten X Parra (3, e-mail) Attachments: Plates 1 - 4 Appendix A ViNji; & MiDDLin oN HNC.iNlMtiNf,, INC. • 2450 AuioP;irk Way • Hscondido. Calirornl.! 92029-1229 • Phone (760)743-1214 GRADING NOTES (m ADDinoN TO mc ncauiRcuCNis or CHAP ien is.>e or me ciotsaAO mMciftL cooc.) me PLAN suMKSfOfs «i. omm PLAMS (wvwuar Awwovto ar IHE arr Of cADLSBiO pccAnomc CRAam SMom OH ms sci or PIAKS. 2. APPDDVAi or IMS PLAN OOCS HOJ LESSOl OR WAHC AMY PORHOH Of THf CARLSBAO UUMIOPAL COOC RESXUIHM CT COOnONM tPPROVAL OTT SIAMOAKOS OR OmCR AOOlllOMAL DOCUttNtS USTED HCRCOH AS Htr UAr PGRMW TO IMIS PROjecJ. TMC CNOMEER m RCSPDNSOII CHAKC€ SHAU Revise mcse PLAMS M^N MON-coHroRUAMce is asancRea 1 OTr APPmifAL OF PLANS OOCS MOT Rcucve me ocvtioPtn OR eioMeeR-oe- MRK FROU RCSPONSiaiUIY FOR INC COARCCIKM Ot eRRORS AM OUlSSnWS ascDvcRCo ouiTiNC coNsmuenaN, AIL PLAH RPASIOHS SIALL SC moui>TLr suBuriro ro TMC orr cwwcn roR APPROVAL 4. A RKHT-Oe-WAr PtRMT FROU me CIJY eHOHSR ILL BC ReOUfOI FOt AHT WORK m me PUBLIC RKHI or mr, PRIOR TO i>EKMr ssu/wcc. A czRiincAii OF MSURANCC AS wu AS AtanoNAL MSUICD oiooRseueMT msr Be ntco NAUMc me air OF CARISBAD AS AN AOOTXMAL wsuto ON IK PCnnrTtcs raucr w THE UMMUU AMOUNT or (i.ooOLOoaoo FOR EACH OCCWNIANCC or uASurr. me IHSURAHCF couPANr mum; me paicr uusT HAVC A BAIMC OF 'A- OH BCnCT AM) A SIZE OlTCOIlr QT OitSS VU OR BCfltB AS ESTAgUSHtO BT -BESTS' KfT gATIMC CHOC s. umcss ueuPieo Br SECDON XLMS OF me UMTORU BUHOHO CODC. DCTAIMNC WAUS OUTSOC Or PUSUC lOCNr OF WAr SCOUAC SEPARAIC pemiis FROU me stMOwc OCPADDICNT. (. NO wow SHAU 8E CauiCNOS UNTU ALL FCRUTS HAVE 8CEN OSTAMCD FROU me arr AHB omen APPSoniiAiE AGENOESL 7. APPROVAL OF THESE T\ANS Sr INE CTTT CNQNCO) OOCS NOT AUIN0«2E ANr MRK OR BRADHO TD SC PCNFaiuCO UNIt INC TWirCffrr ODNCII'S POiUSSlON HAS SCEN OBTAMCO ANO A VAUD OTAOINC PERUT HAS BEEN ISSUEO. a NO ffEMSIOvS MU SE UAOC TO THESE dANS WIHOUT TNE IWIITEN AFPJWVAL or IME OTr CNCMCER, NOTED WINW INC liCUSION SLOW. ON IH[ AWIOmAlE SHEET OF TNE PLANS ANO INE DUE SHEET, SL CRIONAL ORAIUMCS SHALL SeCOME TNE mOPERnr OF TNE Orr UPON SCING SKWfO Sr IHE OTr ENONEER la IHE CRIQNAl ORAWNC SHALL SE REMSCD TO HfnCCT AS-SUtT CONOinONS sr IHE eMcmeeR-cr-tiaRK PRIOR ID FMAL AOXPTANCE OF THE MMK sr INE orr. Tl. ACCESS /OR FME ANO ODCR EUCSCEMCr VCNdCS SHALL SE UAWrAWEO TO INE PffOUECI STC AT AU DUES OUDNC CONSIKUCnON 12. HHEHE mtXCHES AHE WIHIN OTY CASEuCNIS. A SOUS SCPORT COUPSISCO OF: (A] SUOMSr SHEEr. mi LASODATOftr IKRK SHEETS AMD (C) COUPACIIDM CURVES SHAU SC SU8WITI9 sr A IVTOFESSONAL EHONEES OF THE SFA IE OT CAUFORNU. PRWOPALLr OOWC SUSMESS W INE nElO OF APPLCO SOILS UCCHAMCS IHC SOLS REPORT Wu BE SUBUTICD TO INE OIT CNONECRM; wsPEcroR wiHW no WMKMC OA*S or INE COUPICDON or ncu) TESTS. a A SOILS coupAcnoN REPORT AND COMFUANCE VEWICAIIOM RECAROWC AOHCRENCE TO RECOIUENOADONS OunwEO w INC SOILS REPORT S RCDunCD PRIOR TO IHE ISSUANCE or A sunowc PCRUI. ALL coNiRaLCo CRAOWC SHAU sr HONE UNDER TME OaKCIXW OP A PROrCSSIONAL ENONEER OE THE SIATE or CAUFDRNIA PRNOPAUr OOWC BU9NESS IN TNE FKIO OF APPLIED SO«,S ueCHAMKS. ALL FU OR FVniRE FU AREAS SHALL SC CONSIRUCIIO M ACCORDANCE WIH THE OTT OF CARLSBAO STANDARD SPECIFICA TIONS AND INE ' EARTHMMK SPECnCAIIONS ' ATTAOCD TO IHE PRaiWNARr SOUS wvcsDCATiOM. OAJir ncLo COUPACDON REPORTS MLL SE suBwriEO TO THE PROXCIIHSPCCTOR. 14. A PRFrmwiRiiriinM uffnwe SWAII RF Mfin tr mr oir PBMR m IHF nraHMtHR nr mORic Aim tum »r irrrimm ar iii iirpiifynmivr^ RgpowssL^ rqRCONSiRuenoN. ASPfCB suPERMSiow. TESUNC AMI ALL OIWER fAClDR SHALL RCOUetl A MCCONSMIMN HCCIMC sr CALLiNC Die WSPCCnON UMC AJ (710) 4311-Mil AJ LCASI Fni(5) mROMC DArS PRIOR TO STARTMC CDNSIRVCHOM. INC COHIXACTOR WU THEN BE CONTACTEO sr IHC PROjCCr INSPCCrOR TO COOROWAIC A DAII ANO IIIE FOR INE PRCCONSnuCDON NEEIMG. APPROVED ORAWNCS MSI SE AYAILABU PRIOR 10 SCHEOUUNC. THE CRAOWC PERUT WLL SE PROUOCO Sr Ht PROJCCJ WSPCCIDR AT TME UCEDNa IS. All MWriMM Rfmr<;rt niMfR IMAM FOB PRFmnmirim uFrmr. mi nr UABF RY rjiiMi IMF FnoumHur. M-Mmg nKPfrnnti »Fni«r IIMF AT C7linl 4M-IIWI INWrTMH RFniFCr U,KT RF RfrFlVTn PRIOR m 7 m PU OM IHE OAr BEFORE IHC WSPECIMN IS NCCOCDL WSPECIMHS WU SC MACE IHE NExr MJSK OAV ONUSS YOU SfootJr oMSwSE RCOUESTS UAOC VIE? 200 P.U. mx Be SCHCDUCD FOR mo FUL HORK OAIS LAIER IS. IHE OHMEI? AND/OR APPLICANT TNROUCH TNE OEWIOPER ANO/OR CONTRACTOR SHAU OESGN. CONSITiUCT AND UAWTAIN AU SAFEnr OCVICC& INCLUOWG SHORINC. AND SHALL BE SOCir RESPONSIBLE FOR CONFOmnNC TO AU LOCAL. STAIE AMO FEDERAL SAFETr ANO HEALTH STANOAROSL IXHS AMD REOAADONS. 17. IHC CONIRACTOR SHALL CDNFORU TO LABOR CDOE SECTION S703 Sr SUSWriMC A DETAIL PLAN TO THC OFr ENSNEER ANO/K COHCCRNED ACENCr SHOWNC IHE OESICH OF SHORwa BRAONC SLOPINC OR OTHER PROMSONS TD SE UAOE OF HORXER PROIECnON FROM INE HANARO OF CAUNS CROUMO OURINC INE EXCAVAIXm OF SUCH IRENCH OR IRENCHCS OR OURINC Df PIPE OKTALLAHON IMERCIN. THIS PLAN niusr BE PREPARED FOR ALL WENCHES FIVE FECr (S") OR UORC IN DEPTH AND APPROVCD Sr THC Orr ENONEER ANO/DR CONCERMD ACENCr PRIOR TO rjfgAWTMM IF iHf PIAN vARr; FROM IHT omwe swini STANOAROS EfTABLIglEg _Br_ TNE CONSmuCMW SAFl^ ^^"5.- "jU-t 2£ REOSTFRfO EWONCER AT IMF rtlMTRACjan Fl IISAVAIS! ' SE SUSMTfTCO ID BTA COPY OF IHC OSHA WSPCCTDR PRIOR TO l"'j!!!!]::i?„'y'? g stawrirD^ sr mc CONIR^TOR TO mr ENONEER FDR AF-PROWAl TW rijll ' xr- wORIC. IMRKINC 0A»5 PR«1R 21 mc OmeR/APPUCAMr »ALL INSURE THAT ALL CONDiACTDRS SHALL COORDINATE THE WORK OF ITCSE CRAOtNC PLANS MIH THAT SHOHN ON BOTH TME LANDSCAPE ANO ARIGAHON PLANS AND INE IMPROVEUENT PLANS AS REQUIRES FOR TMS WDRX W ACCORDANCE WIN THE LANDSCAPE MANUAL RME REDmRCMENIS. JD HHERE AN EXSmC PIPE LINC S TO SC ABANDONED AS A RESULT OF THE CRAOm oPCRAim IT SHAU BE REMOVED HTHW mENrr FEET or SUIDIM: OR STRECr AREAS AND REPLACED Mm PROPERLr COMPACTED SaLS IN OINER AREAS mE nPE MU BE PLUCCED Mm COHO^ETE OR REUOVEO AS APPROVED Sr mE orr ENONEER. JL mE CONtRACTOR WAU VEWFr IHE LOCA BON OP AU exiSHNB FACVltS ( ABOVE GROUND ANO UMOCR GROUND ) MIMN IHC PROECT SITE SUFFICICNIlr AHEAD OF GRADINC TO PERMIT mC REVISION OF mC GRADING PLANS F IT IS FOUNO mAT INE ACTUAL LOCADONS ARE N CONFUCT mm INE PROPOSED WORK. 33. me CONTRACTOR 9MU NOIIFr AFFECTED UHITr COUPAMfS (SCC BCLOWj AT LEAST 2 FULL MHiaiC DAYS PRIOR TO STARTING GRAOWG NEAR THEIR FAOUnCS AND SHALL COOROMATC THE MMX wm A COUPAMY RCPRCSCHTATIVe. UNDERGROUND SERVICE ALERT SOGtE PAOFTC SELL DUE WARNCR CABLE COX CDUUUMCADONS orr OF CARlSBAOfSTRCCIS A STORU ORAW; r3Tr OF CARlSBADfSCKR.tlUICR * RCCLAJUCD WATCR) 7AN OICGUIIO VAICR OlSIRiCr tCUCADIA ITASIEITAIER DISTRIcr -VALIEOTOS VAIER DISIRIcr «IVTNHAIN HATER DBIRKT «JENA SAMTATION DISTRICT •AS APPROPRIATE JI PERMIT COMPUANCE RCOUREMCNIS A, FOR OLMTRRTLCO CRADWC - TIC APPUCANT HIRES A CIVIL ENONEER. SOLS ENGINEER; AND/OR GEOLOGIST TO OVE IECHNICAL AOTKE. OBSERVE ANO CONTROL ME WRK IN PROGRESS /I1IS.T20 AS/ CARLSSAO MUKOPAL CODE. & PRIOR TO FMlAl APPROIfAl OF A GRAOWG PfRMIT - THC FaiOWNG REPORTS MUST BE SUBMITTED TO THE OFT CNOHCCR VIA Dt PROJCCT INSPECTOR IIS.IS.I20 A.1DI CARLSBAD UONIOPAL CODC: lAmr'/MD il«lT RESTART IB NO BLASTING 9MLI SC PCRFORMCO UNTU A VALID SIASDNC PERUT NAS SEEN OBTAMED FROM MC OTY OF CARlSSAa SUBMIT APPUCATION FDR aASIMC PERMIT HEU w ADvANce OF INC SCHCDUM; or BLASIMG OPCRADONS 19. r ANY AROMmOCICAL RCMUlrrS ARC DISmvmfD WTHIN ANr HORK DORWG CONSIRUCIION. qmiiimM.'i Ml" ffiSF aiiifi PERHiriEE WLL Nonrr THE orr CHONCCR: OPERADONS WU UNK. mc PERMITTEE HAS RECOVEO MIITIEN AUTHOnnr FROU mE OTr ENGINEER ro 00 sa 2a ALL OPERATIONS CONDUCTED (MIME STE DR ABJACCMT THCRfTct wauDINC IWRUINC UP. REPAIR, ARmvM. OEPARIURE OR OPCRAllON OF IRUCXS. EARTHMOVINC COUPMENT, CONSmuCnON EDUPUENT ANO ANr OTHER ASSOOAICD GRADING EOUPMENr SHAU ST (MTED TO mE PERIOO BCnCEN 7:00 AM, ANO SUNSET EACH OAr. MONOAr TNttl FROAr ANO NO EARTHMOVING OR GRADING CPCRAHOHS SHAU BE eONDUCIED ON KEEXENOS OR HOIOAIS ^A UST OF Onr NOUOAVS IS AVAUABLE AT IHf CMONEERmC OCPARIUCHT COUNTER,; lACrOR TO INF tokamiNccir (7SD)7S3-DI33 l7SDj744-D460 l7SD17S3-64eS (760)726-1340 FMAL REPORT sr SUPCRVISWC GRAOWG ENONCCR SrAlING AU GRADING IS COUPlCTC. ALL EROSKW CONTROL. SLOPE PLANTING ANO IRRIGADON ARE WSTALLCO IN CONFORMANCC Wm OTr CDOE AND DIE APPROVED PLANS ( OSFAIN SAMPLE OF COMPUANCE LETTER FROM orr ENONEERNG OEPARTa<ENT;L AS-SULT GRADING PLAN. REPORT FROM INE SOUS ENONEER MUCH mCLUOES RECOMMINOCO SOIL SCARWC CAPACIIICSL A SrATClCNT AS TO mc CAPANSIVE OUAUTY OF me sou. AND SUMUARFS OF nCLO AND LASORATORr lESIS mE REPORT SHALL ALSO wauDC A sTAicMENr sr mc sons ENGINEER IHAT INE a?A0ING WAS DONE M ACCORDANCE wm DT REOmREMEHTS AND ReCOUUCMOATKNS OUTUMCO IN TMC PRWUNARr SOLS XPORT ANO ANY SUPPLEMENTS mCRETO. REPORI wm As-sutr GEOLOOC PLAK r REOUHED Br mE orr. J<, UNLESS A GRADING PERMIT FOR DUS PROJCCT IS ISSUED MffUN ONE fll lEAR AFIER IHE orr ENONEIRS APPROVAL. mESE PLANS MAY 8E REOUIRED ro SE RESUBUITIED FOR PLANCHECK. PLANCMEOT FEES MU SE REOUIRED FOR ANr SUCH RECHECK. JS mC SOLS RtPORT nilfO PRtmiWtT CEOTECHMCM WDtSMAWM PREPARED «> . V»tlf VMinffl fiailttRIMC. >C. , OATEO .2ailt-, SHAU BE CONSIOERCD AS A PART OF DUS GRADING WAU BE DONE IN ACCOROANCC Mm mC l» (2) (V GRAOiNG PLAN, AU RCCOUMENOADONS AND SPEOFICAnONS COHTAIMCO W SAO SOUS REPORT, F1RM:_ ADORESS: 14*2 SECOW A»mjt StM atea. CA lEUPHONE: »n-u<.»<l«l BY- BRUCE HOetRnOM (NAME or ENGINEER; RCOSIRARON EIPIRADON DAIE: SOILS ENGINEER'S CERTIFICATE DOWS BOOIEWII . , A REOSTEREO (OVU/ GEOTECHNICAL) ENGINEER OF DfE STATE OF CAUFORNIA, PRINCIPAlLr DOING BUSINESS IN DIE FIELD OF APPLIED SOILS MECHANICS, NERCSr CERRFr mAT A SAUPUNG ANO STUOr OF mC SOIL CONDIDONS PREVALENT MTMIN miS SIIE WAS MADE Sr Mf OR UNDER Mr OIRCCTION BErwEEN IME OA TES OF JHIf 2O0li ANO UARCH JD4S_. THO COPIES OF mE SOILS REPORT COMPILED FROM IHIS STUOr, MIM ur RECOMAiENOAiiONs. MAS SEEN suSMiTrco ro mf OFFICE OF me CIIY ENGINEER. SKWED: G.E./R.E. NO.: DATC: MO UCCHSE E<PIRA DON DA TE: 22 IMPORT MATERIAL SHAU SE OBTAMED FROM, ANO nSIE MAIERlAL SHAIL BE OCPOSITED Ar. A STE APPROVQ) Br D< OTr CNONCER. mr rnMiRArnrw SHAIL BC RCSPONSjaie FOR ANT llfRRIS OR OAl/ACf nCCURRWC AI/WC IMF HAI. ROUES OR AOJACENr STRflTS AS A RfM T OF mr CTAD^ 23 BRUSH SHAIL Bf REUOVCO ONir WRVW INE AREA TO BE GRADED NO TREES ARE R> BE REMOVCO UNLESS SPEOFIOlir NOID ON DC PLAN. 24. AU AREAS 9IA1L Sf GRAOCO ID ORAHL GRADING RESU UMC IN TMC PONDING OF •WIER IS NOT PCRUtTTEA AU CARTMCN SHALES ANO OirChCS SHALL NAVE A umaiuu ONE PtRCCNJ SLOPE. 2i mESE PLANS ARE suSjtCT lo A SIGNED AND APPROVED SET or EROSION coHmoi PLANS EROSION eoHRHiL SHALL BE AS SHOMI AW AS APPROVED sr DC orr ENGMEER OR AS ORECKD sr mE PRoyecr MSPECTDR. 26. ALL SLOPES 9MU SE IRMUCO TO A FMSI GRADE TO PROOUCC A UNIFORM SURFACC AND CROSS SECDOK, INf SIE SHALL BE LfFT IN A NEAT ANO OROERLr CONOIDONl ALL SIONC^ ROOTS OR ODCR DEBRIS SHALL SE REUOVCO ANO DISPOSED or AT A STF AMKMB Or Sr TNE OPr ENONEER. 27, AU SLOPES SHAU SE IRMGAIEO. STA8IU2E0. PLANTED ANO/DR HyoROSCEOCD WIMN TEN FIO; DATS OF IHE DME IIHCN FACM SLOPE IS SROUCHT Dl CRAOE AS SHOHN ON DIE APPROVED GRAOINC PLANS 28 LANDSCAPING SHAU SE ACCDUPUSHCO ON AU SIOPCS ANO PADS AS REOURED sr me orr OF CARLSBAD LANDSCAPE MANUAL, DIE LANOSCAPINC PLANS roR D«S PROUECr. DRAWNG NO. . ANO^ AS OIRECTEO BY THC OTY CNONCER OR PIANNING DAfCHK OWNER'S CERTIFICATE I ( VC ) MCRCSr CfRDFr THAT A REGISTEREO SOUS ENONEER OR GCOLOCIST HAS SEEN DR Mil SC RCTAIMCD JO SUPERVISE OVER-ALL GRADING ACnvlTr AND AOVISE ON mE COMPACDON ANO STASIIITY OF mis STE, NOSURU TASATA DATE SOURCE OF TOPOGRAPHY TOPOCRAPNr SHOMI ON mESE PIANS WAS GENERA TCD Hr ACWIL SafilMf moos FROM WFDRMADON CADICRCO OW , 20 Br- EROSION CONTROI. NOTES Miirr RnRFRVM, -AT "DECURATION OF RESPONSIBLE CHARGE" I HERCSr DCCLARCmATI AU DIE ENONEER OF kORK FOR DUS PROJCCT, THAT I NAVE EAEROSEO RESPONSSIC CHARGE OVER DIE DESIGN OF DC PROJCCT AS OEFWCO H SECDON 6701 OF DC BUSINESS ANO PROFESSIONS CODE: ANO mAT mE OCSGN IS CONSISTENT Mm CURRENT STANDARDS I UNOCRSTANO DMT THC CHECK OF PROUECT ORAWNCS AND SPEOFTCADONS Br DIE orr or CARLSSAO DOES Nor REUEVE UC, AS ENGWECR or KWK, or Mr RESPONSIBIIIDES FOR PROJCCT DESW. «CC COHSI*l«WIS. MC TOPOCRAPNr SNDWI ICREON ACCURACr STANDARDS. PROJECT LOCATION CONFORMS TO NATUNAL UAP 1. m CASE EWERGENCr HORK IS REOmRCO, CONTACT .6!4i2LSi5I__ (PHONE NUMBER; 2. EOUPUENT ANO HORKCRS FOR EMERGENCr HOK SHAU SE UAOE AVULABLC AT AU DMCS OURINC mE RAINr SEASON. ALL NCCCSSARr UAIERIALS SHAU SE SroCKPlEO O) STE AT CONVEMENT LOCADONS TO FAC«ITAIC RAPlO CONSmoCDON OF lEMPOSARr Deuces HHEN RAW IS CUIMCMT. J. DEVICES SHOHN ON PLANS SHAU NOT BC MOVED OR ItOOlFiCO mlMOUJ THC APPROVAL OF THC ENONtERMC WSPfCTOR. 4. me CONTRACTOR SIAU RESroRE ALL CRDSim CONDIOl DEVICES ro HORXING OROCR TO mc SADSFACDON OF THE OFT ENGHtBI AFIER EACN RUN-OFF PROOOONC RAMFALL 5 mE CONTRACTOR SHALL INSTALL AOOIIKMAL SWSON CONDTOL MCASURCS AS MAY BC REOURED sr RC OIY CNGMCR DUE TD UKCOMPIEIEO GRADING OPERA DOHS OR UNFOtESECN ORCVMSrANCfS HMCN UAY ARSE 6. mc CONTRACTOR SMAU Sf RCSPONSIBLE ANO SHAU TAKE NECESSARr PRECAODONS TO PRfVENT PUBUC TRCSPASS ONTO AREAS HHERE teOUMDCD HATERS CREATE A HAZARDOUS CDMXDON. 7. AU ER090N CDNDia MCASURCS PROVCED PCR DC APPROVED CRAOWG PLAN SHALL Be WCDRPORAIED HEREON. a CRAOCO AREAS AROUND DIE PROfcr PERUCIIR MUST DRAW AWAr FROU DIE FACE OF SLOPE AT DC CDNauSON OF fACH HDRKWCOAr. 9. ALL HEMDVABIE PROIECDVE DEUCES SIDHN SHAU BC IN PLACE AT mE ENO OT EACH HORKWG DAr HHEN DC FIVC (S) DAY RAK PROBABUTY FORCCAST CXCeCDS FORTY PERCENT ^40*;. SHT AND ODIER DEBRIS SUU BE REMOVED AFIER EACH RAWFALL ID ALL GRAVEL SACS SHALL SE BURLAP rVPC MDI 3/4 INCH UMMUM ACCRCGRAIE. II. SHOlAD GfRUNADOH OF HIOROSfCOED SLOPES FAI TO PROMDE EFFECDVE COKRAGf OF GRADED SLOPES (MX COVERAGE; PRIOR ID ROVEMSER IS. DC SLOPES SHAU SE SFABiuJED Br PUNCH STRAW ttSTAiLCO u ACCORDANCE Mm SECDON ji02J OF DC EROSON ANO SEDIMENT CONTROL HANDBOOK OF DC DEPARDUENT OF COHSCRVATKM. STAIE or CAUFORMA TEMPORARY EROSION CONTROL PIANTINO AMn IRHrr.ATIOW AU PERMANENT ANO TEMPORARr CROSDN CONTRa AANDNG ANO KRIGADON SHAU BE WSTAUEO ANO UAIMTMHCD AS REOURED W SECDON 212 OF mE STANDARD specncATioNS ANO THC FOIIOHING: A HIDRDSEEOING SHAU BC APPUCD TO: I. AU SLOPCS mAT ARC GRAOCO 6:1 FH0RI20NTAL TO VERDCAL; OR STEEPER HHEN mcr ARE: a. DIREE FECr OR UORE W HEIGHT ANO ADJACENT TO A PUSUC WAIL OR STREE T. b. ALL SLOPES 4 FEET OR UORE IN HElOIT, 2 AREAS GRADED aAriER mAN 6:1 HNTN ANr DF DIE F10LLDWNC CONDIDONS E»ST: 0. NOT SCHEDULED FOR lUPROVEUERISfCONSDIUCnON OR GENERAL LANDSCAPING; MDIW 60 DAVS OF ROIA» GRADWC «. OENDFCO sr DC PARKS AMO RECREADON OlRECTOR AS HlOlir USBIE TO DIE PUSUC. C NAVE ANr SPECIAL COHOIDON I0CNDF1ED Sr DIE OFY CNONEER DMT WARRANTS mCDIA IE IRCAIUCNl a HyDROSETOEO AREAS SHALL SE ORICAIED N ACCORDANCE Mm DC FOUOWNC CWIERM: L AU SLOPES DMr ARE GRADED 6:1 01 STEEPER AND mAT ARE: OL mREE TD EIGHT FEET m HEKHT SHAU BE MRIGAIEO BY HAND WATERING FROM OUCK COUPIERS/MISE SOS OR A CONVENRONAL SYSTEM OF LOW PREOPITADDN SPRWnER HEADS PROVWNG lOOK COVERAGE. b. GREAIER DMN • FEET w HEIGHT SIAU BE WATERED Sr A CONVCNDONAL SVSTEM OF LOW FRECATADON SPRWKICR HEAOS PROWOWG IDOX COVERAGE, 2 AREAS SOPED LESS DMN 6:1 SIAU BE KRIGAIED AS APPROVED SY DC OTY CMONcen PRIOR ro HVDROSEEDMI DC DEVELOPER SHAU SUBMIT A PROPOSED SCHEME 10 PROMDE URICAJtON ID TKC OTY ENOWER, THE PROPOSAL SHALL BE SPEOFIC REGARDING DC NUMBERS TVCS AMD COSTS OF DC ELEMENTS OF DC DC PROPOSED SYSTEM, 3 IRRIGADON SHALL MAWTAIN DC UOSIURC Uva OF mC SOL AI THC OPDMUU LEVEL FOR THE GROwm DF mE HIWOSEEDED CBOwm, HIDROSEEDING MIX SHAU CONSSr OF ALL OF DC FDLLOHINC: 1. SEED MIX SHALL CONSST OF ND liSS mAK 0. 20 ttl. PER ACRE OF ROSf CLOVER «. » Ru. PER ACRE OF ZORRO FESCUE c. J kx PER ACRE or E SCHOU OA CALlTORMCA d. 4 »t. PCR ACRE or ACHILLEA MIUFOUA •. J ttf. PER ACRE or ALYSSUM FCARPCT or SNOW; 1. 1/2 16. PER ACRE OF 0IU0RP.<IOLf CA 9L ITEMS cit. ANO r OF TMS SUSSECDDN MAY BC OUITIED ON LOCADONS HHERE DC ARCA SCMC HWROSCEDEO IS MOT MSIBIE FROM CimER A PUSUC SOtEET OR RESOCNDAL STRUCIURCS H. ITCM 0 OF DHS SUSSECnON MUST SE MOOUIATED Mm A MnracEN FiaNG BACIERIA AAB APPLCD DRY ETDCR SYORHLMG OR BROADCASDNC SCFORC HOMtlSEEOnC L ALL SEED MATERIALS SHAU SE KANSPDRTED TD IHE JOSSTE IN UNOPENED CONIAttfRS Mm DC CALIFORMIA DEPARTMENT OF FOOD ANO AGRtCUR/Re CUUfKATIOH TAG AJIACHCO TO. OR PRMTED ON SAO CONTAMERS NON-PHYTo-roxe HcrnNc ACCNTS MAY BE ADDED ro mc HIDRDSEED SLURRY AT mf OSCIIEIIOH OF DC CONTACTOR, 2, TVPE I MULCH APPLIED AF DC RATE OF NO LESS DIAN 2000 Ito PER ACRE lYPC 6 MULCH FSDIAw; MAY BE SUBSDTUICD, AU OR PART. FOR HIDRAUUCAILY APPUED RSER UAIERlAL BHEN STRAW S USEO IT MUST SE ANCHORED ro mE SLOPE BY UCCMAMXMLY PUNCHING ND LESS DUN SOC OF DC SDIAV WTO THE SOIL. J, FERDU2ER CONSISDNG OF AWUOMIAI PHOSPHAIE SULFATE. 16-20-D. KTH ISX SUtfHUR APPUCD AT IMC RAIE OF 300 ltr PER ACRE, a AREAS TO SE NIDROSECOED 9IAIL SE PREPARED PRIOR TO HtORDSEEDWG SY: 1. ROUGHENWC DC SURFACf TO SE fllNIED BY ANY OR A COUSfNADOK OF; a DIACK WALKING SOPES SICCPER THAN 61 b. HARROWNG AREAS 6:1 OR ILATIER DMT ARE SUITKCNIIY FRlASl£ c RIPPING AREAS mAT WU MIT BREAK UP USING IDTUS o OR b ABOVE, 2, COtODOMNG mE SOILS SO DMT II S SUIABIC FOR PIANIWG SY: 0, ADJUSDNC mc SURFACf SOI MOSDIRf TO PROMOf A DAMP BUT NOT SAIURAIEO SEED BED b. DC AOOIRON OF SOIL AMENOHdlTS PH AOJUSItlCMT. (EACNWG CDVERWC SALINE SOILS TD MTOVOED tUBLE CONOinONS FOR GROwm E HYORDSCeOCD AREAS SHALL BE MAINTAMED TO PROMOE A VIGOROUS CROWm UNDl DIE DIE PROUECT IS PCRUANENaY LANDSCAPED OR. FOR AREAS MCRE HIDROSEEDING IS mE DC PERMANENT LANOSCAPWC UNDl DiC PROfCT IS COMPLEIED AND AU BONOS RClfASED. LEGAL-DESCRIPTION BEWC A SUSOMSKW OF PARCELS I ANO 2 OT F'RCa MAP NO 24SI. W INC OFY OF CARLSBAO. COUNTY or SAM UCCO. SJATC OF CAUFORM IMO « DC OTFICE OF DC COUNTY RECORDER OF SAN DCGO COUNIY ON MARCH 21. 1971 AS flf NO 71-071006. OFnOAL SECOROS GRADING PLANS FOR TABATA 10 CT 06-13 CITY OF CARLSBAD VICINITY MAP CCTY OF OCEAHSIDE WORK TO BE DONE IHE GRADMG HORK SHAU CmSST OF DC CONSDIUCDON OF ALL CUTS AND FILLS REMEDIAL OUDWG DRAINAGE FAOUDES EROSION CONDIa FAOLIDES ANO PIANDNG or FCniAMNT LANOSCAPmC ANO PREPARA DON Or AS-BULT GRADING PLANS. AS-BU*. r GEaOQC MAPS AND REPORTS AU AS SHOHN OR RCOUIRCO ON IMS SCT or PLANS AMI DCOTYsrAMMRos SPEOFICADONS REOUIREMCNTS RESOLUDONS ANO OROINAMCCS om OM iMCse PLANS DIE GRAOMC HORK SHALL SC PERFDRUEO W ACCDROAMX wm THE FOUOWNG DOCUUENTS CUaiENT AT DIE DME OF CONSnTUCDON. AS OKECIED SY THE orY ENCWEER, CARLSBAO IIUMOPAl COOE OTY or CARLSSAO ENONEfRHG STANOAROS mis SCT or PLANS sfsaunoNm 66DS Q^^QJULYJXXK THE STANDARO SICOF1CAD0NS FOR PUBUC HORKS CONSDIUCDON (CRECN SOOK;L sons REPORT ANO RCCOUUEMM DONS nr WJ MBOLEIPN EWONEERwq MC HATFIl MNC 21 2006 mc SAN BtCO RCOONAL STANDARD ORAWNCS AND AS MAY SE UODlFlCO BY DC OTY or CARLSBAO STAMIAROS CAUFORNU COASTAL COUMIS90N OEVELOPUENT PERMIT CONOIDONS DATED .AAYIS 2009 ft ENVIRONUEIITAL APPROVAL OOCUMEIFIS nAIFll JR Y IS ?009 ID SrORU HHP POUUDON PRCICNDON TSW II-2B7; PLAN PREPARED .y REC OWiUlfANlS wc n..rn MARCH 2011 CITY OF " • MARCOS SY. HOlO NO 9 J75 . STORM WATER UANAGCUCNr PUN (SMP 11-091 PREPARED ... o,-, ™ _ .... mirn uiRai 2011 nr RCC ODMATANIS INC 12. CALirORMA STOni MITER OUAUTY ASSOOADON SUP COHSTRUCTION HANDBOOK AMO CAL DUNS CONSRUCnOH SIE SMP MANUAL PACIFIC OCEAN LEGEND DESCRIPTION DWC-NO, SYMBOL QUANTITY cirr OF ENCiNirAS INDEX OF SHEETS SHEET I - nnr SHEET SHEET 2 - SECDONS ANO OETA«,S SCEr J - ROUGH GRAOINC PIAN SUSnrttSIIM BOUMDARY PROPOSED EVEVATMII PROPOSeO CONTOURS BROYtOITCN rtPC V now DiRccnoN PROPOSCB aOPE CXIST. SLOPE SHMIf FlOHCME srORU DRAW (24- Kf) SKKU DRAW (IB' PvCj nPE A~4 CLEAM OUT uaomen npcccs RIP RAP BKKEirvDIW AREA /KtAIHmC WAUS IB? Lr 109 IF D-9 D-1 D-40 . C-JtC-2 BENCH MARK DESCRIPnON:. LOCADON. EXISTING; EKISLCDPIOORS EnSLEtEwnONS C«si. DVCRHEAS CLCcmic UNE cnsr. siomi DRIIN SEWER uw SEWER MUNOIE WATER UAH GAS UNE TELEPHONE UC ; REFERENCE DRAWINGS CT BJ-25 DHCL 246 CUHD U-2a2 CT 9I-J DEC JJ3 CMHD a5-JD9 cr 91-2 OHt J2S CMHO 90-SOJ EARTHWORK QUANTITIES FU ?ySS cr IMPORT: ^^fff cr EXPORT: cr uwiUD nctTiaHT coimoi BOT TABU TYPI oiscRiPTnn OINIRSHir lUUKrlNlUICI ACniHEHT SHiir NO. HAlHttNANCI rRKUENa BIOUTIKTION SIDB or Ull UHUR BioRnnmoii no a tVERV 3 KONniS OR ArlDI DAIN ntHT PUTHATION UNtAR 9IUI OMER no t SAME a UlNDSCAPI FimUTIOK ptmiABU Ftnt ontx no > IVKRy TEAR msu rnuia pnoim JSSL REMEDIAL-SiSLELcr DHS PROJECT IS LOCATED MD«N ASSESSORS PARCCL MUUBCR(S) ZU-OSO-K t 33 DC CALIFgMA ODORD/NAIE WDEX OF PROJECT IS PLANNING DEPARTMENT APPROVAL UTL / / PIAIWINC DIKECTOS tat / / REVISION DCSCRIPTION GRADINC PUNS FOR: SHCCI 1 'AS BUILT" RCVICWCD BV< DATE CITY OF CARLSBAD 11 ENGINEERING DEPARTHENT J . TABATA 10 DTir ^HFrr APPROVED: GLCN K. VAN PESKI ENONttRWC UANACER PE 4H0« RPWtS 3/JI/I3 DAU OWN BT: _ CHKO BY:. RWIO BT:. PROJECT NO, CT 06-13 DRAWING NO, 472-7A Pi\Acrt(t\857 Tttboto ia\Grod!n9\GRa.«l^«g (0/28/2011 11-4201 AM Ptf PLATE I (SA) 5'PCC soewAui REF. mu (N/W) EJf. 12'STEEL VATEK UAIN PER 246-1 (LOCAHON VARIES) TO BE RCLOCA TEO PaOCAIEO 12 STEEL UMN CAMIHQ HILIS DRIVE NOT TO SCALE CULECTOR smeer FROU STA.IO+56.72 TO STA. 121-14.12 (SEE CITY DW. NO. 472-7) s'pccsaemx EX. 12' STEEL WATER UAIN PER 24S-I (LOCATION VARIES) TO BE RCLOCA TEO RELOCAJEO 12' STEEL A4AIN CAUINO Him DRIVt NOT TO SCALE COLLECTOR STREET FROU STA 12* 14.12 TO STA. IS*l7.SS (SEE arrow, NO 472-7) •MINIMUM SDTUCTURAL SECDON: A' AC/6" AB r,L-6.o I 6 5'PCC SIOEWlUt SDRSD fl-2 CURB * cariCR mm 2 WE cij--uis Evcur 10 NOT TO SCALE COLLECTOR STREET FROU STA.IS-H7.SS rO STA. 19+77.87 (SEE CITY DW. NO 472-7) •UIMUUM SIRUCniRAL SECnOK A" AC/6* AS r,L-&o J'PCC sntwiA- NOT TO SCALE COLLECTOR STREET FROU STA.I9+77.B7 TO STA 27-I-72.27 (SEE OTY OW. NO. 472-7) •MINIMUM SDIUCniRAt SfcnoN: 4' AC/6' AB r.l=6.0 DEEP ROOTEO, DENSE. DROUGHT TOUERANT PIANTMG SUITABLE FOR WELL ORAINED SOIL A 10 5 FOOT lAU RHNNING WAU PER SDRSO IS' ENONEEREO SOIL IUPERUEASLE UNER SIDES ANO BOTTOM 4' PERFOBAlEO PVC PIPE riE moRouooincAmN CONTROL ouncr PVC PIPE ro STORM DRAIN SYSTEM WOM FLOWS OUTLET PIPE SECTION A-A (SEC sen J) STREET "A" / BIORETENTION CROSS SECTION M.T.S. CURB OPENING DETAIL H.T.S. PUBLIC STREET REqUmCD IRElTyEHT COHniOL BMP TABLE DESCRIPnoll l)UMmTY CRASS SHAU 200 LF UIH./ PER Uir PEUIEABLE PAVn OfllVIHAT UP TD R0> PLAN - TYPICAL LOT GRADING PER GS-15 r=20' AS BUILT SHEET 2 CITY OF CARLSBAD I ENGiNEEniNG OEPARTUENT \ SHEETS 3 SHEET 2 CITY OF CARLSBAD I ENGiNEEniNG OEPARTUENT \ SHEETS 3 ! CRAOWC PLANS FOR: TABATA 10 N01CS ANO OCTAJLS CRAOWC PLANS FOR: TABATA 10 N01CS ANO OCTAJLS CRAOWC PLANS FOR: TABATA 10 N01CS ANO OCTAJLS CRAOWC PLANS FOR: TABATA 10 N01CS ANO OCTAJLS CRAOWC PLANS FOR: TABATA 10 N01CS ANO OCTAJLS APPROVED: GLEN K. VAN PESKI APPROVED: GLEN K. VAN PESKI EMOHECRmG UANACER PC 41304 EXP. 3/JI/t3 DATE DATC HHAL REVISION DESCRIPTION OAtt INIIIM 0AM HUM. OWN BY CHKD B RVWD B 1 PROJECT NO, 1 CT 06-13 DRAWING NO 472-7A ENONUf) or WORK REVISION DESCRIPTION citT Amovii OWN BY CHKD B RVWD B Y: 1 PROJECT NO, 1 CT 06-13 DRAWING NO 472-7A PLATE 2 I ©E@L@©ie CM© SCALE: 1" = 20' COMPACTED 130 PROPOSED GRADE (LOT 4} FORMATIONAL ROCK' ^ 130 120 ^ ,110 PROPOSED •GRADE (LOT 7] FORMATIONAL ROCK PLATE 4 V&M JOB #06-210-P APPENDIXA ViNTE & MIDDLETON ENGINEERING, INC. Job #06-210-P ""'^ Escondido. California 92029-1229 Phone(760)743-1214 June 23, 2006 Fax (750)739-0343 Tabata Family Trust c/o Mr. Gregg Harrington P.O. Box 943 Carlsbad, California 92018 PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD (A.P.N.'s 212-050-32 & 33) Pursuant to your request, Vinje and Middleton Engineering, Inc. has completed the enclosed Preliminary Geotechnical Investigation Report for the subject site. The following report summarizes the results of our field investigation, including laboratory analyses and conclusions, and provides recommendations for the proposed development as understood. From a geotechnical engineering standpoint, it is our opinion that the site is suitable for the planned residential subdivision and associated paving and underground improvements provided the recommendations presented in this report are incorporated into the design and construction of the project. The conclusions and recommendations provided in this study are consistent with the indicated site geotechnical conditions and are intended to aid in preparation of final development plans and allow more accurate estimates of development costs. If you have any questions or need clarification, please do not hesitate to contact this office. Reference to our Job #06-210-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of sen/ice to you. VINJE & MIDDLETON ENGINEERING, INC. Dennis Middleton CEG #980 DM/|t Preliminary Geotechnical Investigation Proposed 26-Lot Subdivision Camino Hills Drive Carlsbad, California (A.P.N.'s 212-050-32 & 33) June 23, 2006 Prepared For: TABATA FAMILY TRUST c/o Mr. Gregg Harrington P.O. Box 943 Carlsbad, California 92018 Prepared By: VINJE & MIDDLETON ENGINEERING, INC. 2450 Vineyard Avenue, Suite 102 Escondido, California 92029 Job #06-210-P TABLE OF CONTENTS PAGE NO. I. INTRODUCTION 1 II. SITE DESCRIPTION 1 III. PROPOSED DEVELOPMENT 2 IV. SITE INVESTIGATION 2 V. GEOTECHNICAL CONDITIONS 2 A. Earth Materials 3 B. Groundwater and Surface Drainage 4 C. Slope Stability 4 D. Faults / Seismicity 4 E. Geologic Hazards 7 F. Laboratory Testing / Results 7 VI. SITE CORROSION ASSESSMENT 13 VII. CONCLUSIONS 14 VIII. RECOMMENDATIONS 17 A. Remedial Grading and Earthworks 17 B. Foundations and Interior Floor Slabs 26 C. Post-tensioned / Structural Slab-on-Ground Foundations 28 D. Exterior Concrete Slabs / Flatworks 30 E. Soli Design Parameters 31 F. Asphalt and PCC Pavement Design 32 G. General Recommendations 34 IX. LIMITATIONS 36 TABLE NO. Fault Zone 1 Site Specific Seismic Parameters 2 Soil Type 3 Grain Size Analysis 4 TABLE OF CONTENTS (continued) Liquid Limit, Piastic Limit and Plasticity Index 5 Maximum Dry Density and Optimum Moisture Content 6 Moisture-Density Tests (Undisturbed Chunk and Ring Samples) 7 Expansion Index Test 8 Direct Shear Test 9 pH and Resistivity Test 10 Sulfate Test 11 Chloride Test 12 R-value Test 13 Years to Perforation of Steel Culverts 14 Removals and Over-excavations 15 Asphalt and PCC Pavement Design 16 PLATE NO. Regional Idea Map 1 Site Plan 2 Test Trench Logs / Boring Logs (with key) 3-11 Geologic Cross-Sections 12-14 Fault - Epicenter Map 15 Grain Size Analysis 16-17 Consolidation Tests 18-19 Typical Stabilization Fill or Retaining Wall 20 Isolation Joints and Re-entrant Corner Reinforcement 21 Retaining Wall Drain Detail 22 REFERENCES PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED 26-LOT SUBDIVISION CAMINO HILLS DRIVE, CARLSBAD (A.P.N. 121-060-32 & 33) I. INTRODUCTION The property investigated in this work includes an approximate 10-acre parcel located at the east terminus of Camino Hills Drive, adjacent to El Camino Real, within the City of Carlsbad. The site location is shown on a Regional Index Map enclosed with this report as Plate 1. We understand that the properly is proposed for a 26-lot residential subdivision with associated interior streets and underground improvements. Consequently, the purpose of this investigation was to determine soil and geotechnical conditions at the site and to evaluate their influence upon the planned development. Geologic mapping, test trench and boring excavations, as well as soil sampling and testing were among the activities conducted in conjunction with this effort which has resulted in the geotechnical grading and foundation recommendations presented herein. II. SITE DESCRIPTION A Preliminary Review Site Plan depicting existing topographic conditions and the proposed development scheme has been prepared by Pasco Engineering and is reproduced herein as Plate 2. As shown, much ofthe study property consists of gently sloping terrain that descends in a northeasterly direction to El Camino Real. An anomalous hill marks the northwest property margin adjacent to Camino Hills Drive. Previous grading activities for off-site developments have modified the property to include large graded slopes that ascend to residential developments along the southeriy and easterly site margins. The anomalous hill rises nearly 30 feet above surrounding areas with slope gradients that generally approach 2:1 (horizontal to vertical) maximum. The large graded slopes that mark the southerly and easterly site margins were constructed at 2:1 gradients maximum and range to nearly 50 feet high. Drainage terraces were noted in south and northeast portions of the graded embankments. Pre-development topography from San Diego Topographical Survey Maps No.'s 354-1677 and 354-1683 dated 1975 indicate the perimeter slopes are largely fill embankments with some fill-over-cut slopes. This was confirmed by shallow hand-dug test pits in selected areas of the slopes. Documentation pertaining to slope construction is not available for review. The symetrical hill in the northwesterly portion supports a residential dwelling and associated improvements. Portions of the southwest corner of the property are currently utilized for stockpiling irrigation supplies. Gently sloping areas of the property appear to have been previously used for agricultural purposes, but presently support a modest cover of grass and weeds. Perimeter graded slopes are well landscaped with large trees, shrubs, ) and assorted groundcover plants. ViNli- & MiODun oN 13N0iNi-:i-tiiNC,. INC. • 2450 Auto PinkWay • E-jcondidti, Cilifornia 92029-1229 • Phone (760)743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 2 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Site drainage sheetlfows in a northeasterly direction towards El Camino Real. Excessive scouring or erosion is not in evidence. III. PROPOSED DEVELOPMENT The existing dwelling and associated structures and improvements are planned for demolitiori to allow for the development of a 26-lot residential subdivision with interior roadways and underground improvements. Cut-fill grading techniques will be used to construct level building pads and roadway surfaces. Soils generated from the cutting of the northwest hill will be used as compacted fills placed in lower areas of the site. Vertical cut and fill depths will approach 30 feet and 15 feet maximum respectively. Planned new - graded cut and fill slopes will be modest embankments approaching 10 feet high maximum and are programmed for 2:1 gradients. Perimeter slopes will also be extended at the same gradients (2:1) below the existing toe levels to achieve adjacent pad grades that are approximately up to 6 feet lower. public Interior roadway improvements include a horseshoe-shaped private street that will provide access to individual lots from Camino Hills Drive at two locations. Construction plans are not available. However, future residential constructions are anticipated to consist of conventional wood-framed with exterior stucco buildings supported on shallow foundations with stem-walls and slab-on-grade floors, or slab-on-ground with turned-down footings. IV. SITE INVESTIGATION Subsurface conditions were chiefly determined by the excavation of 10 test trenches dug with a tractor-mounted backhoe and the excavation of 4 small-diameter test borings drilled with a truck-mounted rotary auger drill. A Geotechnical Boring Permit (#LM0N103949 dated May 3, 2006) was issued by the County of San Diego Health Department forthe two deep borings. All trenches and borings were logged by our project geologist who also retained representative soil and rock samples at selected locations and intervals for subsequent laboratory testing. Locations of exploratory excavations are shown on the enclosed Preliminary Site Plan, Plate 2. Logs of the excavations are included with this report as Plates 3-11. Laboratory test results are summarized in following sections of this report. V. GEOTECHNICAL CONDITIONS Much of the project site is modified by previous grading which has altered the original surface contours. Old topographic maps ofthe area indicate that lower, level areas of the site were previously characterized by a natural canyon that drained northward toward El ViNil=. & Mii-ini.i;rON liNCiNKi-.KiNC, INC, • 2450 Auro Park Wny • RwnLHiilo, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 3 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Camino Real, Grading of the area in the late 1960's leveled the site for agricultural purposes. Graded perimeter slopes in the south and east margins were constructed at a later date in support ofthe off-site development above. Consequently, the projiect site exposes natural formational and Terrace Deposit units that are mantled by surficial alluvial and fill deposits. A. Earth Materials The following earth deposits are recognized at the project site: Formafional Rock (Ts) - Eocene age formational rock units are present at shallow to modest depths in south and east portions ofthe property and found at depth beneath younger soil deposits in northerly areas. As exposed in our test excavations site formational rock consists predominantly of pale grey colored siltstone with local interbeds of sandstone. The rocks were typically found weathered soft in upper exposures and grade uniformly dense at depth. Project formational rocks are competent deposits with no indication of instability, and will adequately support planned fills, structures, and improvements. Terrace Deposit (Qt) - Natural Terrace Deposit soils were encountered in north and west portions of the property. The Terrace Deposits thicken northward and pinch out atop formational rocks to the south. Site Terrace Deposits largely consist of dark-colored clayey sands and were found in moist and loose to soft conditions near the surface grading more dense at depth. Noted exposures are stable units that will adequately support new fills, structures, and improvements. Fill - Alluvium (af-Qal) - Undifferentiated fill and alluvial soils occupy lower elevations of the project site approximately as shown on Plate 2. These soils consists chiefly of silty sands with clay and occur in a loose, and soft to medium dense condition. Compacted Fill (Caf) - Structural fill sections mark the south and east perimeter areas of the project site as shown on Plate 2. The fills are locally derived compacted sections that support off-site improvements above. Noted fill slopes at the site are provided with a good plant cover and do not evidence instability. Details of project earth materials are given on the enclosed Test Trench Logs and Boring Logs (Plates 3-11) and further defined in a following section herein. The indicated subsurface relationship is depicted on Geologic Cross-Sections enclosed herein as Plates 12-14. ViNii: JV MiiinLirrON ENCINUHKINI;. INC. • 2450 Auto P.nrkWay • liscondido, Calilbniia 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 4 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 B. Groundwater and Surface Drainage Subsurface water was encountered at depths of 33 and 32 feet below ground surfaces in borings B-2 and B-3 respectively. Elsewhere, groundwater conditions were not encountered to the depths explored. The noted groundwater is sufficiently deep and is not expected to impact the proposed grading as currently planned or the future stability of the developed property provided our recommendations are followed. However, the control of surface run-off and storm water is critical to the continuing stability of the property and graded surfaces. Water should not be allowed to pond on pad surfaces and over-watering of site vegetation may create overly moist to wet ground conditions near finish pad grades. Development of the property should include improved site drainage and construction of engineered surface drainage and storm runoff control facilities as indicated on the project drainage improvement plans. C. Slope Stability Southeriy and easterly site perimeters are marked by 2:1 gradient graded slopes constructed to support residential developments above. Documentation pertaining to the slope construction is not available for review. Older topographic maps indicate the slopes range from fill slopes to fill over cut slopes. These slopes are well landscaped and were carefully inspected by our project engineering geologist. The graded embankments are performing well and do not evidence slope instability. Pad constructions will lower the grades adjacent to the southerly and easteriy embankments where slopes will continue to descend at 2:1 gradients to an additional maximum height of 6 feet The new toe embankment should be reconstructed as a graded stabilization fill slope as recommended in the following sections. Alternatively, a retaining wall may be constructed at the base ofthe slope in orderto achieve design grades and assure stability ofthe existing embankments. New graded slopes planned in connection with the site development are generally minor to modest embankments programmed for 2:1 gradients. New graded slopes will be grossly stable with respect to shallow and deep-seated failures provided slope construction recommendations, specified in the following sections, are followed. D. Faults / Seismicity Faults or significant shear zones are not indicated on or near proximity to the project site. 1 ,icA A iv,.,i. Ml... . i: /•"„(.(".. :,. L^nrtii\ i no - in.. /nriw mi i -i i J PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 5 JUNE 23, 2006 As with most areas of California, the San Diego region lies within a seismically active zone; however, coastal areas of the county are characterized by low levels of seismic activity relative to inland areas to the east. During a 40-year period (1934-1974), 37 earthquakes were recorded in San Diego coastal areas by the California Institute of Technology. None ofthe recorded events exceeded a Richter magnitude of 3.7, nor did any of the earthquakes generate more than modest ground shaking or significant damages. Most of the recorded events occurred along various offshore faults which characteristically generate modest earthquakes. Historically, the most significant earthquake events which affect local areas originate along well known, distant fault zones to the east and the Coronado Bank Fault to the west. Based upon available seismic data, compiled from California Earthquake Catalogs, the most significant historical event in the area of the study site occiirred in 1800 at an estimated distance of 10.0 miles from the project area. This event, which Is thought to have occurred along an off-shore fault, reached an estimated magnitude of 6.5 with estimated bedrock acceleration values of 0.129g at the project site. The following list represents the most significant faults which commonly impact the region. Estimated ground acceleration data compiled from Digitized California Faults (Computer Program EQFAULT VERSION 3.00 updated) typically associated with the fault is also tabulated: TABLE 1 l.77m:W. Maxirn.urn •.:;....-';ProJi>aBle,,.;^ ,• Rose Canyon 6.6 miles 0.210g Newport-Inglewood 8.2 miles 0.182g Coronado Bank 22.6 miles 0.175g Elsinore-Julian 22.6 miles 0.150g The location of significant faults and earthquake events relative to the study site are depicted on a Fault - Epicenter Map enclosed with this report as Plate 15. More recently, the number of seismic events which affect the region appears to have heightened somewhat. Nearly 40 earthquakes of magnitude 3.5 or higher have been recorded in coastal regions between January 1984 and August 1986. Most of the earthquakes are thought to have been generated along offshore faults. ViNii- & Minni.in oN RNC;INI;I;IMN(„ INC. • 2450 Aiim P.nk Way • llscondido, Caliiornia 02029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 6 26-LOT SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD JUNE 23, 2006 For the most part, the recorded events remain moderate shocks which typically resulted in low levels of ground shaking to local areas. A notable exception to this pattern was recorded on July 13, 1986. An earthquake of magnitude 5,3 shook County coastal areas with moderate to locally heavy ground shaking resulting in $700,000 in damages, one death, and injuries to 30 people. The quake occurred along an offshore fault located nearly 30 miles southwest of Oceanside. A series of notable events shook County areas with a (maximum) magnitude 7,4 shock in the early morning of June 28, 1992. These quakes originated along related segments of the San Andreas Fault approximately 90 mites to the north. Locally high levels of ground shaking over an extended period of time resulted; however, significant damages to local structures were not reported. The increase in earthquake frequency in the region remains a subject of speculation among geologists; however, based upon empirical information and the recorded seismic history of County areas, the 1986 and 1992 events are thought to represent the highest levels of ground shaking which can be expected at the study site as a result of seismic activity. In recent years, the Rose Canyon Fault has received added attention from geologists. The fault is a significant structural feature in metropolitan San Diego which includes a series of parallel breaks trending southward from La Jolla Cove through San Diego Bay toward the Mexican border. Test trenching along the fault in Rose Canyon indicated that at that location the fault was last active 6,000 to 9,000 years ago. More recent work suggests that segments of the fault are younger having been last active 1000 - 2000 years ago. Consequently, the fault has been classified as active and included within an Alquist-Priolo Special Studies Zone established by the State of California. Fault zones tabulated in the preceding table are considered most likely to Impact the region of the study site during the lifetime of the project. The faults are periodically active and capable of generating moderate to locally high levels of ground shaking at the site. Ground separation as a result of seismic activity is not expected at the property. For design purposes, site specific seismic parameters were determined as part of this investigation in accordance with the California Building Code. The following parameters are consistent with the indicated project seismic environment based on site specific study and our experience with similar earth deposits in the vicinity of the project site, and may be utilized for project design work: ViNii- & Mmni.in oN 1:NC.INI-I-IUN«;. INC. • 2450 Amo Park Way • Hscimdido. California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGE 7 JUNE 23, 2006 TABLE 2 ; Pr^lP: i •• ••.;26heV •; "SfeteiTiiji',^ • Factbr;- Selisrpfp.-"'' : Siel8iii.ib;jiesp6^^^^ ; Pr^lP: i •• ••.;26heV •; "SfeteiTiiji',^ • Factbr;- Selisrpfp.-"'' ' •M •'• Ga :;:"T?,.-" to • So 4 0.4 B 1.0 1.0 0.44 0.64 0.582 0.116 According to Chapter 16, Divisions IV & V of thie 2001 California Building Code. A site specific probabilistic estimation of peak ground acceleration was also performed using the FRISKSP (T. Blake, 2000) computer program. Based upon Boore et al (1997) attenuation relationship, a 10 percent probability of exceedance in 50 years was estimated to produce a site specific peak ground acceleration of 0.32g (Design-Basis Earthquake, DBE). The results were obtained from the corresponding probability of exceedance versus acceleration curve. E. Geologic Hazards Geologic hazards are not presently indicated at the project site. Perimeter graded slopes are performing well with no indication of gross shallow or deep-seated instability. The most significant geologic hazards at the property will be those associated with ground shaking in the event of a major seismic event. Liquefaction or related ground rupture failures are considered remote to none provided our remedial grading and ground stabilization recommendations are followed. F. Laboratory Testing / Results Earth deposits encountered in our exploratory test excavations were closely examined and sampled for laboratory testing. Based upon our test trench and borings, standard performing penetration tests (SPT), field exposures and site soils have been grouped into the following soil types: TABLE 3 .'>:-^-.7:-ii 7,\'':y 7...: . V-^bi^irlptlbri,^:.-7.'.-.'^. '•^••^\.7 1 pale brown sandy clay / clayey sand (Fill/Topsoil) 2 red-brown clayey sand (Alluvium) 3 red-brown medium to coarse sand w/ trace clay {Fill/Topsoil/Alluvium) 4 grey silty clay / siltstone/ claystone (Topsoil/Formationai Rock 5 grey / yellow-tan fine sand w/ trace clay (TopsoiiyFormationat Rock/Terrace) ViMir fi Mtnnu-.roN BNC.iNi;nKiNC. INC. • 2450 Amo Park Way • liscondido. California 92029-1229 • Phone (760)743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 8 JUNE 23, 2006 The following tests were conducted in support of this investigation: 1. Standard Penetration Test: Standard penetration tests (SPT) were performed at the time of borehole drilling in accordance with the ASTM standard procedure D-1586. The procedure consisted of a standard 51 MM outside diameter sampler, 457 MM in length and 35 MM in inside diameter, sampler driven by a 140-pound hammer mechanically dropped 30 inches using 5-foot long AW drill rods. The bore hose was 200 MM (8 inches) in diameter and water was added for bore hole support and aiding drilling. The test results are indicated at the corresponding locations on the Boring Logs. 2. Grain Size Analysis: Grain size analyses were performed on representative samples of Soil Types 1, 2, 4, and 5. The test results are presented in Table 4 ahd graphically presented on the enclosed Plates 16 and 17, TABLE 4 Sieve Size %" #10 #40 Location Soil Type Percent Passing T-1 @ r 1 100 9? 97 94 89 ,-• 64 ;-. T-1 @ 4' 2 100 . 100 97 ••^8:,..:. 76 '••:;:7m.77 T-3 @ 3' 4 100 ;;-'i^i^::-;; 100 V;'f99:;r,: 98. T-2 @ 5' 5 100 99 86 Liquid Limit. Plastic Limit and Plasticity Index: Liquid limit, plastic limit and plasticity index tests were performed on representative samples of Soil Types 1,2,4, and 5 in accordance with ASTM D-4318, The test results are presented in Table 5, TABLE 5 • LocatLo^ :.: vSdlliliyiS^- l4 J iqlJli|;tirtiit' m!7iamir:- f; fila^ticillimiif -Plasticity Ifidex ••/(feiiilirli;:)^ T-1 @ r 1 45 24 21 T-1 @ 4" 2 32 16 16 T-3 @ 3' 4 49 27 22 T-2 @ 5' 5 36 25 11 ViNin & MinOMiTON I-:N(1IN|-I^IUNI;. INC. • 2450 Amo Park Way • liscondido. Catifornia 92029-1229 • Piione (760) 74.1-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 9 JUNE 23, 2006 4. Maximum Dry Density and Optimum Moisture Content: The maximum dry density and optimum moisture contents of Soil Types 2, 4 and 5 were determined in accordance with ASTM D-1557. The test results are presented in Table 6, TABLE 6 77.4-^^xysM^Si^i}Ji ^^<^07. 7 . ' jyiakiitiun^piy: bptimaiti lUjoijBtujre T-1 @ 4-2 129.6 10.4 T-3 @ 3* 4 110.5 19.8 T-2 @ 5' 5 119.5 12.5 5. Moisture-Density Tests (Undisturbed Chunk and Ring Samples): In-place dry density and moisture contents of representative soil deposits beneath the site were determined from relatively undisturbed chunk samples using the water displacement test method, and undisturbed ring samples using the weights and measurements test method. The test results are presented in Table 7 and tabulated on the enclosed Test Trench Logs and Boring Logs. TABLE 7 |;i:^Siiftiiiii^^£i 'x77i^77:7 If few;,"; pp)||tti(rg.;_^; yiDensiiy--;; ^^^^G07 T-1 @ 2' 1 18.5 100.8 -- T-1 @ 4' 2 12.9 104.1 129.6 80.4 T-1 @ 7' 2 15.4 103.4 129.6 79.8 T-1 @ 9" 2 8.2 112.3 129.6 86.7 T-1 @ 11' 2 7.8 119.3 129.6 92.1 T-1 @ 13' 3 9.7 102.8 -- T-1 @ 15' 3 14.1 103.5 -- T-2 @ 3' 5 16.6 101.0 119.5 84.5 T-2 @ 5' 5 23.6 89.8 119.5 75.1 T-2 @ 8' 5 18.8 107.8 119.5 90.2 VlN|l-. & MilM)l KION KNC,lNI-.i;itlNc-,, INC. • 2450 Amo Park Way • li<condido, Cilifornia 9202'->-l229 • Phone (760) 74.^-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 10 JUNE 23. 2006 TABLE 7 (continued) T-2 @ 10' 5 17.4 114.3 119.5 95.6 T-3 @ 3' . 4 28.6 88.0 110.5 79.6 T-3 @ 5' 4 27.8 88.8 110.5 80.4 T-3 @ 7' 5 18.4 100.6 119.5 84.2 T-4 @5' 4 22.0 106.0 110.5 95.9 T-4@8' 4 22.4 108.0 110.5 97.7 T-4 @ 10" 4 21.2 106.9 110.5 96.7 T-5 @ 5" 2 11.9 109.0 129.6 84.1 T-5 @ 8" 2 13.1 110.8 129.6 85.5 T-5 @ 10' 2 13.9 106.8 129.6 82.4 T-5 @ 14-2 13.5 108.5 129.6 83.7 T-5 @ 16" 5 16.0 102.6 119.5 85.8 T-6@7' 5 13.3 105.5 119.5 88.3 T-7 @ 4' 1 26.1 88.9 -- T-7 @ 7' 5 18.9 99.3 119.5 83.1 T-7 @ 10' 5 25.2 92.8 119.5 77.6 T-7@ 12' 1 22.5 98.3 -- T-7 @ 14' 1 25.7 95.7 -- T-8 @ 5' 2 11.9 101.6 129.6 78.4 T-8 @ 8' 2 12.7 113.9 129.6 87.9 T-8 @ 11' 2 12,2 104.1 129.6 80.3 T-8@12yi' 5 23.7 94.9 119.5 79.4 T-9 @ 5' 5 18.3 96.1 119.5 80.4 T-9 @ 7' 5 12.2 110.6 119.5 92.6 T-9 @ 10" 5 13.1 110.9 119.5 92.8 T-9 @ 12' 5 16.9 99.1 119.5 83.0 T-9 @ 14' 5 17.9 99.3 119.5 83.1 T-9 @ 15' 4 24.3 97.3 110.5 88.1 ViNiii & Minni.inoN liNciNinuuNC. INC. • 2450 Auto Paik Way • liseondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE. CARLSBAD PAGE 11 JUNE 23. 2006 TABLE 7 (continued) B-1 @ 4" 2 . 17.4 113.8 129.6 87.8 B-2 @ 14' 2 18.3 110.1 129.6 84.9 B-2 @ 24' 5 16.9 114.6 119.5 95.8 B-3 @ 4' 2 9.0 113.2 129.6 87.3 B-3 @ 14' 2 9.7 113.8 129.6 87.8 B-3 @ 24* 5 16.2 109.5 119.5 91.6 B-3 @ 34' 5 20.3 110.7 119.5 92.6 B-4 @ 9' 5 11.7 106.2 119.5 88.8 B-4 @ 19' 5 5.8 109.5 119.5 91.6 * Designated as relative compaction for structural fills. Minimum required relative compadion for structural fill is 90% unless otherwise specified. 6. Expansion Index Test: Three expansion index tests were performed on representative samples of Soil Types 1, 4, and 5 in accordance with the California Building Code Standard 18-2. The test results are presented in Table 8. TABLE 8 7 $$i^e^^ • jS^ifijil^ieyV: .V Saturation v.^>m77^ 'Safijiif^te'dt.^ U-mM^7k €^^^h^i.)bn;. T-1 @ r 1 14.8 51.2 31.8 112 higti T-3 @ 3' 4 16.3 50.0 40.1 103 high T-2 @ 5' 5 11.5 49.7 24.4 46 low T-6 @ 6' 5 9.6 51.0 21.2 59 medium (to) = moisture content in percent. Direct Shear Test: Three direct shear tests were performed on representative samples of Soil Types 2, 4, and 5. The prepared specimens were soaked overnight, loaded with normal loads of 1, 2, and 4 kips per square foot respectively, and sheared to failure in an undrained condition. The test results are presented in Table 9. V|N|l-;&. Mmni.inoN lENCINIinuiNC. INC. • 2450 Amo Park Way • l^scondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION. CAMINO HILLS DRIVE. CARLSBAD PAGE 12 JUNE 23. 2006 TABLE 9 ^cSbJI^^ rdettsltyl; ^:'(l^tt T-1 @ 4' 2 remolded to 90% of Ym @ % wopt 127.8 32 75 T-3 @ 3' 4 remolded to 90% of Ym @ % wopt 117.9 23 280 T-2 m 5' 5 remolded fo 90% of Ym @ % ooopt 120.9 28 166 8. pH and Resistivity Test: pH and resistivity of representative samples of Soil Types 1 and 4 were determined using " Method for Estimating the Service Life of Steel Culverts," In accordance with the California Test Method (CTM) 643. The test results are presented in Table 10. TABLE 10 M ^ Wlnimutt) l^esisti^ltvitbHi^^jiik ^ ^ 7^:.him7'7'':'. T-1 @ 1' 1 504 6.2 T-3 m 3' 4 381 6.5 9. Sulfate Test: Sulfate tests were performed on representative samples of Soil Types 1 and 4 in accordance with the California Test Method (CTM) 417. The test results are presented in Table 11. TABLE 11 7.1;:. ArnoMntofiVViStt>r^oiab)e;S^ in;S(oH :(%;bVJvii^ifl;htv ••"•;."•-:; 1 T-1 @ r 1 0.052 1 T-3 @ 3' 4 0.060 10. Chloride Test: Chloride tests were performed on representative samples of Soil Types 1 and 4 in accordance with the California Test Method (CTM) 422. The test results are presented in Table 12. ViNji; & MiDDLinoN liNtiiNiii-iitNU, INC. • 2450 Auro Paik Way • liscondido. California 92029-1229 • Plionc (760) 743-T2I4 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 13 JUNE 23, 2006 TABLE 12 Slaitipie. li.oc9jtion.;. I '^^ijvfypjfr;;;; : AniMnt bf-VVater£idiubte Ch^^^^ • ' V In Soit(% bv Weight) T-1 @ r 1 0.007 T-3 @ 3* 4 0.006 11. Consolidation Tests: Consolidation tests were performed on a representative remolded sample of on-site Soil Type 2. The test result is graphically presented on the enclosed Plate 19-20. 12. R-valuc Test: One R-value test was performed on a representative sample of Soil Type 1 in accordance with the California Test 301. The test result is presented in Table 13. TABLE 13 ; Location sbiiTyjpti, •Oesbrlptien . R^va|u0 T-1 @ 1' 1 brown sandy clay/clayey sand 5 VI. SITE CORROSION ASSESSMENT A site is considered to be corrosive to foundation elements, walls and drainage structures if one or more of the following conditions exists: * Sulfate concentration is greater than or equal to 2000 ppm (0.2% by weight). * Chloride concentration is greater than or equal to 500 ppm (0.05 % by weight). * pH is less than 5.5. For structural elements, the minimum resistivity of soil (or water) indicate the relative quantity of soluble salts present in the soil (or water). In general, a minimum resistivity value for soil (or water) less than 1000 ohm-cm indicates the presence of high quantities of soluble salts and a higher propensity for corrosion. Appropriate corrosion mitigation measures for corrosive conditions should be selected depending on the service environment, amount of aggressive ion salts (chloride or sulfate), pH levels and the desired service life of the structure. Laboratory test results performed on selected representative site samples indicated that the minimum resistivity is less than 1000 ohm-cm suggesting a potential for presence of high quantities of soluble salts. However, test results further indicated pH is greater than ViN)i: & MII)1)I.I:TON HNCINI-IIIKINC. INC. • 2450 Amo Park Way • IL-icondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 14 JUNE 23, 2006 5,5. sulfate concentration is less than 2000 ppm, and chloride concentration is less than 500 ppm. Based on the results of the corrosion analyses, the project site may be considered non-corrosive. Conformation testing should be completed during the actual earthworks and grading operations to further verify site corrosion conditions. The project site is not located within 1000 feet of salt or brackish water. Based upon the result of the tested soil sample, the amount of water soluble sulfate (S04) was found to be 0,052 to 0.060 percent by weight which is considered negligible according to the California Building Code Table No, 19-A-4. Portland cement Type 11 may be used. Table 14 is appropriate based on the pH-Resistivity test result: TABLE 14 :pes|giii3(^i|5|V|ji^ki; '•79-7 1 Years to Perforation of Steel Culverts 5 6 8 11 14 17 4 Years lo Perforation of Steel Culverts 6 7 9 13 16 20 Vll. CONCLUSIONS Based upon the foregoing investigation, development of the study site into an 26-lot residential subdivision with the associated internal roadway and underground improvements is feasible from a geotechnical viewpoint. Adverse geologic conditions which could preclude site development were not indicated at the property. The following factors are unique to the property and will most impact project development procedures from a geotechnical viewpoint: * Slope instability or geologic hazards are not present at or near the project site and will not be a factor in site devolvement. * The property is chiefly a graded site developed to its existing lines and grades for agricultural purposes in the late 1960's. Grading documents including engineering observations and compaction testing records of prior earthworks operations at the site, are not available, * Much of the property is occupied by a modest to thick section of undifferentiated fill/alluvial soil (see mapped areas "af-Qal" on Plate 2). These soils occur in a loose to soft condition particularly in near-surface exposures. Post construction compression and settlement ofthe these deposits are considered to be the primary geotechnical concern at the study site. Consequently, ground stabilization and ViNfi; & Miiini.in oN l-:N(iiNi;i:uiNC.. INC. • 2450 Auro Park Way • liwindidi), California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 15 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 remedial grading earthworks mitigation of the underlying loose to soft soils will be required as a part of project development in order to create safe and stable building surfaces as detailed in the following sections. Post construction settlement of site fills/alluvium after development is not expected to exceed approximately IK inches, and should occur below the heaviest loaded footings. The magnitude of post construction differential settlements of site fills/alluvium (as expressed in terms of angular distortion) is not anticipated to exceed V4-inch between similar elements, in a 20-foot span. * Remaining areas of the site are mostly underlain by formational rocks or Terrace Deposit units (see mapped areas "Ts" and "Qt" on Plate 2). These are suitably dense units and will provide adequate support for the planned new fills, structures and improvements. * Perimeter embankments at the project property are predominantly compacted fill slopes (designated as "Caf in Plate 2) constructed as a part of upper development. The existing perimeter embankment slopes are provided with a well-established cover of vegetation, and have performed well since their construction with no evidence of gross instability. Some additional undercutting is proposed to a maximum height of 6 feet in the south corner of the project (see Plate 20). The lower exposed slopes should be constructed as stabilization fills as recommended in a following section herein. Alternatively, a retaining wall may be constructed in the impacted areas in order to achieve final design grades and enhance the overall gross stability of site embankments, * Soils generated from project fills/alluvium excavations will predominantly consist of marginal quality piastic clay soils which can be detrimental to site structures and improvements if they occur within upper finish pad grades. Excavations of site Terrace Deposits underlaying the northwestern hill are expected to generate better quality low expansive sandy soils. Site marginal quality plastic clayey soils should be buried within deeper fills, and better quality sandy soils available from the excavation of project Terrace Deposits may be placed at finish pad grades using select grading techniques. Alternatively, good quality sandy granular import soils may also be considered to cap the building pad areas. * Plastic clayey soils typically require added processing, moisture conditioning and mixing efforts in order to manufacture a uniform mixture suitable for reuse as new site compacted fills. Potentially expansive clayey soils typically result in thicker pavement sections and will require special geotechnical engineering mitigation and foundations/slab designs which may include presaturation of subgrade soils, deeper foundations and thicker slab-on-grade floors, or post-tensioned / structural VINJJ: &. MiDiM.ivroN KNCINIU-KINC. INC. • 2450 Amo Park Way • Kscondido, California 92029-1229 • Phone (760) 74.VI214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 16 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 slab-on-ground foundations if they occur within upper pad grades. Capping the site with better quality on-site sandy soils or good quality sandy granular import soils will allow the use of more conventional foundations/slab designs and improve pavement structural sections. Moisture sensitive expansive soils and related periodic soil heaving-shrinkage is also considered a major geotechnical concern at the study site. Based on the available laboratory test results and noted site conditions, final bearing and subgrade soils may be anticipated to consist of silty sandy clay to clayey silty sand (SC/CL) with low to high expansion potential (expansion index less than 131) according to the California Building Code classification (Table 18A-I-B). Actual classification and expansion characteristic of the finished grade soil mix can only be provided in the final as-graded compaction report based on proper testing of foundation bearing and subgrade soils when rough finish grades are achieved. Foundation bearing and subgrade soils at finish pad grades should be additionally tested at the completion of rough grading to evaluate actual expansion characteristic of final soil mixture and confirm foundations and slab designs. Uniform bearing conditions should be constructed under the proposed buildings, structures and improvements. For this purpose, added removals of cut ground will be necessary in the case of cut-fill pads which expose formational rock or natural soils, so that uniform soil conditions are constructed throughout the buildings and improvement surfaces. Groundwater was encountered at the depth of 33 feet below the planned Lot 24 and 32 feet within the alluvial soils (B-3) feet along the easternmost portions of the site below the planned street improvements measured from the existing ground surfaces. Elsewhere at the site, groundwater was not encountered in our exploratory excavations to the depths explored. Natural groundwater conditions at the site occur at depth and is not expected to Impact project grading or long term stability of the developed property. However, the proper control of surface drainage and storm water is an important factor in the continued stability of the property. Ponding should not be allowed on graded surfaces, and over-watering of site vegetation should be avoided. Subsurface drains should be provided in stability fills and behind retaining walls(if any planned) as recommended below. Site grading and earthwork constructions will not impact the adjacent properties provided our recommendations are incorporated into the final designs and implemented during the construction phase. Appropriate setbacks shall be maintained, and temporary excavation slope constructions completed as recommended below. Added field recommendations, however, may also be ViNiu et MIIH>I.I:TON IENC,INI;UKINI;, INC. • 2450 Amo Park Way • l-scondido. California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 17 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 necessary and should be given by the project geotechnical consultant for the protection of adjacent properties and should be anticipated. Local groundwater conditions were found to be deep, and a thick section of overburden soils surcharges the impacted areas. Elsewhere over the majority of the property, groundwater was not recorded to the depths explored and formational units occur at the surface or at shallow to modest depths. Additionally, ground stabilization techniques using earth reinforcement Geogrid, and removal and recompaction of foundation bearing and subgrade soils are recommended in connection with the site development as specified below. Consequently, liquefaction of the locally saturated alluvial soils below the water table (primarily areas of boring B-3, see Plate 2) is not considered a major geotechnical concern at the project property. Liquefaction and secondary affects such as seismically induced settlements, lateral spreading and flow slides are considered unlikely to remote provided our ground stabilization and remedial grading recommendations specified in the following sections are followed. Loose to soft surface fill/alluvial deposits are potentially collapsible and compressible, and should be regraded as recommended below. VIII. RECOMMENDATIONS The following recommendations are consistent with the indicated geotechnical conditions at the project site and should be reflected in final plans and implemented during the construction phase. Added or modified recommendations may also be appropriate and can be provided at the final plan review phase: A. Remedial Grading and Earthworks The most effective method to mitigate upper loose to soft soils and accelerate compression of the underlying untreated deposits during the construction phase periods is remedial grading removal and recompaction techniques, and compacted fill surcharging as recommended below. All grading and earthworks should be completed in accordance with the Appendix Chapter 33 of the California Building Code, City of Carlsbad Grading Ordinances, the Standard Specifications for Public Works Construction and the requirements of the following sections: ViNiii & MiDDLinoN RNCINI:UKINC., INC. • 2450 Amo l>.i,k Way • F,^condido,O.ilifoinia 92029-1229 • Phone (760) 74.VI214 I I I I I I I 1 I I i I I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 18 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 1. Clearing and Grubbing - Surface vegetation, trash, deleterious materials, and construction debris generated from the demolition of existing structures / improvements and other unsuitable materials should be removed from the areas proposed for grading, new fills, structures and improvements plus 10 feet outside the perimeter, or as directed in the field, and properly disposed of. Construction debris and site vegetation shall be allowed to contaminate the new site fills. All irrigation lines and existing leach lines, septic tanks, pipes and structures should be properly removed from the construction areas. Existing underground utilities in the construction areas should also be pot-holed, identified and marked priorto the actual work. Abandoned irrigation lines should be properiy capped and sealed off to prevent any future water infiltrations into the foundation bearing and subgrade soils. Voids created by the removals ofthe abandoned underground pipes, tanks and structures should be properly backfilled with compacted fills in accordance with the requirements of this report. The prepared ground should be inspected and approved by the project geotechnical engineer or his designated field representative prior to remedial grading work. 2. Removals and Over-excavations - Uniform and stable bearing soils conditions should be constructed under the planned new buildings and site improvements and limit potential fill soil settlements within tolerable limits as specified. For this purpose, removal and recompaction of the upper fills/alluvium to firm native ground or competent formation units where these deposits occur at shallower depths and removal and recompaction with ground stabilization techniques using earth reinforcement Geogrid placed at the bottom of over-excavations, should be considered. Approximate removal depths in the vicinity of individual exploratory excavations are summarized in Table 15 and depicted on the enclosed Plate 2 based upon site soil conditions and proposed grades. The tabulated values are typical and subject to field changes by the project geotechnical consultant based on actual field exposures. Locally deeper removals may be necessary and should be anticipated. VlN|i; & Minni-inoN IiNc;iNi-i:illNC., INC. • 2450 Amo Park Way • Hscondido, Cnlilornia 92029-1229 • Phone (760) 743-1214 I I I I I I I I I I I I I I I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD PAGE 19 JUNE 23, 2006 TABLE 15 ^ LocatfOTI: Total Depth (ft) Estimated Depth to Ground- waterfft)..: Estimated- ftembvai (ft) T-1 not encountered 9' Lot 13 - private sfreet improvement areas. T-2 10V4' not encountered 7' Lot 8 areas. Depth of undercut may govern. T-3 9' not encountered 8' Lot 5 areas. Depth of undercut may govem. Reconstruct toe slope as a stability fill. T-4 w/2 not encountered 6' Lot 2 areas. Depth of undercut may govern. T-5 1614' not encountered 9' Lot 25 areas. Depth of undercut may govern. T-6 8' not encountered 3' Lot 22 areas. Depth of undetxajt may govern. Stockpile better quality sandy soils from Terrace Deposit excavations for capping the pads. T-7 1414' not encountered 7' Fill slope/private street improvement areas. Toe keyway should be a minimum of 3 feet below adjacent ground level. Place Tensar Geogrid earth reinforcement at bottom of slope keyway excavations as specified herein UGA. T-8 15' not encountered 10' Lots 16,17 areas. Place Tensar Geogrid earth reinforcement at soft and yielding bottom of removals in the impacted areas as spedfied herein UOA. T-9 15/2 not encountered 7' Private street improvement areas. T-10 15' not encountered 414' Private street improvement areas. Depth of undercut may govern. Stockpile better quality sandy soils from Terrace Deposit excavations for capping tiie pads. B-1 not encountered 5' Lot 11 areas. Depth of undercut may govem. B-2 4014' 33' 10' Lot 24 areas. Place Tensar Geogrid earth reinforcement at soft and yielding bottom of removals in the impacted areas as specified herein UOA. B-3 39' 32' 7' Private street improvement areas. Place Tensar Geogrid earth reinforcement at bottom of removals in the impacted areas as specified herein UOA. 8^ 20' not encountered 8' Lot 26 areas. Private street improvements. ViNir; & MIDDLETON l-NCiNEnRiNC, INC. • 2450 Amo Park Way • Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 20 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Notes: 1. UOA = Uniess Othenwise Approved. 2. All depths are measured from the existing ground levels. 3. Actual depths may vary at the time of constmction based on subsurface exposures. 4. Bottom of all removals should be additionally prepared and recompacted to a minimum depth of 6 inches as directed in the field. 5. Firm native ground is defined as undisturbed natural exposures with in-place densities of 85% or greater as approved in the field. 6. In the case of deeper storm drain or utility trenches where the proposed inverts are below the recommended depths, removals should be further extended a minimum of 12 inches below ttie bottom of pipe (or pipe bedding) unless otherwise approved. 7. Exploratory trenches excavated in connection with our study at the indicated locations were backfilled with loose and uncompacted deposits. The loose/uncompacted backfill soils within these trenches shall also be re-excavated and placed back as properly compacted fills as a part of the project grading operations. 8. All grounds steeper than 5:1 receiving fills/backfills should be properly benched and keyed as directed in the field. 3. Ground Stabilization - Fills can only be placed over firm stable native and non-yielding ground (in-place densities of 85% or greater). Ground stabilization techniques using earth reinforcement Geogrid should be used in the areas of the site where yielding soft bottom of removals are exposed at the specified over-excavation depths. Removal and recompaction grading with ground stabilization techniques will also limit potential fill soil settlements within tolerable limits as specified. For this purpose, a layer of Tensar Geogrid BX-1100 (or greater from the same series) earth reinforcement should be placed at the impacted bottom of over- excavations prepared as directed in the field. Initial fill lifts should then be carefully placed over the Geogrid and compacted. Subsequent fill lifts can continue until design grades are achieved. Additional layers of Geogrid may also be necessary within the compacted fill mass as directed in the field, and should be anticipated. 4. Excavations Characteristics - Proposed cut excavations will approach 25 feet deep in the existing hill knob areas ofthe property underiain by Terrace Deposit units. The cuts and recommended undercuts are expected to be achieved with moderate efforts using larger bulldozers (Caterpillar D-8 or equal). Some hard units and cemented beds may also be locally encountered requiring added ripping and more concentrated efforts. However, difficult excavations or the need for special techniques is currently not anticipated. 5. Cut-Fill Transitions and Undercuts - Ground transition from excavated cut to compacted fills should not be permitted underneath the proposed structures and improvements. Transition pads will require special treatment. The cut portion of cut-fill pads plus 10 feet outside the perimeter, where possible and VINJE & MIDDLEJ ON ENGINEERING, INC. • 2450 Auro Park Way • Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 21 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 as directed in the field, should be undercut to a sufficient depth to provide for a minimum of 3 feet of compacted fill mat below rough finish grades, or at least 12 inches of compacted fill beneath the deepest footing(s) whichever is more. In the roadways, driveway, pari<ing and on-grade slabs/improvement transition areas there should be a minimum of 12 inches of compacted soils below rough finish subgrade. Cut pad exposing loose to soft soils at final grades should also be undercut to a minimum depth of 3 feet (or 12 inches below the bottom of deepest footing whichever is more unless otherwise specified) and reconstructed to design grades with compacted fills as specified herein. , Temporary Construction Slopes - Excavations and removals adjacent to existing improvements and graded embankments should be performed under inspection of the project geotechnical engineer. Undermining exisfing improvements, underground ufilities to remain, and perimeter graded slopes should not be allowed by the removal operations. Temporary construcfion slopes should maintain adequate setbacks (minimum of 2 feet) from the toe of existing ascending slopes and adjacent improvements, as directed and approved in the field. Construction slopes, temporary excavations and trenching less than 3 feet high maximum may be constmcted at near vertical gradients. Temporary excavations and trenching greater than 3 feet and less than 12 feet high maximum should be laid back at 1:1 gradient unless otherwise specified or approved. Temporary slopes greater than 12 feet and less than 20 feet high maximum may be constructed at 1:1 within the lower 7 feet and laid back at 1 V4:1 gradient within the upper portions. The remaining wedge of soil should then be properly benched out and new fills/backfills tightly keyed-in as the backfilling progresses. Temporary trench and construction slopes greater than 3 feet maximum constructed at near vertical gradients will require shoring/trench shield support unless othenA/ise approved. All temporary construcfion slopes require continuous geotechnical inspections during the grading operafions. Additional recommendafions including revised slope gradients, setbacks and the need for temporary shoring/trench shield support should be given at that time as necessary. The project contractor shall also obtain appropriate permits, as needed, and conform to Cal-OSHA and local governing agencies' requirements for trenching/open excavations and safety of the workmen during construcfion. Permissions to perform off site grading should also be obtained if necessary and as appropriate. ViNiE & Mn:)DLETON ENGINEERING, INC. • 2450 Amo Park Way • liscondido, California 92029-1229 • Phone (760) 743-1214 I I I I I I I f I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 22 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23. 2006 7. Soli Properties and Select Grading - Soils generated from the excavafions of site exisfing fills, alluvium and formational rock units (map symbols af-Qal and Ts) will consist of marginal quality plastic silty to clayey deposits with high expansion potenfial which can be detrimental to structures and improvements, if they occur at or near finish grades. Plasfic silty to clayey soils also required added processing, mixing and moisture condifioning efforts in order to manufacture a uniform mixture suitable for reuse as site new compacted fills. However, better quality sandy earth deposits which generally work well as compact fills are expected from the excavations of site Terrace Deposits (map symbol Qt). Adverse effects of site highly expansive plasfic silty to clayey soils should be mitigated by selective burial of these deposits, placed a minimum of 4 feet below rough pad grades (or 12 inches below the deepest foofing, whichever is more) and a minimum of 10 feet away from the face of slopes within the fill mass. Better quality sandy soils available from the site Terrace Deposit excavafions should to stockpiled and selectively used within the upper pad grades and outer fill embankment slope surfaces. Improvement areas should be provided with a minimum 18 inches of better quality sandy soils. On-site plastic clayey soils should also not be used for wall or trench backfills. 8. Shrinkage and Import Soils - Based upon our analyses and experience with similar earth deposits, site soils may be expected to shrink approximately 10% to 20% on a volume basis when compacted to at least the minimum compaction levels specified herein. Import soils, if required to complete grading and achieve final pad grades, should be good quality sandy non-corrosive granular deposits (SM/SW) with very low expansion potenfial (100% passing %-inch sieve, more than 50% passing #4 sieve and less than 20% passing #200 sieve with expansion index less than 21). Import soils should be inspected, tested as necessary, and approved hy the project geotechnical engineer prior to delivery to the site. Sandy granular soils should also be considered for wall and trench backfills. 9. Fill Materials and Compaction - Soils generated from the site removals and over-excavations are considered suitable for reuse as site new fills provided they are processed, prepared and placed in accordance with the requirements ofthis report. Project fill soils should be clean deposits free of roots, stumps, vegetafion, deleterious matter, trash, demolition debris, and unsuitable materials as approved in the field by the project geotechnical consultant. Uniform bearing soil condifions should be constructed at the site by the remedial grading and earthwork operations. Site soils should be adequately processed, thoroughly mixed, moisture condifioned to slightly above VJN)E. &L MIDDLETON ENGINEERING, INI;. • 2450 Amo Park Way • Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 23 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 (approximately 2% for sandy soils and 3% to 5% for clayey soils) the optimum moisture levels as directed in the field, placed in thin (8 inches maximum) unifomi horizontal lifts and mechanically compacted to a minimum 90% ofthe corresponding laboratory maximum dry density below 3 feet from the rough finish grades, and minimum 95% ofthe corresponding laboratory maximum dry density within the upper 3 feet of final grades per ASTM D-1557, unless otherwise specified. 10. Permanent Graded Slopes - Project graded slopes are programmed for 2:1 orfiatter gradients maximum. Engineered graded slopes constructed at 2:1 or flatter gradients will be grossly stable with respect to deep seated and surficial failures for the anticipated design maximum vertical heights provided our recommendations are followed. Engineered slopes should be constructed as follows. Fill Slope Construction - Road embankment fills are planned at the site in connection with the private street improvements along the eastern margins. The planned fill slopes should be provided with a lower keyway. The keyway should maintain a minimum depth of 3 feet below the adjacent ground surface at the toe into with a minimum width of 12 feet as approved by the project geotechnical engineer or his designated representative. Deeper keyway depths may also be required based on actual exposures and should be anticipated. Loose to soft soils may be anticipated at the bottom of keyway excavations requiring mitigafion and stabilizafion. Stable bottom of keyway excavations can be achieved by placing a layer of Tensar Geogrid BX-1100 (or greater from the same series) earth reinforcement at the impacted bottom prepared as directed in the field. Inifial fill lifts should then be carefully placed over the Geogrid and compacted followed with subsequent lifts. All keyways should be heeled back a minimum of 2% into the hillside and inspected and approved by the project geotechnical engineer. Addifional level benches should be constructed into the natural hillside as the fill slope construcfion progresses. Fill slopes should also be compacted to a minimum 90% (or 95%) of the laboratory standard out to the slope face unless othenwise specified. Over-building and cutting back to the compacted core, or backrolling at a minimum of 4 feet vertical increments and "track-walking" at the completion of grading is recommended for site fill slope construcfion. Geotechnical engineering inspecfions and tesfing will be necessary to confirm adequate compaction levels within the fill slope face. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auco Park Way • Escondido, California 92029-1229 • Phone (760) 743-1214 r I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 24 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Cut Slope Construction - Proposed graded cut slopes are expected to expose stable, competent Terrace Deposits which will be grossly stable at the planned 2:1 gradients. Small cut slopes are also proposed in the form of lowering the exisfing toe of fill embankments in the south and east perimeter areas to adjacent pad levels are planned at the site. The slopes planned at the rear of Lots 3-6 should be reconstructed as stabilization fills with a minimum bottom equipment-width of 15 feet extended at least 2 feet into the underiying competent formational rock as approved in the field. Temporary construction slopes for the stabilizafion fill should be no steeper than V2:1. The stability fill should then be reconstructied to design grades soon after by placing fill soils tighfiy keyed into the construction slopes as the fill placement progress. Recommended Typical Stabilizafion Fill slope is schematically depicted on the enclosed Plate 16. Alternatively, a retaining wall may be constructed at the base ofthe perimeter slopes as shown. All cut slopes should be inspected and approved by the project geotechnical consultant during the grading to further confirm stability. More specific or revised recommendations will be provided at that fime as necessary and should be anticipated. 11. Surface Drainage and Flood / Erosion Control - A crifical element to the continued stability ofthe graded building pads is adequate surface drainage and flood control. This can most effecfively be achieved by installation of appropriate flood and drainage control stmctures. Building pad surface run-off should be collected in approved drainage facilities and directed to selected locations in a controlled manner. Area drains should be installed. Surface and flood waters should not be allowed to impact site embankments, fills, structures and improvements, or penetrate into the underiying bearing soils. Storm water and surface run-off shall be diverted from entering the site. The finished slope should be planted soon after completion of grading. Unprotected slope faces will be subject to severe erosion and should not be allowed. Over-watering of the slope faces should also not be allowed. Only the amount of water to sustain vegetation should be provided. Temporary erosion control facilifies and silt fences should be installed during the construction phase periods and until landscaping is established as indicated and specified on the approved project erosion plans. VINJE & MIDDLETON ENGINEERING, INC, • 2450 Amo Park Way • Escondido. California 92029-1229 • Phone (760) 743-1214 I I I I I I I I I I I I I I I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 25 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 12. Engineering Inspections - Ail grading operations including removals, suitability of earth deposits used as compacted fill, and compaction procedures should be confinuously inspected and tested by the project geotechnical consultant and presented in the final as-graded compaction report. The nature of finished subgrade soils should also be confinned in the final compacfion report at the completion of grading, Geotechnical engineering inspecfions shall include but not limited to the following: * Bottom of over-excavation/keyway inspection - After the bottom of over- excavation or keyway is exposed and prepared to receive fill but before fill placement is started. * Ground stabilizafion Geogrid placement - During the actual placement. Geogrid shall conform to the specified specificafions. * Excavation inspection - After the excavation is started but before the vertical depth of excavation is more than 3 feet. This includes all temporary excavation slopes and trenching. Safety requirements enforced by the governing agencies for open excavations apply. * Fill/backfill inspection - After the fill/backfill placement is started but before the vertical height of fill/backfill exceeds 2 feet. There should be a minimum of 1-foot in every 100 lineal feet for each 2 feet of vertical gain. Final rough and finish pad grade tests shall be required regardless of the fill/backfill thickness. * Foundation trench inspection - After the foundafion trench excavations but before steel placement. * Foundation bearing/slab subgrade soils inspection - Prior to the placement of concrete for proper moisture and specified compaction levels. * Foundafion/slab steel inspection - After steel placement is completed but before the scheduled concrete pour. * Subdrain/back drain inspection - During the actual placement. All material shall conform to the project material specifications and approved by the project soils engineer. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Amo Park Way • liscondido. California 92029-1229 • Phone (760) 743-1214 I I I I I I I I I I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 26 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 * Underground utility/plumbing trench inspection - After the trench excavafions but before installation of the underground facilities. Safety requirements enforced by Cal-OSHA, and governing agencies for open excavations apply. Inspection of the pipe bedding may also be required by the project soils engineer. * Underground utility/plumbing trench backfill inspecfion - After the backfill placement is started above the pipe zone but before the vertical height of backfill exceeds 2 feet. Testing of the backfill within the pipe zone may also be required by the governing agencies. Pipe bedding and backfill materials shall conform to the requirements of governing agencies and project soils report if applicable. All trench backfills shall be mechanically compacted to the minimum specified compaction levels per ASTM D-1557, unless otherwise superseded. Plumbing trenches over 12 inches deep maximum under the interior floor slabs should also be mechanically compacted and tested for the minimum specified compaction levels. Flooding or jetting techniques as a means of compaction method shall not be allowed. * Pavement/improvements base and subgrade inspections - Prior to the placement of concrete or asphalt for proper moisture and specified compaction levels. B. Foundations and Interior Floor Slabs Proposed buildings may be supported on conventional concrete footings and slab- on-grade floor type foundafions. The following recommendations and geotechnical mitigation are consistent with silty sandy clay to clayey silty sand (SC/CL) foundation bearing and subgrade soils with low to high expansion potential (expansion index less than 131) anticipated at finish grade levels. Added or modified recommendafions may also be necessary and should be given at the time of foundation plan review phase. All foundations and floor slab recommendafions should also be further confinned and / or revised as necessary at the completion of rough grading based on the actual expansion characteristics ofthe foundation bearing and subgrade soils: 1. Perimeter and interior continuous strip foundations should be sized at least 15 inches wide and 24 inches deep for single and two-story structures. Exterior spread pad footings, if any, should be at least 30 inches square and 18 inches deep and structurally tied to the perimeter strip foofings with fie beams at least in one direction. Tie beams should be a minimum of 12 inches wide by 12 Inches deep. Footing depths are measured from the lowest adjacent ground surface, not including the sand/gravel layer beneath floor slabs. ViNiE fit MIDI:)I.ETON ENGINEERING, INC. • 2450 Auto Park Way * liscondido, Cilifornia 92029-1229 * Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 27 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Exterior continuous foofings should enclose the entire building perimeter. Flagpole footings also need to be tied together if the footing depth is less than 4 feet below rough finish grade. 2. Continuous interior and exterior foundations should be reinforced with a minimum of four #5 reinforcing bars. Place 2-#5 bars 3 inches above the bottom of the footing and 2-#5 bars 3 inches below the top of the footing. Tie beams should also be reinforced with 2-#4 bars top and bottom and #3 ties at 30 inches on center maximum. Reinforcement details for spread pad footings should be provided by the project architect/structural engineer. 3. The slab subgrade and foundation bearing soils should not be allowed to dry priorto pouring the concrete, as additional ground preparations, moisture.re- conditioning and presaturation will be necessary as directed in the field. The required moisture content of the bearing soils is approximately 3% to 5% over the optimum moisture content to the depth of 24 inches below slab subgrade. Attempts should be made to maintain as-graded moisture contents in order to preclude the need for presaturation of the subgrade and bearing soils. 4. In the case of presaturation of the slab subgrade and/or non-monolithic pour (two-pour) system, dowel the slab to the footings using #4 reinforcing bars spaced 18 inches on center extending at least 20 inches into the footings and 20 inches into the slab. The dowels should be placed mid-height in the slab. Alternate the dowels each way for all interior footings. 5. After the footings are dug and cleaned, place the reinforcing steel and dowels and pour the footings. 6. This office should be notified to inspect the foundation trenches, and reinforcing prior to pouring concrete. 7. Once the concrete for the foofings has cured and underground utilities tested, place 4 inches of %-inch rock over the slab subgrade. Flood with water to the top of the %-inch rock, and allow the slab subgrade to soak unfil moisture testing indicates that the required moisture content is present. After the slab subgrade soils have soaked, notify this office and schedule for appropriate moisture testing. 8. When the required moisture content has been achieved, place a well- perfonning moisture barrier/vapor retardant (minimum 15-mil plastic) over the %-inch rock, and place 2 inches of clean sand (SE 30 or greater) on top of the plastic. VINJE & MIDDLETON ENGINEERING, INC. • 2450 Amo Park Way • Escondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 28 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 If sufficient moisture is present, flooding/presaturation will not be required. The dowels may be deleted, slab underiayment may consist of 2 inches of clean sand over a well perfonning moisture bamer/vapor retardant (minimum 15-mil plastic) over 2 inches of clean sand, and the footings and slab may be poured monolithically. This office should be notified to inspect the sand, slab thickness, and reinforcing prior to concrete pour. 9. All interior slabs should be a minimum of 5 inches in thickness reinforced with #4 reinforcing bars spaced 18 inches on center each way placed 1 Vi inches below the top of slab. 10. Interior slabs should be provided with "softcut" contraction/control joints consisting of sawcuts spaced 10 feet on center maximum each way. Cut as soon as the slab will support the weight of the saw, and operate without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. The softcuts should be a minimum of %-inch in depth, but should not exceed 1-inch deep maximum. Anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipment across cuts for at least 24 hours. 11. Provide re-entrant corner reinforcement for all interior slabs. Re-entrant corners will depend on slab geometry and/or interior column locations. Plate 21 may be used as a general guideline. 12. Foundation trenches and slab subgrade soils should be inspected and tested for proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. C. Post-tensioned / Structural Slab-on-Ground Foundations Post-tensioned or structural slab-on-ground foundations consistent with the anticipated silty to clayey expansive bearing soils may also be considered. Remedial grading and foundation bearing/slab subgrade soil preparations will remain the same and should be completed as specified. Post-tensioned or structural slab-on-ground foundation design should be completed by the project structural engineer or design/build contractor. The following are appropriate: 1. The foundation design should consider slabs with stiffening beams (ribbed foundafion). In the case of uniform slab thickness foundation, the design shall satisfy all requirements of the design procedure for ribbed foundation. The fully VINJE & MIDDLETON ENGINEERING, INC. • 2450 Auro Park Way • Escondido, Cilifornia 92029-1229 • Phone (760) 743-1214 I I I I I I I I I I I I I I I I I I I PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 29 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 conformant ribbed foundafion is then converted to an equivalent uniform thickness foundation. In this case, however, perimeter edge beams shall be required as specified in the following secfions. 2. All designs shall conform to the latest addifion ofthe Califomia Building Code (CBC), specifications ofthe Posttensioning Institute (PTI), local standards, and the specifications given in this report. 3. Foundation bearing soils should be inspected and tested as necessary prior to trenching and actual construction by the project geotechnical engineer. The required foundation bearing soils in-place densities, and specified moisture contents should be confirmed prior to the foundation pour. 4. A minimum 4 inches of clean sand (SE greater than 30) should be placed over the approved slab subgrade soils. A well performing moisture barrier/vapor retardant (minimum 15-mil plasfic) shall be placed mid-height in the sand. 5. At the complefion of ground and subgrade preparations as specified, and approval ofthe project soil engineer, the post-tensioned or structural slab-on- ground foundations should be constructed as detailed on the structural/construcfion drawings. 6. Based upon our experience on similar projects, available laboratory testing and analysis of the test results, the following soil design parameters are appropriate; * Design predominant clay mineral type Montmorillonite. * Design percent of clay in soil 60%. * Design effective plasticity index 45. * Design depth to constant soil suction 7 feet. * Design constant soil suction Pf 3.6. * Design velocity of moisture flow 0.70 inch/month. * Design edge moisture variation distance for edge lift (em) 3.0 feet. * Design edge moisture variation distance for center lift (em) 6.0 feet. * Design differential swell occurring at the perimeter of slab for edge lift condition (Ym) 1.095 inches. * Design differential swell occurring at the perimeter of slab for center lift condifion (Ym) 5.677 inches. * Design soil subgrade modulus (k) 100 pci. * Design net allowable bearing pressure for Post-tensioned or structural slab-on-ground foundations 1000 psf ViNiE &. MIDDLETON ENGINEERING, INC. • 2450 Auto Park Way • E.srondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 30 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Notes: The net allowable foundation pressure provided herein applies to dead plus live loads and rnay be increased by one-third for wind and seismic loading. 7. Provide a minimum of 15 inches wide by 24 inches deep perimeter edge beam. Perimeter edge beam should enclose the entire building circumference and reinforced wilh at least 1-#5 continuous bar near the bottom. Provide adequate interior stiffening ribs as necessary. 8. Posttension slab should be a minimum of SVi inches thick. Use minimum f'c=3000 psi concrete. We recommend to consider pre-tensioning in order to preclude early concrete shrinkage cracking, D. Exterior Concrete Slabs / Flatworks 1. All exterior slabs (walkways, patios, etc.) should be a minimum of 4 inches in thickness, reinforced with #3 bars at 16 inches on centers in both directions placed 1 Yl inches below the top of slab. Use 6 inches of 90% compacted clean sand beneath all exterior slabs. 2. Provide "tool joint" or "softcut" contraction/control joints spaced 10 feet on center (not to exceed 12 feet maximum) each way. Tool or cut as soon as the slab will support weight and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of %-inch but should not exceed 1-inch deep maximum. In case of softcut joints, anti-ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipments across cuts for at least 24 hours, 3. In order to enhance performance of exterior slabs and flatworks supported on potentially expansive and moisture sensitive subgrade soils, a minimum 8 inches wide by 12 inches deep thickened edge reinforced with a minimum of 1-#4 continuous bar near the bottom may be considered along the free-ends. 4. All exterior slab designs should be confirmed in the final as-graded compaction report, 5. Subgrade soils should be tested for proper moisture and specified compaction levels and approved by the project geotechnical consultant prior to the placement of concrete. ViNii; & MiDDLinoN EN(;INI-.I:IIIN(„ INC. • 2450 Amo Park Way • liscondido, California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 31 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 E. Soil Desiqn Parameters The following soil design parameters are based upon tested representative samples of on-site earth deposits. Expansive clayey soils should not be used for wall backfills. Sandy site soils or good quality granular import soils should be considered within the active zone. Design parameters for import soils can only be given based on actual testing when a representative sample is available. All parameters should be re-evaluated when the characteristics of the final as-graded soils have been specifically determined: * Design wet density of soil = 121 pcf * Design angle of internal friction of soil = 28 degrees. * Design active soil pressure for retaining structures = 44 pcf (EFP), level backfill, cantilever, unrestrained walls. * Design active soil pressure for retaining structures = 69 pcf (EFP), 2:1 sloping backfill surface, cantilever, unrestrained walls. * Design at-rest soil pressure for retaining structures = 64 pcf (EFP), non- yielding, restrained walls, * Design passive soil pressure for retaining structures = 335 pcf (EFP), level surface at the toe. * Design coefficient of friction for concrete on soils = 0,34, * Net allowable foundation pressure (minimum 15 inches wide footings extended a minimum of 24 inches into compacted fill) = 2000 psf * Allowable lateral bearing pressure (all structures except retaining walls) = 150 psf/ft. Notes: * Use a minimum safety factor of 1.5 for wall over-turning and sliding stability. However, because large movements must take place before maximum passive resistance can be developed, a minimum safety factor of 2 may be considered for sliding stability particulariy where sensitive structures and improvements are planned near or on top of retaining/basement walls. * When combining passive pressure and frictional resistance the passive component should be reduced by one-third. * The indicated net allowable foundation pressure provided herein was determined based on a minimum 15 inches wide by 24 inches deep footing and may be increased by 20% for each additional foot of depth and 10% for each VIN|E &. Mini)i.inoN liNGiNEi-RiNG, INC. • 2450 Amo Park Way • liscondido. California 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 32 JUNE 23, 2006 additional foot of width to a maximum of 4500 psf. The allowable foundation pressures provided herein also apply to dead plus live loads and may be increased hy one-third for wind and seismic loading. * The lateral bearing earth pressures may be increased by the amount of designated value for each additional foot of depth to a maximum of 1500 pounds per square foot. Asphalt and PCC Pavement Design Puhlio 1. Asphalt Paving: A new privat© street improvement is planned, and widening of Camino Hills Drive is proposed in connection with the site development. All roadway improvements and paving constructions shall be completed in accordance with the City of Carisbad ordinances. The following asphalt pavement structural sections are based on a tested R- value of 5 performed on selected on-site earth materials and the indicated assumed traffic indices (Tl), and may be considered for initial planning phase cost estimating purposes. A minimum section of 3 inches asphalt (AC) over 6 inches of Class 2 aggregate base (AB) or the minimum structural section required by City of Carlsbad, whichever is more, will be required and shall govern when a lesser pavement section is indicated by design calculations: TABLE 16 Design Traffic Index (Tl) Design R-value 4.5 5.0 6.0 6.5 5 3" AC over 8" AB 3" AC over 10" AB 3" AC over 14" AB 4" AC over 14" AB The Class 2 aggregate base shall meet or exceed the current Caltrans specifications. Final pavement sections will depend on the actual R-value test results performed on finish subgrade soils, design Tl and approval of the City of Carisbad. All design sections should be confirmed and/or revised as necessary at the completion of rough pavement subgrade preparations. Revised pavement sections should be anticipated. Base materials should be compacted to a minimum 95% of the maximum dry density. Subgrade soils beneath the pavement base layer should also be compacted to a minimum 95% of the corresponding maximum dry density within the upper 12 inches. Base materials and subgrade soils should be !iKii;i.'ij I Mf: . 74<;n A,.t.^ P-,.i- W-.W • I- PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 33 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 tested for proper moisture and minimum 95% compaction levels and approved by the project geotechnical consultant prior to the placement of the base or asphalt layers. 2. PCC Paving: PCC driveways and parking supported on expansive subgrade soils should be a minimum of SYt inches in thickness, reinforced with #3 reinforcing bars at 16 inches on center each way, placed 2 inches below the top of slab. Subgrade soils beneath the PCC driveways and parking should also be compacted to a minimum 90% ofthe corresponding maximum dry density within the upper 6 inches, unless othenwise specified. In order to enhance performance of PCC pavements supported on expansive subgrade, a minimum 8 inches wide by 12 inches deep thickened edge reinforced with a minimum 1-#4 continuous bar placed near the bottom is recommended to be considered along the outside edges. Provide "tool Joint" or "softcut" contraction/control joints spaced 12 feet on center (not to exceed 15 feet maximum) each way. Tool or cut as soon as the slab will support weight and can be operated without disturbing the final finish which is normally within 2 hours after final finish at each control joint location or 150 psi to 800 psi. Tool or softcuts should be a minimum of 1-inch but should not exceed 1%-inches deep maximum. In case of softcut joints, anti- ravel skid plates should be used and replaced with each blade to avoid spalling and raveling. Avoid wheeled equipments across cuts for at least 24 hours. 3. General Paving: Base section and subgrade preparations per structural section design, will be required for all surfaces subject to traffic including roadways, travelways, drive lanes, driveway approaches and ribbon (cross) gutters. Driveway approaches within the public right-of-way should have 12 inches subgrade compacted to a minimum of 95% compaction levels, and provided with a 95% compacted Class 2 base section per the structural section design. In the case of potentially expansive subgrade (expansion index greater than 20), provide 6 inches of Class 2 base under curb and gutters and 4 inches of Class 2 base (or 6 inches of Class III) under sidewalks with a thickened edge along the free-end as specified. Base layer under curb and gutters should be compacted to a minimum 95%, while subgrade soils under curb and gutters, and base and subgrade under sidewalks should be compacted to a minimum 90% compaction levels unless othenwise specified. Specific recommendations should be given in the final as-graded compaction report. ViNiH & MiDiii.inoN EN(.;iNi:i-:iiiNc;. INC, • 2450 Auro Park Wav* liscondido, California 92029-1229 • Phone (760~) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 34 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 Base and subgrade should be tested for proper moisture and specified compaction levels, and approved bythe project geotechnical consultant prior to the placement of the base or asphalt/PCC finish surface. G. General Recommendations 1. The minimum foundation design and steel reinforcement provided herein are based on soil characteristics and are not intended to be in lieu of reinforcement necessary for structural considerations. 2. Adequate staking and grading control is a critical factor in properiy completing the recommended remedial and site grading operations. Grading control and staking should be provided by the project grading contractor or surveyor/civil engineer, and is beyond the geotechnical engineering services. Inadequate staking and/or lack of grading control may result in unnecessary additional grading which will increase construction costs. 3. Footings located on or adjacent to the top of slopes should be extended to a sufficient depth to provide a minimum horizontal distance of 7 feet or one-third of the slope height, whichever is greater (need not exceed 40 feet maximum) between the bottom edge of the footing and face of slope. This requirement applies to all improvements and structures including fences, posts, pools, spas, etc. Concrete and AC improvements should be provided with a thickened edge to satisfy this requirement. 4. Open or backfilled trenches parallel with a footing shall not be below a projected plane having a downward slope of 1-unit vertical to 2 units horizontal (50%) from a line 9 inches above the bottom edge ofthe foofing, and not closer than 18 inches from the face of such foofing. 5. Where pipes cross under-footings, the footings shall be specially designed. Pipe sleeves shall be provided where pipes cross through footings or footing walls, and sleeve clearances shall provide for possible footing settlement but not less than 1-inch all around the pipe. 6. Foundations where the surface ofthe ground slopes more than 1-unit vertical in 10 units horizontal (10% slope) shall be level or shall be stepped so that both top and bottom of such foundations are level. Individual steps in continuous footings shall not exceed 18 inches in height and the slope of a series of such steps shall not exceed 1-unit vertical to 2 units horizontal (50%) unless otherwise specified. The steps shall be detailed on the structural drawings. The local effects due to the discontinuity of the steps shall also be considered in the design of foundations as appropriate and applicable. ViNii-: & MiDDLirroN ENI;INI:HRING. INC. • 2450 Amo I'aik Way • liscondido. California 92029-1229 • Phone (7601 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 35 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 7. Expansive clayey soils should not be used for backfilling of any retaining structure. All retaining/basement walls should be provided with a 1:1 wedge of granular, compacted backfill measured from the base ofthe wall footing to the finished surface, and a well constructed back drainage as shown on Plate 22. 8. All underground utility and plumbing trenches should be mechanically compacted to a minimum 90% of the maximum dry density ofthe soil unless othenwise specified. Care should be taken not to crush the utilities or pipes during the compaction ofthe soil. Non-expansive, granular backfill soils should be used. Trench backfill materials and compaction beneath pavements within the public right-of-way shall conform to the City of Carlsbad requirements. 9. On-site soils are expansive clayey deposits subject to continued swelling and shrinkage upon wetting and drying. Maintaining a uniform as-graded soil moisture during the post construcfion periods is essential in the future performance ofthe site structures and improvements. In no case should water be allowed to pond or accumulate adjacent to the improvements and structures. Due to sensitive expansive plastic clayey soils present at the site, construction of swimming pools, spas, patios, etc. should only be allowed based on a review and specific recommendations provided by the project geotechnical consultant. Planfing large trees near the building foundations should be avoided. 10. Site drainage over the finished pad surfaces should flow away from structures onto the street in a positive manner. Care should be taken during the construction, improvements, and fine grading phases not to disrupt the designed drainage patterns. Roof lines ofthe buildings should be provided with roof gutters. Roof water should be collected and directed away from the buildings and structures to a suitable locafion. 11. Final plans should refiect preliminary recommendations given in this report. Final foundations and grading plans may also be reviewed by the project geotechnical consultant for conformance with the requirements of the geotechnical investigation report outlined herein. More specific recommendations may be necessary and should be given when final grading and architectural/structural drawings are available. 12. All foundation trenches should be inspected to ensure adequate footing embedment and confirm competent bearing soils. Foundation and slab reinforcements should also be inspected and approved by the project geotechnical consultant. VINJE & MIDDLIH ON ENI;INI:I:RINI-,, INC. • 2450 Auio Park Way • Eiscondido. c:alifornla 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 36 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 13, The amount of shrinkage and related cracks that occurs in the concrete slab- on-grades, fiatworks and driveways depend on many factors the most important of which is the amount of water in the concrete mix. The purpose of the slab reinforcement is to keep nonnal concrete shrinkage cracks closed tightly. The amount of concrete shrinkage can be minimized by reducing the amount of water in the mix. To keep shrinkage to a minimum the following should be considered: * Use the stiffest mix that can be handled and consolidated satisfactorily. * Use the largest maximum size of aggregate that is practical. For example, concrete made with %-inch maximum size aggregate usually requires about 40-lbs, more (neariy 5-gal.) water per cubic yard than concrete with 1-inch aggregate. * Cure the concrete as long as practical. The amount of slab reinforcement provided for conventional slab-on-grade construction considers that good quality concrete materials, proportioning, craftsmanship, and control tests where appropriate and applicable are provided. 14. A preconstruction meeting between representatives ofthis office, the property owner or planner, city inspector as well as the grading contractor/builder is recommended in order to discuss grading/construction details associated with site development. IX. LIMITATIONS The conclusions and recommendations provided herein have been based on available data obtained from the review of pertinent reports and plans, subsurface exploratory excavations as well as our experience with the soils and formational materials located in the general area. The materials encountered on the project site and utilized in our laboratory testing are believed representative of the total area; however, earth materials may vary in characteristics between excavations. Of necessity we must assume a certain degree of continuity between exploratory excavations and/or natural exposures. It is necessary, therefore, that all observations, conclusions, and recommendations be verified during the grading operation. In the event discrepancies are noted, we should be contacted immediately so that an inspection can be made and additional recommendations issued if required. ViNlE &. MlDDLin oN liNGINEl-RING, INC. • 2450 Aulo \\\rk Way • liscondido, Caiifornia 92029-1229 • Phone (760) 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION PAGE 37 26-LOT SUBDIVISION. CAMINO HILLS DRIVE, CARLSBAD JUNE 23, 2006 The recommendations made in this report are applicable to the site at the time this report was prepared. It is the responsibility of the owner/developer to ensure that these recommendations are carried out in the field. It is almost impossible to predict with certainty the future performance of a property. The future behavior of the site is also dependent on numerous unpredictable variables, such as earthquakes, rainfall, and on-site drainage patterns. The firm of VINJE & MIDDLETON ENGINEERING, INC. shall not be held responsible for changes to the physical conditions of the property such as addition of fill soils, added cut slopes, or changing drainage patterns which occur without our inspection or control. The property owner(s) should be aware that the development of cracks in all concrete surfaces such as floor slabs and exterior stucco are associated with normal concrete shrinkage during the curing process. These features depend chiefly upon the condition of concrete and weather conditions at the time of construction and do not reflect detrimental ground movement. Hairiine stucco cracks will often develop at window/door corners, and floor surface cracks up to Ve-inch wide in 20 feet may develop as a result of normal concrete shrinkage (according to the American Concrete Institute). This report should be considered valid for a period of one year and is subject to review by our firm following that time. If significant modificafions are made to your tentative development plan, especially with respect to the height and location of cut and fill slopes, this report must be presented to us for review and possible revision. This report is issued with the understanding that the owner or his representative is responsible to ensure that the information and recommendations are provided to the project architect/structural engineer so that they can be incorporated into the plans. Necessary steps shall be taken to ensure that the project general contractor and subcontractors carry out such recommendations during construction. The project soils engineer should be provided the opportunity for a general review of the project final design plans and specifications in order to ensure that the recommendations provided in this report are property interpreted and implemented. The project soils engineer should also be provided the opportunity to verify the foundations prior the placing of concrete. If the project soils engineer is not provided the opportunity of making these reviews, he can assume no responsibility for misinterpretation of his recommendations. Vinje & Middleton Engineering, Inc., warrants that this report has been prepared within the limits prescribed by our client with the usual thoroughness and competence of the engineering profession. No other warranty or representation, either expressed or implied, is included or intended. ViNii; & MIDDLETON ENGINEEKINI;, INC. • 2450 Amo Park Way • liscondido, California 92029-1229 • Phone (760') 743-1214 PRELIMINARY GEOTECHNICAL INVESTIGATION 26-LOT SUBDIVISION, CAMINO HILLS DRIVE, CARLSBAD PAGE 38 JUNE 23, 2006 Once again, should any questions arise concerning this report, please do not hesitate to contact this office. Reference to our Job #06-210-P will help to expedite our response to your inquiries. We appreciate this opportunity to be of service to you, VINJE & MIDDLETON ENGINEERING, INC. Steven J. Melzer CEG #2362 DM/SMSS/SJM/jt Distribufion: Addressee (5) c/jt/mynies/prelilms.06/06-210-P VINJE & MIDDLIMON ENGINE.ERING, INC. • 2450 Amo Park Way • Escmdldn, California 92029-1229 • Phone (760) 743-1214 REFERENCES Annual Book of ASTM Standards, Section 4 - Construction, Volume 04.08: Soil And Rock (1); • 420-0 5611,2005. Annual Book of ASTM Standards, Section 4 - Construction, Volume 04.09: Soil And Rock (11); D 5714 - Latest, 2005. Highway Design Manual, Caltrans. Fifth Edition. Corrosion Guidelines, Caltrans, Version 1.0, September 2003. California Building Code, Volumes 1 & 2, International Conference of Building Officials, 2001. "Green Book" Standard Specifications For Public Works Construction, Public Works Standards, Inc., BNi Building News, 2003 Edition. Catifornia Department of Consen/ation, Division of Mines and Geology (California Geological Survey), 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California, DMG Special Publication 117, 71 p. California Department of Conservation, Division of Mines and Geology (California Geological Sun/ey), 1986 (revised), Guidelines for Preparing Engineering Geology Reports: DMG Note 44, California Department of Conservation, Division of Mines and Geology (California Geological Survey), 1986 (revised). Guidelines to Geologic and Seismic Reports: DMG Note 42. EQFAULT, Ver. 3.00, 1997, Deterministic Estimation of Peak Acceleration from Digitized Faults, Computer Program, T. Blake Computer Services And Software. EQSEARCH, Ver 3.00, 1997, Estimation of Peak Acceleration from California Earthquake Catalogs, Computer Program, T. Blake Computer Services And Software, Tan S,S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County. California, Plate(s) 1 and 2. Open File-Report 96-02, California Diviston of Mines and Geology, 1:24,000. UBCSEIS, Ver. 1.03, 1997, Computation of 1997 Uniform Building Code Seismic Design Parameters, Computer Program, T. Blake Computer Services And Software. "Proceeding of The NCEER Workshop on Evaluation of Liquefaction Resistance Soils," Edited by T. Leslie Youd And Izzat M. Idriss, Technical Report NCEER-97-0022, Dated December 31, 1997. "Recommended Procedures For Implementation of DMG Special Publication 117 Guidelines For Analyzing And Mitigation Liquefaction In California," Southern California Earthquake center; USC, March 1999. "Soil Mechanics," Naval Facilities Engineering Command, DM 7.01. "Foundations & Earth Structures." Naval Facilities Engineering Command. DM 7.02. "Introduction to Geotechnical Engineering. Robert D. Holtz. William D. Kovacs. "Introductory Soil Mechanics And Foundations: Geotechnical Engineering," George F. Sowers, Fourth Edition. "Foundation Analysis And Design," Joseph E. Bowels. Caterpillar Performance Handbook, Edition 29,1998. Jennings, C.W., 1994, Fault Activity Map of California and Adjaceni Areas, California Division of Mines and Geology, Geologic Data Map Series, No. 6. Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131, California Division of Mines and Geology, Plate 1 (East/West), 12p. Kennedy, M.P. and Peterson, G.L., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56p. Kennedy, M.P. and Tan. S.S., 1977, Geology of National City, Imperial Beach and Otay Mesa Quadrangles, Southern San Diego Metropolitan Area, Califomia, Map Sheet 24, California Division of Mines and Geology, 1:24,000. Kennedy, M.P., Tan, S.S., Chapman, R.H., and Chase, G.W,, 1975, Character and Recency of Faulting, San Diego Metropolitan Areas, California: Special Report 123, 33p. Caterpillar Performance Handbook, Edition 29, 1998. Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Geologic Data Map Series, No. 6. Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California, Special Report 131, California Division of Mines and Geology, Plate 1 (East/West), 12p. Kennedy, M.P. and Peterson. G.L., 1975, Geology of the San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56p. Kennedy, M.P. and Tan. S.S., 1977, Geology of Nalional City, Imperial Beach and Otay Mesa Quadrangles, Southern San Diego Metropolitan Area, Califomia, Map Sheet 24, California Division of Mines and Geology, 1:24,000. Kennedy, M.P,, Tan, S.S.. Chapman, R.H., and Chase, G.W., 1975, Character and Recency of Faulting, San Diego Metropolitan Areas, California: Special Report 123, 33p. "An Engineering Manual For Slope Stability Studies," J.M. Duncan, A.L. Buchignani And Marius De Wet, Virginia Polytechnic Institute And State University, March 1987. "7" 'TV EOC- /r PLATE H c.|,* Cohvtflo Son / ifl'p-^ I ., ^ V&M JOB #O^@-210 ii :% \ • L if 6' 7 7 -i.'ii... .i.jw<i /^ " 1", ^ Loi tihn^ Canyon I I I C'AfilEftAVE So£ls 1 : 29,000 2050 ft LAT; 33.1452 LONG: H 7.2880 PRIMARY DIVISIONS GROUP SYMBOL SECONDARY DIVISIONS m o tr o UJ CO oc < o o < z < I I- ai cc O 2 o o OJ d Z UJ Z N < to OC LU CD cc < _l w GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE SANDS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE CLEAN GRAVELS (LESS THAN 5% FINES) GW Well graded gravels, gravel-sand mixtures. Utile or no fines. GP Poorly graded gravels or gravel-sand mixtures, little or no fines. GRAVEL WITH FINES GM Silty gravels, gravel-sand-silt mixtures, non-plastic fines. GG Clayey gravels, gravel-sand-clay mixtures, plastic fines. CLEAN SANDS (LESS THAN 5% FINES) SW Well gradeci sands, gravelly sands, litlle or no fines. SP Poorly graded sands or gravelly sands, little or no lines. SANDS WITH FINES SM Silty sands, sand-sill mixtures, non-plaslic lines. SG Clayey sands, sand-clay mixtures, plastic fines. Inorganic slits and very (ine sands, rock flour, silty or clayey fine sands or clayey sills with slight plasticity. I Q UJ 1 i t^ \~ IU OC 1 o u. 5 UJ cc b! Ul w CO CO CO o — o -J CM E O UJ z < I ML SILTS AND CLAYS LIQUID LIMIT IS LESS THAN 50% CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. OL Organic silts and organic silly clays of low plasticity. SILTS AND CLAYS UQUID LIMIT IS GREATER THAN 50% MH Inorganic sills, micaceous or diatomaceous line sandy or silly soils, elastic sills. CH Inorganic clays of high plasticity, lal clays. OH Organic clays of medium lo high plasticity, organic sills. HIGHLY ORGANIC SOILS PT Peal and other highly organic soils. GRAIN'SIZES U.S. STANDARD SERIES SIEVE 200 40 10 CLEAR SQUARE SIEVE OPENINGS 3/4" 3" 12"' SAND GRAVEL FINE MEDIUM COARSE FINE COARSE SILTS AND CLAYS COBBLES BOULDERS RELATIVE DENSITY CONSISTENCY r I SANDS, GRAVELS AND NON-PLASTIC SILTS BLOWS/FOOT VERY LOOSE 0 - 4 LOOSE 4 • 10 MEDIUM DENSE 10 • 30 DENSE 30 - 50 VERY DENSE OVER 50 CLAYS AND PLASTIC SILTS STRENGTH BLOWS/FOOT VERY SOFT 0 • 'A 0 - 2 SOFT 2 • 4 FIRM y, • 1 4-8 STIFF 1 - 2 8 - 16 VERY STIFF 2 - 4 16-32 HARD OVER 4 OVER 32 1. Blow count, 140 pound hammer falling 30 inches on 2 inch O.D. split spoon sampler (ASTM D-1586) 2. Unconfined compressive strength per SOILTEST pocl<et penetrometer CL-700 •r. ^ ^ -,- . M „ ^ , I ^-tfi = standard Penetration Test (SPT) (ASTM D-1586) Sand Cone Test • Bulk Sample | with blow counts per 6 inches QJ Chunk Sample O Driven Rings 11 ^'•e = California Sampler with blow counts per 6 inches VINJE & MIDDLETON ENGINEERING, INC, 2450 Vineyard Ave,, #102 Escondido, CA 92029-1229 KEY TO EXPLORATORY BORING LOGS Unified Soil Classification System {ASTM D-2487) PROJECT NO. KEY Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T-1 uses SYMBOL FIELD MOISTURE m FIELD DRY DENSITY (pel) RELATIVE COMPACTION (%) DEPTH (ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE m FIELD DRY DENSITY (pel) RELATIVE COMPACTION (%) D - • • FILL: Sandy clay. Pale brown color. Moist to very moist. Sofl. Piastic. ST-1 CL/CH 18.5 100.8 - 5 - • TERRACE DEPOSIT Clayey sand. Red-brown color. MoisL Somewhat blocky. Loose to medium dense. Includes sub-angular pebbles. ST-2 SC/CL 12.9 15.4 104.1 103.4 80.4 79.8 - 10- • Silty fine to medium sand with clay. Dark brown color. Medium dense to dense. Grades fine to coarse grained at 10'. Trace of clay. ST-2 SM/SC 8.2 7.8 112.3 119.3 86.7 92.1 - 15- • • 1 Coarse sand. Clay binder. Some gravel and small rock. Red-brown color. Moist. Medium dense. ST-3 SC/GC 9.7 14.1 102.8 103.5 - - 15- • • 1 Clay fine to medium sand. Brown color. Moist. Somewhat blocky. Medium dense. ST-2 \ SC 9.7 14.1 102.8 103.5 - -Clay fine to medium sand. Brown color. Moist. Somewhat blocky. Medium dense. ST-2 \ SC -20- ' Clay fine to medium sand. Brown color. Moist. Somewhat blocky. Medium dense. ST-2 \ SC -20- ' End Test Trench at 16'>4' - extent of backhoe. No caving. No groundwater. Date: 4-11-06 Logged by: SJM T-2 uses FIELD FIELD DRY RELATIVE ' PTH .ft) SAMPLE DESCRIPTION SYMBOL MOISTURE {%) DENSITY (pcf) COMPACTION (%) - 0 -FILL / TOPSOIL: Sandy clay. Pale brown color. Moist. Sofl. Plastic. ST-1 CL - FILL / TOPSOIL: Sandy clay. Pale brown color. Moist. Sofl. Plastic. ST-1 J FORMATIONAL ROCK (Ts): Claystone. Grey color. Weathered. "Popcorn" texture. ST-4 - 5 - u • • Q • • FORMATIONAL ROCK (Ts): Claystone. Grey color. Weathered. "Popcorn" texture. ST-4 CL/CH / 16.6 23.6 101.0 89.8 84.5 75.1 1 - 10- u • • Q • • Silty sandstone. Fine grained. Trace of clay. Tan with rust-colored staining. Includes clasts of claystone. Weathered. Friable. Moderately to poorly cemented. No discernable structure. ST-5 SM/SC 18.8 17,4 107.8 114.3 90.2 95.6 • - \ 1 - 15- End Test Trench at 10Vi. No caving. No groundwater. - 20- VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 TEST TRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 3 T Sand Cone Test Bulk Sample • Chunk Sannple Q Driven Rings Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T-3 uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (•/.) DEPTH (ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (•/.) 0 -FILL/ALLUVIUM faf-Qal): Sandy clay. Pale brown color. Moist. Soft. ST-1 CL/CH ^ - 5 - • Q • FILL/ALLUVIUM faf-Qal): Sandy clay. Pale brown color. Moist. Soft. ST-1 CL/CH ^ 28.6 27.8 88.0 88.8 79.6 80.4 - 5 - • Q • Silty clay. Dark grey color. Moist. Soft to stiff. Plastic. ST-4 CL/CH 28.6 27.8 88.0 88.8 79.6 80.4 -• Fine sand. Trace of clay. Off-white to grey color. Somewhat hinrky Mpflliim riense. ST-5 SC 18.4 10.6 84.2 FORMATIONAL ROCK (Ts): Fine sandy siltstone/claystone. Grey color. Weathered. Fractured. Blocky. ST-4 MH/CH - 10- -15- -20- ! i FORMATIONAL ROCK (Ts): Fine sandy siltstone/claystone. Grey color. Weathered. Fractured. Blocky. ST-4 MH/CH - 10- -15- -20- ! i End Test Trench at 9. No caving. No groundwater. ; Date: 4-11-06 Logged by: SJM T-4 uses FIELD FIELD DRY RELATIVE PTH (ft) SAMPLE DESCRIPTION SYMBOL MOISTURE (%) DENSITY (pet) COMPACTION (%) - 0 -FILL faf>: Sandy clay. Brown color. Moist. Soft. ST-1 CL FILL faf>: Sandy clay. Brown color. Moist. Soft. ST-1 CL -FORMATIONAL ROCK (Ts): Fine sandy siltstone. Grey color. Deeply weathered. Soft ST-4 MH / - 5 - • ) FORMATIONAL ROCK (Ts): Fine sandy siltstone. Grey color. Deeply weathered. Soft ST-4 MH ' / 22.0 106.0 95.5 -10- • ) Pinch-out lens of medium sand. Trace of clay. Red-brown color. Friable. Some gravel and small rock. ST-3 SC/GC / 22.4 108.0 97.7 -10-• 1 Fine sandy siltstone / claystone. Grey color. Maroon colored staining. Polished surfaces. Fractured. Grades blocky at 9'. ST-4 MH/CH ( 21.2 106.9 96.7 - \ Fine sandy siltstone / claystone. Grey color. Maroon colored staining. Polished surfaces. Fractured. Grades blocky at 9'. ST-4 MH/CH ( -15- End Test Trench at IOV2. No caving. No groundwater. - 20- VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 TEST TRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 4 T Sand Cone Test M Bulk Sample • Chunk Sample O Driven Rings Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T-5 uses SYMBOL FIELD MOISTURE m FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DEPTH (ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE m FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) 0 - • FILL - ALLUVIUM (af-Qal): Sandy clay. Pale brown color. Moist. Soft. ST-1 CL 0 - • Clayey sand. Finegrained. Dark brown color. Moist. Loose to medium dense. ST-2 SC - 5 -• • • Clayey sand. Finegrained. Dark brown color. Moist. Loose to medium dense. ST-2 SC 11.9 13.1 109.0 110.8 84.1 85.5 - 5 -• • • TERRACE DEPOSIT (Qt): Clayey sand. Red-brown color. Moist, Medium dense. White carbonate stringers and 3"-6" diameter sub-angular rock below 11'. ST-2 1 SC 11.9 13.1 109.0 110.8 84.1 85.5 -10- - 15- • • j TERRACE DEPOSIT (Qt): Clayey sand. Red-brown color. Moist, Medium dense. White carbonate stringers and 3"-6" diameter sub-angular rock below 11'. ST-2 1 SC 13.9 13.4 106.8 108.5 82.4 83.7 -10- - 15- • • j FORMATIONAL ROCK fTs): Clayey sandstone. Fine grained. Off-white color. Moderately cemented. Somewhat blocky. No apparent structure. ST-2 SC / 13.9 13.4 106.8 108.5 82.4 83.7 • FORMATIONAL ROCK fTs): Clayey sandstone. Fine grained. Off-white color. Moderately cemented. Somewhat blocky. No apparent structure. ST-2 SC / 16.0 102.5 85.5 -20- 1 FORMATIONAL ROCK fTs): Clayey sandstone. Fine grained. Off-white color. Moderately cemented. Somewhat blocky. No apparent structure. ST-2 SC / -20- 1 End Test Trench at le'/z' - extent of backhoe. No caving. No groundwater. Date: 4-11-06 Logged by: SJM T-6 uses FIELD FIELD DRY RELATIVE EPTH (ft) SAMPLE DESCRIPTION SYMBOL MOISTURE (%) DENSITY (pcf) COMPACTION (V.) - 0 -FILLfaf): Clayey sand. Tan color. Moisl. Loose. ST-2 SC - 5 - • TERRACE DEPOSIT (CXi-) Fine sand. Silty. Yellow-tan color. Somewhat blocky. Friable. Moderately cemented. No structure. ST-5 SM/SP 13.3 105.5 88.3 - 10- - 15- End Test Trench at 8'. No caving. No groundwater. - 20- 1 VINJE & MIDDLETON ENGINEERING, INC TEST TRENCH LOGS 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 CAMINO HILLS DRIVE, CARLSBAD Office 760-743-1214 Fax 760-739-0343 PROJECT NO. 06-210-P PLATE 5 V Sand Cone Test Iil Bulk Sample • Chunk Sample O Driven Rings Date: 4-11-06 Logged by: SJM T-7 uses FIELD FIELD DRY RELATIVE DEPTH (ft) SAMPLE DESCRIPTION SYMBOL MOISTURE (%) DENSITY (pcf) COMPACTION (%) 0 - • FILL - ALLUVIUM faf-Qal): Sandy clay. Pale brown color. Moist. Soft. Stiff at 3'. ST-1 CL 26.1 88.9 - 5 - -10- • • TERRACE DEPOSIT fQt): Fine sand. Trace of clay. Tan color. Somewhat blocky. Loose to medium dense. Local clean sand lenses. ST-5 SM/SC 18.9 25.2 99.3 92.8 83.1 77.6 -• n Sandy clay / clayey sand. Brown color. Some rust - colored staining. Blocky. Medium dense. ST-1 SC/CL 22.5 25.7 98.3 95.7 • - 15- -End Test Trench at^4%'. No caving. No groundwater. -20- Date: 4-11-06 Logged by: SJM ' -PTH (ft) SAMPLE T-8 uses SYMBOL FIELD MOISTURE (•/.) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION ' -PTH (ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE (•/.) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION - 0 - - 5 -• FILL- ALLUVIUM faf-Qal): Clayey sand. Fine to medium grained. Red-brown color. Moist. Very loose to loose. ST-2 SC 11.9 101.6 78.4 - 0 - - 5 -• Clayey sand. Dark brown color. MoisL Blocky. Medium dense. Color changes to red-brown color at 10". ST-2 SC 11.9 101.6 78.4 - 10- • FORMATIONAL ROCK (Ts): Sandstone. Fine grained. Trace of clay. Grey to yellow- tan. Deeply weathered. Weakly to moderately cemented. Friable. Local rust-colored staining. ST-5 SC 1 12.7 12,2 113.6 104.1 87.9 80.3 15 • FORMATIONAL ROCK (Ts): Sandstone. Fine grained. Trace of clay. Grey to yellow- tan. Deeply weathered. Weakly to moderately cemented. Friable. Local rust-colored staining. ST-5 SC 1 13,7 94.9 79.4 1 \J - 20- End Test Trench at 15'. No caving. No groundwater. VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 TEST TRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 6 T Sand Cone Test Bulk Sample • Chunk Sample Q Driven Rings Date: 4-11-06 Logged by: SJM DEPTH (ft) SAMPLE T-9 uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) DEPTH (ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) 0 -FILL- ALLUVIUM faf-Qal): Sandy clay. Pale brown color. Moist. Sofl. ST-1 CL - ' \ FILL- ALLUVIUM faf-Qal): Sandy clay. Pale brown color. Moist. Sofl. ST-1 CL - ' \ Fine sandy silt. Grey color. Moist. Sofl. ST-4 MH / llllllllll llllllllll • • • • Fine sandy silt. Grey color. Moist. Sofl. ST-4 MH / 18.3 12.2 13.1 16.9 179 96.1 110.6 110.9 99.1 99.3 80.4 92.6 92.8 83.0 83.1 llllllllll llllllllll • • • • TERRACE DEPOSIT (Ot): Sandstone. Fine grained wilh clay. Yellow-tan color. Moist. Weakly cemented. Weathered. Becomes somewhat blocky at 7'. Local rust - colored staining below 11'. ST-5 SC 18.3 12.2 13.1 16.9 179 96.1 110.6 110.9 99.1 99.3 80.4 92.6 92.8 83.0 83.1 llllllllll llllllllll • • • • • FORMATIONAL ROCK (Ts): Fine sandy siltstone. Grey color. Deeply weathered. Plastic ST-4. MH / 18.3 12.2 13.1 16.9 179 96.1 110.6 110.9 99.1 99.3 80.4 92.6 92.8 83.0 83.1 1 - 15-u • • \ • FORMATIONAL ROCK (Ts): Fine sandy siltstone. Grey color. Deeply weathered. Plastic ST-4. MH / 24.3 97.3 88.1 -20- • FORMATIONAL ROCK (Ts): Fine sandy siltstone. Grey color. Deeply weathered. Plastic ST-4. MH / -20- End Test Trench at ISVa. No caving. No groundwater. Date: 4-11-06 Logged by: SJM :PTH .ft) SAMPLE T-10 uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) :PTH .ft) SAMPLE DESCRIPTION uses SYMBOL FIELD MOISTURE (%) FIELD DRY DENSITY (pcf) RELATIVE COMPACTION (%) - 0 -FILL/TOPSOIL: Clayey sand. Red-brown color. Moist. Loose. ST-2 CL - 0 - TERRACE DEPOSIT (Qt): Silty fine sand. Trace of clay. Red-brown color. Locally blocky. Friable. Some rust-colored staining. ST-5 SM/SC - 6 - TERRACE DEPOSIT (Qt): Silty fine sand. Trace of clay. Red-brown color. Locally blocky. Friable. Some rust-colored staining. ST-5 SM/SC - 6 - Clayey medium to coarse sand. Red-brown color. Medium dense. ST-3 SC - 10 Clayey medium to coarse sand. Red-brown color. Medium dense. ST-3 SC - 10 Sandy clay. Dark grey color. MoisL Blocky. Moderately plastic. Polished surfaces. ST-4 CH \ / Sandy clay. Dark grey color. MoisL Blocky. Moderately plastic. Polished surfaces. ST-4 CH \ / - 1 Sandy clay. Dark grey color. MoisL Blocky. Moderately plastic. Polished surfaces. ST-4 CH \ / - 1 Clayey sand. Brown color. Rust-colored staining. Local polished surfaces. Blocky. Medium dense. ST-2 SC 15 \ Clayey sand. Brown color. Rust-colored staining. Local polished surfaces. Blocky. Medium dense. ST-2 SC - 20- \ Fine sandy silt. Grey color. Blocky. Polished surfaces. Medium dense. ST-4 MH / - 20- End Test Trench at 15'. No caving. No groundwater. VINJE & MIDDLETON ENGINEERING, INC 2450 Vineyard Avenue, Suite 102 Escondido, California 92029-1229 Office 760-743-1214 Fax 760-739-0343 TESTTRENCH LOGS CAMINO HILLS DRIVE, CARLSBAD PROJECT NO. 06-210-P PLATE 7 Sand Cone Test Bulk Sample • Chunk Sample Q Driven Rings BORING LOG B-1 DEPTH FT - 10 15 - 20 25- 30 -35 SAMPLE o 12,20 H 5,9,4 6.10,13 5.10,13- 40 Description FILL fafl: Clayey sand. Brown color. Slightly moist. Loose. ST-2 TERRACE DEPOSIT (Qt): Medium to coarse sand. Clay binder. Red-brown color. MoisL ST-3 Sandy clay. Olive-brown color. Moist. Stiff. Plastic. Local grey-colored staining. Weathered reflection of underlying siltstone. ST-4 FORMATIONAL ROCK fTs): Sandy siltstone. Pale grey color. Friable. Firm. Weathered, ST-4 End Boring at 19y2'. No caving. No groundwater. uses SYMBOL SC SC CL/CH MH MOISTURE (%) 17,4 DRY DENSITY (PCF) 113.8 RELATIVE COMPACTION {%) 87,8 Project;, CAIVIINO HILLS DRIVE. CARLSBAD Project No: 06-210-P Date Drilled: 5-25-06 .Logged By:. SM Truck-mounted rotary drill. 8" hollow-stem auger. Drill, Sample IVlethQd: 140-lb, Hammer, 30" hydraulic drop. 5' AW Rods. Bulk Sample • Ring Sample O SPT Sample |i Groundwater SL PLATE 8 VINJE & MIDDLETON ENGINEERING, INC. BORING LOG B-2 DEPTH FT 0 - 5 - 10- SAfAPLE 3,2.2 3.5,7 Description FILL-ALLUVIUM faf-Qal): Clayey sand I sandy clay. Brown color. Slightly moist. Soft. ST-1 Clayey silt. Grey color. Moist. Soft. ST-5 Sandy clay. Red-brown color. Moist to very moist. Soft. Plastic. ST-1 USGS SYMBOL SC/CL MH CL/CH MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 15- 20 O 9.18 Clayey sand. Red-brown color. Moist. Loose to medium dense. Color Chang es to pale brown at 18'. ST-2 18,3 110.1 SC 4,4.6 84.9 25- -30- 35 40 O 12,24 TERRACE DEPOSIT fQt): Sandy clay. Dark brown color. Moisl. Stiff. Plastic. ST-1 CL/CH 8,13,18 10,11.14 FORMATIONAL ROCK (Ts): Sandy siltstone. Pale grey color. Weathered soft and plastic in upper exposures. Fractured and friable below. Local rust-colored staining. Medium dense. Groundwater encountered at approximately 33'. Becomes somewhat blocky and dense at 39'. Continued rust-colored staining. ST-4 MH 19,20,24 End Boring at AQV2. No caving. Groundwater encountered at 33'. 16.9 114.6 95.8 r I Project: CAIVIINO HILLS DRIVE. CARLSBAD Project No: 06-210-P Date Drilled: 5-25-06 Logged By: SM Truck-mounted rotary drill, 8" hollow-stem auger. Drill, Sample Method: 140-Ib. Hammer, 30" hydraulic drop, 5" AW Rods. Bulk Sample Ring Sample SPT Sample Groundwater PLATE 9 O BORING LOG B-3 DEPTH FT SAMPLE Description uses SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 0 FILL-ALLUVIUM faf-Qal): Clayey sand. Brown color. Slightly moisL Loose. ST-2 SC 5 - 10. -15 -20- -25- -30- 35- -40- TU 13.20 11,12,13 O 18,20 6,10.14 o 13,22 7,13,14 Medium to coarse sand. Clay binder. Red-brown color. Friable. Medium dense. ST-3 SC 9.0 113.2 Silty fine sand. Tan color. Firm to medium dense. ST-5 SM Medium sand. Trace of clay. Red-brown color. Friable, Medium dense. ST-3 SC Clayey fine sand. Red-brown to tan color. Medium dense. Local rust and grey colored staining. Massive. ST-5 SC Medium to coarse sand. Includes gravel and pebbles. Red-brown color. Very moist. Groundwater at approximately 32'. Loose to firm. Blow counts for 34' sample inflated due to pebbles. Wafer added to aid drilling. Caving below 32' prohibited further sampling. ST-3 SP/GP O 12,35. End Boring at 39'. Caving 35' - 39'. Groundwater at 32'. 9.7 113.8 16.2 109.5 20.3 1107 97.3 87.8 91.6 92.6 Project:, CAMINO HILLS DRIVE. CARLSBAD Project No: 06-210-P Drill, Sample Method: Date Drilled: 5-25-06 .Logged By:_ SM Truck-mounted rotary drill. 8" hollow-stem auger. 140-lb, Hammer, 30" hydraulic drop. 5' AW Rods. Bulk Sample Ring Sample SPT Sample Groundwater PLATE 10 O VINJE & MIDDLETON ENGINEERING, INC. BORING LOG B-4 DEPTH FT 0 - - 5 10- 15 -^20- 25 - 30- 35- 40- SAMPLE 9,8,5 O 11,14 Description FILL-ALLUVIUM faf-Qal): Clayey sand. Brown color. Slightly moist. Loose. ST-2 Medium to coarse sand. Clayey sand. Red-brown color. Loose to firm. ST-3 Fine sand. Red-brown color. Weakly cemented. Friable. Massive. Medium dense. ST-5 USGS SYMBOL SC SC SP 9,10,14 o 8,12,17 I TERRACE DEPOSIT (Qt): Clayey sand. Includes gravel and pebbles. Red- brown color. Medium dense. ST-2 Medium to coarse sand with gravel and pebbles. Red-brown color. Medium dense. ST-3 End Boring at 20'. No caving. No groundwater. SC/GC GP MOISTURE m 11.7 5.8 DRY DENSITY (PCF) 106.2 RELATIVE COMPACTION (V.) 88.8 109.5 91,6 r I Project: CAMINO HILLS DRIVE. CARLSBAD Project No: 06-210-P Drill, Sample Method: Date Drilled: 5-25-06 .Logged By:. SM Truck-mounted rotary drill, 8" hollow-stem auger, 140-lb, Hammer, 30" hydraulic drop. 5' AW Rods, Bulk Sample Ring Sample SPT Sample Groundwater PLATE 11 O II 2 VINJE & MIDDLETON ENGINEERING, INC. PLATE 12 120- 100 exlSTDVG Sn. vcTURE TO BE DEMO) {SUED 120- lOO - B-4 (proj.) SCALE; 1"=30' V&M JOB #06-210-P PLATE 13 160 140- 120 - 100 120 100 160 - 140- 120- 100 - SCALE: J"=30' V&M JOB #06-210-P Originut ground .surface approjdnmled frojn County of San Die.gv Topographic Survey Map No. s 35^-1 ()77 Si 354-17)83, dnlcd 1975. PUiTE 14 150 -Ft PROPOSED GRADE iOO- 1' J FOMMATIOMM^ MOCK — B-2 (proj.] - 100 TEMMAm BEFOBET:: so r SCALE: r=50* FAULT - EPICENTER MAP SAN DIEGO COUNTY REGION INDICATED EARTHQUAKE EVENTS THROUGH 75 YEAR PERIOD (1900-1974) Map data is compiled from various sources including California Division of Mines and Geology, California Institude of. Technology and the National Oceanic and Atmospheric Administration. Map is reproduced from California Division of Mines and Geology, "Earthquake Epicenter Map of California; Map Sheet 39." Earthquake Magnitude o 4.0 TO 4.9 O 5.0 TO 5.9 6.0 TO 6.9 ' ' ' 7.0 TO 7.9 - Fault. PROJECT: Job #06-210-P CAMINO HILLS DRIVE. CARLSBAD PLATE: 15 U. S, STANDARD SIEVE IN INCHES U, S. STANDARD E NUMBERS 1 0.5 GRAIN SI2£ MIUIMETERS 0,1 0,05 HYDROMETER 0.01 0.005 0,001 Cobbles Gravel Coarse Fine Sand Ceaesa (o medlunn Rne SILT OR CLAY SAMPLE # DEPTH <FEET) SYMBOL CLASSIRCATION NAT W% LL PL PI PROJECT: 06-210-P T-1 1 • CL/CH -45 24 23 ADDRESS: CAMINO HILLS DRIVE T-1 4 SC/CL 12.9 32 16 16 CARLSBAD DATE: JUNE, 2006 PLATE 16 VINJE AND MIDDLETON ENGINEERING, INC. U. S. STANDARD SIEVE IN INCHES U. S. STANDARD o o E NUMBERS o g HYDROMETER 100 1 0.5 GRAIN SIZE MILLIMETERS 0,1 0,05 0.01 0.005 100 0.001 Cobbles Gravel Sand SILT OR CLAY Coarse Fine Coaeso to medium Fine SILT OR CLAY SAMPLE # DEPTH (FEET) SYMBOL CLASSPHCATION NAT W% LL PL PI PROJECT: 06-210-P T-2 5 • SC/SM 23.6 36 25 11 ADDRESS: CAMINO HILLS DRIVE T-3 3 , CL/CH 28.6 49 27 22 CARLSBAD DATE: JUNE, 2006 PLATE 17 VINJE AND MIDDLETON ENGJWEERING, INC. SAItflPLE (FEET) SYIUIBOL EKFLAMAT80M T-1 4 • •=™====—===-^^ FIELD IVIOISTURE ^ SAMPLE SATURATED _ _ _ REBOUND SampIg condition j 1.O70 1.060 1.050 1,040 1,030 1.020 1.010 1.000 0.990 0,980 0.970 0.960 0.950 0.940 0.930 o o 4— o ooo o ooo CM CO '<t U> o o o o o CM ooo ooo ooo o o o o ooo ooo ooo o ooe CM CO rl- lO o o o NORMAL LOAD (PSF) 06-210-P LOAD CONSOLIDATION TEST PLATE PLATE 18 VINJE & MIDDLETON ENGINEERING, INC. SAMPLE DEPTH (FEET) SYMBOL EXPLANATION T-3 3 A • — — FIELD MOISTURE . _ _ _ „ SAMPLE SATURATED REBOUND Sample condition j 1.070 1.060 1.050 1.040 1.030 1,020 1.010 1.000 0,990 0.980 0.970 0.960 0.950 0.940 0.930 o o o o o o M CO O O o o ^ IO o o o o o CM ooo o o o O Q O CO ^ H> o o o o NORMAL LOAD (PSF) -4 1 \ \ 1 \ \ \ •K. \ L \ o o CM ooo ooo ooo ooo rt If) o o o o o .OB #06-210-P LOAD CONSOLIDATION TEST PLATE PLATE 19 VINJE & MIDDLETON ENGINEERING, INC. RETAINING WALL (See report lor backcut specifications and bearing soil preparation) Wall drain Bench as directed in the field -Minimun^ equiptment width M 75' min. f YFIIOAL STAEELIlAf HOM Wmh\ OM MimiMIM© WA\LL EL CAMINO REAL AT CAMIN(D HILLS DRIVE. CARLSBAD CONSTRUCTION NOTES * Construct bacl<-cut at 1/2:1 gradient ' Heel keyway into hillside 2% * Recompact soil to minimum 90% ol laboratory standard * Trim excess soil to linish grade PLATE 20 06-210-P ISOLATION jniMTS AND RE-ENTRANT CORNER REINFORCEMENT Typical - no scale RE-ENTRANT CORNER REINFORCEMENT NO. 4 BARS PLACED I.5" BELOW TOP OF SLAB RE-ENTRANT CORNER CRACK NOTES: 1. Isolation joints around the colunnns should be either circular as shown in (a) or dianaond shaped as shown in (b). If no isolation joints are used around columns, or if the corners of the isolation Joints do not meet the contraction joints, radial cracking as shown in (c)may occur (reference ACI). 2. In order to control cracking at the re-entrant corners (±270° corners), provide reinforcement as shown in (c). 3. Re-entrant corner reinforcement shown herein is provided as a general guideline only and is subject to verification and changes by the projeci architect and/or structural engineer based upon slab geometry, location, and other engineerinig and construction factors. VINJE & MIDDLETON ENGINEERING, INC. PLATE 21 RETAINING WALL DRAIN DETAIL Typical - no scale Waterproofing Perforated droin pipe droinoge • Gronulor, non-expansive ' backfill. Compacled. •:-viu.-/.'>\-.'/ Filter Moferial. Crushed rock (wrapped in filler fobric) or Class 2 Permeable Material (see specificotions below) Competent, approved soils or bedrock CONSTRUCTION SPECIFICATIONS: , , ^ «t,R(«ljSTBWAi>;f 1^ roo 3/4;'" ''^7'--' ',r'5«-lbO; ' %i-^^'7S7f V>vt??-^.: No 200 " 0-3 Sand Equivalent > 75 1. Provide granular, non-expansive backfill soil in 1:1 gradient wedge behind wall. Compact backfill to minimum 90% of laboratory standard. 2. Provide back drainage for wall to prevent build-up of hydrostatic pressures. Use drainage openings along base of wall or back drain system as outlined below. 3. Backdrain should consist of 4" diameter PVC pipe (Schedule 40 or equivalent) with perforations down. Drain to suitable outiet at minimum 1%. Provide V/" - crushed gravel filter vwapped in filter fabric (Mirafi 140N or equivalent). Delete filter fabric wrap if Caltrans Class 2 permeable material is used. Compact Class 2 material to minimum 90% of laboratory standard. 4. Seal back of wall with waterproofing in accordance with architect's specifications. 5. Provide positive drainage to disallow ponding of water above wall. Lined drainage ditch to minimum 2Vo flow away from wall is recommended. * Use 114 cubic foot per foot with granular backfill soil and 4 cubic foot per foot if expansive backfill soii is used. VINJE & MIDDLETON ENGINEERING, INC. PLATE 22