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Home My WebLink AboutRP 14-10; Laguna Breeze Condominiums; Redevelopment Permits (RP) (4)AGS ZEPHYR PARTNERS 700 2"'' Street Encinitas, CA 92024 ADVANCED GEOTECHNICAL SaUTIONS, INC. 9707 Waples Street, Suite 150 San Diego, California 92121 Telephone: (619) 708-1649 Fax: (714) 409-3287 June 16,2014 PAV 1406-03 Report 1406-03-B-2 Attention: Mr. Jim McMenamin Subject: Preliminary Geotechnical Investigation, Laguna Breeze Condominium Project, 735 Laguna Drive, Carlsbad, California References: See Appendix A Gentlemen: Tn accordance with your request, presented herein are the results of Advanced Geotechnical Solutions, Inc.'s (AGS) preliminary geotechnical investigation for the proposed residential condominium project, Laguna Breeze, located at 735 Laguna Drive, Cadsbad, Califomia. In accordance with our proposal, AGS conducted a preliminary geotechnical investigation of the proposed project site. Tn preparing this report AGS has utilized the 10-scale Preliminary Grading Plan prepared by Landmark Consulting and the referenced geotechnical letters and reports prepared by Vinje & Middleton Engineering, Tne (V&M). Key geotechnical/geologic elements identified onsite that will affect the proposed development and which should be considered in the design and constraction of the project include the following: • Unsuitable soil removals. • Excavation characteristics of soil and bedrock unit. • Undercut recommendations for building pads and improvements. • Grading recommendations. • Preliminary foundation design recommendations in anticipation of as-graded soil characteristics. The recommendations presented in this report are based on AGS's recent observations, familiarity with the area and the information in the previous geotechnical investigation prepared by V&M. Tt is AGS's opinion, from a geotechnical standpoint, that the subject site is suitable for constraction of the proposed multi-family residential development and associated improvements, provided the recommendations presented in this report are incorporated into the design, planning and constraction. Included in this report are: 1) engineering characteristics of the onsite soils; 2) unsuitable soil removal recommendations; 3) grading recommendations; 4) foundation design recommendations; and 5) flatwork recommendations. ORANGE AND L.A. COUNTIES (714) 786-5661 INLAND EMPIRE (619) 708-1649 SAN DIEGO AND IMPERIAL COUNTIES (619) 850-3980 June 16, 2014 PAV 1406-03 Report No. 1406-03-B-2 Advanced Geotechnical Solutions, Inc., appreciates the opportunity to provide you with geotechnical consulting services and professional opinions. If you have questions regarding this report, please contact the undersigned at (619) 708-1649. Respectfully Submitted, Advanced Geotechnical Solutions, Inc. JEFFREY A. CHANEY, Vice President RCE 46544/GE 2314, Reg. Exp. 6-30-15 PAUL J. DERISI, Vice President CEG 2536, Reg. Exp. 5-31-15 Distribution: (3) Addressee Attachments: Figure 1 - Site Location Map Plate 1 - Geologic Map and Exploration Location Plan Appendix A - References Appendix B - Field and Lab Data Appendix C - General Earthwork, Grading Guidelines & Details Appendix D - Homeowner Maintenance Recommendations ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 Pagel PAV 1406-03 Report No. 1406-03-B-2 1.0 INTRODUCTION Ll Purpose and Background The purpose of this report is to provide geotechnical recommendations for the design and constraction of the Laguna Breeze condominium development. In preparing this report, AGS has reviewed the enclosed 10-scale Preliminary Grading Plan prepared by Landmark Consulting. Pertinent subsurface information and laboratory data are included herein. 1.2 Scope of Work The scope of our study consisted of the following: > Review of available geologic and geotechnical literature. > Provide remedial grading recommendations, including undercuts for building pads and underground improvements. > Earthwork specifications. > Estimation of shrink/swell parameters of the various onsite earth materials. > Use of onsite soils as a foundation medium. > Bearing and friction values. > Preliminary foundation design. > Preliminary pavement design. > Design parameters for conventional retaining walls. > Preparation of this report with appropriate exhibits. > Limited slope stability analysis. 1.3 Site Location and Description Currently, the subject site consists of a two contiguous lots, one vacant and one supporting an existing single family stracture. The site is relatively level and encompasses approximately 9,000 square feet. Existing elevations at the site range from a low of 44 msl on the west side to a high of 49 msl on the east side. The site is bounded to the east and south by existing residentiai properties, to the north by Laguna Drive, and to the west by Madison Street. Existing improvements on the easterly lot consist of a single-family residential stracture and associated improvements including retaining and privacy walls. 1.4 Report Limitations The conclusions and recommendations in this report are based on data developed during the referenced geotechnical investigation prepared by V&M, a review of readily available geologic and geotechnical information, and the proposed grading plan prepared by Landmark Consultants. The materials immediately adjacent to, or beneath those observed in the exploratory excavations may have different characteristics and no representations are made as to the quality or extent of materials not observed. The recommendations presented herein are specific to the development ADVANCED GEOTECHNiCAL SOLUTIONS, INC. June 16,2013 Page 2 PAV 1406-03 Report No. 1406-03-B-2 plans reflected on the current grading plan. Modifications to that design or development plans could necessitate revisions to these recommendations. 2.0 PROPOSED DEVELOPMENT As AGS understands the proposed site development the existing stracture and improvements will be removed and the two lots will be graded to support three separate condominium stractures. The condominium stractures will be 3-story "stacked flats" with a garage and living area on the first floor and two additional stories of living area above. One building will support three condominium units with the remaining two buildings supporting one condominium unit each. It is anticipated that the buildings will be wood frame stmctures supported by conventional slab-on-grade or post-tensioned foundations. Access will be provided by a driveway from Madison Street. Based upon the Preliminary Grading Plan prepared by Landmark Consulting it is our understanding that cuts and fills will be less than 3 to 4 feet and proposed cut and fill slopes will be constracted to a maximum height of 2 to 3 feet. 3.0 SUBSURFACE INVESTIGATION AGS has utilized the previous subsurface investigation and laboratory testing by V&M in preparing this report. This previous subsurface investigation consisted of the logging, sampling and testing of three 8-inch diameter hollowstem auger borings (B-1 thra B-3) and three 6-inch diameter solid stem auger borings (B-4 thra B-6). During their work the onsite soil and bedrock was sampled and laboratory testing performed to aid in the determination of the engineering properties of the onsite soils, and evaluate whether any adverse geotechnical conditions were present. The approximate locations of the borings are depicted on Plate 1. Logs of these borings are presented in Appendix B. Laboratory data generated from these borings is also presented in Appendix B. 4.0 ENGINEERING GEOLOGY 4.1 Regional Geologic and Geomorphic Setting The subject site is situated within the Peninsular Ranges Geomorphic Province. The Peninsular Ranges province occupies the southwestem portion of Califomia and extends southward to the southem tip of Baja Califomia. In general, the province consists of young, steeply sloped, northwest trending mountain ranges underlain by metamorphosed Late Jurassic to Early Cretaceous-aged extmsive volcanic rock and Cretaceous-aged igneous plutonic rock of the Peninsular Ranges Batholith. The westemmost portion of the province, where the subject site is located, is predominantly underlain by younger marine and non-marine sedimentary rocks. The Peninsular Ranges' dominant stractural feature is northwest-southeast trending crastal blocks bounded by active faults of the San Andreas transform system. 4.2 Subsurface Conditions Based on our review of subsurface excavations, geologic maps and literature, the area of proposed development is covered with a relatively thin veneer of undifferentiated undocumented fill/topsoil which is underlain by Pleistocene-aged Very Old Paralic deposits. These deposits were underlain at depth by Santiago Formadon. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 Page 3 PAV 1406-03 Report No. 1406-03-B-2 4.3 Geologic Units Based on our review of geologic information provided in the geotechnical investigation prepared by V&M (2007), the project area is mantled with a relatively thin veneer of surficial soil (topsoil/undocumented fill) which is underlain by "Terrace Deposits" and "Formational Rock" corresponding to Santiago Formation (Tsa). Current published regional geologic mapping by Kennedy and Tan (2007) has modified the "Terrace Deposits" nomenclature to "Old Paralic Deposits" with a subunit classification to more specifically define the time period and terrace upon which deposition occurred. AGS has changed the previous unit designations to match current published mapping. The following is a brief summary of the encountered geologic units within the proposed development area. Approximate locations of the test pits are shown on Plate 1. Logs are presented in Appendix B. 4.3.1 Topsoil/Undocumented Ardficial Fill (Map Symbol afu) Undifferentiated undocumented artificial fill and topsoil was encountered in all six V&M borings. As encountered, these materials generally consist of pale gray to brown to red brown, silty to fine- grained sand in a dry to slightly moist and loose condition. These materials overlay old paralic deposits and were found to range from a few feet thick to approximately eight and one-half (8.5) feet thick in boring B-6. Locally deeper undocumented artificial fill and topsoil may exist at the site. 4.3.2 Old Paralic Deposits, Units 6-7 (Map Symbol Qope-?) Old paralic deposits (previously referred to as Terrace Deposits by V&M) were encountered in all six borings beneath the undifferentiated topsoil and undocumented fill soils. As encountered, these materials generally consist of interbedded brown to gray with iron oxide development, silty clay and silty to clayey fine- to medium-grained sand in a moist to wet and medium firm/dense to very stiff/very dense condition. Perched groundwater was encountered as shallow as eight feet below existing grade in boring B-5. 4.3.3 Santiago Formation (Map Symbol Tsa) "Formational Rock" corresponding to Tertiary-aged Santiago Formation was encountered beneath the old paralic deposits in borings B-l and B-2 at depths of 29 and 28 feet below ground surface, respectively. As encountered, these materials generally consist of off-white, fine- to medium-grained sandstone in a dense very dense condition. Santiago Formation is not anticipated to be encountered during site development. 4.4. Groundwater Perched groundwater was encountered in five of the six borings during V&M's site exploration in late September 2007. In general, the perched groundwater encountered onsite is found at or above clay soil lenses contained within the interbedded old paralic deposits. At the time of V&M's exploration, the perched groundwater was encountered deeper than 8 feet below existing grade. However, it should be noted that localized perched groundwater could develop closer to finished grade, due to fluctuations in precipitation, irrigation practices, or factors not evident at the time of our field explorations. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 4 PAV 1406-03 Report No. 1406-03-B-2 4.5 Faulting and Seismicitv The site is located in the tectonically active Southern Califomia area, and will therefore likely experience shaking effects from earthquakes. The type and severity of seismic hazards affecting the site are to a large degree dependent upon the distance to the causative fault, the intensity of the seismic event, and the underlying soil characteristics. The seismic hazard may be primary, such as surface rapture and/or ground shaking, or secondary, such as liquefaction or dynamic settlement. The foliowing is a site-specific discussion of ground motion parameters, earthquake-induced landslide hazards, settlement, and liquefaction. The purpose of this analysis is to identify potential seismic hazards and propose mitigations, if necessary, to reduce the hazard to an acceptable level of risk. The following seismic hazards discussion is guided by the California Building Code (2013), CDMG (2008), and Martin and Lew (1998). 4.5.1 Surface Fault Rupture No known active faults have been mapped at or near the subject site. The nearest known active surface fault is the Oceanside section of the Newport-Tnglewood-Rose Canyon fault zone which is approximately 2 miles west of the subject site. Accordingly, the potential for fault surface rapture on the subject site is very low to remote. This conclusion is based on literature and map review. 4.5.2 Seismicity As noted, the site is within the tectonically active southem Califomia area, and is approximately 6 miles from an active fault, the Oceanside section of the Newport-Inglewood-Rose Canyon fault zone. The potential exists for strong ground motion that may affect future improvements. At this point in time, non-critical stractures (commercial, residential, and industrial) are usually designed according to the Califomia Building Code (2013) and that ofthe controlling local agency. However, liquefaction/seismic slope stability analyses, critical stractures, water tanks and unusual stractural designs will likely require site specific ground motion input. 4.5.3 Liquefaction Due to dense nature of the Old Paralic Deposits and Santiago Formation, and the remedial grading as proposed herein, the potential for seismically induced liquefaction is considered remote. 4.5.4 Dynamic Settlement Dynamic settlement occurs in response to an earthquake event in loose sandy earth materials. This potential of dynamic settlement at the subject site is considered to be remote due to the presence of well consolidated old paralic deposits and the absence of loose, sandy soils after the remedial grading recommended herein is completed. 4.5.5 Seismically Induced Landsliding Evidence of landsliding at the site was not observed during our field observations, nor are there any geomorphic features indicative of landsliding noted in our review of published geologic maps. Further, given the relatively flat nature of the site older, the likelihood for seismically induced landsliding is considered to be remote. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 5 PAV 1406-03 Report No. 1406-03-B-2 4.6 Non-seismic Geologic Hazards 4.6.1. Mass Wasting No evidence of mass wasting was observed onsite nor was any noted on the reviewed maps. 4.6.2. Flooding According to available FEMA maps, the site is not in a FEMA identified flood hazard area. 4.6.3. Subsidence/Ground Fissuring Due to the presence of the dense underlying materials, the potential for subsidence and ground fissuring due to settlement is unlikely. 5.0 ENGINEERING ANALYSIS Presented herein is a general discussion of the geotechnical properties of the various soil types and earth materials summarized from our site-specific analyses of the project and the referenced reports. 5.1 Material Properties 5.1.1 Excavation Characteristics The onsite soils within the anticipated remedial grading depths should be readily excavtable with conventional grading equipment. Deeper excavations (greater than eight feet from original grade) for buried utilities could encountered perched groundwater. Accordingly, dewatering and or additional layback/temporary shoring for constraction may be required efficiently excavate the onsite soils. 5.1.2 Compressibility Onsite materials that are significantly compressible include topsoil, undocumented fill and highly weathered Old Paralic deposits. These materials will require complete removal prior to placement of fill, and where exposed at design grade. If removals are impossible due to property line restraints these improvements should be designed for the total and differential settlement potentials as outlined in Table 5.1.2. Recommended removal depths are presented in Section 7.1, and earthwork adjustment estimates are presented in Section 6.1.5. TABLE 5.1.2 SETTLEMENT POTENTIAL Total (incites) Differential (inches in 20 feet) 3/4 3/8 5.1.3 Expansion Potential Our testing indicates that the upper onsite soils have expansion indices (ET) of 15 and 150 which classifies these soils as having "Very Low" to "Very High" expansion potential (CBC 2013). Generally the onsite soils consist of interbedded sand and silty sands to silty clay. It is anticipated that the expansion potential of the onsite materials will vary from "Low" to "Very High". Final ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 PAV 1406-03 Page 6 Report No. 1406-03-B-2 determination of expansion potential for foundation design purposes should be based on testing of the as-graded soil conditions. 5.1.4 Shear Strength Characteristics Shear strength testing was conducted on "remolded" bulk samples of the onsite soils. Based upon the results of shear testing and our previous experience in the general area with similar soils, the following are assumed shear strengths for compacted fill soils. TABLE 5.1.4 SHEAR STRENGTH Material Cohesion (psf) Friction Angle (degrees) Compacted Fill 50 30 5.1.5 Earthwork Adjustments The following table 5.1.5 presents bulk/shrink values of the various onsite soils for use in estimating earthwork grading quantities. TABLE 5.1.5 SHRINK/SWELL PARAMETERS Topsoil/Undocumented Fill Shrink 8-12% Old Paralic Deposits (Terrace Deposits (V&M)) Bulk 2-5% 6.0 These values may be used in an effort to balance the earthwork quantities. As is the case with every project, contingencies should be made to adjust the earthwork balance when grading is in progress and actual conditions are better defined. 5.1.6 Chemical/Resistivity Analyses Testing of onsite soil samples indicates the soils exhibited "negligible" sulfate exposure when classified in accordance with ACI 318-05 Table 4.3.1 (per 2013 CBC). Accordingly, the use of sulfate resistant concrete is not anticipated. Preliminary resistivity and chloride testing indicates that onsite soils are "moderately" to "severely" corrosive to metals. In the past on similar projects, corrosion protection typically consisted of non- metallic piping for water lines to and below the slabs or by installing above slab plumbing. Consultation with a corrosion engineer is recommended. Final design should be based upon representative sampling of the as-graded soils. GEOTECHNICAL ENGINEERING Development of the subject property as proposed is considered feasible, from a geotechnical standpoint, provided that the conclusions and recommendations presented herein are incorporated ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 7 P/W 1406-03 Report No. 1406-03-B-2 into the design and constraction ofthe project. Presented below are specific issues identified by this study or previous studies as possibly impacting site development. Recommendations to mitigate these issues are presented in the text of this report. 6.1 Site Preparation and Removals Grading should be accomplished under the observation and testing of the project soils engineer and engineering geologist or their authorized representative in accordance with the recommendations contained herein, the current grading ordinance of the City of Carlsbad, and AGS's Earthworic Specifications (Appendix C). Undocumented fill, topsoil, and highly weathered Old Paralic Deposits should be removed in stractural areas planned to receive fill or where exposed at final grade. Removals should expose competent formational materials and be observed and mapped by the engineering geologist prior to fill placement. It is anticipated that the upper three to nine feet of the onsite soils will require removal and recompaction for the support of settlement sensitive stractures. Localized areas may require deeper removals. The resulting imdercuts should be replaced with engineered fill. The extent of removals can best be determined in the field during grading when observation and evaluation can be perfonned by the soil engineer and/or engineering geologist. In general, soils removed during remedial grading will be suitable for reuse in compacted fills, provided they are properly moisture conditioned and do not contain deleterious materials. 6.1.1 Stripping and Deleterious Material Removal Existing vegetation, trash, debris from site demolition activities, and other deleterious materials should be removed and wasted from the site prior to removal of unsuitable soils and placement of compacted fill. 6.1.2 Topsoil/Undocumented Fill (Map Symbol afu) Undocumented fill soil will require complete removal and recompaction to project specifications where encountered below proposed settlement sensitive stractures or improvements. Estimated depths of removal are from two to eight and one-half feet. Locally deeper areas may be encountered. Based on V&M's field exploration, it is anticipated that undocumented fills onsite will be encountered throughout the site. 6.1.3 Old Paralic Deposits - Units 6-7 (Map Symbol Qopa-?) It is anticipated that the existing Old Paralic Deposits (previously mapped as Terrace Deposits) are generally considered to be suitable for support of settiement sensitive stractures. A thin veneer of highly weathered materials at the upper boundary of the unit could require partial removal prior to fill placement in stractural fill areas. Final determination will be made in the field during grading. 6.1.4 Santiago Formation (Map Symbol Tsa) The Santiago Formation is relatively deep onsite (> 28 feet below existing grade) and is not anticipated to be encountered during site development. However, if encountered the Santiago Fonnation is suitable for support of settlement sensitive stractures in its cunent state. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 8 P/W 1406-03 Report No. 1406-03-B-2 6.2 Slope Stabilitv and Remediation Cut and Fill slopes onsite will be graded at 2:1 slope inclinations and are anticipated to be less than three feet onsite. Further, with the proposed remedial grading the cut slope will be replaced as compacted fill slopes. Accordingly, the proposed fill slopes are anticipated to be globally and surficially stable when graded in conformance the City of Carlsbad specifications and our recommendations 6.3 Temporarv Backcut Stability During grading operations, temporary backcuts may be required to accomplish remedial grading. Backcuts in undocumented fill, topsoil, and bedrock areas should be made no steeper than 1:1. Where property limits make 1:1 backcuts impossible, removals can be made utilizing "trenching" methods such that the removals are made and then backfilled and compacted as soon as possible. In consideration of the inherent instability created by temporary constraction backcuts, it is imperative that grading schedules are coordinated to minimize the unsupported exposure time of these excavations. Once started, these excavations and subsequent fill operations should be maintained to completion without intervening delays imposed by avoidable circumstances. Tn cases where five-day workweeks comprise a normal schedule, grading should be planned to avoid exposing at-grade or near-grade excavations through a non-work weekend. Where improvements may be affected by temporary instability, either on or offsite, further restrictions such as slot cutting, extending work days, implementing weekend schedules, and/or other requirements considered critical to serving specific circumstances may be imposed. 6.4 Construction Staking and Survev Removal bottoms, keyways, subdrains and backdrains should be surveyed by the civil engineer after approval by the geotechnical engineer/engineering geologist and prior to the placement of fill. Toe stakes should be provided by the civil engineer in order to verify required key dimensions and locations. 6.5 Earthwork Considerations 6.5.1 Compaction Standards Fill and processed natural ground shall be compacted to a minimum relative compaction of 90 percent as determined by ASTM Test Method: D 1557. Care should be taken that the ultimate grade be considered when determining the compaction requirements for disposal fill areas. Compaction shall be achieved at slightly above the optimum moisture content, and as generally discussed in the attached Earthwork Specifications (Appendix C). 6.5.2 Documentation of Removals and Drains Removal bottoms fill keys, backcuts, backdrains and their outlets should be observed and approved by the engineering geologist and/or geotechnical engineer and documented by the civil engineer prior to fill placement. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 Page 9 PAV 1406-03 Report No. 1406-03-B-2 6.5.3 Treatment of Removal Bottoms At the completion of removals, the exposed bottom should be scarified to a practical depth, moisture conditioned to above optiraum conditions, and compacted in-place to the standards set forth in this report. 6.5.4 Fill Placement After removals, scarification, and compaction of in-place materials are completed, additional fill may be placed. Fill should be placed in thin lifts [eight- (8) inch bulk], moisture conditioned to slightly above the optimum moisture content, mixed, compacted, and tested as grading progresses until final grades are attained. 6.5.5 Benching Where the natural slope is steeper than 5-horizontal to 1-vertical, and where designed by the project geotechnical engineer or geologist, compacted fill material should be keyed and benched into competent bedrock or firm natural soil. 6.5.6 Mixing In order to provide thorough moisture conditioning and proper compaction, processing (mixing) of materials is necessary. Mixing should be accomplished prior to, and as part of the compaction of each fill lift. 6.6 Haul Roads Haul roads, ramp fills, and tailing areas should be removed prior to placement of fill. 6.7 Import Materials Based on the preliminary earthwork quantities, import soils will likely be required to achieve design site grades. Import materials, should have similar engineering characteristics as the onsite soils and should be approved by the soil engineer at the source prior to importation to thc site. 7.0 CONCLUSIONS AND RECOMMENDATIONS Constraction of the proposed multi-family residential stractures and associated improvements is considered feasible, from a geotechnical standpoint, provided that the conclusions and recommendations presented herein are incorporated into the design and constraction of the project. Presented below are specific issues identified by this study as possibly affecting site development. Recommendations to mitigate these issues are presented in the text ofthis report. 7.1 Design Recommendations It is our understanding that the proposed foundations will consist of either conventionally reinforced or post-tensioned slab-on-grade or 'mat' foundation systems supporting the proposed three-story, wood frame stractures. In addition to the stractures, associated driveways, hardscape and landscape ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 P/W 1406-03 Page 10 Report No. 1406-03-B-2 areas are proposed. From a geotechnical perspective these proposed improvements are feasible provided that the following recommendations are incorporated into the design and constraction. 7.1.1 Foundation Design Criteria The multi-family residential stractures can be supported by either post-tensioned or conventional shallow slab-on-grade foundation systems or mat slab foundation systems. The expansion potential of the underlying soils is anticipated to range from "low" to "high" The following preliminary values may be used in the foundation design. Allowable Bearing: Lateral Bearing: Sliding Coefficient: 2000 Ibs./sq.ft. (Assuming 12-inch embedment, 500 Ibs./sq.ft increase for each additional 6-inches of embedment to a maximum of 3000 Ibs./sq.ft) 250 Ibs./sq.ft. at a depth of 12 inches plus 125 Ibs./sq.ft. for each additional 12 inches embedment to a maximum of 2500 Ibs./sq.ft. 0.35 The above values may be increased as allowed by Code to resist transient loads such as wind or seismic. Building Code and stractural design considerations may govem. Depth and reinforcement requirements should be evaluated by the Stractural Engineer. 7.1.2 Post-Tensioned foundation Design Parameters The following post-tensioned design parameters are presented in Table 7.1 for building pads exhibiting "Low" to "High" expansion potential. TABLE 7.1 Post Tensioned Design Parameters Expansion Potential Lot Category Center Lift Edge Lift Expansion Potential Lot Category Em (ft) Ym (ft) Em (ft) Ym (ft) Low I 9 0.23 5.4 0.54 Medium II 9 0.38 4.6 0.9 High TII 7.5 0.51 3.9 1.26 7.1.3 Conventional Foundation Design Recommendations Based upon the onsite soil conditions and information supplied by thc CBC-2013, conventional foundation systems should be designed in accordance with Section 7.1.1 and the following recommendations: > Three-story - Interior and exterior footings should be a minimum of 18 inches wide and extend to a depth of at least 24 inches below lowest adjacent grade. Footing reinforcement ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Pagell P/W 1406-03 Report No. 1406-03-B-2 should minimally consist of four No. 4 reinforcing bars, two top and two bottom or two No. 5 reinforcing bars, one top and one bottom > Slab - Conventional, slab-on-grade floors or parking garage slabs, underlain by "low to medium" expansive compacted fill, should be five or more inches thick and be reinforced with No. 3 or larger reinforcing bars spaced 15 inches on center each way. For "high" to "very high" expansive compacted fill, should be five or more inches thick and be reinforced with No. 3 or larger reinforcing bars spaced 12 inches on center each way. The slab reinforcement and expansion joint spacing should be designed by the Stractural Engineer. > Embedment - If exterior footings adjacent to drainage swales are to exist within five feet horizontally of the swale, the footing should be embedded sufficiently to assure embedment below the swale bottom is maintained. Footings adjacent to slopes should bc embedded such that a least seven feet are provided horizontally from edge of the footing to the face of the slope. > Garage - A grade beam reinforced continuously with the garage footings shall be constracted across the garage entrance, tying together the ends of the perimeter footings and between individual spread footings. This grade beam should be embedded at the same depth as the adjacent perimeter footings. A thickened slab, separated by a cold joint from the garage beam, should be provided at the garage entrance. Minimum dimensions of the thickened edge shall be six (6) inches deep. Footing depth, width and reinforcement should be the same as the stracture. Slab thickness, reinforcement and under-slab treatment should be the same as the stracture. > Isolated Spread Footings - Isolated spread footings should be embedded a minimum of 24 inches below lowest adjacent finish grade and should at least 24 inches wide. A grade beam should also be constracted for interior and exterior spread footings and should be tied into the stracture in two orthogonal directions footing dimensions and reinforcement should be similar to the aforementioned continuous footing recommendations. Final depth, width and reinforcement should be determined by the stractural engineer. > Presaturation - Prior to concrete placement the subgrade soils should be moisture conditioned to the following: Low Expansion Potential - Minimum of optimum moisture prior to concrete placement. Medium Expansion Potential - Minimum of 120% of optimum moisture at least 24 hours prior to concrete placement. High to Very High Expansion Potential - Minimum of 130% of optimum moisture at least 48 hours prior to concrete placement. 7.1.4 Seismic Design Parameters The following seismic design parameters are presented to be code compliant to the Califomia Building Code (2013). The subject lots have been identified to be Site Class "C" in accordance with CBC, 2013, Section 1613.3.2 and ASCE 7, Chapter 20. The lots are located at Latitude 33.1678° N ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 P/W 1406-03 Page 12 Report No. 1406-03-B-2 and Longitude -117.3506° W. Utilizing this information, the United States Geological Survey (USGS) web tool (http://earthquake.usgs.gov/hazards/designmaps/) and ASCE 7 criterion, the mapped seismic acceleration parameters Ss, for 0.2 seconds and Si, for 1.0 second period (CBC, 2013, 1613.3.1) for Risk-Targeted Maximum Considered Earthquake (MCER) can be determined. The mapped acceleration parameters are provided for Site Class "B". Adjustments for other Site Classes are made, as needed, by utilizing Site Coefficients Fa and Fv for determination of MCER spectral response acceleration parameters SMS for short periods and SMI for 1.0 second period (CBC, 2013 1613.3.3). Five-percent damped design spectral response acceleration parameters SDS for short periods and SDI for 1.0 second period can be determined from the equations in CBC, 2013, Section 1613.3.4. Seismic Design Criteria Mapped Spectral Acceleration (0.2 sec Period), Ss 1.151g Mapped Spectral Acceleration (1.0 sec Period), Si 0.441g Site Coefficient, Fa 1.00 Site Coefficient, Fv 1.359 MCE Spectral Response Acceleration (0.2 sec Period), SMs 1.151g MCE Spectral Response Acceleration (1.0 sec Period), SMi 0.600g Design Spectral Response Acceleration (0.2 sec Period), SDs 0.767g Design Spectral Response Acceleration (1.0 sec Period), SDi 0.400g Utilizing a probabilistic approach, the CBC recommends that stractural design be based on the peak horizontal ground acceleration (PGA) having of 2 percent probability of exceedance in 50 years (approximate retum period of 2,475 years) which is defined as the Maximum Considered Earthquake (MCE). Using the United States Geological Sui^vey (USGS) web-based ground motion calculator, the site class modified PGAM {FJ>GA*PGA) was determined to be 0.455g. This value does not include near-source factors that may be applicable to the design of stractures on site. 7.1.5 Under Slab A moisture and vapor retarding system should be placed below the slabs-on-grade in portions of the stracture considered to be moisture sensitive. The retarder should be of suitable composition, thickness, strength and low permeance to effectively prevent the migration of water and reduce the transmission of water vapor to acceptable levels. Historically, a 10-mil plastic membrane, such as Visqueen, placed between one to four inches of clean sand, has been used for this purpose. More recently Stego® Wrap or similar underlayments have been used to lower permeance to effectively prevent the migration of water and reduce the transmission of water vapor to acceptable levels. The use of this system or other systems, materials or techniques can be considered, at the discretion of the designer, provided the system reduces the vapor transmission rates to acceptable levels. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 PAV 1406-03 Page 13 Report No. 1406-03-B-2 7.1.6 Deepened Footings and Structural Setbacks It is generally recognized that improvements constracted in proximity to natural slopes or properly constracted, manufactured slopes can, over a period of time, be affected by natural processes including gravity forces, weathering of surficial soils and long-term (secondary) settlement. Most building codes, including the California Building Code (CBC), require that stractures be set back or footings deepened, where subject to the influence of these natural processes. For the subject site, where foundations for residential stractures are to exist in proximity to slopes, the footings should be embedded to satisfy the requirements presented in Figure 3. FIGURE 3 FACE OF STRUCTURE H/3 BUT NEED NOT EXCEED 40 FT. MAX. H/2 ~~BUT NEED NOT EXCEED 15 FT. MAX. 7.1.7 Concrete Design Preliminary testing indicates onsite soils exhibit a "negligible" sulfate exposure when classified in accordance with ACT 318-05 Table 4.3.1 (per 2013 CBC). However, some fertilizers have been known to leach sulfates into soils otherwise containing "negligible" sulfate concentrations and increase the sulfate concentrations to potentially detrimental levels. It is incumbent upon the owner to determine whether additional protective measures are wananted to mitigate the potential for increased sulfate concentrations to onsite soils as a result of the fitture homeowner's actions. 7.1.8 Retaining Walls The following earth pressures are recommended for the design of conventional retaining walls onsite: Static Case Level Backfill Rankine Coefficients Coefficient of Active Pressure: Ka = 0.33 Equivalent Fluid Pressure (psf/lin.ft.) 42 ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 P/W 1406-03 Coefficient of Passive Pressure: Kp = 3.00 Coefficient of at Rest Pressure: Ko = 0.50 2 : 1 Backfill Rankine Coefficients Page 14 Report No. 1406-03-B-2 375 63 Equivalent Fluid Pressure (psf/lin.ft.) Coefficient of Active Pressure: Ka = 0.54 Coefficient of At Rest Pressure: Ko = 0.81 67 101 Seismic Case In addition to the above static pressures, unrestrained retaining walls located should be designed to resist seismic loading as required by the 2013 CBC. The seismic load can be modeled as a thrast load applied at a point 0.6H above the base of the wall, where H is equal to the height of the wall. This seismic load (in pounds per lineal foot of wall) is represented by the following equation: Pe = ys *y*tf *kh Seismic thrust load Where: Pe = H = Height ofthe wall (feet) Y = soil density = 125 pounds per cubic foot (pcf) kh = seismic pseudostatic coefficient acceleration / g 0.5 * peak horizontal ground The peak horizontal ground accelerations are provided in Section 7.1.4. Walls should be designed to resist the combined effects of static pressures and the above seismic thrast load. The foundations for retaining walls of appurtenant stractures stracturaUy separated from the building stractures, may bear on properly compacted fill. A bearing value of 3,000 psf may be used for design of retaining walls. Retaining wall footings should be designed to resist the lateral forces by passive soil resistance and/or base friction as recommended for foundation lateral resistance. To relieve the potential for hydrostatic pressure wall backfill should consist of a free draining backfill (sand equivalent "SE" >20) and a heel drain should be constracted (see Figure 4). The heel drain should be place at the heel of the wall and should consist of a 4-inch diameter perforated pipe (SDR35 or SCHD 40) sunounded by 4 cubic feet of crashed rock (3/4-inch) per lineal foot, wrapped in filter fabric (Mirafi* MON or equivalent). Proper drainage devices should be installed along the top of the wall backfill, which should be properly sloped to prevent surface water ponding adjacent to the wall. Tn addition to the wall drainage system, for building perimeter walls extending below the finished grade, the wall should be waterproofed and/or damp-proofed to effectively seal the wall from moisture infiltration through the wall section to the interior wall face. The wall should be backfllled with granular soils placed in loose lifts no greater than 8-inches thick, at or near optimum moisture content, and mechanically compacted to a minimum 90 percent relative compaction as determined by ASTM Test Method D1557. Flooding or jetting of backfill materials generally do not result in the required degree and uniformity of compaction and, therefore, is not recommended. The soils engineer or his representative should observe the retaining wall footings, ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2013 PAV 1406-03 Page 15 Report No. 1406-03-B-2 backdrain installation and be present during placement of the wall backfill to confirm that the walls are properly backfilled and compacted. FIGURE 4 VWTERPROOFNO MEMBRA^E (OPTKmjN PROVIDE SMME 1:1 JIVICRFUTIER ISaSX <<)DBiit«JNCHPERFOmmD/iraORI>VCIVEOII»T(ICWa>EaUnM.E« SUmmffi njICQ) PERFOmilONt DOWII«M) SMROtMieiBVA l«MMWOF1CU8H:fST0l=MIICHflCKX0RWn(0tS>EaUnM£Kr 7.2 Utilitv Trench Excavation All utility trenches should be shored or laid back in accordance with applicable OSHA standards. Excavations in bedrock areas should be made in consideration of underlying geologic stracture. AGS should be consulted on these issues during constraction. 7.3 Utilitv Trench Backfill Mainline and lateral utility trench backfill should be compacted to at least 90 percent of maximum dry density as determined by ASTM D 1557. Onsite soils will not be suitable for use as bedding material but will be suitable for use in backfill, provided oversized materials are removed. No surcharge loads should be imposed above excavations. This includes spoil piles, lumber, concrete tracks or other constraction materials and equipment. Drainage above excavations should be directed away from the banks. Care should be taken to avoid saturation of the soils. Compaction should be accomplished by mechanical means. Jetting of native soils will not be acceptable. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 P/W 1406-03 Page 16 Report No. 1406-03-B-2 7.4 Exterior Slabs and Walkways 7.4.1 Subgrade Compaction The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be compacted to a minimum of 90 percent relative compaction as determined by ASTM D 1557. 7.4.2 Subgrade Moisture The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be moisture conditioned to a minimum of UO (low expansive soils), 120 (medium expansive soils), 130 (high expansive soils) percent of optimum moisture content prior to concrete placement, dependent upon the expansion potential of the subgrade soils. 7.4.3 Slab Thickness Concrete flatwork and driveways should be designed utilizing four-inch minimum thickness. 7.4.4 Control Joints Weakened plane joints should be installed on walkways at intervals of approximately eight to ten feet. Exterior slabs should be designed to withstand shrinkage of the concrete. 7.4.5 Flatwork Reinforcement Consideration should be given to reinforcing any exterior flatwork. 7.4.6 Thickened Edge Consideration should be given to constract a thickened edge (scoop footing) at the perimeter of slabs and walkways adjacent to landscape areas to minimize moisture variation below these improvements. The thickened edge (scoop footing) should extend approximately eight inches below concrete slabs and should be a minimum of six inches wide. 7.5 Pavement Design Preliminary anticipated "R"-Values are anticipated to range from a low of 20 to a high of 40. Final detennination should be made in the field based upon sampling of subgrade soils once rough grading is complete. For preliminary design the following preliminary pavement sections are presented. Location Traffic Index (T.I.) Design R-Value Asphaltic Concrete (in.) Class 2 Aggregate Base (in.) Driveway 5.0 20 3.0 7.5 Driveway 5.0 40 3.0 4.0 ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 17 PAV 1406-03 Report No. 1406-03-B-2 7.6 Plan Review Once approved grading and foundation design plans become available, they should be reviewed by AGS to verify that the design recommendations presented are consistent with the proposed constraction. 7.7 Geotechnical Review As is the case in any grading project, multiple working hypotheses are established utilizing the available data, and the most probable model is used for the analysis. Information collected during the grading and constraction operations is intended to evaluate the hypotheses, and some of the assumptions summarized herein may need to be changed as more information becomes available. Some modification of the grading and constraction recoinmendations may become necessary, should the conditions encountered in the field differ significandy than those hypothesized to exist. AGS should review the pertinent plans and sections of the project specifications, to evaluate conformance with the intent ofthe recommendations contained in this report. Tf the project description or final design varies from that described in this report, AGS must be consulted regarding the applicability of, and the necessity for, any revisions to the recommendations presented herein. AGS accepts no liability for any use of its recommendations if the project description or final design varies and AGS is not consulted regarding the changes. 8.0 SLOPE AND LOT MAINTENANCE Maintenance of improvements is essential to the long-term performance of stractures and slopes. Although the design and constraction during mass grading is planned to create slopes that are both grossly and surficially stable, certain factors are beyond the control of the soil engineer and geologist. Thc homeowners must implement certain maintenance procedures. The following recommendations should be implemented. 8.1 Slope Planting Slope planting should consist of ground cover, shrabs and trees that possess deep, dense root stractures and require a minimum of irrigation. The resident should be advised of their responsibility to maintain such planting. 8.2 Lot Drainage Roof, pad and lot drainage should be collected and directed away from stractures and slopes and toward approved disposal areas. Design fine-grade elevations should be maintained through the life of the stracture or if design fine grade elevations are altered, adequate area drains should be installed in order to provide rapid discharge of water, away from stractures and slopes. Residents should be made aware that they are responsible for maintenance and cleaning of all drainage tenaces, down drains and other devices that have been installed to promote stracture and slope stability. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2013 Page 18 PAV 1406-03 Report No. 1406-03-B-2 8.3 Slope Irrigation The resident, homeowner and Homeowner Association should be advised of their responsibility to maintain inigation systems. Leaks should be repaired immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wastefiil ran-off and ground saturation should be avoided. Tf automatic sprinkier systems are installed, their use must be adjusted to account for natural rainfall conditions. 8.4 Burrowing Animals Residents or homeowners should undertake a program for the elimination of burrowing animals. This should be an ongoing program in order to maintain slope stability. 9.0 LIMITATIONS This report is based on the project as described and the information obtained from the excavations at the approximate locations indicated on the Plate 1. The findings are based on the results of the field, laboratory, and office investigations combined with an interpolation and extrapolation of conditions between and beyond the excavation locations. The results reflect an interpretation of the direct evidence obtained. Services performed by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession cunently practicing in the same locality under similar conditions. No other representation, either expressed or implied, and no wananty or guarantee is included or intended. The recommendations presented in this report are based on the assumption that an appropriate level of field review will be provided by geotechnical engineers and engineering geologists who are familiar with the design and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and conesponding recommendations presented in this report. AGS should be notified of any pertinent changes in the project plans or if subsurface conditions are found to vary from those described herein. Such changes or variations may require a re-evaluation of the recommendations contained in this report. The data, opinions, and recommendations ofthis report are applicable to the specific design of this project as discussed in this report. They have no applicability to any other project or to any other location, and any and all subsequent users accept any and all liability resulting from any use or reuse of the data, opinions, and recommendations without the prior written consent of AGS. AGS has no responsibility for constraction means, methods, techniques, sequences, or procedures, or for safety precautions or programs in connection with the constraction, for the acts or omissions of the CONTRACTOR, or any other person performing any of the constraction, or for the failure of any of them to carry out the constraction in accordance with the final design drawings and specifications. ADVANCED GEOTECHNICAL SOLUTIONS, INC. N SITE LOCATION MAP LAGUNA BREEZE CARLSBAD, CALIFORNIA SOURCE MAP - TOPOGRAPHIC MAP OF THE SAN LUIS REY 7.5 MINUTE QUADRANGLE, SAN DIEGO COUNTY, CALIFORNIA P/W 1406-03 (®AGS FIGURE 1 ADVANCED GEOTECHNICAL SOLUTIONS, INC. 9707 Waples Street, Suite 150 San Diego, Califomia 92121 Telephone: (619) 850-3980 Fax: (714)409-3287 CITY OF CARLSBAD MAJOR REVIEW PERMIT PRELIMINARY GRADING PLANS FOR LAGUNA BREEZE B-1 \ 0-3' Fill/Topsoil 3-29' Qt 29-41' Tsa Water@14'XPerched) Water @^4' (Perched) TD = 41' B-6 0-8.5' Fill/Topsoil 8^-13.5! Qt _ Water® 10' (Pei^ited) TD = 13.5' (Refusal) B-5 0-4' Fill/Topsoil 4-42.5MJt Water @ 8' (Perched) TD = 12.5' ^-4 0-4' Fill/Topsoil 4-15.5'Qt Water© 10' (Perched) TD = 15.5' cnr OF CAKLSBAD PBEmaiURT GIUDIIIG PLAN FOR LAQUNA BREEZE PRELIMINARY GRADING PLAN LEGEND: ^'^ Approximate location of soil boring • (V&M, 2007) gfu Undifferentiated Topsoil/Undocumented Fill (braciteted where buried) Q-_ Old Paralic Deposits, previously mapped "6-7 as Qt (bracketed where buried) Santiago Formation, previously mapped as Fonnational (bracl<eted where buried) PLATE 1 Geologic Map and Exploration Location Plan (0)AGS /\PVANCEP GEOTECHISIIML SOUJTIONS, INC. Project: Report: Date: P/W 1406-03 1406-03-B-2 June 2014 APPENDIX A REFERENCES ADVANCED GEOTECHNICAL SOLUTIONS, INC. REFERENCES American Concrete Institute, 2002, Building Code Requirements for Structural Concrete (ACI318M-02) and Commentary (ACI 318RM-02), ACI International, Farmington Hills, Michigan. American Society for Testing and Materials, 2008, Annual Book of ASTM Standards, Section 4, Construction, Volume 04.08, Soil and Rock (I), ASTM International, West Conshohocken, Pennsylvania. American Society of Civil Engineers, 2013, /Minimum Design Loads for Buildings and Other Structures (7-10, third printing). Califomia Building Standards Commission, 2013, California Building Code, Title 24, Part 2, Volumes I and 2. Jennings, C.W., 1994, Fault Activity Map of California and Adjacent Areas: California Geological Survey, California Geologic Data Map No. 6, Scale 1:750,000. Kennedy, M.P. and Tan, S.S., 2007. Geologic Map of the Oceanside 30' x 60' Quadrangle, California, 1:100,000 Scale. Vinje & Middleton Engineering Inc., 2008, Foundation Plan Review Conformance Letter. Proposed Laguna Breeze Condominiums, 735 Laguna Drive, Carlsbad, California, Joh #07-334-P, dated June 26, 2008. Vinje & Middleton Engineering Inc., 2008, Grading and Foundation Plan Review, Proposed Laguna Breeze Condominiums, 735 Laguna Drive, Carlsbad, California, Job W7-334-P, dated April 28, 2008. Vinje & Middleton Engineering Inc., 2008, Alternate Temporary Vertical Cut Option, Proposed Laguna Breeze Condominiums, 735 Laguna Drive, Carlsbad, California, Job iK)7-334-P, dated April 18, 2008. Vinje & Middleton Engineering Inc., 2007, Geotechnical Investigation, Proposed Condominium Development, 735 Laguna Drive, Carlsbad, California, (A. P. N. 203-110-42&43). Job #07-334-?, dated October 25, 2007. United States Geological Survey, U.S. Seismic Design Maps, World Wide Web, http://earthquake.usgs.gov/hazards/designmaps/. ADVANCED GEOTECHNICAL SOLUTIONS, INC. APPENDIX B FIELD AND LAB DATA BORING LOGS B-l THROUGH B-6 LABORATORY TEST RESULTS ADVANCED GEOTECHNICAL SOLUTIONS, INC. PRIMARY DIVISIONS QROUP SYMBOL SECONDARY DIVISIONS 0? o CO 0 U. "i o 1 i oc < a X Ul OT o o d Z UJ CO cc UJ a. < CO GRAVELS MORE THAN HALF OF COARSE FRACTION IS LARQER THAN NO. 4 SIEVE SANDS MORE THAN HALF OF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE CLEAN GRAVELS (LESS THAN 5% FINES) QW Wetl graded gravels, gravel-sand mixtures, little or no fines. QP Poorly graded gravels or gravel-sand mixtures, little or no fines. GRAVEL WITH RNES GM Sllty gravels, gravel-sand-sHt mixtures, non-plastlo fines. GC Clayey gravels, gravel-sand-clay mixtures, plastic fines. CLEAN SANDS (LESS THAN 5% FINES) SW WeU graded sands, gravelly sands, little or no fines. SP Poorly graded sands or gravelly sands, Httle or no fines. SANDS wrrn FINES SM Silty sands, sand-silt mixtures, non-plastic fines. SC Clayey sands, sand-clay mixtures, plastic fines. 3 O u. UJ tn N UJ 55 to CO o CO Q X Ul 7 i ^ s I » Ui Ul oc S O ^ 5 SILTS AND CLAYS UQUID LIMIT IS LESS THAN 50% ML Inorganic slits and very fine sands, rock flour, silty or clayey fine sands or clayey silts with sllgtit plasticity. CL Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, sllty clays, lean clays. 28 a. O Ul z OL Organic silts and organic silty clays of low plasticity. SILTS AND CLAYS LIQUID LIMIT IS QREATER THAN 50% MH Inorganic slits, micaceous or diatomaceous fine sandy or silty soils, elastic silts. CH Inorganic clays of higti plasticity, fat clays. OH Organic clays of medium to high plasticity, organic silts. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. GRAIN'SIZES U.S. STANDARD SERIES SIEVE 200 40 10 CLEAR SQUARE SIEVE OPENINGS 3/4" 3" 12" SILTS AND CLAYS SAND FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES BOULDERS RELATIVE DENSITY CONSISTENCY SANDS, GRAVELS AND NON-PLASTIC SILTS BLOWS/FOOT VERY LOOSE 0 - 4 LOOSE 4 • 10 MEDIUM OENSE 10-30 OENSE 30-50 VERY DENSE OVER 50 CLAYS AND PLASTIC SILTS STRENGTH BLOWS/FOOT VERY SOFT 0 • Yi. 0 - 2 SOFT '/. -2-4 FIRM V4 - 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 pocket penetrometer CL-700 •Mni. o . I = Standard Penetration Test (SPT) (ASTM D-1586) Sand Cone Test • Bulk Sample | « with blow counts per 6 inches n Chunk Sample O Driven Rings 11 " California Sampler with blow counts per 6 Inches VINJE & MIDDLETON ENGINEERING, ING. 24S0 VInvyard Ave., #102 Escondido. CA 92029-1229 KEY TO EXPLORATORY BORING LOQS Unified Soil Classification System (ASTM D-2487) VINJE & MIDDLETON ENGINEERING, ING. 24S0 VInvyard Ave., #102 Escondido. CA 92029-1229 VINJE & MIDDLETON ENGINEERING, ING. 24S0 VInvyard Ave., #102 Escondido. CA 92029-1229 PROJECT NO. KEY VINJE & MIDDLETON ENGINEERING, ING. 24S0 VInvyard Ave., #102 Escondido. CA 92029-1229 KEY BORING LOG B-l DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 0 - • FILLn-OPSOIL: Silty fine sand. Pale grey color. Dry. Loose. ST-I SM - 5 - - 10- I112,14,11 It „ „, FILLn-OPSOIL: Silty fine sand. Pale grey color. Dry. Loose. ST-I SM 11.9 116.7 98.1 - 5 - - 10- I112,14,11 It „ „, TERRACE DEPOSIT: Silty clay grades to clayey fine sand. Grey color. Moist Local rust-colored staining and white- colored carbonate deposits. Moist. Cemented. Dense to firm. ST-2 SC/CH 11.9 116.7 98.1 - 15- I112,23,30 IL... TERRACE DEPOSIT: Silty clay grades to clayey fine sand. Grey color. Moist Local rust-colored staining and white- colored carbonate deposits. Moist. Cemented. Dense to firm. ST-2 SC/CH - 15- I112,23,30 IL... Clayey fine to medium sand. Pale grey color. Very moist Little cohesion. Loose to medium dense. Perched water at approximately 14', ST-3 SC/CH > - 20- ||4B15 I114,31.45 Silty clay. Grey color. Moist Stiff to very stiff. Plastic. ST-4 CH - 20- ||4B15 I114,31.45 Fine to medium sand. Off-white color. Moderately cemented. Dense. Moist to very moist. Perched water at lower contact ST-5 SW .2. -, - 25-114,2S,34 Fine to medium sand. Off-white color. Moderately cemented. Dense. Moist to very moist. Perched water at lower contact ST-5 SW .2. -, - 25-114,2S,34 Clayey fine sand. Brown color. Some rust- colored staining. Dense. < ST-3 SC - Clayey fine sand. Brown color. Some rust- colored staining. Dense. < ST-3 SC - FORMATIONAL ROCK: Fine to medium sandstone. Off-white color. Dense to very dense. Backfilled with Bentonite. No structure. Weakly cemented. ST-5 SP - 30- - 35- - 40- j|l6,44,50ffiX" |24.50/5VS' II 30.50/3" FORMATIONAL ROCK: Fine to medium sandstone. Off-white color. Dense to very dense. Backfilled with Bentonite. No structure. Weakly cemented. ST-5 SP - 45- - 50- End Boring at 41'. No caving. Perched water at approx.14' and 25'. Static water level at approx. 30' at completion of drilling. PROJE Project Drill, Si CT: LAGUNA DRIVE. CARLSBAD No: 07.334-P Date Drilled: 9-27-07 Loaaed Bv: SJM Bulk Sample • Ring Sample O SPT Sample 1 Groundwater y_ PLATE 3 PROJE Project Drill, Si Truck-mounted rotary drill. 8" hollow-stem auger, ample Method: 140-lb. Hammer. 30" Drop - Trip-hammer 5' AW Rods. Bulk Sample • Ring Sample O SPT Sample 1 Groundwater y_ PLATE 3 VINJE & MIDDLETON ENGiNEERING, INC. BORING LOG DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) REUVTIVE COMPACTION (%) - 0 - ~- s— FILLn-OPSOIL: Silty fine sand. Red-brown to pale grey color. Slightly moist, Loose. ST-1 SM "tnd 7 o 6,15 TERRACE DEPOSIT: Clayey fine sand. Grey color. Moist Medium Hpn^p to ripn^p SL 1 o.o lUH. 1 oo.u - 10-o 11,36 IOC lw w 1 ^ SL 15.5 114.2 - 10-o 11,36 Clayey fine to medium sand. Pale grey color to off-white colored. Moist Weekly cemented medium dense to dense. ST-3 SC 15.5 114.2 -15 Clayey fine to medium sand. Pale grey color to off-white colored. Moist Weekly cemented medium dense to dense. ST-3 SC 16.7 114.6 - - 20- o 11,23 Silty clay. Grey color. Moist Stiff to very stiff. Plastic. ST-4 CH - 20- o 11,23 Clayey fine sand. Grey Color. Moist Some rust-colored staining. Very Dense. ST-2 SC -o SW6" Clayey fine sand. Grey Color. Moist Some rust-colored staining. Very Dense. ST-2 SC 10.1 118.5 99.6 - 25-o 33,50/4" Clayey fine sand. Grey Color. Moist Some rust-colored staining. Very Dense. ST-2 SC 10.1 118.5 99.6 - 25-o 33,50/4" Fine to medium sand. Off-white color. Slightly moist Weakly cemented. Dense ST-5 SW |,a.o 105.5 88.7 - 30-\ Fine to medium sand. Off-white color. Slightly moist Weakly cemented. Dense ST-5 SW / 10.2 119.7 - 35- - 40- - 45- - 50- soier I ' Clayey fine sand. Brown to grey color. Some rust-colored staining. Dense. ST-2 SC / 10.2 119.7 - 35- - 40- - 45- - 50- soier I ' Clayey fine sand. Brown to grey color. Some rust-colored staining. Dense. ST-2 SC 'l - 35- - 40- - 45- - 50- soier I FORMATIONAL ROCK: Fine to medium sandstone. Off-white color. Weakly cemented. Dense to very dense. No apparent structure. ST-5 SP 'l - 35- - 40- - 45- - 50- soier I End Boring at 30-14'. No caving. No groundwater. Backfilled with Bentonite. 'l PROJECT: LAGUNA DRIVE. CARLSBAD Project No: 07-334-P Date Drilled: 9-18-07 Logged By:_ SJM Truck-mounted rotary drill. 8" hollow-stem auger. Drill, Sample Method: 140-lb. Hammer. 30" Drop by trip-hammer 5' AW Rods. Bulk Sample • Ring Sample O SPT Sample || Groundwater f PLATE 4 VINJE & MIDDLETON ENGINEERING, INC. BORING LOG B-3 DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) -10- 15- 20 25- -30- 14,10 \. FILL/TOPSOIL: Silty fine sand. Red brown to grey color. Slightly moist. Loose. ST-1 SM 5.4 108.9 J O 8,13 TERRACE DEPOSIT: Clayey fine sand. Grey color. Moist. 18.5 Medium dense to dense. ST-2 SC Sample Disturbed Perched water at 14' (Lower contact). 9,14,16 J Clayey silt/silty clay. Grey color. Cemented. Dense. ST-4 \ ML/CH 9, 18, 27 End Boring at 1614'. No Caving. Perched Groundwater at Approx. 14'. Backfilled with Bentonite. PROJECT: Laguna Drive / Madison Street. Carlsbad Project No: 07-334-P Date Drilled: 9-27-07 Loqqed Bv: SJM Drill, Sample Method: Truck-mounted rotary drill. 8" hollow stem auger. 1401b. hammer - 30" drop by trip-hammer. 5'AW rods. Bulk Sample • Ring Sample O SPT Sample || Groundwater PLATE 5 Vinje & Middleton Engineering, Inc. 2450 Vineyard Avenue #102 Escondido, California 92029-1229 BORING LOG B-4 DEPTH FT SAMPLE Description uses SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 0 - o FILUTOPSOIL: Silty fine sand. Pale grey color. Dry to slightly moist. Dense. ST-1 SM 3.9 113.8 87.8 - 5 - 10 15 20 25- -30 35, 50/5" o 25. 60/3" z " II 11,16.32 o 50/5' TERRACE DEPOSIT; Clayey fine sand. Brown to tan color with some rust-colored staining. Moist. Somewhat plastic. Relatively slow drilling. Medium dense to dense. Perched water at approx. 10'. Below 10' some coarser grained constituents. Color changes to olive brown. ST-2 18.5 111.2 SC 110.3 End Boring at 151^' No Caving. Perched Groundwater at Approx. 10', Static water level at approx. 7' at completion of drilling. Backfilled with Bentonite. 93.5 92.3 PROJECT: Laguna Drive / Madison Street. Carlsbad Project No: 07-334-P Date Drilled: 9-27-07 Logged Bv: KS Drill, Sample Method: Limited access beaver drill. 6" solid stem auger. 1401b. hammer - 30" drop by rope and cathead. 5' AW rods. Bulk Sample Ring Sample SPT Sample Groundwater PLATE 6 Vinje & Middleton Engineering, inc. 2450 Vineyard Avenue #102 Escondido, California 92029-1229 BORING LOG B-5 DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (%) - 0 - II FILL/TOPSOIL: Silty fine sand. Pale grey color. Dry. Loose. ST-1 SM - 5 - - 10-• Ils 18, 18,"54 O TERRACE DEPOSIT: Clayey fine sand. Olive brown color. Some rust-colored staining and carbonate deposits. Moist. Medium dense to dense. ST-2 SC 21.5 107.2 90.1 -27,56\ Perched water at approx. 8'. / -15- "All 15, 25,34 \ Fine to medium sand. Includes some small pebbles. Pale grey color. Very moist. Medium dense to dense. ST-5 '/ / I' 1 1 1 1 1 to o llllll End Boring at 12/2'. No Caving. Perched Groundwater at Approx. 8'. Backfilled with Bentonite. -25- -30- PROJECT: Laauna Drive / Madison Street. Carlsbad Bulk Sample • Ring Sample O SPT Sample || Groundwater ..T PLATE 7 Proiect No: 07-334-P Date Drilled: 9-27-07 Logged Bv: KS Bulk Sample • Ring Sample O SPT Sample || Groundwater ..T PLATE 7 Drill, Sample Method: Limited access Kubata / beaver drill. 6" solid stem auger. 1401b. hammer - 30" drop by rope and cathead. 5' AW rods. Bulk Sample • Ring Sample O SPT Sample || Groundwater ..T PLATE 7 Vinje & Middleton Engineering, Inc. 2460 Vineyard Avenue #102 Escondido, California 92029-1229 BORING LOG B-6 DEPTH FT SAMPLE Description USGS SYMBOL MOISTURE (%) DRY DENSITY (PCF) RELATIVE COMPACTION (•/.) - 0 - - 5 - FILUTOPSOIL: Silty fine sand. Pale brown color. Loose. Grades tight to moderately compacted within lower exposures, ST-1 SM J TERRACE DEPOSIT: Silty fine to medium sand. Brown color., \ \ -10-II 17, 17. 20 Some rust-colored staining and carbonate deposits. Moist. Moderately SW -cemented. ST-3 y -\ Perched water at approx. 10'. / - 15- \ Clayey fine sand. Pale brown color. Moist to very moist. ST-2 ......y SC 1 -Refusal on rock at 1 ZVi'. -20- -25- End Boring at 1 SVi' - Refusal on rock. No Caving. Perched Groundwater at Approx. 10'. Static water level at approx. 9' at completion of drilling. Backfilled with Bentonite. -30- PROJECT: Laguna Drive / Madi$on Street. Carisbad Project No: 07-334-P Date Drilled: 9-27-07 Logged Bv: KS Drill, Sample Method: Limited access Kubata / beaver drill. 6" solid stem auger. 1401b. hammer - 30" drop by rope and cathead. 5' AW rods. Bulk Sample • Ring Sample O SPT Sample II Groundwater PLATE 8 Vinje & Middleton Engineering, Inc. 2450 Vineyard Avenue #102 Escondido, California 92029-1229 GEOTECHNICAL INVESTIGATION CONDOlVIINiUlM DEVELOPiVIENT, LAGUNA DR, CARLSBAD PAGE 7 OCTOBER 25, 2007 TABLE 3 Soli Type ' Description 1 pale grey sllty fine sand {Fill/Topsoil) 2 clayey fine sand (Terrace Deposit) 3 pale grey to off-white clayey fine to medium sand (Terrace Deposit) 4 grey silty clay to clayey silt (Ten-ace Deposit) 5 off-white fine to medium sand (Tenrace Deposit/Formational Rock) The following tests were conducted in support of this investigation: 1. Standard Penetration Test: Standard penetration tests (SPT) were performed atthe time of borehole drilling in accordance with ASTM standard procedure D- 1586, using automatic trip hammer and rope and Cathead. The procedure consisted of a standard 51 MM putside diameter sampler without liner, 457 MM in length and 35 MM In inside diameter driven with a 140 pounds hammer dropped 30 inches using 5-foot long AW drill rods. The bore holes were 150 (6 inches) and 200 MM (8 inches) in diameter and drill fluid or water was not necessary to aid drilling. The test results are indicated at the corresponding locations on the boring Logs. 2. Grain Size Analysis: Grain size analyses were peri'ormed on representative samples of Soil Types 2, 3,4 and 5. The test results are presented in Table 4 and graphically presented on the enclosed Plates 11 and 12. TABLE 4 Sieve Size VJ' 1 #4 #10 1 #20, #40 #200 Location Soil Type Percent Passing B-1 @ 5' 2 ICQ 100 100 100 97 47 B-1 @ 10' 3 100 100 100 99 94 22 B-1 @ 15' 4 100 100 100 100 99 63 B-1 @ 20' 5 100 100 99 83 57 26 B-1 @ 25" 3 100 100 99 83 57 26 B-1 @ 35' 5 100 100 100 98 90 53 B-1 @ 40' 5 100 100 98 82 58 22 GEOTECHNiCAL INVESTIGATiON GONDOMINIUM DEVELOPIVIENT, LAGUNA DR. CARLSBAD PAGE 8 OCTOBER 25, 2007 3. Liquid Limit. Plastic Limit and Plasticity index: Liquid limit, plastic limit and plasticity index tests were performed on representative samples of Soil Types 2, 3, and 5 in accordance with the ASTM D-4318. The test results are presented In Table 5. TABLE 5 Location Soil Type Liquid Limit (LL-%) Plastic Limit (PL-%) Plasticity Index {PI=LL-PL) B-1 @ 5' 2 43 17 26 B-1 @ 10' 3 22 21 1 B-1 @ 20' 3 56 25 31 B-1 @ 25' 3 46 27 19 B-1 @ 35' 5 28 25 3 4. IVIaximum Dry Densitv and Optimum Moisture Content: The maximum dry density and optimum moisture content of Soil Types 1 and 2 were determined in accordance with the ASTM D-1557. The test results are presented in Table 6. TABLE 6 Soil Maximum Dry Optimum Moisture Location Type Density (Ym-pcf) Content ((Oopt-%) B-1 @ 2' 1 129.6 10.1 B-1 @ 5' 2 118.9 14.6 Moisture-Density Test (Undisturbed Ring Samples): In-place dry density and moisture content of representative soil deposits beneath the site were determined from relatively undisturbed ring samples using the weights and measurements test method. The test results are presented in Table 7 and tabulated on the attached Boring Logs (Plates 3-8). GEOTECHNICAL INVESTIGATiON CONDOMINIUM DEVELOPMENT. LAGUNA DR. CARLSBAD PAGE 9 OCTOBER 25. 2007 TABLE 7 Sample Location Soii Type Field 'Moisture Content (0)-%) i FleldDry - Density, (Yd-pcf) Max. Dry Density (Ym-pcf) Ratio Of in-Place Dry Density To Max. Dry Density* (Yd/Ym X 100) B-1 @ 3' 2 11.9 116.7 118.9 98.1 B-2 @ 5' 2 19.5 104.7 118.9 88,0 B-2 @ 10' 3 15.5 114.2 -- B-2 @ 15' 4 16.7 114.6 -- B-2 @ 20 2 10.1 118.5 118.9 99.6 B-2 @ 25' 2 16.0 105.5 118.9 88.7 B-2 @ 30' 5 10.2 119.7 -- B-3 @ 2' 1 5.4 108.9 -- B-3 @ 5' 2 18.5 -118.9 Sample disturbed B-4 @ 3' 1 3.9 113.8 129.6 87.8 B-4@5' 2 9.2 111.2 118.9 93.5 B-4 @ 15' 2 19.7 110.3 118.9 92.8 B-5@ 10' 2 21.5 107.2 118.9 90.1 'Designated as relative compaction for structural f lis. Minimum required relative compaction for structural fill is 90% unless othenvise specified. 6. Expansion Index Tests: Two expansion index tests were performed on representative samples of Soil Types 1 and 2 in accordance with the California Building Code Standard 18-2. The test results are presented in Table 8. TABLE 8 Sample 1 Location iiipiii ilipei Remolded (0(%) ' Saturation (%) Saturated (0 (%) Expansion index (El) Expansion Potential 1 B-1 @ 2' 1 8.4 50.1 16.2 15 very low I B-1 @ 5' 2 14.4 50.3 37.8 150 very high 1 (0)) = moisture content in percent. GEOTECHNiCAL INVESTIGATiON CONDOMINIUM DEVELOPMENT. LAGUNA DR, CARLSBAD PAGE 10 OCTOBER 25. 2007 7. Direct Shear Test: One direct shear test was performed on a representative sample of Soil Type 1. The prepared specimen was 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 result is presented in Table 9. TABLE 9 Sample Location Soil Type Sample Condition Wet Density (Yw-pcf) Angle of Int. Fric. (0-Deg.) Apparent Cohesion (c-psf) B-1 2' 1 remolded to 90% of Ym (® % ©opt 128.0 30 50 pH and Resistivitv Test: pH and resistivity of a representative sample of Soil Type 2 was determined using" Method for Estimating the Service Life of Steel Culverts," in accordance with the California Test Method (CTM) 643. The test result is presented in Table 10. TABLE 10 Sample Location Soil Type Minimum Resistivity (OHM-CM) pH B-1 @ 5' 2 436.8 7.31 9. Sulfate Test: A sulfate test was performed on a representative sample of Soil Type 2 in accordance with the California Test Method (CTM) 417. The test result is presented in Table 11. TABLE 11 Sample tLocation Soil Type Amount of Water Soluble Sulfate in Soii (% by Weight) B-1 @ 5' 2 0.039 10. Chloride Test: A chloride test was performed on a representative sample of Soil Type 2 in accordance with the Califomia Test Method (CTM) 422. The test result is presented in Table 12. TABLE 12 Sample Location Soil Type Amount of Water Soluble Chloride In Soil (% by Weight) B-1 @ 5' 2 0.012 GEOTECHNICAL INVESTIGATION PAGE 11 CONDOMINIUM DEVELOPMENT. LAGUNA DR. CARLSBAD OCTOBER 25, 2007 11. Consolidation Test: Consolidation tests were performed on representative undisturbed samples of on-site Soil Type 2. The test results are graphically presented on the enclosed Plate 13. 12. Revalue Test: One R-value test was performed on a representative sample of Soil Type 1 in accordance with the California Test Method 301. The test result is presented in Table 13. TABLE 13 Location Soil Type . Description R-value B-4M3' 1 grey fine to medium sand 70 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) indicates 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, amountof aggressive ion salts (chloride or sulfate), pH levels and the desired service life of the structure. The results of limited laboratory testing performed on selected representative site samples indicated that the minimum resistivity is less than 1000 ohm-cm suggesting presence of high quantities of soluble salts. However, test results further indicated that pH levels are greater than 5.5, sulfate concentrations are less than 2000 ppm, and chloride concentration levels are less than 600 ppm. Based on the results ofthe limited corrosion analyses, the project site is considered non-corrosive. Additional corrosion conformation testing is recommended and should be considered near the completion of remedial grading and earthwork operations. The project site is not located within 1000 feet of salt or brackish water. GEOTECHNiCAL INVESTIGATION CONDOMINIUM DEVELOPMENT, LAGUNA DR^ GARLSBAD PAGE 12 OCTOBER 25, 2007 Based upon the result ofthe tested soil sample, the amount of water soluble sulfate (S04) was found to be 0.039 percent by weight which is considered negligible according to the California Building Code Table No. 19-A-4. Portland cement Type II may be used. Table 14 is appropriate based on the pH-Resistivity test result: TABLE 14 Design Soil Type iili liil iiii iiii iiil 8 2 Years to Perforation of Steel Culverts 17 22 27 37 47 57 Vll. CONCLUSIONS Based upon the foregoing investigation, redeyeloprnent ofthe study property substantially as proposed is feasible from a geotechnical viewpoint. The property is underiain by generally competent and stable Terrace Deposits at relatively shallow depths which will adequately support new structures and improvements. The following factors are unique to the site and will impact the planned development and construction procedures: * Instability or geologic hazards including flooding, landslides, faults orthick unstable soils are not present at the project site and will not be a factor in the site redevelopment. The most significant long-term geologic phenomenon likely to impact the property is periodic ground shaking associated with earthquake activity along distant active faults. * The project site is directly underiain by a relatively thin to modest section of undifferentiated fill and topsoil atop dense and stable natural Terrace Deposits. Site upper soil mantle occur in a loose to soft conditions and are not suitable in their present condition for the support of planned new fills, structures and improvements. These deposits should be regraded as recommended in the following sections. Below, the dense and stable Terrace Deposits are competent units that can suitably provide adequate structural support. * Existing structures and improvements occupy the project property. All trash debris generated from the demolition and removal of site existing structures and improvements should be removed and properly disposed of from the site as approved. Construction debris should not be allowed within site new fills and backfills as specified in the following sections. * The project site is relatively level ground and major surface grade alterations or creation of larger graded slopes are not anticipated. Stability of natural or permanent graded embankments will not be a factor in the redevelopment of the project property. U. S. STANDARD SIEVE IN INCHES - - a CO T U. S. STANOARD SIEVE NUMBERS o HYDROMETER 1 0.5 GRAIN SIZE MILUMETERS 0.01 0.005 Cobbles Gravel Coane Fine Sand Coaese to medium Fine SILT OR CLAY SAMPLE # DEPTH (FEET) SYMBOL CLASSIFICATION NAT W% LL PL PI Cu <D6o/Dio) Cc CSlo/DioDeo) PROJECT: 07-334-P B-l 5 • SC/CH 11.6 43 17 26 15.0 0.711 LAGUNA DRIVE B-l 10 • SC -22 21 1 2.04 1.193 CARLSBAD B-l 15 SC 14,0 -----DATE: DCTDBER, 2007 B-l ao CH 25.5 56 25 31 --PLATE 11 1 VINJE AND MIDDLETON ENGINEERING, INC. U. S. STANDARD SIEVE IN INCHES U. S. STANDARD SIEVE NUMBERS Q 8 8 HYDROMETER 1 0.5 GRAIN SIZE MILLIMETERS 0.01 0.005 Cobbles Gravel Coarse Rne Sand Coaese to medium Rne SILT OR CLAY SAMPLE # DEPTH (FEET) SYMBOL CUSSIFICATION NAT W% LL PL Pi Cu (Dfio/Dio) Cc (DM/Dio Deo) PROJECT: 07-334-P B-l 25 • CL/CH 18.7 46 27 19 58.0 24.95 LAGUNA DRIVE B-l 35 a SC 13.6 28 25 3 --CARLSBAD B-l 40 SP 13.8 ---16.67 11.93 DATE: DCTDBER, 2007 PLATE: 12. VINJE AND MIDDLETON ENGiNEERING, INC. SAMPLE DEPTH (FEET) SYMBOL SAMPLE CONDITION EXPLANATION B-2 5 • IN-PLACE RING SAMPLE FIELD MOISTURE B-2 25 • IN-PLACE RING SAMPLE REBOUND o o OOO OOO to -* IO o o o ooo o ooo o ooo cv CO IO o o o o NORMAL LOAD (PSF) o o o o ooo OOO ooo ooo o o o o o JOB# 07-334-P LOAD CONSOLIDATION TEST PLATE 13 VINJE & MIDDLETON ENGINEERtNG, INC. APPENDIX C GENERAL EARTHWORK SPECIFICATIONS AND GRADING GUIDELINES ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16,2014 Page C-1 PAV 1406-03 Report No. 1406-03-B-2 GENERAL EARTHWORK SPECIFICATIONS I. General A. General procedures and requirements for earthwork and grading are presented herein. The earthwork and grading recommendations provided in the geotechnical report are considered part of these specifications, and where the general specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the geotechnical report shall govem. Recommendations provided herein and in the geotechnical report may need to be modified depending on thc conditions encountered during grading. B. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans, specifications, applicable building codes, and local goveming agency requirements. Where these requirements conflict, the stricter requirements shall govem. C. It is the contractor's responsibility to read and understand the guidelines presented herein and in the geotechnical report as well as the project plans and specifications. Information presented in the geotechnical report is subject to verification during grading. The infonnation presented on the exploration logs depict conditions at the particular time of excavation and at the location of the excavation. Subsurface conditions present at other locations may differ, and the passage of time may result in different subsurface conditions being encountered at the locations of the exploratory excavations. The contractor shall perform an independent investigation and evaluate the nature of the surface and subsurface conditions to be encountered and the procedures and equipment to bc used in performing his work. D. The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the earthwork in accordance with applicable requirements. When the quality of work is less than that required, the Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions are corrected. E. Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading procedures and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines presented herein. All remedial removals, clean-outs, removal bottoms, keyways, and subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill. It is the contractor's responsibility to appraise the Geotechnical Consultant of their schedules and notify the Geotechnical Consultant when those areas are ready for observation. F. The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading and conduct tests. II. Site Preparation A. Clearing and Grabbing: Excessive vegetation and other deleterious material shall bc sufficiently removed as required by the Geotechnical Consultant, and such materials shall be properly disposed of offsite in a method acceptable to the owner and goveming agencies. Where applicable, the contractor may obtain permission from the Geotechnical Consultant, owner, and goveming agencies to dispose of vegetation and other deleterious materials in designated areas onsite. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2014 Page C-2 PAV 1406-03 Report No. 1406-03-B-2 B. Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as necessary to the satisfaction of the Geotechnical Consultant. C. Any underground stractures such as cesspools, cistems, mining shafts, tunnels, septic tanks, wells, pipelines, other utilities, or other stractures located within the limits of grading shall be removed and/or abandoned in accordance with the requirements of the goveming agency and to the satisfaction of the Geotechnical Consultant. D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be scarified to a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally unifonn moisture content that is at or near optimum moisture content. The scarified materials shall then be compacted to the project requirements and tested as specified. E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill. A licensed surveyor shall provide survey control for determining elevations of processed areas and keyways. III. Placement of Fill A. Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion potential, and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved prior to being imported. B. Generally, different fill materials shall be thoroughly mixed to provide a relatively unifonn blend of materials and prevent abrapt changes in material type. Fill materials derived from benching should be dispersed throughout the fill area instead of placing the materials within only an equipment-width from the cut/fill contact. C. Oversize Materials: Rocks greater than 8 inches in largest dimension shall be disposed of offsite or be placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for oversize rock placement. Rocks that are smaller than 8 inches in largest dimension may be utilized in the fill provided that they are not nested and are their quantity and distribution are acceptable to the Geotechnical Consultant. D. The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain a near uniform moisture content and uniform blend of materials. E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as recommended by the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water shall be added, and the fill materials shall be blended so that a near uniform moisture content is achieved. If the moisture content is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by discing, blading, or other methods until the moisture content is acceptable. ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2014 Page C-3 PAV 1406-03 Report No. 1406-03-B-2 F. Each layer of fill shall be compacted to the project standards in accordance to the project specifications and recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical Consultant, the fill shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM Test Method: Dl 557-09. G. Benching: Where placing fill on a slope exceeding a ratio of 5 to 1 (horizontal to verficai), the ground should be keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable materials such as firm materials or sound bedrock or as recommended by the Geotechnical Consultant. The minimum keyway width shall be 15 feet and extend into suitable materials, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. The minimum keyway width for fill over cut slopes is also 15 feet, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. As a general rale, unless otherwise recommended by the Geotechnical Consultant, the minimum width of the keyway shall be equal to 112 the height of the fill slope. H. Slope Face: The specified minimum relative compacfion shall be maintained out to the finish face of fill and stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the compacted core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may be achieved by backrolling the slope face with suitable equipment or other methods that produce the designated result. Loose soil should not be allowed to build up on the slope face. If present, loose soils shall be trimmed to expose the compacted slope face. I. Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and goveming agencies, permanent fill slopes shall be designed and constracted no steeper than 2 to 1 (horizontal to vertical). J. Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation is needed. K. Fill materials shall not be placed, spread, or compacted during unfavorable weather condifions. When grading is interrapted by rain, filing operafions shall not resume until the Geotechnical Consultant approves the moisture and density of the previously placed compacted fill. IV. Cut Slopes A. The Geotechnical Consultant shall inspect all cut slopes, including fill over cut slopes, and shall be notified by the contractor when cut slopes are started. B. If adverse or potenfially adverse condifions are encountered during grading, the Geotechnical Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions. C. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the requirements of the local goveming agencies. Short-term stability of the cut slopes and other excavations is the contractor's responsibility. V. Drainage ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2014 Page C-4 PAV 1406-03 Report No. 1406-03-B-2 A. Backdrains and Subdrains: Backdrains and subdrains shall be provided in fill as recommended by the Geotechnical Consultant and shall be constracted in accordance with the goveming agency and/or recommendafions of the Geotechnical Consultant. The locafion of subdrains, especially outlets, shall be surveyed and recorded by the Civil Engineer. B. Top-of-slope Drainage: Posifive drainage shall be established away from the top of slope. Site drainage shall not be permitted to flow over the tops of slopes. C. Drainage terraces shall be constracted in compliance with the goveming agency requirements and/or in accordance with the recommendafions of the Geotechnical Consultant. D. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the prevailing drainage. VT. Erosion Control A. All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the project specifications and/or landscape architect's recommendations. Such measures to protect the slope face shall be undertaken as soon as pracfical after completion of grading. B. During constraction, the contractor shall maintain proper drainage and prevent the ponding of water. The contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control measures have been installed. VII. Trench Excavation and Backfill A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavafions. Knowing and following these requirements is the contractor's responsibility. All trench excavafions or open cuts in excess of 5 feet in depth shall be shored or laid back. Trench excavafions and open cuts exposing adverse geologic condifions may require further evaluation by the Geotechnical Consultant. If a contractor fails to provide safe access for compacfion testing, backfill not tested due to safety concems may be subject to removal. B. Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetfing. C. Backfill: Jetting of backfill materials is generally not acceptable. Where pennitted by the Geotechnical Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a Sand Equivalent greater than 30. VIII. Geotechnical Observation and Testing During Grading A. Compacfion Tesfing: Fill shall be tested by the Geotechnical Consultant for evaluafion of general compliance with the recommended compaction and moisture condifions. The tests shall be taken in the compacted soils beneath the surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant by excavafing suitable test pits for testing of compacted fill. B. Where tests indicate that the density of a layer of fill is less than required, or the moisture content not within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory condifions of the fill. The portions of the fill that are not within specifications shall be reworked until the required density and/or moisture content has been attained. No additional fill shall be placed until the last ADVANCED GEOTECHNICAL SOLUTIONS, INC. June 16, 2014 Page C-5 PAV 1406-03 Report No. 1406-03-B-2 lift of fill is tested and found to meet the project specificafions and approved by the Geotechnical Consultant. C. If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill placement, results in a quality of work that is unacceptable, the consultant shall nofify the contractor, and the contractor shall recfify the condifions, and if necessary, stop work until condifions are satisfactory. D. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's discretion. Generally, compaction tests shall be taken at intervals not exceeding two feet in fill height and 1,000 cubic yards of fill materials placed. E. Compacfion Test Locations: The Geotechnical Consultant shall document the approximate elevafion and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations. Altemately, the test locations can be surveyed and the results provided to the Geotechnical Consultant. F. Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be removed and recompacted at the contractor's expense. The depth and extent of removals will be detennined by the Geotechnical Consultant. G. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with the approved geotechnical report and project specificafions. H. Reporting of Test Results: After complefion of grading operafions, the Geotechnical Consultant shall submit reports documenting their observafions during constraction and test results. These reports may be subject to review by the local goveming agencies. ADVANCED GEOTECHNICAL SOLUTIONS, INC. APPENDIX D HOMEOWNER MAINTENANCE RECOMMENDATIONS ADVANCED GEOTECHNICAL SOLUTIONS, INC. HOMEOWNER MAINTENANCE AND IMPROVEMENT CONSIDERATIONS Homeowners are accu.stomed to maintaining their liome.s. They expect to paint their house.s periodically, replace wiring, clean out clogged plumbing, and repair roofs. Maintenance ofthe home site, particularly on hillsides, should be considered on the same basis or even on a more serious basis because neglect can result in serious consequences. In most cases, lot and site maintenance can be taken care of along with landscaping, and can be carried out more economically than repair after neglect. Most slope and hillside lot problems arc associated with water. Uncontrolled water from a broken pipe, cesspool, or wet weather causes most damage. Wet weather is thc largest cause of slope problems, particularly in Califomia where rain is intermittent, but may bc torrential. Therefore, drainage and erosion control are the most important aspects of home site stability; these provisions must not be altered without competent professional advice. Further, maintenance must be carried out to assure their continued operation. As geotechnical engineers concemed with the probleras ofbuilding sites in hillside developments, we offer the following list of reconmiended home protection measures as a guide to homeowners. Expansive Soils Some of the earth materials on site have been identified as being expansive in nature. As such, these materials are susceptible to volume changes with variations in their moisture content. These soils will swell upon the introduction of water and shrink upon drying. The forces associated with these volume changes can have signiticant negative impacts (in thc form of differential movement) on foundations, walkways, patios, and other lot improvements. In recognition ofthis, the project developer has constmcted homes on these lots on post-tensioned or mat slabs with pier and grade beam foundation systems, intended to help reduce the potential adverse effects of these expansive materials on thc residential structures within the project. Such foundation systems are not intended to offset the forces (and associated movement) related to expansive soil, but are intended to help soften their effects on the stmctures constracted thereon. Homeowners purchasing property and living in an area containing expansive soils must assume a certain degree of responsibility for homeowner improvements as well as for maintaining conditions around their home. Provisions should be incorporated into the design and constmction of homeowner improvements to account for the expansive nature ofthe onsite soils material. Lot maintenance and landscaping should also be conducted in consideration of the expansive soil characteristics. Of primary importance is minimizing the moisture variation below all lot improvements. Such design, constraction and homeowner maintenance provi.sions should include: • Employing contractors for homeowner improvements who design and build in recognition of local building code and site specific soils conditions. • Establishing and maintaining positive drainage away from all foundations, walkways, driveways, patios, and other hardscape improvements. • Avoiding the constraction of planters adjacent to stractural improvements. Altematively, planter sides/bottoms can be sealed with an impermeable membrane and drained away from the improvements via subdrains into approved disposal areas. • Sealing and maintaining constraction/control joints within concrete slabs and walkways to reduce the potential for moisture infiltration into the subgrade soils. • Utilizing landscaping schemes with vegetation that requires ininimal watering. Altematively, watering should bc done in a uniform manner as equally as possible on all sides of the foundation, keeping the soil "moist" but not allowing the soil to become saturated. • Maintaining positive drainage away from stmctures and providing roof gutters on all stractures with downspouts installed to caiTy roof ranoff directly into area drains or discharged well away from the stractures. • Avoiding the placement oftrees closer to the proposed stmctures than a distance of one-half thc mature height of thc tree. • Observation of the soil conditions around the perimeter of the stracture during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to maintain relatively constant moisture conditions. Sulfates Homeowners should be cautioned against the import and use of certain fertilizers, soil amendments, and/or other soils from offsite sources in the absence of specific information relating to their chemical composition. Some fertilizers have been known to leach sulfate compounds into soils otherwise containing "negligible" sulfate concentrations and increase the sulfate concentrations in near-surface soils to "moderate" or "severe" levels. In some cases, concrete improvements constracted in soils containing high levels of soluble sulfates may be affected by deterioration and loss of strength. Water - Natural and Man Induced Water in concert with the reaction of various natural and man-made elements, can cause detrimental effects to your stracture and surrounding property. Rain water and flowing water erodes and saturates the ground and changes thc engineering characteristics of thc underlying earth materials upon saturation. Excessive irrigation in concert with a rainy period is commonly associated with shallow slope failures and deep seated landslides, saturation of near stracture soils, local ponding of water, and transportation of water soluble substances that are deleterious to building materials including concrete, steel, wood, and stucco. Water interacting with the near surface and .subsurface soils can initiate several other potentially detrimental phenomena other then slope stability issues. These may include expansion/contraction cycles, liquefaction potential increase, hydro-collapse of soils, ground surface settlement, earth material consolidation, and introduction of deleterious substances. ADVANCED GEOTECHNICAL SOLUTIONS, INC. The homeowners should be made aware of the potential problems which may develop when drainage is altered through constraction of retaining walls, swimming pools, paved walkways and patios. Ponded water, drainage over the slope face, leaking irrigation systems, over-watering or other conditions which could lead to ground saturation must be avoided. • Before the rainy season arrives, check and clear roof drains, gutters and down spouts of all accumulated debris. Roof gutters are an important element in your arsenal against rain damage. If you do not have roof gutters and down spouts, you may elect to install them. Roofs, with their, wide, flat area can shed tremendous quantities of water. Without gutters or other adequate drainage, water falling from the eaves collects against foundation and basement walls. • Make .sure to clear surface and terrace drainage ditches, and check them frequently during the rainy season. This task is a community responsibility. • Test all drainage ditches for functioning outlet drains. This should be tested with a hose and done before thc rainy season. All blockages should be removed. • Check all drains at top of slopes to be sure they are clear and that water will not overflow the slope itself, causing erosion. • Keep subsurface drain openings (weep-holes) clear of debris and other material which could block them in a storm. • Check for loose fill above and below your property if you live on a slope or terrace. • Monitor hoses and sprinklers. During the rainy season, little, if any, irrigation is required. Oversaftiration of the ground is unnecessary, increases watering costs, and can cause subsurface drainage. • Watch for water backup of drains inside the house and toilets during the rainy season, as this may indicate drain or sewer blockage. • Never block terrace drains and brow ditches on slopes or at the tops of cut or fill slopes. These are designed to carry away ranoff to a place where it can be safely distributed. • Maintain the ground surface upslope of lined ditches to ensure that surface water is collected in thc ditch and is not permitted to be trapped behind or under the lining. Do not permit water to collect or pond on your home site. Water gathering here will tend to cither seep into thc ground (loosening or expanding fill or natural ground), or will overflow into the slope and begin erosion. Once erosion is started, it is difficult to control and severe damage may result rather quickly. • Never connect roof drains, guUers, or down spouts to subsurface drains. Rather, arrange them so that water either flows off your property in a specially designed pipe or flows out into a paved driveway or street. The water then may be dissipated over a wide surface or, preferably, may bc carried away in a paved gutter or storm drain. Subdrains arc constracted to take care of ordinary subsurface water and cannot handle the overload from roofs during a heavy rain. • Never permit water to spill over slopes, even where this may seem to be a good way to prevent ponding. This tends to cause erosion and, in thc case of fill slopes, can cat away carefully designed and constracted sites. Do not cast loose soil or debris over slopes. Loose soil soaks up water more readily than compacted fill. It is not compacted to the same strength as the slope itself and will tend to slide when laden with water; this may even affect the soil beneath the loose soil. The sliding may clog terrace drains below or may cause additional damage in weakening thc slope. If you live below a slope, try to bc sure that loose fill is not dumped above your property. • Never discharge water into subsurface blanket drains close to slopes. Trench drains are sometimes used to get rid of excess water when other means of disposing of water are not readily available. Overioading these drains saturates the ground and, if located close to slopes, may cause slope failure in their vicinity. '.' Do not discharge surface water into septic tanks or leaching fields. Not only are septic tanks constracted for a different purpose, but they will tend, because of their constniction, to naturally accumulate additional water from the ground during a heavy rain. Overloading them artificially during the rainy season is bad for the same reason as subsurface subdrains, and is doubly dangerous since their overflow can pose a serious health hazard. In many areas, the use of septic tanks should be discontinued as soon as sewers are made available. • Practice responsible irrigation practices and do not over-inigate slopes. Naturally, ground cover of ice plant and other vegetation will require some moisture during the hot .summer months, but during the wet season, irrigation can cause ice plant and other heavy ground cover to pull loose. This not only destroys the cover, but also starts serious erosion. In some areas, ice plant and other heavy cover can cause surface sloughing when saturated due to the increase in weight and weakening of the near-surface soil. Planted slopes should be planned where possible to acquire sufficient moisture when it rains. • Do not let water gather against foundations, retaining walls, and basement walls. These walls are built to withstand thc ordinary moisture in the ground and are, where necessary, accompanied by subdrains to carry off the excess. If water is permitted to pond against them, it may seep through the wall, causing dampness and leakage inside the basement. Further, it may cause thc foundation to swell up, or the water pressure could cause stmctural damage to walls. • Do not try to compact soil behind walls or in trenches by flooding with water. Not only is flooding the least efficient way of compacting fine- grained soil, but it could damage the wall foundation or saturate the subsoil. • Never leave a hose and sprinkler ranning on or near a slope, particularly during thc rainy season. This will enhance ground saturation which may cause damage. • Never block ditches which have been graded around your house or the lot pad. These shallow ditches have been put there for the purpose of quickly removing water toward the driveway, street or other positive outlet. By all means, do not let water become ponded above slopes by blocked ditches. • Seeding and planting of the slopes should be planned to achieve, as rapidly as possible, a well-established and deep-rooted vegetal cover requiring minimal watering. • It should be the responsibility of the landscape architect to provide such plants initially and of thc residents to maintain such planting. Alteration of .such a planting scheme is at the resident's risk. • The resident is responsible for proper irrigation and for maintenance and repair of properly installed irrigation systems. Leaks .should be fixed immediately. Residents must undertake a program to eliminate burrowing animals. This must be an ongoing program in order to promote slope stability. The burrowing animal control program should be conducted by a licensed exterminator and/or landscape professional with expertise in hill side maintenance. ADVANCED GEOTECHNICAL SOLUTIONS, INC. Geotechnical Review Due to the fact that soil types may vary with depth, it is recommended that plans for the constraction of rear yard improvements (swimming pools, spas, barbecue pits, patios, etc.), be reviewed by a geotechnical engineer who is familiar with local conditions and the current standard of practice in the vicinity of your home. In conclusion, your neighbor's slope, above or below your property, is as important to you as the slope that is within your property lines. For this reason, it is desirable to develop a cooperative attitude regarding hillside maintenance, and we recommend developing a "good neighbor" policy. Should conditions develop off your property, which are undesirable from indications given above, necessary action should be taken by you to insure that prompt remedial measures arc taken. Landscaping of your property is important to enhance slope and foundation stability and to prevent erosion of thc near surface soils. In addition, landscape improvements should provide for efficient drainage to a controlled discharge location downhill of residential improvements and soil slopes. Additionally, recommendations contained in the Geotechnical Engineering Study report apply to all fiiture residential site improvements, and we advise that you include consultation with a qualified professional in planning, design, and constraction of any improvements. Such i mprovements include patios, swimming pools, decks, etc., as well as building stmctures and all changes in the site configuration requiring earth cut or fill constraction. ADVANCED GEOTECHNICAL SOLUTIONS, INC.