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Home My WebLink AboutCT 14-01; STATE MIXED USE 30; PRELIMINARY GEOTECHNICAL EVALUATION; 2013-12-24C , V 1 NOV 2 2 2016 LAND D V LO~MENT ENGjl\J ING Geotechnical • Coastal • Geologic • Environmental W .0. 6636-A-SC j ( L DECEMBER 24, 2013 (760) 438-3155 • Revised July 15, 2015 "-> -:\t ~ . ~ µ ~ •.u ~ ct oCJ . "2 • Geotechnical • Geologic • Coastal • Environmental 26590 Madison Avenue •Murrieta.California 92562 • (951) 677-9651 • FAX (951) 677-9301 • www.geosorlsinc.com State and Oak, LLP c/o MAA Architects 2173 Salk Avenue, Suite 250 Carlsbad, California 92008 Attention: Mr. Kirk Moeller December 24, 2013 W.O. 6636-A-SC Subject: Preliminary Geotechnical Evaluation, 3068 State Street, Carlsbad, San Diego County, California Dear Mr. Moeller: In accordance with your request and authorization, GeoSoils, Inc. (GSI) is pleased to present the results of our preliminary geotechnical evaluation at the subject site. The purpose of our study was to evaluate the geologic and geotechnical conditions at the site in order to develop preliminary recommendations for site earthwork and the design of foundations, walls, and pavements related to the proposed residential construction at the property. EXECUTIVE SUMMARY Based upon our field exploration, geologic, and geotechnical engineering analysis, the proposed development appears feasible from a soils engineering and geologic viewpoint, provided that the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of our study are summarized below: • In general, the site may be characterized as being underlain by Quaternary-age paralic, or deposits (formerly termed terrace deposits), which are mantled by deposits of colluvium (topsoil). At depths on the order of approximately 20 feet below existing grades, paralic deposits overly older, tertiary-age sediments belonging tho the Santiago Formation. Fill soils mantle the surficial soils. • Due to their relatively low density and lack of uniformity, all surficial deposits of undifferentiated fill/colluvium are considered unsuitable for the support of settlement-sensitive improvements (i.e., residential foundations, concrete slab-on- grade floors, site walls, exterior hardscape, etc.) and/or engineered fill in their existing state. Based on the available data, the thickness of these soils across the site is anticipated to vary between approximately 1 % feet and 3 feet. However, (760) 438-3155 Revised July 15, 2015 • • • • • localized thicker sections of unsuitable soils cannot be precluded, and should be anticipated. Conversely, the underlying unweathered paralic deposits are generally considered suitable for the support of settlement-sensitive improvements and/or engineered fill. It should be noted that the 201 O California Building Code ([201 o CBC], California Building Standards Commission [CBSC], 2010) indicates that removals of unsuitable soils be performed across all areas to be graded, under the purview of the grading permit, not just within the influence of the residential structure. Relatively deep removals may also necessitate a special zone of consideration, on perimeter/confining areas. This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite or offsite. Thus, any settlement-sensitive improvements (walls, curbs, flatwork, etc.), constructed within this zone may require deepened foundations, reinforcement, etc., or will retain some potential for settlement and associated distress. This will also require proper disclosure to any owners and all interested/affected parties should this condition exist at the conclusion of grading. Expansion index (E.I.) testing performed on a representative sample of the onsite soils indicates an E.I. of less than 20 (very low expansive). As such, site soils are considered non-detrimentally expansive and no specific foundation design appears necessary to mitigate expansive soil effects on a preliminary basis. Soil expansivity should be re-evaluated at the conclusion of grading and provide updated data for final foundation design. Corrosion testing performed on a representative sample of the onsite soils indicates site soils are mildly to moderately alkaline, moderately corrosive to exposed buried metals when saturated, present negligible sulfate exposure to concrete and are below action levels for chloride exposure. A perched groundwater table was previously encountered at a depth of approximately 13 feet below existing grades (GSI, 2008), with the regional water table anticipated at greater depths, near sea level. Regional groundwater is not anticipated to significantly affect the planned improvements. Perched water may also occur in the future along zones of contrasting permeability and/or density. This potential should be disclosed to all interested/affected parties. Our evaluation indicates there are no known active faults crossing the site and the natural slope upon which the site is located has very low susceptibility to deep-seated landslides. Owing to the depth to groundwater and the dense nature of the paralic deposits, the potential for the site to be adversely affected by liquefaction/lateral spreading is considered very low. Site soils are considered erosive. Thus, properly designed site drainage is necessary in reducing erosion damage to the planned improvements. State and Oak, LLP File:e:\wp12\6600\6636a.pge GeoSoils, Inc. W.0. 6636-A-SC Page Two (760) 438-3155 Revised July 15, 2015 • The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. The adverse effects of seismic shaking on the structure(s) will likely be wall cracks, some foundation/slab distress, and some seismic settlement. However, it is anticipated that the structure will be repairable in the event of the design seismic event. This potential should be disclosed to any owners and all interested/affected parties. • Additional adverse geologic features that would preclude project feasibility were not encountered, based on the available data. • The recommendations presented in this report should be incorporated into the design and construction considerations of the project. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. RGC/JPF/DWS/jh Distribution: (4) Addressee State and Oak, LLP File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC Page Three Revised July 15, 2015 TABLE OF CONTENTS SCOPE OF SERVICES ................................................... 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ......................... 1 FIELD STUDIES ......................................................... 3 REGIONAL GEOLOGY ................................................... 3 SITE GEOLOGIC UNITS .................................................. 4 Artificial Fill -Undocumented (Not Mapped) ............................. 4 Colluvium (Not Mapped) ............................................ 4 Quaternary-age Paralic (Terrace) Deposits (Map Symbol -Qt) .............. 4 Tertiary-age Santiago Formation (Not Mapped) .......................... 5 Structural Geology ................................................. 5 GROUNDWATER ........................................................ 5 GEOLOGIC HAZARDS EVALUATION ........................................ 6 Mass Wasting/Landslide Susceptibility ................................. 6 FAULTING AND REGIONAL SEISMICITY ..................................... 6 Regional Faults .................................................... 6 Local Faulting ..................................................... 6 Seismi~ ........................................................ 6 Seismic Shaking Parameters ......................................... 7 SECONDARY SEISMIC HAZARDS .......................................... 9 Liquefaction Potential ............................................... 9 Other Secondary Seismic Hazards .................................... 9 SLOPE STABILITY ...................................................... 10 LABORATORY TESTING ................................................. 10 Classification ..................................................... 1 O Expansion Index .................................................. 1 O Particle-Size Analysis .............................................. 1 O Direct Shear Test ................................................. 11 Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides ............. 11 Corrosion Summary ......................................... 11 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS .................... 12 GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................... 14 General ......................................................... 14 Preliminary Earthwork Factors ....................................... 14 Demolition/Grubbing .............................................. 15 Treatment of Existing Ground ....................................... 15 Fill Suitability ..................................................... 16 Fill Placement .................................................... 16 Graded and Temporary Slopes ...................................... 17 PRELIMINARY RECOMMENDATIONS -FOUNDATIONS ....................... 17 General ......................................................... 17 Preliminary Foundation Design ...................................... 18 PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS ........... 19 Mat Foundations Construction ....................................... 20 SOIL MOISTURE TRANSMISSION CONSIDERATIONS ........................ 21 WALL DESIGN PARAMETERS ............................................ 23 Conventional Retaining Walls ....................................... 23 Restrained Walls ............................................ 24 Cantilevered Walls ........................................... 24 Seismic Surcharge ................................................ 25 Retaining Wall Backfill and Drainage .................................. 25 Wall/Retaining Wall Footing Transitions ............................... 29 DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS ....................... 29 PRELIMINARY PAVEMENT DESIGN ....................................... 31 DEVELOPMENT CRITERIA ............................................... 33 Slope Maintenance and Planting ..................................... 33 Drain~e ........................................................ 33 Erosion Control ................................................... 34 Landscape Maintenance ........................................... 34 Gutters and Downspouts ........................................... 34 Subsurface and Surface Water ...................................... 35 Site Improvements ................................................ 35 Tile Flooring ..................................................... 35 Additional Grading ................................................ 35 Footing Trench Excavation ......................................... 35 Trenching/Temporary Construction Backcuts .......................... 36 Utility Trench Backfill .............................................. 36 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING ........................................................ 37 State and Oak, LLP File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Table of Contents Page ii Revised July 15, 2015 OTHER DESIGN PROFESSIONALS/CONSULTANTS .......................... 37 PLAN REVIEW ......................................................... 38 LIMITATIONS .......................................................... 39 FIGURES: Figure 1 -Site Location Map ......................................... 2 Detail 1 -Typical Retaining Wall Backfill and Drainage Detail .............. 26 Detail 2 -Retaining Wall Backfill and Subdrain Detail Geotextile Drain ....... 27 Detail 3 -Retaining Wall and Subdrain Detail Clean Sand Backfill ........... 28 ATTACHMENTS: Plate 1 -Geotechnical Map ................................. Rear of Text Appendix A -References ................................... Rear of Text Appendix B -Hand Auger Borings (This Study) and Boring B-1 from GSI (2008) .................................................. Rear of Text Appendix C -Seismicity Data ................................ Rear of Text Appendix D -Laboratory Data (This Study and GSI [2008]) ........ Rear of Text Appendix E -General Earthwork and Grading Guidelines ......... Rear of Text State and Oak, LLP File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Table of Contents Page iii Revised July 15, 2015 PRELIMINARY GEOTECHNICAL EVALUATION 3068 STATE STREET, CARLSBAD SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of readily available published literature, aerial photographs, and maps of the vicinity (see Appendix A), including proprietary in-house geologic/geotechnical reports for this site. 2. Site reconnaissance mapping and the excavation of four (4) hand excavated exploratory test borings to evaluate the soil/bedrock profiles, sample representative earth materials, and delineate the horizontal and vertical extent of earth material units (see Appendix B). 3. General areal seismicity evaluation (see Appendix C). 4. Appropriate laboratory testing of relatively undisturbed and representative bulk soil samples collected during our geologic mapping and subsurface exploration program (see Appendix D). 5. Analysis of field and laboratory data relative to the proposed development. 6. Appropriate engineering and geologic analyses of data collected, and the preparation of this summary report and accompaniments. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The site consists of a rectangular-shaped property located at the northeast corner of the State Street and Oak Avenue intersection in the City of Carlsbad, San Diego County, California (see Figure 1, Site Location Map). The site's physical addresses are 3068 State Street and 542 Oak Avenue. The site is bounded by existing residential development to the north, by Oak Avenue to the south, by an alley to the east, and by State Street to the west. The property is relatively flat-lying to very gentle west and south sloping. Based on a review of United States Geological Survey (USGS, 1997), the elevation of the site is estimated to be approximately 45 feet Mean Sea Level (MSL}. Site drainage is accommodated by sheet flow directed to the south and west into Oak Avenue and State Street. Numerous, one-story, residential buildings and associated out buildings occupy a majority of the site. Vegetation consists of typical residential landscaping. Based on a review of the current plan for the project, prepared by MAA Architects (MAA, 2013), is our understanding that the existing structures will be removed, and the site prepared for the construction of a four-story, multi-unit residential building, with ground floor parking, commercial space, mechanical room, and "timeshare activity space." GSI GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 SITE Base Map: TOPO!® ©2003 National Geographic, U.S.G.S. San Luis Rey Quadrangle, California --San Diego Co., 7.5 Minute, dated 1997, current, 1999. SITE Base Map: Google Maps, Copyright 2013 Google, Map Data Copyright 2013 Google This map Is copyrighted by Google 2013. It Is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without pennlsslon. All rlghts reserved. N w.o. e. 6636-A-SC SITE LOCATION MAP Figure 1 (760) 438-3155 Revised July 15, 2015 anticipates that the construction would be four stories (i.e., three supported floor levels), and consist of wood frames with typical foundations and slab-on-grade ground floors. Building loads are assumed to be typical for this type of residential application. Sewage disposal is anticipated to be connected into the regional, municipal system. Storm water may be treated onsite prior to its delivery into the municipal system. FIELD STUDIES Site-specific field studies were conducted by GSI during December 2013, and consisted of reconnaissance geologic mapping and the excavation of four (4) exploratory test borings with a hand auger, for an evaluation of near-surface soil and geologic conditions onsite. The test borings were logged by a representative of this office who collected representative bulk soil samples for appropriate laboratory testing. The logs of the test borings are presented in Appendix B. The approximate location of the test borings are presented on the Geotechnical Map (see Plate 1), which uses the site plan, prepared by MAA (2013) as a base. A deep, hollow stem auger boring, completed during a previous study (GSI, 2008) is also shown on Plate 1. REGIONAL GEOLOGY The subject property lies within the coastal plain physiographic region of the Peninsular Ranges Geomorphic Province of southern California. This region consists of dissected, mesa-like terraces that transition inland to rolling hills. The encompassing Peninsular Ranges Geomorphic Province is characterized as elongated mountain ranges and valleys that trend northwesterly (Norris and Webb, 1990). This geomorphic province extends from the base of the east-west aligned Santa Monica -San Gabriel Mountains, and continues south into Baja California. The mountain ranges within this province are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic (granitic) rocks. In the Southern California region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited during the Tertiary Period (Eocene-age) into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed from the deposition of marine terrace deposits. During mid to late Pleistocene time, this plain was uplifted, eroded and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. Regional geologic mapping by Kennedy and Tan (2005) indicate the site is underlain by Quaternary-age paralic deposits (formerly termed "terrace deposits"), which is considered bedrock, or State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC December 24. 2013 Page 3 Revised July 15, 2015 formational soil, at the site. Based on our experience in the vicinity, older deposits of Eocene-age sedimentary bedrock likely underlie the site at depths. SITE GEOLOGIC UNITS The site geologic units observed and/or encountered during our subsurface investigation and site reconnaissance included surficial fill colluvium (topsoil), Quaternary-age paralic (terrace deposits), and Tertiary-age Santiago Formation. The earth materials are generally described below from the youngest to the oldest. The distribution of these geologic units is shown on Plate 1. Artificial Fill -Undocumented (Not Mapped) Discontinuous, thin surficial deposits of existing fill are likely distributed throughout the site as small berms, areas of disturbed surface soil, pavement, existing trench backfills, etc. Consisting of similar, native derived soils such as silty sand and on the order of less than 1 foot in thickness. This undocumented fill is unsuitable to support the proposed improvements/fill in its existing state. Removal and recompaction of these materials is recommended should settlement-sensitive structures and/or engineered fill be proposed within their influence. Locally, the thickness of undocumented fill will be variable (i.e., trench backfill, pavement) and will be known only after removal of the existing site improvements. Colluvium (Not Mapped) As observed in Hand Auger Borings (HA-1 through HA-4), colluvium (topsoil) occurs at the surface and consists of dark brown, dry to damp, loose, porous silty sands and sands with silt. Where encountered in our borings, the thickness of these earth materials was on the order of 112 to 1 foot thick. All topsoil/colluvium is prone to settlement under loading and therefore should be removed and reused as properly engineered fill. Quaternary-age Paralic (Terrace) Deposits (Map Symbol -Qt) Quaternary-age paralic (terrace) deposits were observed underlying the undocumented fill ortopsoil/colluvium in all of the borings. Where unweathered, these materials generally consist of light brown, light reddish brown, and light reddish yellow, dry to saturated, dense to very dense silty sand and sand with silt. The upper 1 foot to 2% feet of these materials were weathered and contained some visible porosity, which decreased with depth. The near-surface, weathered terrace deposits are considered potentially compressible in their existing state, and removal and recompaction is recommended, if settlement-sensitive improvements and/or engineered fill are proposed within their influence. State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24. 2013 Page 4 Revised July 15, 2015 Tertiary-age Santiago Formation (Not Mapped) As observed in Boring B-1 (see Appendix B), the Quaternary-age paralic (terrace) deposits are underlain by sedimentary bedrock belonging to the Tertiary-age Santiago Formation at an approximate depth of about 20 feet beneath the surface. The Santiago Formation generally consisted of a gray to brown, dry to wet, dense to very dense silty fine-to medium-grained sandstone. These bedrock sediments are considered suitable for support of settlement-sensitive improvements and/or engineered fill. However, it is unlikelythatthe formation will be encountered during site development. Structural Geology Bedding within Quaternary-age paralic (terrace) deposits is generally flat lying to gently dipping to the west. Based on our observations, and experience in the vicinity, older deposits of Eocene-age sedimentary bedrock that underlie the site at an approximate depth of 20 feet, are in contact with the overlying paralic (terrace) deposits along a relatively flat lying plane. However, there is most likely a slight westerly dip in this contact. GROUNDWATER Regional groundwater is expected to generally be coincident with sea level. However, perched groundwater was encountered in Boring B-1 at an approximate depth of 13 feet below the existing grade. Perched groundwater is not anticipated to adversely affect site development, provided that the recommendations contained in this report are properly incorporated into final design and construction. However, foundation elements have the potential to occur near this depth, and perched water may present difficulties during construction in the form of saturated foundation soils and caving/sloughing foundation excavations. Further, the presence of perched water increases the potential for vapor or water transmission through the slab, foundations, and subterranean walls. Footings will need to be placed on firm, unyielding soils with no standing groundwater and therefore, some pumping/dewatering may be necessary, and this will need to be considered during planning. These observations reflect site conditions at the time of our investigation and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious at the time of our investigation. Based on the permeability contrasts between any proposed fill and the terrace deposits, perched groundwater conditions may develop in the future due to excessive irrigation, poor drainage or damaged utilities, and should be anticipated. Should manifestations of this perched condition (i.e., seepage) develop in the future, this office could assess the conditions and provide mitigative recommendations, as necessary. The potential for perched water to occur after development should be disclosed to all interested/affected parties. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 5 Revised July 15, 2015 GEOLOGIC HAZARDS EVALUATION Mass Wasting/Landslide Susceptibility Due to the relatively flat lying condition of the site, and the nature of the underlying soils, the site is not considered susceptible to mass wasting or landsliding. The onsite soils are, however, considered erosive. Therefore, slopes comprised of these materials may be subject to rilling, gullying, sloughing, and surficial slope failures depending on rainfall severity and surface drainage. However, such risks can be minimized through properly designed and controlled surface drainage. FAUL TING AND REGIONAL SEISMICITY Regional Faults Our review indicates that there are no known active faults crossing the project and the site is not within an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007). However, the site is situated in an area of active faulting. The Rose Canyon fault part of the Newport- Inglewood -Rose Canyon fault system, is the closest known active fault to the site (located at a distance of approximately 5.0 miles [8.1 kilometers]), and should have the greatest effect on the site in the form of strong ground shaking, should the design earthquake occur. The location of the Rose Canyon fault and other major faults relative to the site is shown on the "California Fault Map" in Appendix C. The possibility of ground acceleration, or shaking at the site, may be considered as approximately similar to the southern California region as a whole. Local Faulting Although active faults lie within a few miles of the site, no local active faulting was noted in our review, nor observed to specifically transect the site during the field investigation. Additionally, a review of available regional geologic maps does not indicate the presence of local active faults crossing the specific project site. Seismicity The acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999) has been incorporated into EQFAULT {Blake, 2000a). EQFAULT is a computer program developed by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. The program estimates the closest distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound (formerly "maximum credible State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC December 24, 2013 Page 6 Revised July 15, 2015 earthquake"), on that fault. Upper bound refers to the maximum expected ground acceleration produced from a given fault. Site acceleration (g) was computed by one user-selected acceleration-attenuation relation that is contained in EQFAUL T. Based on the EQFAUL T program, a peak horizontal ground acceleration from an upper bound event on the Rose Canyon fault may be on the order of 0.57 g. The computer printouts of pertinent portions of the EQFAUL T program are included within Appendix C. Historical site seismicity was evaluated with the acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999), and the computer program EQSEARCH (Blake, 2000b, updated to December 2012). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 100-kilometer radius, between the years 1800 through December 2012. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration is estimated, which may have affected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through December 2012 was about 0.24 g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of the EQSEARCH program are presented in Appendix C. A probabilistic seismic hazards analysis was performed using the 2008 Interactive Deaggregations (Beta [2012 update]) Seismic Hazard Analysis tool available at the USGS website (https://geohazards.usgs.gov/deaggnit/2008/) which evaluates the site specific probabilities of exceedance for selected spectral periods. Based on a review of these data, and considering the relative seismic activity of the southern California region, a probabilistic horizontal ground acceleration (PHGA) of 0.48 g and 0.26 g were calculated. The calculated values are within the range typical for the southern California region. These values were chosen as they correspond to a 2 and 1 O percent probability of exceedence in 50 years, respectively. Probabilistic vertical ground acceleration may be assumed as 50 percent of the PHGA. Printouts from this analysis are also included in Appendix C. Seismic Shaking Parameters Based on the site conditions, the following table summarizes the updated site-specific design criteria obtained from the 201 O CBC (CBSC, 2010), Chapter 16 Structural Design, Section 1613, Earthquake Loads. The computer program "U.S. Seismic Design Maps, provided by the United States Geologic Survey (USGS, 2013) was utilized for design (http://geohazards.usgs.gov/designmaps/us/application.php). The short spectral response utilizes a period of 0.2 seconds. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 7 Revised July 15, 2015 CBC SEISMIC DESIGN PARAMETERS PARAMETER VALUE 2010 CBC REFERENCE Site Class D Table 1613.5.2 Spectral Response -(0.2 sec), S, 1.321 Figure 1613.5(1) Spectral Response -(1 sec), S, 0.497 Figure 1613.5(2) Site Coefficient, Fa 1.0 Table 1613.5.3(1) Site Coefficient, F, 1.503 Table 1613.5.3(2) Maximum Considered Earthquake Spectral 1.321 Section 1613.5.3 Response Acceleration (0.2 sec), SM, (Eqn 16-36) Maximum Considered Earthquake Spectral 0.746 Section 1613.5.3 Response Acceleration (1 sec), SM, (Eqn 16-37) 5% Damped Design Spectral Response 0.881 Section 1613.5.4 Acceleration (0.2 sec), Sos (Eqn 16-38) 5% Damped Design Spectral Response 0.498 Section 1613.5.4 Acceleration (1 sec), Sa, (Eqn 16-39) GENERAL SEISMIC DESIGN PARAMETERS PARAMETER VALUE Distance to Seismic Source (Rose Canyon fault) 5.0 mi (8.1 km)1'1 Upper Bound Earthquake (Rose Canyon fault) Mw 6.9(2!/Mw 7.2(3) Probabilistic Horizontal Ground Acceleration ([PHGA] 2%/10% 0.48g/0.26g probabilitv of exceedance in 50 years, respectively).1'1 1'1 -From Blake (2000a) 1'1 -International Conference of Building Officials (ICBO, 1998) "' -Cao, et al. (2003) ,,, -Probabilistic Vertical Ground Acceleration mav be assumed as about 50% of these values. Conformance to the criteria above for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur in the event of a large earthquake. The primary goal of seismic design is to protect life, not to eliminate all damage, since such design may be economically prohibitive. Cumulative effects of seismic events are not addressed in the 201 O CBC (CBSC, 2010) and regular maintenance and repair following locally significant seismic events (i.e., Mw5.5) will likely be necessary, as is the case in all of southern California. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 8 Revised July 15, 2015 SECONDARY SEISMIC HAZARDS Liquefaction Potential Seismically-induced liquefaction is a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in soils. The soils may thereby acquire a high degree of mobility, and lead to lateral movement, sliding, sand boils, consolidation and settlement of loose sediments, and other damaging deformations. This phenomenon occurs only below the water table; but after liquefaction has developed, it can propagate upward into overlying, non-saturated soil as excess pore water dissipates. Typically, liquefaction has a relatively low potential at depths greater than 50 feet and is unlikely below a depth of 60 feet. Liquefaction susceptibility is related to numerous factors and the following conditions should be concurrently present for liquefaction to occur: 1) sediments must be relatively young in age and not have developed a large amount of cementation; 2) sediments generally consist of medium to fine grained relatively cohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present in the sediment; and 5) the site must experience a seismic event of a sufficient duration and magnitude, to induce straining of soil particles. The condition of liquefaction has two principal effects. One is the consolidation of loose sediments with resultant settlement of the ground surface. The other effect is lateral sliding. Significant permanent lateral movement generally occurs only when there is significant differential loading, such as fill or natural ground slopes within susceptible materials. No such loading conditions exist on the site. In the site area, we found there is a potential for seismic activity and a perched groundwater table located approximately 13 feet below the ground surface. However, the terrace deposits and the underlying Santiago Formation are considered to possess cemented soils with a dense to very dense nature. Inasmuch as at least one or two of these five required concurrent conditions discussed above do not currently have the potential to affect the site and considering that the low density surficial soils not removed by the planned excavation would be replaced with engineered fill, the potential for liquefaction and associated adverse effects within the site is low, even with a future rise in regional groundwater levels. Therefore, it is our opinion that the liquefaction potential does not constitute a significant risk to site development. Other Secondary Seismic Hazards The following list includes other geologic/seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or mitigated as a result of site location, soil characteristics, and typical site development procedures: State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24. 2013 Page 9 Revised July 15, 2015 • Lateral Spreading • Subsidence • Ground Lurching or Shallow Ground Rupture • Tsunami • Seiche SLOPE STABILITY Based on site conditions and planned improvements, significant cut and/or fill slopes are not anticipated. Therefore, no recommendations are deemed necessary. Temporary slopes for construction (i.e., trenching, etc.) are discussed in subsequent sections of our report. LABORATORY TESTING Laboratory tests were performed on representative samples of site earth materials collected during our subsurface exploration in order to evaluate their physical characteristics. Test procedures used and results obtained are presented below. Classification Soils were visually classified with respect to the Unified Soil Classification System (U.S.C.S.) in general accordance with ASTM D 2487 and D 2488. The soil classifications of the onsite soils are provided on the Test Pit Logs in Appendix B. Expansion Index Tests were performed on a representative soil sample to evaluate expansion potential. Testing was performed in general accordance with ASTM D 4829, and indicates a very low expansion potential (Expansion Index [E.I.J = <20), where tested. Particle-Size Analysis A particle-size evaluation was performed on a representative, soil sample in general accordance with ASTM D 422-63. The grain-size distribution curve is presented in Appendix D. The testing was utilized to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The results of the particle-size evaluation indicate that the tested soil is a silty sand (SM). State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 1 O Revised July 15, 2015 Direct Shear Test Shear testing was performed on a relatively undisturbed sample of site soil in general accordance with ASTM test method D 3080 in a Direct Shear Machine of the strain control type. The shear test results are presented as follows: PRIMARY RESIDUAL LOCATION AND DEPTH (FEET) COHESION FRICTION ANGLE COHESION FRICTION ANGLE (PSF) (DEGREES) (PSF) (DEGREES) B-1@ 3 (remolded) 133 29 98 29 (GSI, 2008) B-1 @ 10 (undisturbed) 113 36 87 35 (GSI, 2008) Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides GSI conducted sampling of onsite earth materials for general soil corrosivity and soluble sulfates, and chlorides testing. The testing included evaluation of soil pH, soluble sulfates, chlorides, and saturated resistivity. Test results are presented in Appendix D and the following table: SAMPLE LOCATION SATURATED SOLUBLE SOLUBLE AND DEPTH (FT) pH RESISTIVITY SULFATES CHLORIDES (ohm-cm) (ppm) (ppm) I B-1 Composite I 7.98 I 9,100 I 0.0010 I 104 I Corrosion Summary Laboratory testing indicates that tested samples of the on site soils are mildly alkaline with respect to soil acidity/alkalinity, are corrosive to exposed, buried metals when saturated, present negligible ("not applicable" per ACI 318-08) sulfate exposure to concrete, and are below action levels for chloride exposure (per State of California Department of Transportation, 2003). Reinforced concrete mix design for foundations, slab-on-grade floors, and pavements should minimally conform to "Exposure Class C1" in Table 4.3.1 of ACI 318-08, as concrete would likely be exposed to moisture. It should be noted that GSI does not consult in the field of corrosion engineering. The client and project architect should agree on the level of corrosion protection required for the project and seek consultation from a qualified corrosion consultant as warranted. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W .0. 6636-A-SC December 24, 2013 Page 11 Revised July 15, 2015 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the subject site is suitable for the proposed residential development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development and improvements are: • • • • • • • Earth materials characteristics and depth to competent bearing material. Potential for existing utilities to influence proposed foundations . On-going expansion and corrosion potential of site soils . Erosiveness of site earth materials . Potential for perched water during and following site development. Temporary slope stability . Regional seismic activity . The recommendations presented herein consider these as well as other aspects of the site. The engineering analyses performed concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work. In the event that any significant changes are made to proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report verified or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. 1. Soil engineering, observation, and testing services should be provided during grading to aid the contractor in removing unsuitable soils and in his effort to compact the fill. 2. Geologic observations should be performed during any grading and foundation construction to verify and/or further evaluate geologic conditions. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted. 3. Surficial fill and deposits of colluvium and weathered paralic deposits are considered unsuitable for the support of the planned settlement-sensitive improvements (i.e., residential structure, walls, concrete slab-on-grade floors, and exterior pavements, etc) or new planned fills. Unsuitable soils within the influence of planned settlement-sensitive improvements and/or planned fill should be removed to expose unweathered paralic deposits and then be reused as properly State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 12 Revised July 15, 2015 engineered fill. Based on the available data, remedial grading excavations are anticipated to extend to depths of approximately 1 Va to 3 feet below the existing grade. 4. In order to provide for the uniform support of the improvements and to mitigate the potential for near surface, perched groundwater conditions and moisture vapor transmission through the floor slab, undercutting, or overexcavation of the underlying paralic deposits is recommended to at least 3 feet below finish grade. 5. Testing performed on a representative sample of the onsite soils indicates very low expansive soil conditions. On a preliminary basis, specific foundation design to resist expansive soil effects is not necessary. However, GSI suggests that the soil moisture within the underlying subgrade is near, or above optimum moisture content prior to the placement of the underlayment sand and vapor retarder. 6. Laboratory testing indicates that site soils are mildly alkaline and slightly corrosive to exposed buried metals when saturated. Testing also indicates that site soils present negligible ("not applicable" per ACI 318-08) sulfate exposure to concrete and are below the action levels for chloride exposure. The client and project architect should agree on the level of corrosion protection required for the project and seek consultation from a qualified corrosion consultant as warranted. 7. Site soils are considered erosive. Surface drainage should be designed to eliminate the potential for concentrated flows. Positive surface drainage away from foundations and tops of slopes is recommended. Temporary erosion control measures should be implemented until vegetative covering is well established. The owner will need to maintain proper surface drainage over the life of the project. 8. No evidence of a high regional groundwater table was observed during our subsurface exploration within the property. Perched water may exist as shallow as ±13 feet below existing grade, and will need to be considered during planning. However, due to the nature of site earth materials, there is a potential for perched water to occur both during and following site development, nearer the surface. This potential should be disclosed to all interested/affected parties. Should perched water conditions be encountered, this office could provide recommendations for mitigation. Typical mitigation includes subdrainage system, cut-off barriers, etc. 9. On a preliminary basis, temporary slopes should be constructed in accordance with CAL-OSHA guidelines for Type "B" soils. All temporary slopes should be evaluated by the geotechnical consultant, prior to worker entry. Should adverse conditions be identified, the slope may need to be laid back to a flatter gradient or require the use of shoring. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 13 Revised July 15, 2015 10. The seismicity-acceleration values provided herein should be considered during the design and construction of the proposed development. 11. General Earthwork and Grading Guidelines are provided at the end of this report as Appendix E. Specific recommendations are provided below. EARTHWORK CONSTRUCTION RECOMMENDATIONS General All earthwork should conform to the guidelines presented in the 201 O CBC (CBSC, 201 O), the requirements of the City of Carlsbad, and the General Earthwork and Grading Guidelines presented in Appendix E, except where specifically superceded in the text of this report. Prior to earthwork, a GSI representative should be present at the preconstruction meeting to provide additional earthwork guidelines, if needed, and review the earthwork schedule. This office should be notified in advance of any fill placement, supplemental regrading of the site, or backfilling underground utility trenches and retaining walls after rough earthwork has been completed. This includes grading for driveway approaches, driveways, and exterior hardscape. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GS/. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act (OSHA), and the Construction Safety Act should be met. It is the onsite general contractor and individual subcontractors responsibility to provide a save working environment for our field staff who are onsite. GSI does not consult in the area of safety engineering. Preliminary Earthwork Factors Preliminary earthwork factors (shrinkage and bulking) for the subject property have been estimated based upon our field and laboratory testing, visual site observations, and experience on surrounding properties. It is apparent that shrinkage would vary with depth and with areal extent over the site based on previous site use. Variables include vegetation, weed control, discing, and previous filling or exploring. Therefore, based on our evaluation, the existing deposits of fill/colluvium are anticipated to shrink on the order of 5 percent to 10 percent upon recompaction. Significant large trees, with root systems that could affect earthwork factors were not noted onsite. Subsidence in the bedrock areas is anticipated to be nil. Further, methods employed by the grading contractor may effect these values, above, by up to about State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 14 Revised July 15, 2015 4 percent. The above facts indicate that earthwork balance for the site would be difficult to define and flexibility in design is essential to achieve a balanced end product. Demolition/Grubbing 1. Vegetation and any miscellaneous debris should be removed from the areas of proposed grading. 2. Any existing subsurface structures uncovered during the recommended removal should be observed by GSI so that appropriate remedial recommendations can be provided. 3. Cavities or loose soils remaining after demolition and site clearance should be cleaned out and observed by the soil engineer. The cavities should be replaced with fill materials that have been moisture conditioned to at least optimum moisture content and compacted to at least 90 percent of the laboratory standard. 4. Onsite septic systems (if encountered) should be removed in accordance with San Diego County Department of Environmental Health standards/guidelines. 5. Subsequent to demolition of the existing structures, test pits should be performed in the vicinity of proposed foundations to evaluate utility trenches, easements, and the adjoining alley with respect to conduits and lateral separation, and their effects of proposed and overlying settlement-sensitive improvements. Treatment of Existing Ground 1. Removals should consist of all surficial deposits of undifferentiated fill/colluvium. Based on our site work, removals depths on the order of 11/2 to 3 feet should be anticipated. These soils may be re-used as fill, provided that the soil is cleaned of any deleterious material and moisture conditioned, and compacted to a minimum 90 percent relative compaction per ASTM D 1557. Removals should be completed throughout the entire lot. 2. In addition to removals within the building envelope, overexcavation of the underlying formational soil should be performed in order to provide for at least 3 feet of compacted fill below finish grade. Once removals and overexcavation is completed, the fill should be cleaned of deleterious materials, moisture conditioned, and recompacted to at least 90 percent relative compaction per ASTM D 1557. 3. Subsequent to the above removals/overexcavation, the exposed bottom should be scarified to a depth of at least 8 inches, brought to at least optimum moisture content, and recompacted to a minimum relative compaction of 90 percent of the laboratory standard, prior to any fill placement. State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 15 Revised July 15, 2015 4. Existing fill and removed natural ground materials may be reused as compacted fill provided that major concentrations of vegetation and miscellaneous debris are removed from the site, prior to or during fill placement. 5. Localized deeper removals may be necessary due to buried drainage channel meanders or dry porous materials, septic systems, etc. The project soils engineer/geologist should observe all removal areas during the grading. 6. Based on the test pit exploration subsequent to demolition, existing utilities may be treated as follows: a). If utilities are '.'. 4 feet in depth, the utilities should be removed entirely and replaced with similar native soils compacted to at least 95 percent relative compaction per ASTM D 1557, or backfilled with a lean, 3-sack slurry. b). If utilities are > 4 feet in depth, either i) the top 4 feet should be removed entirely and replaced with similar native soils compacted to at least 95 percent relative compaction per ASTM D 1557, or backfilled with a lean, 3-sack slurry; and, the pipes below that depth be completely grouted solid in-place. Utilities should be plugged only where they extend offsite, but not onsite. Or ii), the utilities may be treated for the entire depth as in a) above. The above assumes that the conduits are not within one footing width (B), or 1 x (B) away from the face of the footing. Fill Suitability Existing earth materials on site should generate relatively fine grained fill material. Oversize material (i.e., greater than 12 inches in long dimension) is not anticipated. However, some foundation concrete remaining from the previous structure may be present. If soil importation is planned, samples of the soil import should be evaluated by this office prior to importing in order to assure compatibility with the onsite site soils and the recommendations presented in this report. Import soils, if used, should be relatively sandy and very low expansive (i.e., expansion index less than 20). Fill Placement 1. Subsequent to ground preparation, fill materials should be brought to at least optimum moisture content, placed in thin 6-to 8-inch lifts, and mechanically compacted to obtain a minimum relative compaction of95 percent of the laboratory standard. 2. Fill materials should be cleansed of major vegetation and debris prior to placement. State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 16 Revised July 15, 2015 3. Any import materials should be observed and deemed suitable by the soils engineer prior to placement on the site. Foundation designs may be altered if import materials have a greater expansion value than the onsite materials encountered in this investigation. Graded and Temporary Slopes The site is relatively flat lying and significant slope are not planned. Temporary slopes for excavations greater than 4 feet, but less than 20 feet in overall height should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils. Temporary slopes, up to a maximum height of ±20 feet, may be excavated at a 1: 1 (h:v) gradient, or flatter, provided groundwater and/or running sands are not exposed. Construction materials or soil stockpiles should not be placed within 'H' of any temporary slope where 'H' equals the height of the temporary slope. All temporary slopes should be observed by a licensed engineering geologist and/or geotechnical engineer prior to worker entry into the excavation. PRELIMINARY RECOMMENDATIONS -FOUNDATIONS General Preliminary recommendations for foundation design and construction are provided in the following sections. These preliminary recommendations have been developed from our understanding of the currently planned site development, site observations, subsurface exploration, laboratory testing, and engineering analyses. Foundation design should be re-evaluated at the conclusion of site grading/remedial earthwork for the as-graded soil conditions. Although not anticipated, revisions to these recommendations may be necessary. In the event that the information concerning the proposed development plan is not correct, or any changes in the design, location or loading conditions of the proposed additions are made, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are not meant to supercede design by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional input/consultation regarding soil parameters, as related to foundation design. We anticipate average and maximum static column loads of 100 and 250 kips, respectively. Maximum wall loads are anticipated to be on the order of 5 kips per foot. Based on the above, we have considered the following design alternatives: State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W .0. 6636-A-SC December 24, 2013 Page 17 Revised July 15, 2015 • Isolated spread/continuous footings. • Mat foundation Preliminary Foundation Design 1. The foundation systems should be designed and constructed in accordance with guidelines presented in the 201 O CBC. 2. Based on the anticipated foundation loads and preliminary design information provided us, it is our opinion that the proposed structure can favorably be supported on engineered fill, or dense paralic deposits. Building loads may be supported on continuous or isolated spread footings designed in accordance with the following recommendations. ALLOWABLE BEARING VALUES FOR FOOTINGS DEPTH BELOW LOWEST ALLOWABLE BEARING ALLOWABLE BEARING ADJACENT FINISHED CAPACITY FOR CAPACITY FOR CONTINUOUS GRADE (INCHES) SPREAD FOOTINGS WALL FOOTINGS (MINIMUM WIDTH = 4 FEET) (MINIMUM WIDTH = 2 FEET) 30 3.5 ksf 3.0 ksf 36 4.0 ksf 3.5 ksf 48 4.5 ksf 4.0 ksf The above values are for dead plus live loads and may be increased by one-third for short-term wind or seismic loads. The above values are for dead plus live loads and may be increased by one-third for short-term wind or seismic loads. Where column or wall spacings are less than twice the width of the footing, some reduction in bearing capacity may be necessary to compensate for the effects of group action. GSI should review the foundation plans and overlying building load patterns and evaluate this potential with the structural consultant. Reinforcement should be designed in accordance with local codes and structural considerations. 3. Isolated pad footings should have a minimum dimension of at least 36 inches square and a minimum embedment of 24 inches below the lowest adjacent grade into properly engineered fill. Foundation embedment depth excludes concrete slabs-on-grade, and/or slab underlayment. Foundations should not simultaneously bear on unweathered paralic deposits and engineered fill. 4. For foundations deriving passive resistance from engineered fill (i.e., adjoining mitigated existing utilities [95 percent relative compaction]), a passive earth State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp t 2\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC December 24, 2013 Page 18 Revised July 15, 2015 pressure may be computed as an equivalent fluid having a density of 300 pcf, with a maximum earth pressure of 3,000 psf. For embedment in unweathered paralic deposits, a pressure of 400 pcf may be used if the footing face is embedded entirely in formation, and the embedment is greater than 30 inches. 5. The upper 6 inches of passive pressure should be neglected if not confined by slabs or pavement. 6. For lateral sliding resistance, a 0.30 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. 7. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 8. All footing setbacks from slopes should comply with Figure 1808.7.1 of the 201 O CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face, if applicable. 9. Footings for structures adjacent to retaining/privacy walls should be deepened so as to extend below a 1 :1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the "Retaining Wall" section of this report. PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. The following foundation construction recommendations are intended to support planned improvements underlain by at least 7 feet of non-detrimentally expansive soils (i.e., E.l.<21 and P.I. <15). Although not anticipated based on the available data, should foundations be underlain by expansive soils they will require specific design to mitigate expansive soil effects as required in Sections 1808.6.1 or 1808.6.2 of the 201 O CBC. 1. Exterior and interior footings should be founded into engineered fill as indicated in the previous "preliminary foundation design" section of this report. Reinforcement should be designed in accordance with local codes and structural considerations. 2. All interior and exterior column footings, and perimeter wall footings, should be tied together via grade beams in at least one direction. The grade beam should be at least 24 inches square in cross section, and the base of the reinforced grade beam should be at the same elevation as the adjoining footings. Reinforcement should be designed in accordance with local codes and structural considerations. State and Oak, LLP 3068 State Street. Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 19 Revised July 15, 2015 3. A grade beam, reinforced as previously recommended and at least 24 inches square, should be provided across large (garage) entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 4. Floor slabs should have a minimum thickness of 5 inches and be reinforced (at a minimum) with No. 4 rebars at 18 inches on center (each way), placed at mid-height in the slab. Actual reinforcement should be based on structural considerations and local codes. Concrete shrinkage cracking may be reduced by addition of fiber mesh into the concrete and careful control of concrete water-to-cement ratios. Slabs should have crack control joints with appropriate spacings as designed by the structural engineer. Concrete slab-on-grade floor underlayment and concrete mix design should conform to the recommendations in the "Soil Moisture Considerations" section of this report if the transmission of water or vapor through the slab is unwanted. 6. All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. "Hooking" of reinforcement is not an acceptable method of positioning. 7. Specific slab subgrade pre-soaking is recommended for these soil conditions. Prior to the placement of underlayment sand and vapor retarder, GSI recommends that the slab subgrade materials be moisture conditioned to at least optimum moisture content to a minimum depth of 12 inches. Slab subgrade pre-soaking should be evaluated by the geotechnical consultant within 72 hours of the placement of the underlayment sand and vapor retarder. 8. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction of 90 percent of the laboratory standard (ASTM D 1557), whether the soils are to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street. 9. Reinforced concrete mix design should conform to "Exposure Class C1" in Table 4.3.1 of ACl-318-08 since concrete would likely be exposed to moisture. Mat Foundations Construction For a mat foundation bearing uniformly in competent soils, a maximum gross allowable bearing capacity of 2,500 psf is recommended. This value may be increased by one-third for short-term loads including wind or seismic. Reinforcement should be designed in accordance with local codes and structural considerations. The recommended bearing capacity is based on an anticipated maximum total and differential settlement of 2 inches and 1 inch, respectively. The majority of the settlement should occur during construction. For foundation design, a vertical modulus of subgrade State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC December 24, 2013 Page 20 Revised July 15, 2015 reaction (k) of 125 pounds per square inch (psi) per inch of depth may be utilized. This is a unit value for a 1-foot square footing and should be reduced in accordance with the following equation when used with the design of larger foundations. K -K--rB-'-l]' R -2B where: = unit subgrade modulus = reduced subgrade modulus = foundation width (in feet). Mat foundations may utilize the applicable sections of the 201 O CBC (CBSC, 201 O) and Wire Reinforcement Institute method (WRI, 1996). Alternative methods that accommodate the geotechnical parameters in this report may also be presented. The resulting design will likely be a uniform thickness or interconnected grade beams and integrated slab. An under-slab drain and permanent dewatering system with a sump pump should be considered. Floor slabs should be a minimum of 5 inches in thickness and be reinforced with rebars at the spacing recommended by the structural engineer, in light of expansive soil conditions. SOIL MOISTURE TRANSMISSION CONSIDERATIONS GSI has evaluated the potential for vapor or water transmission through the concrete floor slabs in living areas, in light of typical floor coverings and improvements. Please note that slab moisture emission rates range from about 2 to 27 lbs/ 24 hours/1,000 square feetfrom a typical slab (Kanare, 2005), while floor covering manufacturers generally recommend about 3 lbs/24 hours as an upper limit. The recommendations in this section are not intended to preclude the transmission of water or vapor through the foundation or slabs. Foundation systems and slabs shall not allow water or water vapor to enter into the structure so as to cause damage to another building component or to limit the installation of the type of flooring materials typically used for the particular application (State of California, 2013). These recommendations may be exceeded or supplemented by a water "proofing" specialist, project architect, or structural consultant. Thus, the client will need to evaluate the following in light of a cost vs. benefit analysis (owner expectations and repairs/replacement), along with disclosure to all interested/affected parties. It should also be noted that vapor transmission will occur in new slab-on-grade floors as a result of chemical reactions taking place within the curing concrete. Vapor transmission through concrete floor slabs as a result of concrete curing has the potential to adversely affect sensitive floor coverings depending on the thickness of the concrete floor slab and the duration of time between the placement of concrete, and the floor covering. It is possible that a slab moisture sealant may be needed prior to the placement of sensitive floor State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 21 Revised July 15, 2015 coverings if a thick slab-on-grade floor is used and the time frame between concrete and floor covering placement is relatively short. Considering the E.I. test results presented herein, and known soil conditions in the region, the anticipated typical water vapor transmission rates, floor coverings, and improvements (to be chosen by the Client and/or project architect) that can tolerate vapor transmission rates without significant distress, the following alternatives are provided: • • • • • Concrete slabs should be a minimum of 5 inches thick . Concrete slab underlayment should consist of a 10-15-mil vapor retarder, or equivalent, with all laps sealed per the 2010 CBC and the manufacturer's recommendation. The vapor retarder should comply with the ASTM E 1745 - Class A criteria, and be installed in accordance with ACI 302.1 R-04 and ASTM E 1643. The 10-15-mil vapor retarder (ASTM E 1745 -Class A) shall be installed per the recommendations of the manufacturer, including g!! penetrations (i.e., pipe, ducting, rebar, etc.). Concrete slabs, including the garage areas, shall be underlain by 2 inches of clean, washed sand (SE> 30) above a 10 mil vapor retarder (ASTM E-1745 -Class A, per Engineering Bulletin 119 [Kanare, 2005]) installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). The manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing, and either supply or specify suitable products for lap sealing (ASTM E 1745), and per code. ACI 302.1 R-04 (2004) states "If a cushion or sand layer is desired between the vapor retarder and the slab, care must be taken to protect the sand layer from taking on additional water from a source such as rain, curing, cutting, or cleaning. Wet cushion or sand layer has been directly linked in the past to significant lengthening of time required for a slab to reach an acceptable level of dryness for floor covering applications." Therefore, additional observation and/or testing will be necessary for the cushion or sand layer for moisture content, and relatively uniform thicknesses, prior to the placement of concrete. The vapor retarder shall be underlain by 2 inches of sand (SE > 30) placed directly on the prepared, moisture conditioned, subgrade and should be sealed to provide a continuous retarder under the entire slab, as discussed above. As discussed previously, GSI indicated this layer of import sand may be eliminated below the vapor retarder, jf laboratory testing indicates thatthe slab subgrade soil have a sand equivalent (SE) of 30 or greater. State and Oak, LLP W.O. 6636-A-SC December 24, 2013 Page 22 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 • Concrete should have a maximum water/cement ratio of 0.50. This does not supercede Table 4.3.1 of Chapter 4 of the ACI (2008) for corrosion or other corrosive requirements. Additional concrete mix design recommendations should be provided by the structural consultant and/or waterproofing specialist. Concrete finishing and workablity should be addressed by the structural consultant and a waterproofing specialist. • Where slab water/cement ratios are as indicated herein, and/or admixtures used, the structural consultant should also make changes to the concrete in the grade beams and footings in kind, so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. • The owner(s) should be specifically advised which areas are suitable for tile flooring, vinyl flooring, or other types of water/vapor-sensitive flooring and which are not suitable. In all planned floor areas, flooring shall be installed per the manufactures recommendations. • Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer and should be consistent with the specified floor coverings indicated by the architect. Regardless of the mitigation, some limited moisture/moisture vapor transmission through the slab should be anticipated. Construction crews may require special training for installation of certain product(s), as well as concrete finishing techniques. The use of specialized product(s) should be approved by the slab designer and water-proofing consultant. A technical representative of the flooring contractor should review the slab and moisture retarder plans and provide comment prior to the construction of the foundations or improvements. The vapor retarder contractor should have representatives onsite during the initial installation. WALL DESIGN PARAMETERS Conventional Retaining Walls The design parameters provided below assume that either non expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials (up to and including an E.I. of 20) are used to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed. The foundation system for proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Footings should be embedded a minimum of 18 inches below adjacent grade into unweathered paralic deposits or engineered fill (excluding landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. Recommendations for State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 23 Revised July 15, 2015 specialty walls (i.e., crib, earthstone, geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid pressure (EFP) of 55 pounds per cubic foot (pcf) and 65 pcffor select and very low to low expansive native backfill, respectively. The design should include any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 10 feet high. Design parameters for walls less than 3 feet in height may be superceded by City of Oceanside and/or County standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. SURFACE SLOPE OF EQUIVALENT FLUID WEIGHT EQUIVALENT FLUID WEIGHT RETAINED MATERIAL P.C.F. (SELECT PRE-APPROVED P.C.F. (NATIVE IH OR IZO NTAL:VERTICAL l BACKFILLll'l SAND BACKFILLJl3l I Leve1(1l I 38 I 45 I 2 to 1 50 60 (I) · Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall. <2>-E.I. ~20, P.I. <15, SE ..:::_30, with <10°/o passing No. 200 sieve. (3) -E.I. <50, P.I. <15, SE >25, with 15% oassina No. 200 sieve. Once retaining wall locations are known with respect to property lines, these preliminary design parameters should be reviewed by the geotechnical consultant, in light of the potential for offsite expansive soils that may influence design. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 24 Revised July 15, 2015 Seismic Surcharge For engineered retaining walls, GSI recommends that the walls be evaluated for a seismic surcharge (in general accordance with 2010 CBC requirements), should walls be within 6 feet of ingress/egress areas. The site walls in this category should maintain an overturning Factor-of-Safety (FOS) of approximately 1.25 when the seismic surcharge (increment), is applied. For restrained walls, the seismic surcharge should be applied as a uniform surcharge load from the bottom of the footing (excluding shear keys) to the top of the backfill at the heel of the wall footing. This seismic surcharge pressure (seismic increment) may be taken as 15H where "H" for retained walls is the dimension previously noted as the height of the backfill to the bottom of the footing. The resultant force should be applied at a distance 0.6 H up from the bottom of the footing. For the evaluation of the seismic surcharge, the bearing pressure may exceed the static value by one-third, considering the transient nature of this surcharge. For cantilevered walls the pressure should be an inverted triangular distribution using 15H. Reference for the seismic surcharge is Section 1802.2 of the 201 O CBC. Please note this is for local wall stability only. The 15H is derived from a Mononobe-Okabe solution for both restrained cantilever walls. This accounts for the increased lateral pressure due to shakedown or movement of the sand fill soil in the zone of influence from the wall or roughly a 45° -cj)/2 plane away from the back of the wall. The 15H seismic surcharge is derived from the formula: Where: = = H Seismic increment Probabilistic horizontal site acceleration with a percentage of "g" total unit weight (115 to 125 pcf for site soils @ 90% relative compaction). Height of the wall from the bottom of the footing or point of pile fixity. Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1, 2, and 3, present the back drainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or %-inch to 1 %-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has up to medium expansion potential, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e., full height) behind the wall, and it should be State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 25 Revised July 15, 2015 (1) Waterproofing membrane ···-· CMU or reinforced-concrete . wall ±12 inches sloped to drain per precise civil drawings ~ Weep hole -·-.. ~:::::Ill+' \ ---1 T/T'7'ii"I( .· .· • :;(·(~\'01\(::::0 1\\·:, Footing and wall design by others (1) Waterproofing membrane. Structural footing or settlement-sensitive improvement . Provide surface drainage via an engineered V-ditch (see civil plans for details) 1-2=1 (h:v) slope \ ~--- i,~ .. // ··:.>~ Slope or level ,,/ ---~/------ Native backfill l1 (h=v) or flatter backcut to be properly benched (6) Footing (2) Gravel= Clean, crushed, % to 1Yz inch. (3) Filter fabric= Mirafi 140N or approved equivalent. (4) Pipe= 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient sloped lo suitable, approved outlet point (perforations down). (5) Weep hole= Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Footing: If bench is created behind the fooling greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE A Detail 1 (760) 438·3155 Revised July 15, 2015 (1) Waterproofing membrane (optional) -- CMU or reinforced-concrete wall - l_ 6 inches --r (5) Weep hole-1 1 Proposed grade I sloped to drain 1 per precise civil drawings .,;3:,\\);(\~~\S);:\\\(('( Structural footing or settlement-sensitive improvement Provide surface drainage via engineered V-ditch (see civil plan details) S 2=1 (h=v) slope // ~- / ~-Slope or level . ~,------__ -- -- 1:1 (h:v) or flatter backcut to be properly benched (6) 1 cubic foot of 31,i-inch crushed rock (7) Footing (1) Waterproofing membrane (optional): Liquid boot or approved mastic equivalent. (2) Drain= Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls: Miradrain 6200 or J-drain 200 or equivalent for waterproofed walls (all perforations down). (3) Filter fabric= Mirafi 140N or approved equivalent: place fabric flap behind core. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole= Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Gravel= Clean, crushed, % to 1Y.! inch. (7) Footing= If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE B Detail 2 (760) 438-3155 Revised July 15, 2015 (1) Waterproofing membrane Structural footing or -----, settlement-sensitive improvement / ---Provide surface drainage CMU or reinforced-concrete wall \ 2,1 (h:v) slope ~ - / // ~--? -Slope or level // / ~/_-_ -- -- --~ ±12 inches t (5) Weep hole - H L Proposed grade sloped to drain per precise civil drawings --((/-;-):::\\):(\ /'.;\~ H/2 ____ 1 minimum Footing and wall design by others (3) Filter fabric J----+--------1-:-~ ~ -(2) Gravel -1 ·-~~-(4) Pipe '---(7) Footing (1) Waterproofing membrane: Liquid boot or approved masticequivalent. (2) Gravel: Clean, crushed, % to lt2 inch. (3) Filter fabric: Mirafi 140N or approved equivalent. backcut to be properly benched (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Clean sand backfill: Must have sand equivalent value (S.E.) of 35 or greater: can be densified by water jetting upon approval by geotechnical engineer. (7) Fooling: If bench is created behind the footing greater than the fooling width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geolechnical consultant. (8) Native backfill: If E.I. (21 and S.E. )35 then all sand requirements also may not be required and will be reviewed by the geolechnical consultant. RETAINING WALL DETAIL ALTERNATIVE C Detail 3 (760) 438-3155 Revised July 15, 2015 constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an E.I. potential of greater than 50 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill). Drain outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ± 100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. <50). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Wall/Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Although not anticipated, should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1 /360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural engineer's/wall designer's recommendations, regardless of whether or not transition conditions exist. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation "a" (above) and until such transition is between 45 and 90 degrees to the wall alignment. DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS The soil materials on site may be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W .0. 6636-A-SC December 24, 2013 Page 29 Revised July 15, 2015 and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is important that the homeowner be aware of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: 1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum moisture content, to a depth of 18 inches below subgrade elevation. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. The moisture content of the subgrade should be proof tested within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. If very low expansive soils are present, the rock or gravel or sand may be deleted. The layer or subgrade should be wet-down completely prior to pouring concrete, to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs should be a minimum of 4 inches thick. approaches should be deigned and constructed recommendations presented in the following section. Driveway slabs and in accordance with 4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. If subgrade soils within the top 7 feet from finish grade are very low expansive soils (i.e., E.I. s20), then 6x6-W1 .4xW1 .4 welded-wire mesh may be substituted for the rebar, provided the reinforcement is placed on chairs, at slab mid-height. The exterior slabs should be scored or saw cut, Va to 3/s inches deep, often enough so that no section is greater than 1 O feet by 1 O feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be separated from the foundations and sidewalks with expansion joint filler material. 5. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi. State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3 t 55 W.O. 6636-A-SC December 24, 2013 Page 30 Revised July 15, 2015 6. Driveways, sidewalks, and patio slabs adjacent to the building should be separated from the building with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 7. Planters and walls should not be tied to the building. 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 9. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 11. Positive site drainage should be maintained at all times. Finish grade on the lot should provide a minimum of 1 to 2 percent fall to the street, as indicated herein. It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the homeowner. 12. Air conditioning (A/C) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. A/C waste water lines should be drained to a suitable non-erosive outlet. 13. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. PRELIMINARY PAVEMENT DESIGN Based on the relatively granular nature of site soil, and our experience in the vicinity, the following preliminary asphalt and concrete pavement sections are provided, in accordance with the respective value of the traffic index (T.I.). Pavement subgrade should not be allowed to be saturated during placement and should have detailed positive drainage to extend pavement life. State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24. 2013 Page 31 Revised July 15, 2015 I PRELIMINARY ASPHALTIC CONCRETE PAVEMENTS (ACP) I TRAFFIC AREA TRAFFIC SUBGRADE A.C. THICKNESS AGGREGATE BASE INDEx<1I A-VALUE /INCHES) THICKNESs<21 /INCHES) Parking Area 4.5 28 4.0 4.0 Local Street 5.0 28 4.0 4.0 <11 The type of street appropriate for the traffic index to be evaluated by the traffic engineer. <21 Denotes Class 2 Annreaate Base (A-value > 78, SE > 25\, or eauivalent at 95 oercent relative com oaction. I PORTLAND CONCRETE CEMENT PAVEMENTS (PCCP) I TRAFFIC CONCRETE PCCP TRAFFIC CONCRETE PCCP AREAS TYPE THICKNESS AREAS ·TYPE THICKNESS °(inches) (inches) 520-C-2500 7.0 520-C-2500 8.0 Light Vehicles Heavy Truck Traffic 560-C-3250 6.0 560-C-3250 7.0 NOTE: All PCCP is designed as un-reinforced and bearing directly on compacted subgrade. However, a 2-4 inch thick leveling course of compacted aggregate base, or crushed rock may be considered where pavement subgrade is uneven due to the presence of coarse rock. All PCCP should be properly detailed Oointing, etc.) per the industry standard. Pavements may be additionally reinforced with #4 reinforcing bars, placed 12 inches on center, each way, for improved performance. Trash truck loading pads shall be 8 inches per the City. The recommended pavement sections are meant as minimums. If thinner or highly variable pavement sections are constructed, increased maintenance and repair may be needed. The recommended pavement sections provided above are intended as a minimum guideline. If thinner or highly variable pavement sections are constructed, increased maintenance and repair could be expected. If the ADT (average daily traffic) or ADTT (average daily truck traffic) increases beyond that intended, as reflected by the Tl used for design, increased maintenance and repair could be required for the pavement section. Consideration should be given to the increased potential for distress from overuse of paved street areas by heavy equipment and/or construction related heavy traffic (e.g., concrete trucks, loaded supply trucks, etc.), particularly when the final section is not in place (i.e., topcoat). Best management construction practices should be followed at all times, especially during inclement weather. All pavement installation, including preparation and compaction of subgrade, compaction of base material, and placement and rolling of asphaltic concrete, etc., shall be done in accordance with the City guidelines, and under the observation and testing of the project geotechnical engineer and/or the City. All subgrade (upper 6 inches) should be compacted to at least 95 percent relative compaction (per ASTM D 1557) prior to base paving. Aggregate base should be compacted to at least 95 percent relative compaction (per ASTM D 1557). All pavement construction should minimally be performed in general accordance with industry standards State and Oak, LLP 3068 State Street, Carlsbad F\le:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 32 Revised July 15, 2015 and properly transitioned. Final pavement design should be based on the actual design traffic index for a given street area, and R-value testing performed at the conclusion of grading. DEVELOPMENT CRITERIA Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it adversely affects site improvements, and causes perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face of fill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These recommendations regarding plant type, irrigation practices, and rodent control should be provided to all interested/affected parties. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to mitigate ponding of water anywhere on the property, and especially near structures and tops of slopes. Surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within the property should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and tops of slopes, and not allowed to pond and/or seep into the ground. In general, site drainage should conform to Section 1804.3 of the 2010 CBC. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Building pad drainage should be directed toward the street or other approved area(s). Although not ageotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 33 Revised July 15, 2015 a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 10 feet. As an alternative, closed-bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture barrier to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Gutters and Downspouts As previously discussed in the drainage section, the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or other non-erosive devices (e.g., paved swales or ditches; below grade, solid tight-lined PVC pipes; etc.), that will carry the water away from the building, to an appropriate outlet, in accordance with the recommendations of the design civil engineer. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously). State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 34 Revised July 15, 2015 Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Site Improvements If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to all interested/affected parties. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Grading This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 35 Revised July 15, 2015 observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site. Trenching/Temporary Construction Backcuts Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees [except as specifically superceded within the text of this report]), should be anticipated. All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to CAL-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors, or homeowners, etc., that may perform such work. Utility Trench Backfill 1. All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to evaluate the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1 :1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results. 3. All trench excavations should conform to CAL-OSHA, state, and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 36 Revised July 15, 2015 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: • • • • • • • • • • • During grading/recertification . During excavation . During placement of subdrains or other subdrainage devices, prior to placing fill and/or backfill. After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.). During retaining wall subdrain installation, prior to backfill placement. During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. During slope construction/repair . When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. When any homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed, prior to construction. A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum State and Oak, LLP 3068 State Street, Carlsbad File: e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.0. 6636-A-SC December 24, 2013 Page 37 Revised July 15, 2015 design criteria for the design of slabs, foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer should provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums, the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement's designer should confirm to GSI and the governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. PLAN REVIEW Final project plans (grading, precise grading, foundation, retaining wall, landscaping, etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 38 Revised July 15, 2015 LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services forth is portion of the project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. State and Oak, LLP 3068 State Street, Carlsbad File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 W.O. 6636-A-SC December 24, 2013 Page 39 Revised July 15, 2015 APPENDIX A REFERENCES GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 APPENDIX A REFERENCES Allen, V., Connerton, A., and Carlson, C., 2011, Introduction to Infiltration Best Management Practices (BMP), Contech Construction Products, Inc., Professional Development Series, dated December. ACI Committee 318, 2008, Building code requirements for structural concrete (ACl318-08) and commentary, dated January. ACI Committee 302, 2004, Guide for concrete floor and slab construction, ACI 302.1 R-04, dated June. American Society for Testing and Materials (ASTM), 1998, Standard practice for installation of water vapor retarder used in contact with earth or granular fill under concrete slabs, Designation: E 1643-98 (Reapproved 2005). , 1997, Standard specification for plastic water vapor retarders used in contact with soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved 2004). American Society of Civil Engineers, 2006, Minimum design loads for buildings and other structures, ASCE Standard ASCE/SEI 7-05. Blake, Thomas F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. , 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Updated to December 2009, Windows 95/98 version. Bozorgnia, Y., Campbell K.W., and Niazi, M., 1999, Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49. Bryant, W.A., and Hart, E.W., 2007, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Geological Survey, Special Publication 42, interim revision. California Building Standards Commission, 2010, California building code. California Department of Transportation, 2010, Caltrans, Standard specifications, May printing. GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 Cao, T., Bryant, W.A., Rowshandel, B., Branum, D., and willis, C.J., 2003, The revised 2002 California probalistic seismic hazard http://www.conversation.ca.gov/cgs/rghm/psha/fault /2002 ca hazardmaps.pdf maps, dated June, parameters/pdf/documents Carlsbad, City of, 1993, Standards for design and construction of public works improvements in the City of Carlsbad. County of San Diego, Department of Planning and Land Use, 2007, Low impact development (LID) handbook, stormwater management strategies, dated December 31. GeoSoils, Inc., 2008, Geotechnical boring log submission, Permit No. LMON106013, 542 Oak Avenue, APN 203-297-09-00, City of Carlsbad, San Diego County, California, W.O. 5775-A-SC, dated December 17. International Conference of Building Officials, 2001, California building code, California code of regulations title 24, part 2, volume 1 and 2. __ , 1998, Maps of known active fault near-source zones in California and adjacent portions of Nevada. Jennings, C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1 :750,000. Kanare, H.M., 2005, Concrete floors and moisture, Engineering Bulletin 119, Portland Cement Association. Kennedy, M.P., and Tan, SS., 2005, Geologic map of the Oceanside 30' by60' quadrangle, California, regional map series, scale 1: 100,000, California Geologic Survey and United States Geological Survey, www.conservation.ca.gov/ cgs/rghm/rgm/preliminary geologic maps.html -- Naval Facilities Engineering Command, 1986a, Soil mechanics design manual 7.01, Change 1 September: U.S. Navy. , 1986b, Foundations and earth structures, design manual 7.02, Change 1 September: U.S. Navy. Romanoff, M., 1989, Underground corrosion, National Bureau of Standards Circular 579, Published by National Association of Corrosion Engineers, Houston, Texas, originally issued April 1, 1957. State and Oak, LLP File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Appendix A Page 2 Revised July 15, 2015 Seed, 2005, Evaluation and mitigation of soil liquefaction hazard "evaluation of field data and procedures for evaluating the risk of triggering (or inception) of liquefaction", in Geotechnical earthquake engineering; short course, San Diego, California, April 8-9. Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. State of California Department of Transportation, Division of Engineering Services, Materials Engineering, and Testing Services, Corrosion Technology Branch, 2003, Corrosion Guidelines, Version 1.0, dated September. State of California, 2013, Civil Code, Title 7, Division 2, Section 895, et seq. State of California, Department of Transportation, 2012, Highway design manual of instructions, dated May 7. Tan, S.S., and Giffen, D.G., 1995, Landslide hazards in the northern part of the San Diego Metropolitan area, San Diego County, California, Landslide hazard identification map no. 35, Plate 35G, Department of Conservation, Division of Mines and Geology, DMG Open File Report 95-04. United States Geological Survey, 2013, U.S. Seismic design maps, earthquake hazards program, http://geohazards.usgs.gov/design maps/us/application. php. Version 3.1.0, dated July. , 2012, 2008 Earthquake Hazards Program, 2008 interactive deaggregations (Beta), Earthquake Hazards Program; http://eqint.cr.usgs.gov/deaggint/2008/. State and Oak, LLP File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Appendix A Page 3 Revised July 15, 2015 APPENDIX B HAND AUGER BORING LOGS (This Study) AND BORING LOG B-1 FROM GSI (2008) GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 UNIFIED SOIL CLASSIFICATION SYSTEM Major Divisions Highly Organic Soils C ~ "'u © C -"' () <n Unified Soil Classification Cobbles 3" Group Symbols GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT Typical Names Well-graded gravels and gravel- sand mixtures, little or no fines Poorly graded gravels and gravel-sand mixtures, little or no fines Silty gravels gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well-graded sands and gravelly sands, little or no fines Poorly graded sands and gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts, very fine sands, rock flour, silty or clayey fine sands Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sands or silts. elastic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity Peat, mudc, and other highly organic soils 3/4" #4 Gravel CONSISTENCY OR RELATIVE DENSITY CRITERIA Standard Penetration Test Penetration Resistance N Relative (blows/ft) Density 0-4 Very loose 4 -10 Loose 10-30 Medium 30-50 Dense > 50 Very dense Standard Penetration Test Penetration Resistance N (blows/ft) <2 2-4 4-8 8-15 15-30 >30 #10 Sand Consistency Very Soft Soft Medium Stiff Very Stiff Hard #40 Unconfined Compressive Strength (tons/fl') <0.25 0.25 -.050 0.50 -1.00 1.00 -2.00 2.00 -4.00 >4.00 #200 U.S. Standard Sieve Silt or Clay coarse I fine coarse I medium I fine MOISTURE CONDITIONS Dry Slightly Moist Moist Very Moist Wet Absence of moisture: dusty, dry to the touch Below optimum moisture content for compaction Near optimum moisture content Above optimum moisture content Visible free water; below water table BASIC LOG FORMAT: MATERIAL QUANTITY trace few little some 0-5o/o 5-10 % 10-25 % 25-45 % OTHER SYMBOLS C Core Sample S SPT Sample B Bulk Sample T Groundwater Qp Pocket Penetrometer Group name, Group symbol, (grain size), color, moisture, consistency or relative density. Additional comments: odor, presence of roots, mica, gypsum, coarse grained particles, etc. EXAMPLE: Sand (SP), fine to medium grained, brown, moist, loose, trace silt, little fine gravel, few cobbles up to 4" in size, some hair roots and rootlets. File:Mgr: c;\SoilClassif.wpd (760) 438-3155 Revised July 15,~~TE B-1 TI~~~G ,:~~, t,c. ~ I (_) HAND ELEV. DEPTH AUGER NO. (fl.) (ft.) HA-1 47' MSL 0-1 1-2V2 2V2-4 HA-2 46W MSL 0-1 1/2 11/2-21/2 21/2-4 GROUP SYMBOL SM SM SM/SP SM SM SM W.O. 6636-A-SC State and Oak, LLP 3068 State Street, Carlsbad Logged By: RGC December 4, 2013 LOG OF EXPLORATORY HAND AUGER BORINGS SAMPLE MOISTURE FIELD DRY DEPTH DENSITY DESCRIPTION (fl.) (%) (pcf) Bulk@ TOPSOIL/COLLUVIUM: SILTY SAND, dark brown, moist, loose; 0-1 porous. Bulk@ HIGHLY WEATHERED TERRACE DEPOSITS: SILTY SAND, brown, 1-21/2 moist, loose to medium dense; few pinhole pores. Bulk@ TERRACE DEPOSITS: SILTY SAND to SAND, orange brown, moistto 21/2-4 damp, medium dense to dense; weakly cemented. Total Depth = 4' No Groundwater/Caving Encountered Backfilled 12-4-2013 TOPSOIL/COLLUVIUM: SILTY SAND, dark brown, moist, loose; porous, few roots. HIGHLY WEATHERED TERRACE DEPOSITS: SILTY SAND, brown, moist, loose; porous, trace roots. TERRACE DEPOSITS: SILTY SAND, orange brown, damp, medium dense; weakly cemented. Total Depth = 4' No Groundwater/Caving Encountered Backfilled 12-4-2013 PLATE B-2 (760) 438-3155 Revised July 15, 2015 ~-(;&Sr Gtg~,J!'~· ~:_/ ~ ~,) HAND ELEV. DEPTH AUGER NO. (ft.) (fl.) HA-3 47' MSL 0-11/2 11/2-21/2 21/2-4 HA-4 45' MSL 0-1 1-21/2 21/2-4 GROUP SYMBOL SM SM SP SM SP SP/SM W.0. 6636-A-SC State and Oak, LLP 3068 State Street, Carlsbad Logged By: RGC December 4, 2013 LOG OF EXPLORATORY HAND AUGER BORINGS SAMPLE MOISTURE FIELD DRY DEPTH DENSITY DESCRIPTION (fl.) (%) (pcf) TOPSOIL/COLLUVIUM: SILTY SAND, dark brown, moist, loose; porous, few roots. HIGHLY WEATHERED TERRACE DEPOSITS: SILTY SAND, brown, moist, loose; few pores. TERRACE DEPOSITS: SAND with SILT, light reddish brown, damp, medium dense; weakly cemented. Total Depth = 4' No Groundwater/Caving Encountered Backfilled 12-4-2013 TOPSOIL/COLLUVIUM: SILTY SAND, dark brown, moist, loose; porous, few roots. HIGHLY WEATHERED TERRACE DEPOSITS: SAND with SILTY, brown, damp to moist, medium dense. TERRACE DEPOSITS: SILTY SAND to SAND, orange brown, damp, medium dense to dense; weakly cemented. Total Depth = 4' No Groundwater/Caving Encountered Backfilled 12-4-2013 PLATE B-3 (760) 438-3155 Revised July 15, 2015 ---·-· --· ----···--·---- BORING LOG GeoSoils, Inc. WO. 5775-A_-_s_c __ , PROJECT:ANASTASI REAL ESTATE BORING B-1 SHEET_ OF 2 _ State & Oak Senior Condos DATE EXCAVATED_ 10-21-08 LOGGED BY: RB_B __ ----1-Sample '5' 0 .9, ;, SAMPLE METHOD: Modified California -~ampler a~~ Standard Pen~!~ometer Approx. Elevation: 45' MSL a Standard Penetration Test _V Groundwater ~ ID ~ D 5 ~ ;; 1i 1 'o ID 0 C 0 aJ ::, 10 15 l D E ~ ~ ;! <fl ·a • <fl ::, ~ u 0 <fl cc in ::, 0 --- -- ---- SM ~ C 0 e ·~ 2 • 2 0 m " <fl ~ Undisturbed, Ring Sample ----·--- Description of Material . l\ ARTIFlciACTILLUNDOCUMENTED: -·· ·-- 1 L ~~;s~~~~n~~minor SILT, grayish brown, dry, loose: fineto--··· HIGHLY WEATHERED QUATERNARY TERRACE DEPOSITS: 1/.' ~ANDw/minor SILT, brown, dry, medium dense. J QUATERNARY TERRACE DEPOSITS: @ 2%' SIL TY SAND, light brown, damp, medium dense. -------- 37 SP 109.4 4.3 22.3 @ 5' SAND w/SIL T, light brown, dry, dense; iron-stone concretions. -----· SW 102.6 4.9 21.4 30 109.8 18.8 98.4 50-4%" SM 103.8 22.6 --------1-4'-~-"-· 100.0 J· I~-- @ 1 O' SAND w/minor SILT, light brown, dry, dense; trace iron-oxide staining. @ 13' Perched water encountered. @ 15' As per 1 O', light brown, saturated, very dense; micaceous, fine to medium grained. @ 18' Gravels encountered (basal conglomerate?). TERTIARY SANTIAGO FORMATION: @ 20' SIL TY SANDSTONE, gray, saturated, very dense; fine grained. I I (760) 438-3155--- j State & Oak Senior Condos i , . __ L::::_ GeoSoils, Inc. !!- ~ 15. ID 0 35 GeoSoils, Inc. PROJECT: ANASTASI REAL ESTATE State & Oak Senior Condos ~ -s <Il ---- Sample ' J ID i' a 00 '6 C ::, "' w • 0 iii 50-41h" 50-6" 20 50-31h" 13 0 8 L ~ E >, <I) ·c <I) ::, () <I) "' ::, 0 SM 40-50-6%" 45 I i I i ~& Oak Senior Condos _____ _ ;.- ~ C e 0 3 ~ w 3 ·15 ro :a; <I) 19.3 BORING LOG W.O. 5775-A-SC BORING ____ _ _B_-1 __ SHEET_2_ OF 2 _ DATE EXCAVATED 10-21_-0_8 __ LOGGED BY: RBB SAMPLE METHOD: Modified California Sampler and Standard Penetrometer Approx. Elevation: 45' MSL m Standard Penetration Test V Groundwater ~ Undisturbed, Ring Sample JI ' Description of Material --------@ 25' SIL TY SANDSTONE, gray, moist, dense; fine to medium grained. @ 30' SIL TY SANDSTONE, gray, wet, dense; fine grained. @ 35' SIL TY SANDSTONE, light brown to gray, dry to moist, very dense, trace highly cemented beds, fine grained. @ 40' SIL TY SANDSTONE, gray, dry to wet, dense; trace highly cemented beds, fine to medium grained. Practical Refusal @ 41 'I,' Perched Water@ 13' Flowing Sands between 13' and 20' Backfilled 10-21-2008 with Bentonite Grout and Bentonite Chips GeoSoils, Inc. (760)4Jll-:>.!55 Plate B-3 RevisedJuly-1-~ APPENDIX C SEISMICITY DATA GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER, 6636 JOB NAME, state and oak llp CALCULATION NAME: Test Run Analysis FAULT-DATA-FILE NAME, CDMGFLTE.DAT SITE COORDINATES, SITE LATITUDE, SITE LONGITUDE, 33.1588 117.3477 SEARCH RADIUS, 62.4 mi DATE, 12-11-2013 ATTENUATION RELATION, 11) Bozorgnia Campbell Niazi (1999) Hor.-Pleist. Soil- Cor. UNCERTAINTY (M=Median, S=Sigma), S DISTANCE MEASURE: cdist SCOND, 1 Number of Sigmas: 1.0 Basement Depth, .10 km Campbell SSR, 0 Campbell SHR, 0 COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED, CDMGFLTE.DAT MINIMUM DEPTH VALUE (km), 3.0 W. 0. 6636-A-SC PLATE C-1 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ABBREVIATED FAULT NAME ROSE CANYON NEWPORT-INGLEWOOD (Offshore) CORONADO BANK ELSINORE-TEMECULA ELSINORE-JULIAN ELSINORE-GLEN IVY PALOS VERDES EARTHQUAKE VALLEY NEWPORT-INGLEWOOD (L.A.Basin) SAN JACINTO-ANZA SAN JACINTO-SAN JACINTO VALLEY CHINO-CENTRAL AVE. (Elsinore) WHITTIER SAN JACINTO-COYOTE CREEK COMPTON THRUST ELYSIAN PARK THRUST ELSINORE-COYOTE MOUNTAIN SAN JACINTO-SAN BERNARDINO !ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE 1------------------------------ DISTANCE mi (km) 1 MAXIMUM I EARTHQUAKE I MAG. (Mw) PEAK SITE ACCEL. g EST. SITE INTENSITY MOD.MERC. ==============I==========------------------- 5. 0 ( 5 .1 ( 20.9( 24.4( 24.6( 33.5( 35.3( 44.4( 45.5( 46.9( 47.3( 47. 4 ( 50.9( 52.8( 55.2( 58. 2 ( 8 .1) I 8. 2 l I I I I I 33. 7) 3 9. 2) 3 9. 6) 53. 9) 56. 8) I 11.4) I 13. 3 l I 75.4) 76 .1) 76.3) 81. 9) I I I I 85. O) I 88. 9 l I 93. 1) I 58.6( 94.3) I s9.6< 95.9) I 6.9 6.9 7.4 6.8 7.1 6.8 7.1 6.5 6.9 7.2 6.9 6.7 6.8 6.8 6.8 6.7 6.8 6.7 0. 571 0.567 0.241 0.139 0.168 0.100 0 .116 0.061 0.077 0.093 0.074 0.091 0.064 0.062 0.084 0.074 0.055 0.051 X X IX VIII VIII VII VII VI VII VII VII VII VI VI VII VII VI VI ******************************************************************************* -END OF SEARCH-18 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 5.0 MILES (8.1 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION, 0.5709 g W.O. 6636-A-SC PLATE C-2 CALIFORNIA FAULT MAP state and oak lip 1000 900 800 700 600 500 400 300 200 100 0 -100-+--"~~ .......... ~~-t-'-~~t---'-~-'-t~~""'"""--+~~~~~""+-~~----t-~~--~~ -400 -300 -200 -100 0 100 200 300 400 500 600 W. 0 . 6636-A-SC PLATE C-3 ...--.. O') '-"' C 0 +--' ro !.... Q) Q) (.) (.) <( MAXIMUM EARTHQUAKES state and oak Up 1 X . 1 .01 .001 . 1 1 10 Distance (mi) X X X X XX ~ W.O. 6636-A-SC PLATE C-4 EARTHQUAKE MAGNITUDES & DISTANCES state and oak lip 7.4 7.3 7.2 7 .1 ,.-... ~ 7.0 ..._.. (]) "'O ::::, 6.9 ...... C 0) ro ~ 6.8 6.7 6.6 6.5 • • . 1 1 10 Distance (mi) • • • • • • - •• • W.O 6636-A-SC PLATE C-5 JOB NUMBER: 6636 ************************* * * * * * * EQSEARCH * * Version 3.00 * * ************************* ESTIMATION OF PEAK ACCELERATION FROM CALIFORNIA EARTHQUAKE CATALOGS DATE: 12-11-2013 JOB NAME: state and oak llp EARTHQUAKE-CATALOG-FILE NAME: ALLQUAKE.DAT SITE COORDINATES: SITE LATITUDE: 33.1588 SITE LONGITUDE: 117.3477 SEARCH DATES: START DATE: 1800 END DATE: 2012 SEARCH RADIUS: 62.4 mi 100.4 km ATTENUATION RELATION: 11) Bozorgnia Campbell Niazi (1999) Hor.-Pleist. Soil- Cor. UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0 ASSUMED SOURCE TYPE: SS [SS=Strike-slip, DS=Reverse-slip, BT=Blind-thrust] SCOND: 1 Depth Source: A Basement Depth: .10 km Campbell SSR: O Campbell SHR: O COMPUTE PEAK HORIZONTAL ACCELERATION MINIMUM DEPTH VALUE (km): 3.0 W.O 6636-A-SC PLATE C-6 ------------------------- EARTHQUAKE SEARCH RESULTS ------------------------- Page 1 ------------------------------------------------------------------------------- I I I TIME I I I SITE ISITEI APPROX. FILEI LAT. I LONG. I DATE (UTC) IDEPTHIQUAKEI ACC. I MM I DISTANCE CODEI NORTH I WEST I HM Seel (km) I MAG. I g I INT. I mi [km] ----+-------+--------+----------+--------+-----+-----+-------+----+------------ DMG l33.0000l117.3000l11/22/1800l2130 o. o I 0.01 6.501 0.243 IX I 11. 3 ( 18.2) MGI 133.0000 111.0000109/21/18561 730 o. o I o. o I 5.ool 0.048 VI I 22.9( 36. 9) MGI 132.8000 117.lOOOI05/25/1803I 0 0 o. o I o. o I 5.ool 0.038 V I 28.6( 46 .1) DMG 132.7000 117.2000I05/27/1862l20 0 0.01 o. o I 5.901 0.057 VI I 32.8( 52.8) PAS 132.9710 111.8100101/13/198611341 8. 21 6.01 5.301 0.039 V I 32.9( 52. 9) T-A 132.6700 111.1100110/21/18621 0 0 o. o I o. o I 5.ool 0.031 V I 35. 3 ( 56.8) T-A 132.6700 117.1700I05/24/1865I 0 0 0.01 o. o I 5.ool 0.031 V I 35.3( 56. 8) T-A 132.6700 111.1100112/00/18561 0 0 0.01 o. o I 5.ool 0.031 V I 35. 3 ( 56. 8) DMG 133.7000 117.4000I05/15/1910ll547 o. o I 0.01 6.001 0.052 VI I 37.5( 60. 3) DMG 133.7000 111.4000104/11/19101 757 0.01 o. o I 5.ool 0.029 V I 3 7. 5 ( 60.3) DMG 133.7000 117.4000I05/13/1910I 620 0.01 o. o I 5.ool 0. 029 V I 37.5( 60.3) DMG 133.2000 116.1000101/01;19201 235 0.01 0.01 5.ool 0.029 V I 37.5( 60.4) DMG 133.6990 117.5110I05/31/1938I 83455.41 10.01 5.5ol 0.037 V I 38.5( 61. 9) DMG 132.8000 116.8000l10/23/1894l23 3 0.01 o. o I 5.701 0.040 V I 40. 2 ( 64. 8) MGI 133.2000 116.6000ll0/12/1920ll748 o. o I o. o I 5.301 0.029 V I 43.3( 69. 7) DMG l33.7100l116.9250I09/23/1963ll44152.6I 16.51 5.ool 0.024 IV I 45.2( 72.7) DMG l33.7500l117.0000I04/21/1918l223225.0I 0.01 6.801 0.072 VII I 45.5( 73. 2) DMG l33.7500l117.0000I06/06/1918l2232 0.01 o. o I 5.ool 0.024 IV I 45.5( 73.2) DMG 133.57501111.9830103/11/19331 518 4.01 o. o I 5.201 0.026 V I 46.6( 74.9) MGI l33.8000l117.6000I04/22/1918l2115 o. o I 0.01 5.ool 0.023 IV I 46.6( 75. 0) DMG 133.61101111.9610103/11/19331 154 7.81 0.01 6.301 0. 049 VI I 47. 7 ( 76.8) DMG l33.BOOOl117.0000l12/25/1899l1225 0.01 o. o I 6.401 0.052 VI I 48. 6 ( 78.2) DMG 133.61101118.0110103/14/1933119 150.01 o. o I 5.101 0.023 IV I 49.9( 80. 3) GSP l33.5290lll6.5720I06/12/2005ll54146.5I 14.0 5.201 0.023 IV I 51.5( 82. 9) DMG l33.90001111.2000112/19/18so1 0 0 o. o I 0.0 6.001 0.037 V I 51. 9 ( 83.5) GSG l33.42001116.4890101;01;2010 235333.51 14.0 5.5ol 0.027 V I 52. 7 ( 84. 9) PAS l33.50101116.513olo2/25/198o 104738.51 13.6 5.501 0.026 V I 53.6( 86. 3) GSP l33.5080lll6.5140ll0/31/2001 075616.61 15.0 5.101 0.021 IV I 53. 8 ( 86. 6) DMG l33.00001116.433olo6/04/1940 1035 8. 3 I 0.0 5.101 0.021 IV I 54. 0 ( 87. 0) DMG 133.50001116.5000109/30/1916 211 o. o I 0.0 5.ool 0.020 IV I 54.3( 87. 3) DMG 133.68301118.0500103;11/1933 658 3.01 0.0 5.5ol 0.026 V I 54.3( 87.4) DMG 133.10001118.0610103;11/1933 51022.01 0.0 5.101 0.020 IV I 55. 8 ( 89.8) DMG 133.10001118.0610103/11/1933 85457.ol 0.0 5.101 0.020 IV I 55.8( 89. 8) DMG 134.00001111.2500101/23/1923 13026.ol 0.0 6.251 0.039 V I 58. 3 ( 93. 9) MGI l34.0000l117.5000l12/16/1858 10 0 0.01 0.0 7.001 0.063 VI I 58.7( 94.5) DMG l33.75001118.083olo3/11/1933 910 o. o I o. o I 5.101 0.019 IV I 58. 8 ( 94. 7) DMG l33.75001118.083olo3/11/1933 230 0.01 o. o I 5.101 0.019 IV I 58. 8 ( 94.7) W.O. 6636-A-SC PLATE C-7 DMG l33.75001110.003olo3/11/1933I 323 o. o I o. o I 5.001 0.018 IV 58. 8 ( 94. 7) DMG l33.7500l118.0830I03/13/1933ll31828.0I o. o I 5.301 0.021 IV 58.8( 94. 7) DMG 133.75001110.0030103/11/19331 2 9 o. o I o. o I 5.001 0.018 IV 58. 8 ( 94. 7) DMG l33.34301116.346olo4/20/1969l232042.9I 20.01 5.801 0.029 V 59.2( 95.3) GSG l33.9530lll7.7610I07/29/2008ll84215.7I u. o I 5.301 0.021 IV 59. 8 ( 96 .2) DMG 133.95001116.0500109/20/19461 719 9.01 o. o I 5.001 0.017 IV 61.7( 99. 3) ******************************************************************************* -END OF SEARCH-43 EARTHQUAKES FOUND WITHIN THE SPECIFIED SEARCH AREA. TIME PERIOD OF SEARCH: 1800 TO 2012 LENGTH OF SEARCH TIME: 213 years THE EARTHQUAKE CLOSEST TO THE SITE IS ABOUT 11.3 MILES (18.2 km) AWAY. LARGEST EARTHQUAKE MAGNITUDE FOUND IN THE SEARCH RADIUS: 7.0 LARGEST EARTHQUAKE SITE ACCELERATION FROM THIS SEARCH: 0.243 g COEFFICIENTS FOR GUTENBERG & RICHTER RECURRENCE RELATION: a-value= 0.986 b-value= 0.384 beta-value= 0.883 TABLE OF MAGNITUDES AND EXCEEDANCES: Earthquake I Number of Times I Cumulative Magnitude I Exceeded I No. / Year -----------+-----------------+------------ 4.0 43 0.20283 4.5 43 0.20283 5.0 43 0.20283 5.5 15 0.07075 6.0 8 0.03774 6.5 3 0.01415 7.0 1 0.00472 W.O. 6636-A-SC PLATE C-8 EARTHQUAKE EPICENTER MAP state and oak lip 1000 900 800 7 00 600 500 400 300 200 LEGEND x M =4 100 0 -1 004-l.....1-.L.....L4--J-_L....1.---L...-l---'-.J........L....J......l--'----'.....1-'-+.-..L......L_L....1.--!--JL-l-J.......J....4--l-_L....l ............. 1---'-.J........L....J......f-___.L_L.......1--'-4--L.....I....J......I~ -400 -300 -200 -100 0 100 200 300 400 500 600 W . 0 . 6636-A-SC PLATE C-9 .... ro Q) >---~ z ~ 1/l -C Q) > w -0 .... Q) .a E :::J z Q) > :.:; ro :::J E E :::J u EARTHQUAKE RECURRENCE CURVE 100 10 1 .1 .01 .001 state and oak llp ...... ............ "'-...... ' ........ -............ I t ............._ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Magnitude (M) W.O. 6636-A-SC PLATE C-10 ~ z ~ 1/) ..., C Q) > w -0 '-Q) .0 E :, z Q) > :;:::; ro :, E :, 0 Number of Earthquakes (N) Above Magnitude (M) state and oak lip 40 20 10 8 6 4 2 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Magnitude (M) W.O. 6636-A-SC PLATE C-11 ~ ""O 9 rm )> 0) --i (,.) mm I () =f> ~(/) I\) () ;i 2010ed • :\4 • i t;j .c 7....._ ~ !; ~ -0 = ~ : .. ,. ; ·11· B 'i: 0 > ~ state_ and_ oak Geographic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.4792 g PGA Exceedance Return Time: 24 75 year Max. significant source distance 111 . km. Vie\.\ angle is 35 degrees above horizon Gridded-source hazard accum . in 45° intervals Soil site. Vs30(m/s)f1= 350.0 ~ • •• liil ~ rn1u=t i1r,~ ~ /II ...... cj ' -D II fflflll'lf-1 Ir • • -\ " • .... 11 -........... . / ' km t! • 8.4 8.1 7.8 7.5 7.2 M 6.9 6.6 6.3 6.0 5 7 • \ • I" I :)4 t-J.:S mD[2013 Dec 11 19 38.55 Sitt Coord9:,117.)t7 33.1588 (ytltow disll) V•»-350.0. Mu ..,ua, E.lodR8le .SS73f~ (c:olullt!I helg .. piq, to Ex!bte) Red cbrnonds; hil1otQI eanhqual!es, M>e ~ -09 r0> }>O> ~ (,.) rn m I 0 ::p- ~ (/) (,.) 0 .... aa· n 2010ed I .c ;:!e ~ I:> 19 ~ -a u 'E u > • state_ and_ oak Geograph ic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.2587 g PGA Exceedance Return Time: 4 75 year Max. signi ticant source distance 130. km . View angle is 35 degrees above horizon Gridded-source hazard accum. in 45° intervals Soil site. Vs30(m/s) =ii 35(10 ... ~ • 0 0 11 ~ac • • fl.o I • • • Iii • I! • • 0 ~ • D II • - km I!: 0 • 8.3 8.0 7.7 7.4 7.1 M 6.8 6.5 6.2 5.9 5.6 ~ ~ .,.. 3 3 J.2 Bil 2013 Dec 11 19:39.13 Site Coo!ds;-111,3,'7 33.1588 (yelk!w dl$kl VtJO-:UO.O .... It annual ExcdRate .21 SSE~ {C(,llumn height prop. to Edlatel, Red diamonds: historieal earlhquokes. M>6 *********************** * * * EQFAULT * * * * Version 3.00 * * * *********************** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER, 6636 JOB NAME, state and oak llp CALCULATION NAME, Test Run Analysis FAULT-DATA-FILE NAME, CDMGFLTE.DAT SITE COORDINATES, SITE LATITUDE, 33.1588 SITE LONGITUDE, 117.3477 SEARCH RADIUS, 62. 4 mi DATE, 12-11-2013 ATTENUATION RELATION: 11) Bozorgnia Campbell Niazi {1999) Hor.-Pleist. Soil- Cor. UNCERTAINTY (M=Median, S=Sigma), S DISTANCE MEASURE, cdist SCOND, 1 Number of Sigmas: 1.0 Basement Depth: .10 km Campbell SSR: O Campbell SHR, 0 COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED, CDMGFLTE.DAT MINIMUM DEPTH VALUE (km), 3.0 W O 6636-A-SC PLATE C-1 APPENDIX D LABORATORY DATA (This Study and GSI [2008]) GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 U.S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I HYDROMETER 6 4 3 2 1.5 1 4 1/23/8 3 6 510 1416 20 30 40 50 60 100140200 100 I I I I ' -I I 95 90 85 80 " 75 70 f-65 I C) ~60 fu 55 O'. W50 ~ ~45 • z ~40 O'. ~35 30 \ ' 25 " 20 - 15 10 - 5 -- 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS ~OBBLES I GRAVEL I coarse i SAND I I I I SILT OR CLAY coarse fine medium fine Sample Depth Range Visual Classification/USCS CLASSIFICATION LL PL Pl Cc Cu • HA-1 0.0 Silty Sand -- --f--------------~-- f---------· -~-~------·-----______ ._c____ ------------ Sample Depth 0100 D60 D30 D10 %Gravel %Sand %Silt %Clay ·----• HA-1 a.a 19 0.316 0.16 0.1 80.2 19.7 ·-----~---~ C----------~ -f--------~-··--C---~-- ··-~-------f-----~ -----··---- ---· ----~---~--- ---·---------·----· -----,-------.. --·----- GeoSoils, Inc. GRAIN SIZE DISTRIBUTION ---·---· ~~U.,Inc. 5741 Palmer Way Project: STATE & OAK Carlsbad, CA 92008 Telephone: (760) 438-3155 Number: 6636-A-SC Fax: (760) 931-0915 Date: December 2013 Plate: D -1 (760) 438-3155 Revised July 15, 2015 3,000 2,500 2,000 'l;; / C. :r' >-{!) z w 1,500 a'. >-en a'. u'i r en / 1,000 ?' / / 500 .. ~ . / 0~. . 0 500 1,000 1,500 2,000 2,500 3,000 NORMAL PRESSURE, psf . Sample Depth/El. Range Classification I Primary/Residual Sample Type 'Y.t MC% C <I> . Silty Sand . • 8-1 3.0 3-6 Primary Shear Re molded 120.6 8.5 133 29 ~ ------~-···--··--· .. D 8-1 3.0 e----~idualShear Remolded 120.6 8.5 98 29 e-----·--- Reshear Shear Re molded ~ -· ··------------·· . ·-~ ... .. . ·--··· ··~ .. ~--· Note: Sample lnnundated Prior To Test r ·--··--------··· ,----------·----··· . - GeoSoils, Inc. DIRECT SHEAR TEST ·----···--·-- ~Soils;I~ 5741 PalmerWay Project: ANASTASI Carlsbad, CA 92008 Telephone: (760) 438-3155 Number: 5775-A-SC Fax: (760) 931-0915 Date: October 2008 Plate: D -2 (760) 438-3155 Revised July 15, 2015 3,000 2,500 t 2,000 ~b ··-V ~ 1;; C. :r' f-(!) z / UJ 1,500 "' ~D f-V) "' .,: UJ I V) v~ 1,000 . ~ / 500 . . . --/;::: V 0 0 500 1,000 1,500 2,000 2,500 3,000 NORMAL PRESSURE, psi ---- Sample Depth/El. Range Classification Primary/Residual Sample Type Y., MC% C $ .. .. • B-1 10.0 Sand w/ Silt Primary Shear Undisturbed 103.1 4.9 113 36 .. . D B-1 10.0 Residual Shear Undisturbed 103.4 4.9 87 35 .. . . - Reshear Shear Undisturbed . ·-~--- --- Note: Sample lnnundated Prior To Test ~ ---------------··- GeoSoils, Inc. DIRECT SHEAR TEST ~-·- GeoSo~J...,_ 5741 PalmerWay Project: ANASTASI Carlsbad, CA 92008 Telephone: (760) 438-3155 Number: 5775-A-SC Fax: (760) 931-0915 Date: October 2008 Plate: D -3 (760) 438-3155 Revised July 15, 2015 Cal Land Engineering, Inc. dba Quartech Consultant GeotectmlcaL Erwira~:1:~n_1:31,_and Civil l:ngin'::!:'.~~------------- SUMMARY OF LABORATORY TEST DATA G,x)Solis. ln,r;. 574 i Palmer ',Vay, Surte D Cali!sbad, GA 9201 () Client: Stale & Oak Project Name: Composite Sam pie W.O 6636-A·SC QCI Project No.: 13-029-01:Zb D<lte: December 9, 2013 Surnms rized by: /\BK Gonosivity Test Resulls -<-N= pH Chloridie Sample CT-532 CT-422 Depth (643} {ppm) Sample ID •~ 'C+, ___ ,www,w I-IA-1 Composite N/A 7.98 104 ,w•~w~n'•><--- Sulfate CT-417 % By Weight ... <0.0010 ' .. I Resistlv;t CT-532 (" y 643) ) (ahrn-orn --- 9,100 PLATE D-4 -·---· ··--·····-·---------576 E2-s1 Lam;!Jert Read, Bre(\ (:e.:•liiorn,ia 92821; Tel: 714·67't-1D5D_ Ff.r,;: 7!·1-G71-1090 (760) 438-3155 Revised July 15, 2015 APPENDIX E GENERAL EARTHWORK AND GRADING GUIDELINES GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, excavations, and appurtenant structures or flatwork. The recommendations contained in the geotechnical report are part of these earthwork and grading guidelines and would supercede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new or revised recommendations which could supercede these guidelines or the recommendations contained in the geotechnical report. Generalized details follow this text. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications and latest adopted code. In the case of conflict, the most onerous provisions shall prevail. The project geotechnical engineer and engineering geologist (geotechnical consultant), and/or their representatives, should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for general conformance with the recommendations of the geotechnical report(s), the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that an evaluation may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All remedial removals, clean-outs, prepared ground to receive fill, key excavations, and subdrain installation should be observed and documented by the geotechnical consultant prior to placing any fill. It is the contractor's responsibility to notify the geotechnical consultant when such areas are ready for observation. GeoSoils, Inc. (760) 438-3155 Revised July 15, 2015 Laboratory and Field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557. Random or representative field compaction tests should be performed in accordance with test methods ASTM designation D-1556, D-2937 or D-2922, and D-3017, at intervals of approximately ±2 feet of fill height or approximately every 1,000 cubic yards placed. These criteria would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by a geotechnical consultant, and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the geotechnical consultant, and to place, spread, moisture condition, mix, and compact the fill in accordance with the recommendations of the geotechnical consultant. The contractor should also remove all non-earth material considered unsatisfactory by the geotechnical consultant. Notwithstanding the services provided by the geotechnical consultant, it is the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the earthwork in strict accordance with applicable grading guidelines, latest adopted codes or agency ordinances, geotechnical report(s), and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material, should be removed and disposed of off-site. These removals must be concluded prior to placing fill. In-place existing fill, soil, alluvium, colluvium, or rock materials, as evaluated by the geotechnical consultant as being unsuitable, should be removed prior to any fill placement. Depending upon the soil conditions, these materials State and Oak, LLP File: e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 2 Revised July 15, 2015 may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the geotechnical consultant. Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading, are to be removed or treated in a manner recommended by the geotechnical consultant. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to firm ground and approved by the geotechnical consultant before compaction and filling operations continue. Overexcavated and processed soils, which have been properly mixed and moisture conditioned, should be re-compacted to the minimum relative compaction as specified in these guidelines. Existing ground, which is determined to .be satisfactory for support of the fills, should be scarified (ripped) to a minimum depth of 6 to 8 inches, or as directed by the geotechnical consultant. After the scarified ground is brought to optimum moisture content, or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is greater than 6 to 8 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 to 8 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report, or by the on-site geotechnical consultant. Scarification, disc harrowing, or other acceptable forms of mixing should continue until the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollows, hummocks, mounds, or other uneven features, which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5: 1 (horizontal to vertical [h:vl), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the geotechnical consultant. In fill-over-cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet, with the key founded on firm material, as designated by the geotechnical consultant. As a general rule, unless specifically recommended otherwise by the geotechnical consultant, the minimum width of fill keys should be equal to 112 the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toes of fill benches, should be observed and approved by the geotechnical consultant prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. State and Oak, LLP Flle:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 3 Revised July 15, 2015 COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been evaluated to be suitable by the geotechnical consultant. These materials should be free of roots, tree branches, other organic matter, or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the geotechnical consultant. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other approved material. Benching operations should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock, or other irreducible materials, with a maximum dimension greater than 12 inches, should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the geotechnical consultant. Oversized material should be taken offsite, or placed in accordance with recommendations of the geotechnical consultant in areas designated as suitable for rock disposal. GSI anticipates that soils to be utilized as fill material for the subject project may contain some rock. Appropriately, the need for rock disposal may be necessary during grading operations on the site. From a geotechnical standpoint, the depth of any rocks, rock fills, or rock blankets, should be a sufficient distance from finish grade. This depth is generally the same as any overexcavation due to cut-fill transitions in hard rock areas, and generally facilitates the excavation of structural footings and substructures. Should deeper excavations be proposed (i.e., deepened footings, utility trenching, swimming pools, spas, etc.), the developer may consider increasing the hold-down depth of any rocky fills to be placed, as appropriate. In addition, some agencies/jurisdictions mandate a specific hold-down depth for oversize materials placed in fills. The hold-down depth, and potential to encounter oversize rock, both within fills, and occurring in cut or natural areas, would need to be disclosed to all interested/affected parties. Once approved by the governing agency, the hold-down depth for oversized rock (i.e., greater than 12 inches) in fills on this project is provided as 1 O feet, unless specified differently in the text of this report. The governing agency may require that these materials need to be deeper, crushed, or reduced to less than 12 inches in maximum dimension, at their discretion. To facilitate future trenching, rock (or oversized material), should not be placed within the hold-down depth feet from finish grade, the range of foundation excavations, future utilities, or underground construction unless specifically approved by the governing agency, the geotechnical consultant, and/or the developer's representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the geotechnical consultant to evaluate it's physical properties and suitability for use onsite. Such testing should be performed three (3) days prior to importation. If any material other than that State and Oak, LLP File: e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 4 Revised July 15, 2015 previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the geotechnical consultant as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers, that when compacted, should not exceed about 6 to 8 inches in thickness. The geotechnical consultant may approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification, or should be blended with drier material. Moisture conditioning, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at, or above, optimum moisture. After each layer has been evenly spread, moisture conditioned, and mixed, it should be uniformly compacted to a minimum of90 percent of the maximum density as evaluated by ASTM test designation D-1557, or as otherwise recommended by the geotechnical consultant. Compaction equipment should be adequately sized and should be specifically designed for soil compaction, or of proven reliability to efficiently achieve the specified degree of compaction. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the geotechnical consultant. In general, per the latest adopted version of the California Building Code (CBC), fill slopes should be designed and constructed at a gradient of 2:1 (h:v), or flatter. Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final evaluation of fill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (h:v), prior approval from the governing agency, specific material types, a higher minimum relative compaction, special reinforcement, and special grading procedures will be recommended. If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 10 feet of each lift of fill by undertaking the following: State and Oak, LLP File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 5 Revised July 15, 2015 1. An extra piece of equipment consisting of a heavy, short-shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should also be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subject to re-rolling. 3. Field compaction tests will be made in the outer (horizontal) ±2 to ±8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion ofthe slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to evaluate compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to evaluate compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix, and recompact the slope material as necessary to achieve compaction. Additional testing should be performed to evaluate compaction. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The geotechnical consultant may recommend and direct changes in subdrain line, grade, and drain material in the field, pending exposed conditions. The location of constructed subdrains, especially the outlets, should be recorded/surveyed by the project civil engineer. Drainage at the subdrain outlets should be provided by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the geotechnical consultant. If directed by the geotechnical consultant, further excavations or overexcavation and refilling of cut areas should be performed, and/or remedial grading of cut slopes should be performed. When fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be observed by the geotechnical consultant prior to placement of materials for construction of the fill portion of the slope. State and Oak, LLP File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 6 Revised July 15, 2015 The geotechnical consultant should observe all cut slopes, and should be notified by the contractor when excavation of cut slopes commence. If, during the course of grading, unforeseen adverse or potentially adverse geologic conditions are encountered, the geotechnical consultant should investigate, evaluate, and make appropriate recommendations for mitigation of these conditions. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the geotechnical consultant, whether anticipated or not. Unless otherwise specified in geotechnical and geological report(s), no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractor's responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the recommendations of the geotechnical consultant. COMPLETION Observation, testing, and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and fill areas are graded in accordance with the approved project specifications. After completion of grading, and after the geotechnical consultant has finished observations of the work, final reports should be submitted, and may be subject to review by the controlling governmental agencies. Nofurtherexcavation or filling should be undertaken without prior notification of the geotechnical consultant or approved plans. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. JOB SAFETY General At GSI, getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On-ground personnel are at highest risk of injury, and possible fatality, on grading and construction projects. GSI recognizes that construction activities will vary on each site, and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor, and GSI personnel must be maintained. State and Oak, LLP File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 7 Revised July 15, 2015 In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractor's regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for, and are to be worn by GSI personnel, at all times, when they are working in the field. Safety Flags: Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacons, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation, and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technician's safety. Efforts will be made to coordinate locations with the grading contractor's authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractor's authorized representative (supervisor, grade checker, dump man, operator, etc.) should direct excavation of the pit and safety during the test period. Of paramount concern should be the soil technician's safety, and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away from oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration, which typically decreases test results. When taking slope tests, the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the State and Oak, LLP File:e:\wp 12\6600\6636a.pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 8 Revised July 15, 2015 slope. The contractor's representative should effectively keep all equipment at a safe operational distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technician's safety is jeopardized or compromised as a result of the contractor's failure to comply with any of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractor's representative will be contacted in an effort to affect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill placed can be considered unacceptable and subject to reprocessing, recompaction, or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor bring this to the technician's attention and notify this office. Effective communication and coordination between the contractor's representative and the soil technician is strongly encouraged in order to implement the above safety plan. Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with Cal/OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractor's representative will be contacted in an effort to affect a solution. All backfill not tested due to safety concerns or other reasons could be subject to reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify Cal/OSHA and/or the proper controlling authorities. State and Oak, LLP File:e:\wp 12\6600\6636a. pge GeoSoils, Inc. (760) 438-3155 Appendix E Page 9 Revised July 15, 2015 ~ 8 ,. w "" ~ 0, 0, ;o :1 ~-ro C. ~ C ,;;c -"' N ~ 0, 1 Toe of slope as shown / on grading plan I Original ground surface to be ~1 I / / .,,,,---------- restored with compacted fill · .. / / \ . / i= =:l/ Compacted Fill ---~~~~~~~~~-2D / " / / t ----\ .if'/0 / · \__Original ground surface o' ~ '<' / D = Anticipated removal of unsuitable material .~s / (depth per geotechnical engineer) ~~ ' \\' //// \\\ ..._,/ I \:::\ /\ I /\ / \ I \\\\ ''/X'~,, "'\'\"\ _7 .. ,.\-\-----------'--- <1/;,,~\ \/ \___ Provide a 1:1 (HV) minimum projection from toe of slope as shown on grading plan to the recommended removal depth. Slope height, site conditions, and/or local conditions could dictate flatter projections. L Back-cut varies. For deep removals, backcut should be made no steeper than 1:1 (HV), or flatter as necessary for safety considerations. GioSails1 l,ac:. ·--/ '--· ' ' ' ' FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON DETAIL Plate E-3 -:::; a, 8 ... w 'f' ~ u, u, ;u ro < ~· ~ ~ C '< _u, " ~ u, Proposed grade -, \\\ _\_ r--Previously placed, temporary / compacted fill for drainage only I I ------- --------I Ge~Sc,ils,inc. Proposed additional compacted fill 7 ~ --~" "' " ~" ----- % " Unsuitabl ~,.,6,, e material (to b /\', \ e removed) ..,,..,,~:;..,,,..,,.-,,~~1.,,...,...---,,,-:,~.~~v::\\V',;/\ \ \\/\ ~',\\·~·\\\\'::;,\VA\'(\\\·\~W~):.C\\'0'\\\\)\', :,,:\,\ \ ,;(\07'\'\,//\\ / y\ 7 Existing compacted fill /•<c<<"''v.•••,P"•·•··•··"' < \ ~ \_______ 8 To be cemo edcock o, a addiliooal c:ed befoce placicg oa1"e mateci.\'pm,ed mpacted fill REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL DETAIL Plate E-4 Natural grade Proposed pad grade ------- __ l_ Subgrade at 2 percent gradient, draining toward street ~V//\\ <(V::::,>~/\\\\\:;<~.~\ ::0.\'.<~//\\\\0v/ /\\ <(\//,>::,\ \\\Y ~ 3-to 7-foot m1n1mum• \.,..,...:; overexcavate and recompact ~\""""/"'""~~\ -Bedrock or per text of report /\ \ //\ approved native material -Typical benching CUT LOT OR MATERIAL-TYPE TRANSITION Natural grade __ _ Proposed pad grade l__ ------- ---------- --~----J_ Subgrade at 2 percent gradient, draining toward street * Deeper overexcavation may be recommended by the geotechnical consultant in steep cut-fill transition areas, such that the underlying topography is no steeper than 3•1 (HV) CUT -FILL LOT (DAYLIGHT TRANSITION) TRANSITION LOT DETAILS Plate E-12 (760) 438-3155 Revised July 15, 2015 NOTES, // ~ 2-foot x 2-foot x ~-inch steel plate v -Standard 31,i-inch pipe nipple welded to top of plate ~/ -~ ---%-inch x 5-foot galvanized pipe, standard pipe threads top and bottom; extensions threaded on both ends and added in 5-foot increments -......... ........ --~-............. --...... ........._......._ _ v V - 3-inch schedule 40 PVC pipe sleeve, add in 5-foot increments with glue joints / Proposed finish grade _/_ T { _ t , Bottom of cleanout Provide a minimum 1-foot bedding of compacted sand l Locations of settlement plates should be clearly marked and readily visible (red flagged) to equipment operators. 2. Contractor should maintain clearance of a 5-foot radius of plate base and withiin 5 feet (vertical) for heavy equipment. Fill within clearance area should be hand compacted to project specttications or compacted by alternative approved method by the geotechnical consultant (in writing, prior to construction). 3. After 5 feet (vertical) of fill is in place, contractor should maintain a 5-foot radius equipment clearance from riser. 4. Place and mechanically hand compact initial 2 feet of fill prior to establishing the initial reading. 5. In the event of damage to the settlement plate or extension resulting from equipment operating within the specified clearance area, contractor should immediately notify the geotechnical consultant and should be responsible for restoring the settlement plates to working order. 6. An alternate design and method of installation may be provided at the discretion of the geotechnical consultant. GeoSoits, lnc. SETTLEMENT PLATE AND RISER DETAIL Plate E-18 ' .. / . ,, , , . (760) 438-3155 Revised July 15, 2015 ~ .s .. w a, "' °' °' ;o ~ in ro " ~ C "' ,°' N s °' Finish grade \\ G~oSoils, Inc. ' '_/ ' ! / ""' ' ~ _ -----------%-inch-diameter X 6-inch-long <J ..-~ carriage bolt or equivalent <J ~ <I ~ Le <J 6-inch diameter X 3 to 6 feet ~ " 3~-inch-long hole c'.i <J ~ <J <J ' c'.i '~ 1"--~ ~ Concrete backfill <J _, ___ IJ TYPICAL SURFACE SETTLEMENT MONUMENT Plate E-19 SIDE VIEW Spoil pile \ Test pit TOP VIEW / Flag --Flag Spoil pile -Test pit -Light -----< >---- I ~ Vehicle ----50 feet------------- --------50 feet--------- --------100 feet .-· . . / Get)$~iis, lnc. TEST PIT SAFETY DIAGRAM Plate E-20 (760) 438-3155 Revised July 15, 2015