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Home My WebLink AboutCT 81-46; Airport Business Center; Preliminary Geotechnical; 1990-07-17LEIGHTON AND ASSOCIAnS; INC Geotechnical and Environmental Engineering Consultants PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED STATE FARM SERVICE CENTER, LOT 12 OF CARLSBAD TRACT NO. 81-46, AIRPORT BUSINESS CENTER, o .... „ CITY OF CARLSBAD, CALIFORNIA Building Design and JUL 2 6 1990 .Construction Division July 17, 1990 Project No. 8900827-01 t^^^o.;. ^1 -v, -'^ 1V093 Prepared For: STATE FARM INSURANCE COMPANY One State Farm Plaza Bloomington, Illinois 61710 5421 AVENIDA ENCINAS, SUITE C, CARLSBAQ CALIFORNIA 92008 (619)-93h=9753 FAX (619) 931-9326 LEIGHTON AND ASSOCIATES, INC Geoteciinicai and Environmental Engineering Consultants July 17, 1990 Project No. 8900827-01 To: Sta,te Farm Insurance Company One State Farm Plaza Bloomington, Illinois 61710 Attention: • Mr. Gene Schmidt Subject: Preliminary Geotechnical Investigation, Proposed State Farm Service Center, Lot 12 of Carlsbad Tract No. 81-46, Airport Business Center, City of Carlsbad, California In accordance with your authorization, we have conducted a preliminary geotechnical investigation of the subject site. Our investigation consisted of a review of pertinent geotechnical literature and aerial photographs, subsurface field exploration, laboratory testing and geotechnical analysis of the data obtained. This report presents a summary of our investigation and provides conclusions and recommendations relative to site development. If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service. Respectfully submitted, LEIGHTON AND ASSOCIATES, INC. RKW/MRS/SRH/bje Distribution: Randall K. Wagner * / u in Senior Staff Geologist Michael R. Stewart, CEG 1349 (Exp. 6/30/91) Chief Geologist Stan Helenschmidt, GE 2064 (Exp. 6/30/92) Chief Engineer/Manager ^/5<y94 (1) (3) (2) Addressee State Farm Insurance Company Attention: Mr. Tom Novosad Castillo Company, Inc. Attention: Mr. Richard Lloyd 5421 AVENIDA ENCINAS, SUITE C. CARLSBAD, CALIFORNIA 92008 (619) 931-9953- FAX (619) 931-9326 8900827-01 TABLE OF CONTENTS Section paqe 1.0 INTRODUCTION 1 1.1 Site Description and Proposed Development 1 1.2 Purpose and Scope of Services 2 1.3 Subsurface Investigation and Laboratory Testing 2 2.0 GEOTECHNICAL CONDITIONS 4 2.1 Regional Geology 4 2.2 Site Geology 4 2.2.1 Scripps Formation (Map Symbol - Tsc) 4 2.2.2 Artificial Fill (Map Symbol - Afl) 4 2.3 Geologic Structure 5 2.4 Ground Water 5 2.5 Faulting 5 2.6 Seismicity 6 2.6.1 Lurching and Shallow Ground Rupture 6 2.6.2 Liquefaction and Dynamic Settlement 6 2.7 Existing Slope Conditions 7 2.8 Expansion Potential 7 2.9 Reactivity 8 3.0 CONCLUSIONS 9 3.1 Summary of Geotechnical Conclusions 9 4.0 RECOMMENDATIONS H 4.1 Earthwork n 4.1.1 Compacted Fill H 4.1.2 Overexcavation and Recompaction 11 4.1.3 Temporary Excavations 12 4.1.4 Trench Excavation and Backfill 12 4.2 Foundation and Slab Design Considerations 12 4.2.1 Foundation and Slab Design 12 4.2.2 Moisture Conditioning 13 4.2.3 Foundation Setbacks 14 - 1 - ItlGHnN AMD ASSOCIATIS, I, 890082*7-01 TABLE OF CONTENTS (Continued) Section Page 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 Settlement 2^ Lateral Earth Pressures and Resistance ...... 14 Type of Cement for Construction 15 Exterior Concrete Flatwork 16 Pavement Design ig Graded Slopes ............. 17 Ponded Water at Northeast Port ion of Pad 17 Surface Drainage and Lot Maintenance .... 17 Oversteepening of Existing Slopes 17 Construction Observation 17 Appendices Appendix A Appendix B Appendix C Appendix D Appendix E References Boring Logs Laboratory Testing Procedures and Test Results General Earthwork and Grading Specifications Pavement Section Design and Requirements for Paving LIST OF TABLES AND IIIUSTRATTONS Tables Table 1 Table 2 Seismic Parameters for Active and Potentially Active Faults Minimum Foundaiton and Slab Recommendations for Expansive Soils R^^^ j^^^ Rear of Text Figures Figure 1 Figure 2 Figure 3 Figure 4 Site Location Map Rear Regional Seismicity Index Map " ' Rear Retaining Wall Drainage Detail * * Rear Subdrain Drainage Oetail • • • • ^^^^ of Text of Text Text Text of of Plates Plate 1 - Geotechnical Map In Pocket - n - UICHTON AND ASSOCIATES, 8900827-01 1.0 INTRODUCTION 1.1 Site Description and Proposed Development The site is located in the City of Carlsbad northeast of the intersection of Palomar Airport Road and Palomar Oaks Way (Figure 1). It is bounded on three sides by paved streets (Palomar Airport Road to the south, Palomar Oaks Way to the west, and Wright Place to the north) and to the east by an undeveloped sheet-graded pad. An approximate 2:1 to 3:1 (horizontal to vertical) slope extends down from the pad on the northwest, west and south sides of the lot, while a 2:1 to 3:1 (horizontal to vertical) slope extends upward from the pad on the east and northeast sides. The subject site known as Lot 12 of the Airport Business Center Unit No. 1 (Carlsbad Tract No. 81-46) consists of an approximately 3.8-acre sheet- graded pad with perimeter slopes which was graded between November 1985 and November 1986 by Templeton Construction. Geotechnical observation and testing during grading operations were performed by Moore and Taber and summarized in the Report of Geotechnical Services dated February 25, 1987 (Moore and Taber 1987). According to the report and based on data accumulated during our subsurface exploration program, the site was graded as a cut-fill transition pad. A maximum of approximately 23 feet of fill was placed in the southeast portion of the pad, while a maximum of approximately 35 feet of cut was made in the northwest corner. The 2:1 to 3:1 (horizontal to vertical) slopes around the perimeter of the lot range from an approximately 24-foot-high cut slope on the west side to an approximately 26-foot-high fill slope on the south side of the lot. The cut-fill transition line generally transects the sheet-graded pad in a northeast-southwest direction from the southwest corner to the middle of the pad on the east side. Topographically, the sheet-graded pad ranges in elevation from 163 to 171 feet (mean sea level) with a gradient sloping to the southeast. The sheet-graded pad is sparsely vegetated with minor weeds and small brush. The slopes have been planted with trees, flowers, and other shrubs and are currently irrigated. During our subsurface exploration program it was noted that phreatophytic vegetation and ponded surface water was observed at the base of the slope along the northeast corner of the site. Based on conceptual site and floor plans and communications with Mr. Richard Lloyd of Castillo Company, Inc., the proposed development will be a single-story structure consisting of WAQW tru^gog u;«>rui_k^;^ ^j^r] steel columns on a concrete slab-on-grade foundation. Maximum anticipated column footing and wall footing loads are 60,000 pounds and 2,500 pounds per foot, respectively. Approximately 132 parking spaces, driveways, concrete flatwork, landscaping and associated improvements (i.e., utility lines) are also planned. Based on our review of the preliminary site plan, minor grading and/or construction of retaining walls will be required since the site plan indicates parking areas will extend over existing slopes. 1 - LEIGHTON AMD ASSOCIATES, IN 8900827-01 1-2 Purpose and Scooe of Services This report presents the results of our preliminary geotechnical investigation of the subject lot. The purpose of our preliminary investigation was to identify and evaluate the geotechnical conditions present on the site and to provide geotechnical recommendations relative to the proposed development. Our scope of services included: Review of available geotechnical publications and maps (including the Report of Geotechnical Services during grading) pertinent to the site (Appendix A). Review and analysis of aerial stereophotographs to identify the pregraded geologic conditions of the site (Appendix A). Limited subsurface exploration consisting of the excavation, sampling and logging.of nine small-diameter borings. Logs of the borings are presented in Appendix B. Laboratory testing of representative bulk and undisturbed samples obtained from our subsurface exploration program (Appendix C). Geotechnical analysis of the data obtained (including geotechnical site conditions). existing Preparation of this report presenting our findings, conclusions, a recommendations with respect to the proposed site development T presentation of the geotechnical data (Geotechnical Map - Plate 1) w accomplished by utilizing the topographic base map provided by Bod Engineering (Appendix A). 1-3 Subsurface Investigation and Laboratorv Testina Our subsurface exploration program consisted of the excavation, logging and sampling of nine small-diameter borings to a maximum depth of 26 feet' Five of the borings were excavated to evaluate the proposed building location while the remaining four were placed in the parking areas to evaluate the subgrade soils. The location of the borings were surveyed by Bodas Engineering and are presented on the Geotechnical Map (Plate 1) Logs of the borings are presented in Appendix B. The purpose of this program was to evaluate the engineering characteristics of the onsite near-surface soils. The borings were logged by a geologist from our firm who obtained representative (bulk and undisturbed) samples of the soils encountered for laboratory testing. Sampling for the presence of hydrocarbons was also performed and the results of that phase of our investigation will be presented under separate cover. Subsequent to field exploration, all excavations were backfilled. - 2 LEIGHTOM AND ASSOCIATES, INC 8900827-01 Laboratory testing was performed on the representative soil samples and included moisture/density determinatibns, maximum dry density, remolded direct shear, expansion potential, soluble sulfate content and R-value testing. A discussion of the tests performed and a summary of the laboratory test results are presented in Appendix C. The density and moisture content of the undisturbed sampTes from the borings are shown on the boring logs (Appendix B). - 3 LEIGHTON AND ASSOCIATES, INC 8900827-01 2.0 GEOTECHNICAL CONDITIONS 2.1 Regional Geologv The subject site is situated in-the coastal section of the Peninsular Range Province, a California geomorphic province with a long and active geologic history throughout southern California. Through the last 54 million years, the area known as the "San Diego Embayment" has undergone several episodes of marine inundation and subsequent marine regression. This has resulted in a thick sequence of marine and nonmarine sediments deposited on rocks of the southern California batholith with relatively minor tectonic uplift of the area, 2,2 Site Geology Based on our subsurface exploration (Appendix B), aerial photographic analysis, and review of pertinent geotechnical literature (Appendix A) the soils underlying the site consist of the sedimentary, Tertiary-aged Scripps Formation and documented fill soils. This site-specific geology IS depicted on the Geotechnical Map (Plate 1). A brief description of the geologic units encountered on the subject lot is presented below. 2.2.1 Scrioos Formation (Mao Svmbol - Tsc) The bedrock unit underlying the site is the Tertiary-aged Scripps Formation. The unit consists of massive to poorly bedded sandstone with interbedded clayey siltstone. The sandstone encountered consisted primarily of pale gray, light brown, and light yellow- brown, dense, silty, fine- to occasionally medium-grained sandstone The sandstone was generally friable, sl ightly micaceous and massive! The siltstone consisted of medium brown and olive-brown, stiff, clayey siltstones that were fissile to indistinctly bedded and contained abundant yellow limonite and iron-oxide staining. The units were not differentiated on the Geotechnical Map (Plate 1). 2.2.2 Artificial Fill (Mao Svmbol - Afl) Compacted fill was placed during grading of the site generally in the southeast portion of the lot. The fill soils encountered generally consisted of intermixed silty to clayey sand wfth occasional zones or layers of sandy clay. The soils appeared to be relatively well mixed and relatively tight. Borings that extended down into bedrock beneath the fill indicated that surficial topsoil and/or colluvial soils were removed or benched to competent formational material prior to fill placement. - 4 LEIGHTON AND ASSOOATES, INC 8900827-01 2.3 Geologic Structure Our geotechnical investigation indicates that the sedimentary formational units are generally massive to poorly bedded. Geologic observations during grading of the site (Moore and Taber 1987) indicated the general dip of bedding on the project was 4 to 12 degrees to the south-southeast. Jointing was not noted in the as-grade report, however, based on our experience with similar materials on nearby sites, jointing is generally sparse, randomly oriented and relatively steeply dipping. 2.4 Ground Water Ground water was not encountered during our subsurface exploration program except for the ponded water condition noted in the northeast corner of the lot. Brief observations indicate either 1) the south-facing slope along Wright Place is currently being over-watered, and/or 2) due to out-of- slope bedding in the south-facing slope, ground water seepage is occurring at the base of the slope. 2.5 Faulting Our discussion of faults on the site is prefaced with a discussion of California legislation and state policies concerning the classification and land-use criteria associated with faults. By definition of the California Mining and Geology Board, an active fault is a fault which has had surface displacement within Holocene time (about the last 11,000 years). The State Geologist has defined a potentially active fault as any fault considered to have been active during Quaternary time (last 2,000,000 years). This definition is used in delineating Special Studies Zones as mandated by the Alquist-Priolo Geologic Hazards Zones Act of 1972 and as subsequently revised in 1975 and 1985, The intent of this act is to assure that unwise urban development does not occur across the traces of active faults. The subject site is not included within any special study zones as created by the Alquist-Priolo Act (Hart 1985). A review of geotechnical and geologic publications, maps, and aerial photographs pertaining to the site indicates that there are no known faults crossing the site (Appendix A). Evidence of onsite faulting was not encountered during our investigation nor noted in the As-Graded Report of Rough Grading (Moore and Taber 1987), although several faults have been mapped in the Carlsbad area (Hannan 1975 and Eisenberg 1985). These inactive faults do not appear to transect the site. The nearest known active, regional faults are the offshore extension of the Coronado Banks fault zone located approximately 22 miles to the west and the Elsinore fault zone located approximately 23 miles northeast. The nearest potentially active fault is the Rose Canyon fault mapped by the California Division of Mines and Geology as being offshore approximately 6.5 miles southwest of the site. Figure 2 indicates the location of the site in relationship to known major faults in the southern California - 5 - LEIGHTON AND ASSOCIATES, INC 8900827-01 region. Included on Figure 2 are the approximate epicentral area and magnitude of earthquakes recorded during the period of 1769 to 1973. 2.6 Seismicitv The subject site can be considered to lie within a seismically active region, as can all of southern California. Table 1 (rear of text) indicates potential seismic events that could be produced by maximum probable earthquakes. A maximum probable earthquake is the maximum expectable earthquake produced from a causative fault during a lOO-year interval. Site-specific seismic parameters included in Table 1 are the distances to the causative fauHs, Richter earthquake magnitudes, expected peak/repeatable high ground accelerations (RHGA), and estimated period and duration of ground shaking. As indicated in Table 1, the Elsinore fault zone is considered to have the most significant effect at the site from a design standpoint. A maximura probable earthquake of Richter Magnitude 6.7 on the Elsinore fault zone could produce a peak horizontal bedrock acceleration of approximately 0.16g, Therefore, a design RHGA of 0.16g should be utilized. The effect of seismic shaking may be mitigated by adhering to the Uniform Building Code or state-of-the-art seismic design parameters of the Structural Engineers Association of California, Secondary effects associated with severe ground shaking which affect sites following a relatively large earthquake include ground lurching and shallow ground rupture, soil liquefaction and dynamic settlement. These secondary effects of seismic shaking are discussed below, 2.6,1 Lurching and Shallow Ground Rupture Soil lurching refers to the rolling motion on the surface by the passage of seismic surface waves. Effects of this nature are likely to be significant where the thickness of soft sediments vary appreciably under structures. Damage to the proposed development due to lurching should not be significant due to the relatively dense characteristics of the fill and formational soils. Ground rupture generally is considered to occur along pre-existing faults. Due to the absence of onsite faults, cracking due to shaking from distant seismic events is not considered a significant hazard although it is a possibility at any site, in seismically active southern California. 2.6.2 Liguefaction and Dvnamic Settlement Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Both research and historical data Indicate that loose, saturated, granular soils are susceptible to liquefaction and dynamic settlement while the stability of silty - 6 - LEIGHTON AND ASSOCIATES, IN 8900827-01 clays and clays is not adversely affected by vibratory motion (Seed 1982). Liquefaction is typified by a total loss of shear strength in the affected soil layer, thereby causing the soil to flow as a liquid. This effect may be manifested by excessive settlements and sand boils at the ground surface. The Scripps Formation is not considered liquefiable due to its high density characteristics. The onsite fill soils also are not considered 1 iquefiable due to their generally unsaturated condition, fine-grained nature and relatively dense characteristics. 2.7 Existing Slope Conditions Existing slopes have been manufactured around the perimeter of the sheet- graded pad and range from 3:1 (horizontal to vertical) slopes on the south and west sides of the site to 2:1 (horizontal to vertical) slopes on the north and east sides. The slopes consist of fill, fill-over-cut and cut slopes. Fill placement was limited to the southeast portion of the lot, therefore, the south-facing and east-facing slopes on the southeast portion of the lot are fill slopes constructed during rough and fine-grading operations in 1985 and 1986. During grading, geologic mapping of Carlsbad Tract No. 81-46 indicated that the generalized dip of the formational soils was to the south-southeast, creating potential slope stability problems in south-facing slopes. Therefore, the south-facing slope of Lot 12 along Palomar Airport Road was replaced with a stability fill, A stability fill key approximately 20 feet wide was constructed at the base of the slope and the backcut benched as fill was placed (Moore and Taber 1987). The approximate limits of the stability fill key and fill are shown on the Geotechnical Map (Plate 1). The slopes on the west, north and northeast sides of the lots were constructed as cut slopes exposing formational bedrock. The formational soils in these slopes (which are west-facing, north-facing and south to southwest-facing) have generalized bedding attitudes that dip slightly out- of-slope, neutral or into-slope. During rough grading, geologic mapping indicated these slopes were not adversely affected by bedding, so the slopes were not rebuilt. During our field exploration, observations indicate an abundance of ponded water at the northeast corner of the pad adjacent to the south-southwest-facing slope, 2.8 Expansion Potential The formational soils at the site which are predominately silty sands with some interbedded silty clay to clayey silts, based on our visual classification, range from low to medium expansive. The fill soils derived from the onsite formational soils are similar. Expansion testing (Appendix C) of a representative sample of the soils anticipated to support - 7 - LEIGHTON AND ASSOCIATES, INC the building foundation was expansion. 8900827-01 ' found to possess a medium potential for 2.9 Reactivity t?fZ A \ ^ """P]! °^ the soils anticipated to be at finish grade was tested to determine the soluble sulfate content. Soluble sulfates if present in significant amounts, can be damaging to conventional Type I/II - 8 - UIGHTON AND ASSOCIATES, INC 8900827-01 3,0 CONCLUSIONS 3.1 Summarv of Geotechnical Conclusions Based on our preliminary geotechnical investigation, it is our opinion that the proposed property development is feasible from a geotechnical standpoint provided the recommendations of this report are incorporated into the design and construction of the property. The following is a summary of those significant geotechnical factors which may affect development of the site. • Laboratory test results and visual observation indicates the engineering characteristics of the onsite soils include a medium expansion —4^^ considerable soluble sulfate content, afi3 reiativSIjTliTgh shear^Erength. Our subsurface exploration program indicated fill thicknesses beneath the proposed service center range from 0 to approximately 19 feet. Anticipated differential settlement is estimated to be on the order of 1 inch, provided the recommendations of this report are incorporated into the design and construction of the project. Field exploration of the site indicated the pad is a cut-fill transition lot. Based on preliminary site plans, the proposed service center building will be located on this cut-fill transition. Due to the varying densities of the fill and formational material, differential settlement is potentially a problem when a structure is placed over a cut-fill transition. Therefore, remedial measures (i.e., overexcavation of the building pad) will be required. Recommendations,goncerning the overexcavation of the building pad are discussed^itj^cTfolTT^' Based on visual observations of the fill and formational soils encountered, the site may be excavated using conventional heavy-duty construction equipment. In addition, based on laboratory studies, the soils are suitable for use.as structural fill. Due to the granular nature of the onsite soils, erosion of the existing slopes could be a potential problem unless provisions for site drainage O and maintenance of the slope vegetation are provided. Y^-^C Ground water was not encountered during our subsurface exploration program, but ponded surface water was observed on the northeast corner of the site. The subject site is located in an area of Mediterranean climate characterized by alternating summer dry periods and winter precipitation. Average annual rainfall is approximately 10 to 12 inches with most occurring in December through April. Average temperatures rarely are below freezing, therefore, the potential for frost damage is considered negligible. - 9 LEIGHTON AND ASSOCIATES, IN( 8900827-01 The most significant seismic hazard is ground shaking due to a major earthquake. The closest active faults are the offshore extension of the Coronado Banks and Elsinore fault zone located approximately 22 miles to the west and 23 miles to the east, respectively. Estimated peak horizontal bedrock accelerations are provided in Table 1. - 10 UIGHTOM AMD ASSOQATES, IMC 8900827-01 4.0 RECOMMENDATIONS 4.1 Earthwork Prior to grading of the lot, the pad should be cleared of surface vegetation and debris and disposed of off site. Grading and earthwork should be performed in accordance with the requirements of the City of Carlsbad, the recommendations of this report, and the General Earthwork and Grading Specifications included in Appendix D, Based on our preliminary investigation and review, grading of the site should not produce oversized rock, - 4.1.1 Compacted Fill Onsite soils are'^^nerajl^^uitaPle for use as compacted fill provided they are free of organic materials, debris, trash, and oversized rock (greater than 12 inches in dimension). All fill soils should be brought to near optimum moisture content and compacted in uniform lifts to at least 90 percent relative compaction (based on ASTM Test Method D1557-78), The optimum lift thickness required to produce a uniformly compacted fill depends on the type and size of compaction equipment used. In general, fill should be placed in uniform lifts not exceeding 8 inches in thickness. Placement and compaction of fill should be performed in accordance with the requirements of the City of Carlsbad and this report. Testing and observation should be performed by the geotechnical consultant during grading. General Earthwork and Grading Specifications are provided in Appendix D. 4.1.2 Overexcavation and Recompaction Due to the cut/fill transition condition and a fill thickness differential of approximately 19 feet, we recommend that the building pad (to a distance of 5 feet outside the building Ky foundation) be overexcavated a minimum depth of 5 feet below finish "^/^ grade and replaced with compacted nil. we recommend that the ^ entire building pad be overexcavated so as to create a uniform fill under the building foundation. Prior to fill placement the overexcavated bottom should be scarified 6 to 12 inches, moisture conditioned and properly compacted. The fill soils placed should have adequate moisture (i.e., at least optimum moisture content) and be compacted to a minimum 90 percent relative compaction (based on American Standard of Testing and Materials (ASTM) Test Method D1557-78). 11 - LEIGHTON AND ASSOCIATES, INC 8900827.-01 4.1.3 Temporarv Excavations Temporary excavations should satisfy OSHA requirements, and excavations deeper than 5 feet should be shored or slopes laid back to 1:1 (horizontal to vertical) if construction workers are to enter the excavation. 4.1.4 Trench Excavation and Backfill It is anticipated that trench excavations can be accomplished with light backhoe equipment.- The onsite soils may be used as trench backfill provided they are screened of organic materials, oversized rock (if any) and debris. Trench backfill should be compacted in uniform lifts (not exceeding 8 inches in compacted thickness) by mechanical means to at least 90 percent relative compaction (based on ASTM Test Method D1557-78) and in accordance with Appendix D. 4.2 Foundation and Slab Design Considerations Foundations and slabs should be designed in accordance with structural considerations and the following recommendations. These recommendations assume that the soils encountered within 4 feet of pad grade have a medium potential for expansion. Additional expansion tests should be performed during grading to verify that the expansion potential does not change after site grading, 4.2.1 Foundation and Slab Design Conventional shallow spread footings may be used to support the load of the proposed structure provided the recommendations concerning overexcavation and recompaction are adhered to. Continuous building footings should be designed using the following parameters: Allowable Bearing Pressure Minimum Footing Depth Minimum Footing Width Minimum Footing Reinforcement - 2,500 psf - 18 inches - 15 inches - One No, 4 rebar top and bottom Square building footings should be designed using the followinq parameters: Allowable Bearing Pressure Minimum Footing Depth Minimum Footing Width Minimum Footing Reinforcement 12 - 2,500 psf 24 inches 24 inches Four No. 4 direction rebars, two each LEIGHTON AND ASSOCIATES, INC 8900827-01 The allowable bearing pressure for continuous or spread footings may be increased by one-t+iird for wind or seismic loads. Footing embedments should be measured from lowest adjacent grade. In order to help mitigate the potential for misalignment of the proposed bay door opening(s), we recommend a grade beam be provided across the bay door opening. This grade beam should be designed in accordance with the structural engineer's requirements and have a minimum reinforcement of two No. 4 rebars (one top and bottom). All building slabs should be a minimum of 4 inches thick. Slabs should have a minimum reinforcement consisting of 6x6-6/6 welded wire mesh placed midheight in the concrete!Additional reinforcement may be recommended at the completion of remedial grading when finish grade soil samples can be tested for expansion potential. A moisture barrier consisting of a 6-mil Visoueen laver properly lapped and covered by a minimum 3-incli layer or sand above and 1-inch layer below should be provided beneath floor slabs. The potential for slab cracking may be reduced by careful control of water/cement ratios. The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to minimize cracking of slabs. We recommend that a slipsheet (or Sequivalent) be utilized if grouted tile, marble tile, or other Icrack-sensitive floor covering is planned directly on concrete islabs. All slabs should be designed in accordance with structural |Considerations. 4.2.2 Moisture Conditioning It is recommended that the subgrade soils in the building pad area be presoaked prior to slab and foundation construction to minimize the effects of the prevailing expansive soils. This is usually achieved either by ponding or sprinkling. Ponding or sprinkling of the pad area is recommended to continue until the moisture content of the subgrade soils meets the following criteria: Expansion Potential Presoak Level . Medium 1.2 x optimum moisture 1? 12 inches The optimum moisture content of the finish grade soils was determined in the laboratory (ASTM Test Method D1557-78). Once the presoaking criteria is reached, the top few inches of the pad soils may be overly soft for convenient foundation trenching and utility installation. The contractor may consider scheduling the work such that presoaked pads could be left for two to three days until a working crust develops. After the foundations are cut to grade and a 2-inch blanket of sand is placed on the pad area, the sand should be moistened to make up for moisture deficiency which may have affected the top few inches of the subgrade. - 13 - LEIGHTON AND ASSOCIATES, INC 8900827-01 4.2.3 Foundation Setbacks We recommend a minimum horizontal setback distance from the face of slopes for all structural footings. This distance is measured from the outside edge of the footing, horizontally to the slope face (or to the face of a retaining wall) and should be a minimum of H/2, where H is the slope height (in feet). The setback should not be less than 5 feet and need not be greater than 10 feet. Please note that the soils within the structural setback area possess poor lateral stability, and improvements (such as retaining walls, sidewalks, fences, pavements, etc.) constructed within this setback area may be subject to lateral movement and/or differential settlement. Potential distress to such improvements may be mitigated by providing a deepened footing to support the improvement. The deepened footing should meet the seteback as described above. 4.3 Settlement The fill thickness differential obtained during our subsurface exploration program is approximately 19 feet. Anticipated differential settlement is anticipated to be on the order of 1 inch. Total settlements are anticipated to be less than 1 inch for the proposed structure founded on compacted fill based on the maximum anticipated column footing and wall footing loads of 60,000 pounds and 2,500 pounds per foot, respectively. 4-4 Lateral Earth Pressures and Resistance Embedded structural walls should be designed for lateral earth pressures exerted on them. The magnitude of these pressures depends on the amount of deformation that the wall can yield under load. If the wall can yield enough to mobilize the full shear strength of the soil, it can be designed for active" pressure. If the wall cannot yield under the applied load the shear strength of the soil cannot be mobilized and the earth pressure will be higher. Such walls should be designed for "at rest" conditions If a structure moves toward the soils, the resulting resistance developed by the soil is the "passive" resistance. For design purposes, the recommended equivalent fluid pressure for each case for walls founded above the static ground water table and backfilled with nonexpansive soils is provided below. The onsite medium expansive soils are not considered suitable for retaining wall backfill. Therefore we recommend nonexpansive, granular soil be imported for use as compacted wall backfill. - 14 - LEIGHTOM AND ASSOCIATES, INC 8900827-01 Equivalent Fluid Weiqht (pcf) Condition Level 3:1 Slope 2:1 Slope Active 35 50 55 At-Rest 55 60 65 Passive 300 200 150 (Fill Soils) (Maximum of 3 ksf) (Sloping Down) (Sloping Down) Passive 750 400 300 (Formational (Maximum of 6 ksf) (Sloping Down) (Sloping Down) Material)' The above values assume nonexpansive backfill and free-draining conditions. If conditions other than those assumed above area anticipated, the equivalent fluid pressure values should be provided on an individual-case basis by the geotechnical engineer. All retaining wall structures should be provided with appropriate drainage. Typical drainage design is illustrated in Figure 3 (rear of text). As an alternative, a drain board may be utilized behind the retaining wall in addition to normal waterproofing. This system may consist of Miradrain 6000 (or Geotech Systems Drainage Board) lined with filter fabric. At the wall base, we recommend that a minimum of the bottom 24 inches of the drain board and a 6-Inch perforated PVC drain be surrounded by approximately 4 cubic feet of clean gravel per foot of wall length and wrapped in filter cloth (Mirafi HON or equivalent). The pipe should be sloped to drain to a suitable outlet. The back cut for walls less than 5 feet in height can be made near vertical frora the heel of the walls. For walls greater than 5 feet in height, but less than 15 feet in height, the back cut should be flattened to a gradient of not steeper than 1:1 (horizontal to vertical) slope inclination. For the back cut in excess of 15 feet in height, specific recommendations should be requested from the geotechnical consultant. As previously mentioned, the walls should be backfilled with granular, nonexpansive material. The granular material backfill should be brought up to a height of approximately 2 feet below the top of the walls and capped with compacted fill consisting of native soils. The granular and native backfill soils should be compacted to at least 90 percent relatively compaction (based on ASTM Test Method D1557-78). The granular fill should extend horizontally to a minimum distance equal to one-half the wall height behind the walls. The walls should be constructed and backfilled as soon as practical after back cut excavation. Prolonged exposure of back cut slopes may result in some localized slope instability. Soil resistance developed against lateral structural movement can be obtained frora the passive pressure value provided above. Further, for sliding resistance, a friction coefficient of 0.30 may be used at the concrete and soil interface. These values may be increased by one-third 15 - LEIGHTOM AMD ASSOCIATES^ IMC 8900827-01 when considering loads of short duration including wind or seismic loads The total resistance may be taken as the sum of the frictional and passive resistances provided the passive portion does not exceed two-thirds of the total resistance. To miniraize differential uplift due to soil expansion on wall footings such as for retaining and free-standing walls, the footings should penetrate the soil zone that is most likely prone to volume change It IS recommended the footings be embedded at least 24 inches below lowest adjacent finish grade. In addition, the wall footings should be designed and reinforced with structural considerations. 4.5 ' Type of Cement fnr Construction A representative sample of soil anticipated to be near finish grade was obtained and tested for soluble sulfate content. The test result (Appendix C) indicates the soil possesses a soluble sulfate content of approximately 0,36 percent (or 3600 ppm). Based on California Cement Industry Technical Committee (CCITC) guidelines, a considerable potential for sulfate attack exists for sulfate contents of greater than 0.20 percent. Therefore, sulfate resistant cement (i.e.. Type V or equivalent) is required, , JH^ * 4.6 Exterior Concrete FlatwnrW To reduce potential cracking, exterior concrete flatwork should be a mimmum of 4 inches In thickness, reinforced with 6x6-6\6 welded wire mesh placed at midheight. Construction or sawcut joints should be provided at honzontal intervals not exceeding 10 feet. Sidewalks or walkways should have the construction or sawcut joints at intervals not exceedinq the walkway width. Exterior flatwork should be underlain by a 4-inch thick sons *^ " ^^"'^ ^^^"^ equivalent of 30 or greater) or nonexpansive fill 4.7 Pavement Desiqn In order to provide the preliminary pavement design for the parkinq areas and driveways, a representative sample of the anticipated subgrade soil was R-value tested (Appendix C). For preliminary design purposes, we have fl^ l^t fJ'^'.^l^^ °^ ^"^ ^ t'^a^^ic i"dex of 4.0 (based on the expected CS.^W^PM"^'"^^^ by Castillo Company and City of Carlsbad minimum standards). The recommended structural pavement section is 3 inches of asphaltic concrete (A.C.) over 6 inches of Caltrans Class II aggregate base The pavement section design calculations along with the Requirements for Paving form (requested by Castillo Company) is presented in Appendix E. InL^^f^F^^J iP^^^^ °^ subgrade soils should be scarified, moisture conditioned and corapacted to a rainiraum of 90 percent relative compaction d^^?nn°" Test Method D1557-78. If fill is'required to reach TubgrlTe design grade, fill placement should be performed in accordance with the - 16 LEIGHTOM AMD ASSOCIATES, IMC 8900827-01 recomraendations presented in Section 4.1. The aggregate base material should be compacted to 95 percent relative compaction. 4.8 Graded Slopes In order to reduce the potential for erosion and surficial sloughing and/or slumping, the ground cover vegetation and deep-rooted vegetation already planted on the slopes should be maintained. Watering of the landscape areas should be limited to that amount necessary to maintain plant vigor. Over-watering of slope areas should be avoided. 4.9 Ponded Water at Northeast Portion of Pad The ponded water condition on the northeast portion of the pad will need to be addressed if potential distress to the parking area pavement is to be avoided. We recommend that a subdrain be placed along the edge of the parking lot pavement adjacent to the slope to limit the lateral movement of the water. A typical detail is provided in Figure 4. The location and extent of this drain should be determined by the geotechnical consultant "^--^ when final plans are available. 4.10 Surface Drainage and Lot Maintenance Surface drainage should be controlled at all times. The subject structure should have appropriate drainage systems to collect roof runoff. Positive surface drainage should be provided to direct surface water away frora the structure and toward the pavement or other suitable collective drainage facilities. Surface waters should not be allowed to pond adjacent to footings. Planters should not be designed below grade adjacent to the structures unless provisions for drainage such as catch basins and pipe drains are made. We recommend positive drainage away from slopes be provided and maintained so that run-off over the slopes does not occur. 4.11 Oversteepening of Existing Slopes Oversteepening of existing slopes should be avoided during fine grading and construction unless supported by appropriately designed retaining structures. Retaining structures should be designed with structural considerations and appropriate soil parameters provided herein. 4.12 Construction Observation The recommendations provided in this report are based on the subsurface conditions disclosed by widely spaced borings. We recommend all excavations be geologically mapped by an engineering geologist for the presence of adverse geologic conditions during grading. All foundation excavations and grading operations should be observed and/or tested by a representative of this firm so that construction is performed in accordance with the recommendations of this report. - 17 - LEIGHTON AMD ASSOCIATES, INi 8900827-01 TABLE 1 SEISMIC PARAMETERS FQR ACTIVE AND POTENTIALLY ACTIVE FAULTS State Farm Service Center/Carlsbad Maximum MAXIMUM PROBABLE EARTHQUAKE (Functional Basis Earthquake) Potential Causative Fault Distance From Fault To Site (Miles) Credible Earthquake Richter Magnitude Richter Magnitude Peak Bedrock/ Repeatable Horizontal Ground Acceleration** (Gravity) Predominant Period at Site in Seconds Duration of Strong Shaking at Site in Seconds Elsinore 23 NE 7.5 6.7 0.16 0.32 17 Coronado Banks (offshore) 22 SW 6.5 6.0 0.10 . 0.26 7 San Jacinto 47 NE 7.5 7.2 0.08 0.43 12 San Andreas 66 NE 8.5 8.3 0.08 0.62 5 San Clemente (offshore) 54 SW 7.5 7.0 0.06 0.42 7 Rose Canyon* (offshore) 6.5 SW 7.1 NA ~ * - - • ** ^5^f/^c^^ considered "potentially active," based on our current knowledge of the geologic conditions of the San Dlego County area. a a For design purposes, the repeatable horizontal ground acceleration may be taken as 65 percent of the peak acce eration for the site within approximately 20 miles of the epicenter (after Ploessel and Slosson, 1974). 1-story Footings (See Note 1) TABLE 2 MINIMUM FOUWDATIOM ANO SLAB RECOtMENDATIOMS FOB FXPAMSIVE SOILS (ONE- ANO TUO-STORY RESIDENTIAL BUILDINGS) U.B.C. EXPANSION INDEX 0 - 20 VERY LOU EXPANSION AU footings 12" deep. Reinforcement for con- tinuous footings: one No. 4 bar top and bottom. U.B.C. EXPANSION INDEX 21 - 50 LOU EXPANSION AU footings 12" deep. Reinforcement for con- tinuous footings; one No. 4 bar top and bot- tom. U.B.C. EXPANSION INDEX 51 - 90 MEDIUM EXPANSION Exterior footings 18" deep. Interior footings 12" deep. Reinforcement for continuous footings: one No. 4 bar top and bottom. U.S.C. EXPANSION INDEX 91 - 130 HIGH EXPANSION Exterior footings 24" deep. Interior footings 18" deep. Reinforcement for continuous footings: one No. 5 bar top and bottom; alternately, two No. 4 bars top, two No. 4 bars bottom. 2-Story Footings (See Note 1) Exterior footings 18" deep. Interior footings 12" deep. Reinforcement for continuous footings: one No. 4 bar top and bottom. Exterior footings 18" deep. Interior footings 12" deep. Reinforcement for continuous footings: one No. 4 bar top and bottom. Exterior footings 18" deep. Interior footings 12" deep. Reinforcement for continuous footings: one No. 4 bar top and bottom. Exterior footings 24" deep. Interior footings 18" deep. Reinforcement for continuous footings: one No. 5 bar top and bottom; alternately, two No. 4 bars top, two No. 4 bars bottom. Minimum Footing Uidth Garage Door Grade Beam (See Note 2) Living Area Floor Slabs (See Notes 3, 4 and 5) Garage Floor Slabs (See Notes 4 and 6) Presoaking of Living Area and Garage Slabs Continuous: 12" for one- story. Continuous: 15" for two-story. Isolated column: 24" A grade beam 12" wide x 12" deep (18" deep for 2- story) should be provided across the garage en- trance. Nominal 4" thick slab, 6x6-10/10 UUF reinforce- ment at midheight. 6- mil Visqueen moisture barrier on pad grade with 1" sand above Visqueen. Nominal 4" thick slab on pad grade. Garage slabs should be quarter-sawn. Near-optimLia to a depth of 6". Continuous: 12" for one- story. Continuous: 15" for two-story. Isolated column: 24" A grade beam 12" wide x 12" deep (18" deep for 2- story) should be provided across the garage en- trance. Nominal 4" thick slab. 6x6-10/10 UWF reinforce- ment at midheight. 6- mil Visqueen moisture barrier above 2" sand base with 1" sand above Visqueen. Nominal 4" thick slab on 2" sand base. Garage slabs should be quarter- sawn. (1.2) X optimuH to a depth of 12". Continuous: 12" for one- story. Continuous: 15" for two-story. Isolated coluin: 24" A grade beam 12" wide x 18" deep should be pro- vided across the garage entrance. Nominal 4" thick slab. 6x6-6/6 UUF reinforcement at midheight. 6-raiI Vis- queen moisture barrier above 3" sand base with 1" sand above Visqueen. Nominal 4" thick slab on 3" sand base. Garage should be quarter-sawn or reinforced with 6x6-10/10 UUF at midheight. (1.3} X optimum to a depth of 18". Continuous: 12" for one- story. Continuous: 15" for two-story. Isolated column: 24" A grade beam 12" wide x 24" deep should be pro- vided across the garage entrance. Full 4" thick slab. 6x6- 6/6 UUF reinforcement at midheight. 6-mil Vis- queen moisture barrier above 4" sand base with 1" sand above Visqueen. Nominal 4" thick slab on 4" sand base. Garage slabs should be quarter- sawn and reinforced with 6x6-6/6 UUF at-midheight. (1.4) X optimum to a depth of 24". NOTES: 5. 6. 7. Depth of interior or exterior footings to be measured from lowest adjacent finish grade. The base of the grade beam should be at the same elevation as that of the adjoining footings. Living area slabs may be tied to the footings as directed by the structural engineer. For HIGH EXPANSION: Dowels consisting of No. 3 bars should be placed at 36 inches on centers in the footings and bent 3 feet into the slab. It has been observed that welded wire fabric reinforcement seldom stays at the design height within concrete slabs. Ue recommen< the use of No. 3 bars at 24 inches O.C. instead of 6x6-10/10 UUF and No. 3 bars at 18 inches O.C. instead of 6x6-6/6 UUF. 6-mil Visqueen sheeting has proved successful. Equivalents are acceptable. Garage slabs should be isolated from stem wall footings with a minimun 3/8" felt expansion joint. Sand base should have a Sand Equivalent of 30 or greater (e.g., washed concrete sand). Post-Tensioned Slabs As an alternative to conventional foundations, buildings may be supported on post-tensioned slabs, to be designed by a structura engineer in consultation with the geotechnical consultant. In addition, a post-tensioned slab is also recoomended for VERY HIGi expansion potential below the adjacent grade. The slabs should be designed such that they can be deformed approximately 1 inc! vertically over a width of 30 feet without distress in the event of shrinkage or swelling of the supporting soils. Living are. slabs should be underlain by a 6-mil Visqueen moisture barrier covered by a 1-inch layer of sand. Presoaking is recommended fo post-tensioned slabs: (1.2) x optimum to a depth of 12 inches, (1.3) x optimLin to a depth of 18 inches, and (1.4) x optimum to depth of 24 inches for MEDIUM, HIGH, and VERY HIGH expansion potential soils, respectively. Placement of sand base below Visquee is also suggested for post-tensioned slabs: 2, 3, and 4 inches thick for miedium, high, and very high expansive potential soils respectively. •'.•-V r:-/«- :t K'.'.'.'.'.'.'.'.'.'.-.'.'.i :-:.:.:.:.:.S<tf'>.'.*>^ Project No. 8900827-01 ItlCHTON AHO ASSOaATtS SITE LOCATION MAP STATE FARM - CARLSBAD CARLSBAD, CALIFORNIA Figure KlLOMCTCNS M I i. e s MAJOR EARTHQUAKES AND RECENTLY ACTIVE FAULTS IN THE SOUTHERN CALIFORNIA REGION ACTIVE FAULTS EXPLANATION* •fetal lenath of fouit zone mot breoks Holocene deposits or that has hod tcisinic octivity. Foult seqment with surface rupture during an historic •orthquoke, or with oseismic foull CTeep. • Holocene voicomc octivity (Amboy. Psgoh, Ceno Prieto aid Salton Buttes) IMS 1177 EARTHQUAKE LOCATIONS Approximate eptcenirai area of eorthquokes thot occurred 1769-1933. Magnitudes not recorded by instruments pnor to 1906 vere estimated from doffloqe reports assigned on Intensity Ml (Modified Mcrcali scole) or 7«oter; Ittis is roughly eguivalent to Richter M 6.0. 31 moderotr** eorthguokts, 7 major and one gwit earthquake (1857) «cre reported in ttte 164-year period 1769-1933. Eonitquakc epicenters since 1933, piotted fccr inproMd tBtnmnts. 29 moderote** and ttme major tontiguokes «crc recorded in 9tt 40-)car pcrnd 1933-1973. •• tt4t niM i I tilii III tf »c SintcW CH«>««i 'Aueci*«M* d Cililaraa • ^ft MflMMto m tm IUI CM«IM W Riclt^ X Praetor mtinh hem pMi^tti and w<p«Witli(d dots of Ike Ctetanit Omsim tf Umtt 6tohrr, Cathmm Api y Mryopw A>/«f/i*//*-/( 1964); Mitctient fcvn bUktmt ef lUe ftohfinf md Sinmolegkal Socmhn i/Amtna, IIM C F. Ritfiftr. REGIONAL SEISMICITY INDEX MAP ProjectNo. 8900827-01 Project Miifno State Farm/Carlsbacj Date 7/16/90 Figure No_2__ D 2095 788 30IL BACKFILL, COMPACTED TO 90 PERCENT RELATIVE COMPACTION* RETAINING WALL WALL WATERPROOFINQ PER ARCHITECT'S SPECIFtCATIONS FILTER FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT! ** 3/4*-1-1/2' CLEAN QRAVEL 4* (MIN.3 OIAMETER PERFORATED PVC PIPE (SCHEDULE 40 OR EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN AS DEPICTED MINIMUM 1 PERCENT QRADIENT TO SUITABLE OUTLET SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size S Passing 1" 100 3/4" 90-100 3/8" 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equ1va1ent>75 3' MIN. COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE QEOTECHNICAL CONSULTANT * BASED ON ASTM 015S7 IF CALTRANS CLASS 2 PERMEABLE MATERIAL (SEE QRADATION TO LEFT) IS USED IN PLACE OF 3/4'-1-1/2' QRAVEL. FILTER FABRIC MAY BE DELETED. CALTRANS CLASS 2 PERMEABLE MATERIAL SHOULD BE COMPACTED TO 90 PERCENT RELATIVE COMPACTION * NOT TO SCALE PROJECT NO. 8900827-01 STATE FARM/CARLSBAD RETAINING WALL DRAINAGE DETAIL Figvure 3 A.C. IJo M/N'. FAU^ TO OUTLET ^CATIOJV SUBDRAIN DRAINAGE DETAIL State Farm/Carlsbad Project No. Scale Engr7GeoL _ Drafted By Date 8900827-01 Not tn <;r;>)p SRH/RKW RKU July 1990 1042 089 Figure No. 4 LEIGHTON AMD ASSOCIATES, INC 8900827-01 APPENDIX A References ''•^M^ ^f^^' °" "^""^^ Deposition of the Eocene Strata in F?e StHn nr/n^'^? °i^90 Association of Geo?og s nel(jtnp Guidebook, April 13, 1985, • uyii,ts Albee, A-L-'^J'd Earthquake Characteristics and Fault Activity bouthern California in Lunq, R and Prortnr R FWC ?^'''v;'-y Special Publication, dated October 1966. "ly ueoiogists, Bolt, B-A., 1973 Dur^^^^^^ Ground Motion, Proc. Fifth World Conference Le 1973 ' ^"9ineenng, Rome, Paper No. 292, pp. 1304-1313 daSed , Ed., 47-74. Bonilla, M.J. 1970 Surface Faulting and Related Effects, in Wieqel R Earthquake Engineering, New Jersey, Prentice-H^lf iJc pp ' ^^^^in^AbboU°'^"\'''"Ii?tn^^ ^''ll' l^''^^"^' Di^go County ''•No'rtL'rn'./'n""^ Oceanside, Carlsbad, and Vista Areas ?r i?" 0'ego County, California in Ross, A. and Dowlen R J Co nty California'' Itfl'' PeTdleton'and Western s";, oi gi SLk pp.°™6 60. *"0^'ation of Geologist Field Tr?p Hart, "«=-3/j;;;«^"Pt^";^^^^^^^^ fl''^--"'!- A'P"-t-Pr1olo Special l"^VfZl. seismological "L^toTat'o'/y',' '^Iir^e™!! A-l 8900827-01 . References (Continued) « Joyner, W.B., and Boore, D.M., 1982, Prediction of Earthquake Response Spectra, in Proceeding 51st Annual Convention, Structural Engineers Association of California; Also U.S. Geological Survey Open-File Report 81-977, p. 16. Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recurrence Intervals on Major Faults in Southern California, in Moran, O.E., Slosson, J.E., Stone, R.O., and Yelverton, C.A., Eds., 1973, Geology, Seismicity, and Environmental Impact, Association of Engineering Geologists, Special Publication. Moore and Taber, 1987, Report of Geotechnical Services, Carlsbad Tract No. 81-46, Airport Business Center Unit No. 1, City of Carlsbad, California, Job No. 285-256, dated February 25, 1987. Ploessel, M.R., and Slosson, J.E., 1974, Repeatable High Ground Accelerations From Earthquakes -- Important Oesign Criteria, California Geology, V. 27, No. Schnabel, R., and Seed, H.B., 1973, Accelerations in Rock From Earthquakes in the Western United States, Bulletin of the Seismological Society of America, V. 63, No. 2, pp. 501-516. Seed, H.B., and Idriss, I.M., 1982, Ground Motions and Soil Liquefaction During Earthquakes, Monogram Series, Earthquake Engineering Research Institute, Berkeley, California. Seed, H.B., and Idriss, I.M., and Kiefer, R.W., 1969, Characteristics of Rock Motions During Earthquakes, Journal of Soil Mechanics and Foundations Division, ASCE, V. 95, No. SMS, Proc. Paper 6783, pp. 1199-1218. Weber, F.H., Jr., 1982, Recent Slope Failures, Ancient Landslides, and Related Geology of the North-Central Coastal Area, San Diego County, Cal ifornia, Cal ifornia Division of Mines and Geology, Open-File Report 82-12LA. Wilson, K.L., 1972, Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles, San Diego, California. A-2 8900827-01 References (Continued) MAPS California Division of Mines and Geology, 1975, Fault Map of California, Scale r'=750,000'. Bodas Engineering, Inc., Undated, Topographic Map, State Farm Insurance Service Center, Carlsbad, California, Scale 1"=20'. United States Department of the Interior Geologic Survey, 1968, 7.5-Minute Encinitas Quadrangle, Scale 1:24,000, Photo Revised 1975. AERIAL PHOTOGRAPHS Date Source Flight Photo No. Scale 1953 USDA AXN8M 72, 73, 99 and 100 1"=2,000' A-3 . , , , , LEIGHTON Ata ASSOCIATED INC Oate June 29, 1990 ucuicunniL/^U auKING LOG Drill Hole No. B-l P-roject State Fann/Carlsbad Drilling Co. Hole Diameter Project No. Sheet 1 of 8900827-01 1 Geodri11 ±6" Elevation Top of Hole ±163' Drive Weight Ref. or Datum Type of Rig Hollow Stem Auge' Tbs- Drop 30 in u Q. O •a Z3 5 — IO- IS— 20- 25- 3 r— h- a. 00 See Geotechnical Map ca > I. o 1|19 ® I 2130 I 3118 I 4117 L. • 3 +J C o c z: o o 99.8 1/1 ITJ , (/I (/I GEOTECHNICAL DESCRIPIION Logged by DWC/RKW Sampled by DWC 20.3 102 99.5 5121 6 182/ "1011 105.0 111.6 16. 22.7 20.4 15.4 SM/ SC SM/ sc SM and CL sc SM SM Medium brown, mottled, orange-brown, slight ly moist, medium dense, silty to clayey, fine grained sand; massive; slightly mica- ceous @ 5' Mottled light-gray, orange-brown and medium brown, slightly moist to moist, dense, silty to clayey sand; contains scattered chunks of medium brown clay; micaceous @ 10' Intermixed, mottled light gray and medium brown, moist, medium dense, silty clay and orange-brown, silty clayey sand (3 15' Mottled light gray and brown, moist to very moist, medium dense, clayey, fine to occasionally medium grained sand; contains yellow limonite blebs and stringers @ 20' Orange light brown to light gray, very moist, medium dense, silty, fine grained sand; intermixed I,SCRIPPS FORMATION to i Orange-brown, moist, dense, silty, fine occasionally medium grained sandstone; massive; friable slightly micaceous; sharp upper contact with fill above; scattered decomposed organics (small branch) encoun tered iust above contort Total Depth = 26 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Oate June 29, 1990 GEOTECHNICAL BORING LOG Drill Hole No. B-2 Sheet 1 of 1 Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 :6" Elevation Top of Hole ±164' Drive Weight Ref. or Datum 140 lbs. Type of Rig Hoi low Stem Auge 30 See Geotechnical Map Drop 11 O a. o "3 _J T3 3 .a >^ i- Q 2: -J :^ OO 3 +J -U C CO IU •r- *J o c s o u o o. oo GEOTECHNICAL DESCRIPIION Logged by DWC/RKW Sampled by DWC •1 122 5 — I 21 18 10 — I 3| 59 107.2 15 — 20- 25 — 30 © ! 82/. 11"' 98.1 23.9 11.5 SM/ SC SC/ CL SM i^FILL: Gray-brown to medium dense, ed silty sand light brown, slightly moist silty, clayey sand; scatter chunks (%-inch diameter) (3 5' Mottled medium brown, light brown and greenish gray; slightly moist, medium dense, silty clayey sand to silty, sandy clay; intermixed; mine iron oxide staining SCRIPPS FORMATION: Light orange-brown, slightly moist, medii dense to dense, silty, fine grained sand massive; minor yellow limonite stringers (3 10' Mottled light gray to light brown, moist, dense, slightly silty, fine grained sand; occasional medium an< coarse grained sand; massive to indistinctly bedded; slightly mica- ceous (3 15' Light gray, slightly moist, dense very dense, slightly silty, fine t* medium grained sand; occasional coarse grained sand; massive; occ. sional iron oxide stained blebs; abundant quartz grains Total Depth = 16 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Date June 29, 1990 ocui tunnit^L BUKirib LU(i Drill Hole No. B-3 Sheet 1 of Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 :6" Elevation Top of Hole ±165.5' Drive Weight Ref. or Datum Type of Rig Hollow Stem Auc 140 lbs. Drop 30 See Geotechnical Map o Q. O S- o 3 ^-> •i-> C 0) •r- +J o c s o u 1/1 1/1 GEOTECHNICAL DESCRIPTION Logged by DWC/RKW Sampled by DWC I 5 — IO- IS— 20- 25- 30 1116 ® I 2122 N/A 3|23 107.4 SM/ SC ''FILL: 13.9 14.2 4| 18 101.0 ® 19.6 SM Medium brown, slightlymoist, medium densf silty to clayey sand; occasional root hai (3 5' Mottled brown, orange brown and ligi gray, moist, medium dense, silty to clayey, fine to medium grained sand intermixed; occasional small chunks of light gray, silty sand @ 10' Light brown and mottled light gray, moist, medium dense, silty, fine to medium grained sand; occasional coa grained sand; massive; micaceous <3 15' Light brown, moist to very moist, dense, clayey to silty, fine to medium grained sand; massive, scat- tered iron oxide stained blebs SM SCRIPPS FORMATION: Light gray, mottled orange-brown, moist, dense, silty, fine to medium grained sand- stone; slightly micaceous; friable; massi\ scattered iron oxide ( including yellow limonite) stained blebs and stringers Total Depth = 21 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Date June 29, 1990 GEOTECHNICAL BORING LOG Drill Hole No. B-4 Sheet of 1 Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 Type of Rig Hollow Stem Auger t6" Elevation Top of Hole ±167' Drive Weight Ref. or Datum 140 lbs. See Geotechnical Map Drop 30 1 n — Ol a. o s- T3 41 J3 (U 3 •— h- a. IO oo 2,? o. C '4- Q Q. >i"^ o ^ - 3 4-> •!-> C vt <U O C S O GEOTECHNICAL DESCRIPTION Logged by DWC/RKW Sampled by DWC 5- 10 15 — 20- 25- 30 ©1 16 100.3 10.2 SM I 2120 103.1 3|85A 10".^ 12.2 SM/ SC SC/ CL SM 'FILL: Light to medium brown, moist, medium dense, silty, fine to medium grained sand; occa- sional medium brown, clayey sand blebs and small chunks up to is-inch in size; friable; micaceous; appears relatively well mixeo (3 5' Mottled medium brown and red-brown, moist, medium dense, silty to clayey, fine to medium grained sand; inter- mixed; iron oxide staining Material becomes medium brown, moist, medium dense, silty, clayey sand to sandy clay @ 8' SCRIPPS FORMATION: Light gray, slightly moist, dense, silty, fine grained sandstone; occasional medium grained sand; very friable; very micaceous Total Depth = 11 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Date June 29. 1990 (ifcUltCHNICAL BORING LOG Drill Hole No. B-5 Project State Farm/Carlsbad Project No. Sheet 1 of i 8900827-01 Drilling Co. Hole Diameter Geodri11 ±6" Elevation Top of Hole ±168' Drive Weight Ref. or Datum Type of Rig Hoi low Stem Auger 140 lbs. Drop 30 in. See Geotechnical Mao Q. O <a _i vt — Q. E ns 00 IU Q. i^ i-a s- 3 *J C Vt O C s o to vt oo GEOTECHNICAL DESCRIPTION Logged by DWC/RKW Sampled by DWC 5- 10- 15- 20- 25- 30 I 1 18 108.2 1.1 26 13.8 SM FILL: Light to medium brown, slightly moist, medium dense, silty , fine to medium grainec sand; slightly friable; micaceous; relative- ly homogeneous; minor iron oxide staining SCRIPPS FORMATION; J SM Light brown to light gray, slightly moist to moist, medium dense, silty, fine grained sand; occasional medium grained sand; mo- derately friable micaceous; near vertical, medium brown, clayey sand stringers Total Depth =9.0 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. GEOTECHNICAL BORING LOG Oate June 29, 1990 Drill Hole No. B-6 Sheet r of" 1 Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 Type of Rig Hollow Stem Auger :6" Elevation Top of Hole ±168' Drive Weight Ref. or Datum 140 lbs. See Geotechnical Map Drop 30 1 n. Si JZ at a. o la _j s- vt <u •a 3 (U .a (u 3 t— ^— Q. E IO oo ' IU a. to.—. c <^ IU o o cx S- 3 *J •U C vt 01 o c S O o to • 1 «-J o. </1 GEOTECHNICAL DESCRIPTION Logged by DWC/RKW Sampled by DWC 5 — 10- 15- 20- 25- 30 I 11 75/ 10"" 105.6 15.5 SM/ SC SM FILL: if Medium-brown, mottled light brown, moist, medium dense, silty to clayey, fine grainec sand; slightly friable; micaceous; iron oxide stained blebs SCRIPPS FORMATION; Light gray, moist, dense, silty, fine grained sandstone; friable; very micaceous; (appears like beach sand) occasional iron oxide stained blebs @ 8' Same material as above; contains mica- rich, short, discontinuous laminae Total Depth = 9.0 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Date June 29, 1990 GEOTECHNICAL BORING LOG Drill Hole No. B-7 Sheet 1 of i Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Dicmeter Geodri11 ±6" Elevation Top of Hole ±169' Drive Weight Ref. or Datum 140 Type of Rig Hollow Stem Auger bs. Drop 30 in See Geotechnical Map II tj — o> Q. O lO _1 L. o vt 01 T3 3 0) (U 3 I— h- a. la Q. 4) U o a. o GEOTECHNICAL DESCRIPTION Logged by DWC/RKW Sampled by DWC 10- 15- 20- 25- 30. I 1|16 2 I 75/ In" 38.7 29. SM/ TSC SCRIPPS FORMATION: CL SM Pale orange-brown, mottled medium brown, moist, medium dense, silty to clayey, fine to medium grained sandstone; slightly friabl slightly micaceous; occasional coarse sand grains; homogeneous; disturbed and reworked @ 1.0' Green-gray, moist, very stiff, silty claystone; fissile; moderately wea- thered; iron oxide stained; short, discontinuous shears; dessiminated gypsum (3 5' @ 8' Light gray, moist, dense, silty, fine to medium grained sandstone; friable; massive; iron oxide stained (limonite blebs and stringers; very micaceous Light gray, mottled yellow-brown, moist, dense, silty, fine-grained sandstone; abundant limonite staining throughout; becomes light-brown with depth Total Depth = 9.0 Feet ^0 Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Oate June 29. 1990 GEOTECHNICAL BORING LOG Drill Hole No. B-8 Sheet 1 • of • 1 Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 ±6" Drive Weight Type of Rig Hollow Stem Auger 140 lbs. Drop 30 in. Elevation Top of Hole -168' Ref. or Datum See Geotechnical Map IU JZ Ol Q. O ra _J S- vt O) -o 3 lU J3 IU 3 /— h- a. (O 00 I- Si c vt • . C M_ 1"^ L. Q s. 3 *J C Vt QJ Vt , CJ : o CJ o. oo GEOTECHNICAL DESCRIPIION Logged by DWC/RKW Sampled by DWC 5- 10- 15 — 20- 25- 30 2I75/ 10"' 106.1 14.3 1 SM SCRIPPS FORMATION: ML/I CL It I f SM Medium brown, moist, medium dense, silty, fine to medium grained sandstone; occasional clay; occasional claystone fragments; slightlv friable: disturbed and reworked @ 0.5' Medium red-brown, moist, very stiff, silty claystone to clayey siltstone; generally massive to slightly fissile; abundant yellow limonite staining @ 8' Gray-brown, slightly moist to moist, dense, silty, fine to medium grained sandstone; occasional coarse grained sand; abundant quartz sand grains; very friable; massive Total Depth = 9.0 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 Leighton and Associates, Inc. Data June 29, 1990 GEOTECHNICAL BORING LOG Drill Hole No. B-9 Sheet 1 of i Project State Farm/Carlsbad Project No. 8900827-01 Drilling Co. Hole Diameter Geodri11 ±6" Elevation Top of Hole ±166' Drive Weight Ref. or Datum Type of Rig Hollow Stem Auger 140 lbs. Drop 30 in. See Geotechnical Map 5^ a. a. u .s: Ol Q. O <a _i s. CD vt — H- g. io 00 CQ Vt • C i" i-o •>-> c CO IU o c 51 O CJ CJ o. oo GEOTECHNICAL DESCRIPIION Logged by DWC/RKW Sampled by DWC ®1 20 92.1 25.7 ML ASCRIPPS FORMATION: 5- 10 15- 20- 25- 30. I 64 SM Medium brown, moist, medium stiff, clayey siltstone; massive to slightly fissile; iron oxide staining; slightly micaceous; abundant limonite staining below 1.5 feet (3 8.5' Light to medium gray, moist, dense, silty, fine to medium grained sand- stone; massive; slightly friable; micaceous; minor iron oxide stained blebs Total Depth = 11.0 Feet No Ground Water Encountered No Detectable/Visual Contaminants Observed (PID = less than 1 ppm) Backfilled 6/29/90 I Leighton and Associates, Inc. •mm . • 'V'.^- •! r V" '. • .1). LEIGHTON AND ASSOCIATES, INC 3900827-01 APPENDIX C Laboratory Testinq Procedures and Test Results Moisture and Densitv Tests: Moisture content and dry density determinations were perl-ormed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was determined from "undisturbed" or disturbed samples. Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during testing. After transfer of the sample to the shear box, and reloading the sample, pore pressures set up in the sample due to the transfer were allowed to dissipate for a period of approximately 1 hour prior to application of shearing force. The samples were tested under various normal loads, a motor-driven, strain-controlled, direct- shear testing apparatus at a strain rate of 0.005 inches per minute. After a travel of 0.300 inches of the direct shear machine, the motor was stopped and the sample was allowed to "relax" for approximately 15 minutes. The "relaxed" and "peak" shear values were recorded. It is anticipated that, in a majority of samples tested, the 15 minutes relaxing of the sample is sufficient to allow dissipation of pore pressures set up in the samples due to application of shearing force. The relaxed values are therefore judged to be a good estimation of effective strength parameters. The test results were plotted on the "Direct Shear Summary". Maximum Density Tests: The maximum dry density and optimum moisture content of typical materials were determined in accordance with ASTM D1557-78 (five layers) . The results of these tests are presented in the test data. Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index Test, U..B.C. Standard No. 29-2. Specimens are molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium is reached. The results of these tests are presented in the test data. Soluble Sulfates: The soluble sulfate contents of selected samples were determined by the California Materials Method No. 417. "R"-Value: The resistance "R"-value was determined by the California Materials Method No. 301 for base, subbase, and basement soils. Three samples were prepared and exudation pressure and "R"-value determined on each one. The graphically determined "R"-value at exudation pressure of 300 psi is reported. C-1 3600 3000- 2500 2000 a CJ CO UJ cr I-co a: S 1600 03 1000 500 So* OMCTH) iflorc Med brn clayey sano i i 1 So* OMCTH) 1 \ Type of Samp4«: •Reni oided to 90 i 1 ! Type of Samp4«: •Reni tiv9 Ccmpactio 1 i 1 • Un<aiturt«d Loading Rate: 0.005 in ! 1 1 • Un<aiturt«d Loading Rate: 0.005 in ! ; • 1 —i 1 1 1 1 1 j 1 1 1 j •1 i 1 i 1 1 1 1 I ' ' 1 —1 f 1 1 ' 1 ' —J—— L__j —1 — 1 ^ ! 1 1 1 ' 1 1 1 ^ T I 1 1 j —1 1 1 1 1 —i \ 1 • 1 1 1 500 Sample Location Symbol B3 3'-5' • 1CXX3 1500 2000 NORMAL STRESS, paf Average Moisture Contents Before After Friction Angie 2500 N/A N/A 27' Cohesion 350 psf 3000 Remarks DIRECT SHEAR TEST RESULTS Project No. 89008?7-m Project Naitf State Farm/C;irUh;^r| Date Jiilv 'onFlQure No. C-1 [T 1 3015 108f EXPANSION INDEX TEST RESULTS TEST i SAMPLE j INfTlAL i NO. : LOCATION j MOlSTb'RE (%)t COMPAcrrED j i , ' QRY j FINAL ; VOLUMETnIC I EXPANSION | EXPANSIVE DENSITY : MOISTURE j SWELL (%) j ,NDEX i POTENTIAL Bl ?(D I {3 iO-12 il.O 106.3 23.9 065 OD Mea i um SAMPLE MAXIMUM DENSITY TEST RESULTS SOIL DESCRIPTION i33 #(D j Medium brown, silty to clayey, fine to j (3 3'-5' 1 medium grained sand j MAXIMUM j OPTIMUM I DRY DENSITY I MOISTURE ' (PCF) i CONTENT (%) 111.0 15.5 TEST METHOD: U.B.C. Std. No. 29-2 and ASTM Test Method D1557-78 EXPANSION INDEX AND MAXIMUM DENSITY TEST RESULTS Project No. 8900827-01 Project Name State Farm/Carlsbad Date July 1990 Figure No. C-2' SOIL TYPE OR SAMPLE LOCATION SOIL DESCRIPTION LABORATORY R-VALUE B-9 # ® @ 1 Medium brown ?o olive-brown, clayey silt/ silty clay 18 TEST METHOD: Cal Trans Test No. 301 R-VALUE TEST RESULTS Project No. 8900827-01 Project Name statP F;^rm/r;irich^n Date July 1990 Figure No. C-3 SOIL TYPE OR SAMPLE LOCATION DILUTION READING PPM % SULFATES POTENTIAL DEGREE OF SULFATE ATTACK B-4 #(D(3 1 (silty sand 20 : 1 3600 TEST METHOD: Caltrans Test No. 417 0.36 Considerable SOLUBLE SULFATE TEST RESULTS Project No. 8900827-01 . Project Name State Farm/Carlsbad Dat8_i2iiJxJ990___Figure No. C-4 1-'; -.v.?;.-. ; ^ UIGHTON AND ASSOCIATES, INC 8900827-01 APPENDIX D General Earthwork and Grading Specification'; 1.0 General TntPnt fSrar'/dfni^lnH^'°"'.K'"' presented as general procedures and recommendations arJi2 lil earthwork to be utilized in conjunction with the approved olrt of f J r^ These general earthwork and grading specifications are a part ot the recommendations contained in the geotechnical reoort and sh;?!! be superseded by the recommendations in the geotechnical report in the 5a e cr.5?n^ performed by the consultant during the course of tZrlf^ ''""^^ "^"^ recommendations which could supersede these specifications or the recommendations of the geotechnical report It shall be the responsibility of the contractor to -read and understand these specifications as well as the geotechnical report and approved graSing 2-0 Earthwork Observation and Testinq shISl'dVpLin'IloH"^r^'ll °^ grading a qualified geotechnical consultant tes? na thp'^ f/iic °/ P^P^" observing earthwork procedures and ^pnfl^L,-^^? /°"f°'^"'^"" with the recommendations of the geotechnical report and these "rpecTfV^atio^sy^^U shan be the annf?SpH^iV^^ f the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance so schedule his personnel accordingly. No gradinq operations n?^.?L^'°:i?! °^ th'e geotecLical'coSsuMn;! Tho /-nn<-*.,/.4. u 11 1— .xMwn.cuyc ui me yeuuecnnica COI JJ^frgr^dlng' oJe^iatJon's""^^ '''' geotechnical consultant is aware ILfll!!^^''^ fu^! responsibility of the contractor to provide adeouate q?adino codP^ TH*^"^' '° accomplish the work in accordance with applt^abfe lonnlf^ J^M ^""^ ^5^"^^ ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant. If, in the opinion Sf ?hp consultant, unsatisfactory conditions, such as unsuitable oil noSr moisture condition, inadequate compaction, adverse weather etc Tri resulting in a quality of work less than recommended in the opinion oV the consultant, unsatisfactory conditions, such as unsuitable siil poor moisture condition inadequate compaction, adverse weather, ele ^a?e reooit .SH'JHP '^"'^ than recommended in the geotechnical fhS CLJ specifications, the consultant will be empowered to reject Irl that construction be stopped until the condUions Maximum dry density tests used to evaluate the degree of compaction should Sorfp^v^r^'".^'""''! accordance with the latest vers on oflhe Ame??cln Society for Testing and Materials test Method ASTM D1557. American Preparation of Arpa<; to be FillpH 3.1 Clearinq and Gnihhing: Sufficient brush, vegetation, roots and all other de eterious material should be removed or prop^rlTdisposed of n a method acceptable to the owner, design engineer gSSernino agencies, and the geotechnical consultant. ' governing D-l 8900827-01^ General Earthwork and Gradinq Specifications (Cont'd.) The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section, scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, 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 competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a 1 icensed land surveyor/civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material, and moisture- conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. D-2 8900827-01 General Earthwork and Grading Specifications (Cont'd.) 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting mltp°.?,?\" '"'terial does not occur, and such that the oversize material is completely surrounded by compacted or densified fill Oversize materials should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces in accordance with the attached detail. ' 4.3 IfliEori: If importing of fill material is required for gradinq the import material should meet the requirements of slctii^^U 1 Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import mateHals 5-0 Fill Placement and Compaction 5.1 miJJfis: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal Tave^s approximately 6 inches in compacted thickness. Each layer should be LT^^isr]\h^;;Vhrt^ ^^^'^^''^ °^ ^"-^'^ 5.2 Moisture Conditinninq: Fill soils should be watered, dried-back cJS;^n1'ne\ro°;ti:r' " "^""^^' ^ -i^tSr'e 5.3 Compaction of Fill: After each layer has been evenly spread, moisture- conditioned, and mixed, it should be uniformly compacted to nit less '"f^^T ^'^y ^^"^ity (unless otherwise specified) Compaction equipment should be adequately sized and be e ther specifically designed for soil compaction or of proven reliabi ity compaction ' ^'^^ specified • degree and uniformity of 5.4 Fill Slopes: Compacting of slopes should be accomplished in additional to normal compacting procedures, by backrollinq of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gam or by other methods producing satisfactory resu ts At the completion of grading, the relative Compaction of the fi 1 out to fhe slope face should be at least 90 percent. T:O tne 5.5 Compaction Testing: Field tests of the moisture content and degree consuTant^°" ll'^' ''V- ^e performed by the geotecSnfc coJ^M t^nJ'c H location and frequency of tests should be at the consultant s discretion based on field conditions encountered In general the tests should be taken at approximate intervals of 2 fee? n ^HJ-J"^ '''' r^/^*; ^"''^^ ^^'ds of compacted fill soils .SnMiHV^'T\°"/^°P^ ^ guideline approximately one Jest should be taken for each 5,000 square feet of slope face and/or each 10 feet of vertical height of the slope. D-3 8900827-01 General Earthwork and Grading Specifications (Cont'd.) 6.0 Subdrain Installation Subdrain systems, if recommended should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant, however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor/civil engineer for line and grade after installation. Sufficient time shall be allowed for the surveys, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation, and refilling of cut areas and/or remedial grading of cut slopes (i.e., stability fills or slope buttresses) may be recommended. 8.0 Quantitv Determination For purposes of determining quantities of materials excavated during grading and/or detennining the limits of overexcavation, a licensed land surveyor/civil engineer should be utilized. D-4 KEY AND BENCHING DETAILS FILL SLOPE PROJECT 1 TO 1 UNE Fnou TOE OP SLOPE TO COMPETENT MATERIAL EXISTINQ anOUNO SURFACE REWOVS UN3UITA3LE MATERIAL BENCH 2' MIN-j—-15' WIN. ! KEY I LOWEST I OEPTH BENCH (KEY) FILL-OVER-CUT SLOPE EXISTING QROUNO SURFACE 2' ' LOWEST ' WIN. BENCH CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL • PLACEMENT) EXISTING GROUNO SURFACE- REMOVE UNSUfTABLE MATEHUL CUT-OVER-FILL SLOPE CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) PROJECT 1 TO 1 UNE FROM TOE OF SLOPE TO COMPETENT MATERIAL REMOVE UNSUITABLE MATERIAL BENCH MIN r MJN.' LOWEST KEY DEFTH ^JNCH NOTE: Back drain may be recommended by the geotechnical consultant baaed on actual field conditions encountered. Bench dimension recommendatlona may alao be altered based on field conditions «ncountered. TRANSITION LOT DETAJLS CUT-FILL LOT EXISTING QROUND SURFACE VEREXCAVATE ANO RECOMPACT COMPETENT BEDROCK OR MATERIAL EVALUATED BY THE GEOTECHNICAL CONSULTANT CUT LOT •-r REMOVE ^UNSUITABLE EXISTINQ QROUND SURFACE .COMPETENT BEDROCK OR MATERIAL EVALUATED. BY THE QEOTECHNICAL CONSULTANT *NOTE; Deeper or laterally more extensive overexcavation and recompaction may be recommended by the geotechnical consultant baaed on actual field conditiont encountered and locationa of proposed improvements RETAINING WALL DRAINAGE DETAiL SOIL BACKFILL, COMPACTEO TO 90 PERCENT RELATIVE COMPACTION* RETAININQ WALL WALL WATERPROOFINQ PER ARCHITECT'S SPECIFICATIONS FILTER FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT)** 3M--1-W2' CLEAN QRAVEL* 4' (MJNJ DIAMETER PERFORATED PVC PIPE (SCHEDULE 40 OR EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN A3 DEPICTED MINIMUM 1 PERCENT GRADIENT TO SUITABLE OUTLET SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size X Passino 1" 100 3/4" 90-100 3/8' 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equfva]ent>7S 3' MIN. COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT •BASED ON ASTM 01557 **IF CALTRANS CLASS 2 PERMEABLE MATERIAL (SEE GRADATION TO LEFT) IS USED IN PLACE OF 3/4--1-1/2- QRAVEL. FILTER FABRIC MAY BE DELETED. CALTRANS CLASS 2 PERMEABLE MATERIAL SHOULD BE COMPACTED TO 80 PERCENT RELATIVE COMPACTION * NOT TO SCALE SIDE HILL STABILITY FILL DETAIL EXISTINQ QROUNO SURFACE. FINISHED SLOPE FACE PROJECT 1 TO 1 UNE FROM TOP OF SLOPE TO OUTSIDE EDGE OF KEY OVERBURDEN OR UNSUITABLE MATERIAL PAO OVEREXCAVATION OEPTH ANO RECOMPACTION MAYBE RECOMMENDED BY THE QEOTECHNICAL CONSULTANT BASED ON ACTUAL FIELD CONDITIONS ENCOUNTERED. ;OMPETENT BEOROCK OR MATERIAL A3 EVALUATED BY THE QEOTECHNICAL CONSULTANT- NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions KEY WIDTH AS NOTED OM QRADINQ PLANS IS' MIN. 6' MIN OVERLA 3/4'-1-1/2* CLEAN GRAVEL (3ft.3/(t. UIN.) *' 0 NON-PERFOHATED PIPE^ FILTER FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT)* SEE T-CONNECTION OETAIL a' MIN. COVER 4- fi PERFORATED PIPE 4* MIN. BEDDING SUBDRAIN TRENCH DETAIL *IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 3/4'-1-l/2' QRAVEL, FILTER FABRIC MAY BE DELETED MOTES: SPECIFICATIONS FOR CALTRANS CLASS 2 PE.RMEABLE MATERIAL U.S. Standard Sieve Size S Passinq 1" 100 3/4" 90-100 3/8" 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equivalent>75 • •• end subdrain «v'h-"etl!lJL'ir K^'lt""' ••• ''•'••chnlcal r.port/pl.n.. Actual dimensions of buttr •«y ba clunoad by tha saotaennical conauitant baaad on flaid conditions. P'"* Partoratlons down aa dapictad Al locatioaa racommandad by, tha gaotachnical. conauitant. nonparforatad plpa should ba Inatalla'd ?i?ci"JJ'!.J« ^^"H""?'". Acrylonltrlla But.dlana Styran. (A.8.S.), Polyvinyl Chlorlda Claaa 20Q,80R 21 should ba uaad for maxifflum fill daptha of 100 faat. CANYON SUBDRAIN DETAILS EXISTINQ BENCHINO REMOVE UNSUITABLE MATERIAL ^ "T/l It SUBORAIN TRENCH SEE BELOW SUBDRAIN TRENCH DETAILS a' MIN. OVERLAP FILTER FABRIC ENVELOPE ^(MIRAFI 140N OR APPROVED EQUIVALENT)* a' MIN. OVERLAP 3M'-1-1/2' CLEAN QRAVEL (9ft3/ft. MINJ 8' MIN. PERFORATED PIPE 3/4--1-1/2- CLEAN QRAVEL (9ft,3/ft- MINJ *IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE- OF 3/4'-1-1/2- GRAVEL. FU.TER FABRIC MAY BE DELETED DETAIL OF CANYON SUBDRAIN TERMINAL DESIQN FINISH QRAOE SUBORAIN TRENCH SEE ABOVE NONPERFORATED 8* 0 MIN. PERFORATED 8- j0 MIN. PIPE SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size I Passinq 1" 100 3/4" 90-100 3/8" 40-100 No. 4 25-40 No. 8 18-33 No. 30 5-15 No. 50 0-7 No. 200 0-3 Sand Equiva1ent>75 Subdrain ahould ba constructad only on compatant matariai aa avaluatad by tha gaotachnical conauitant. SUBORAIN INSTALLATION Subdrain plpa ahould ba Inatallad with parforatlona down aa daplctad. At locationa racommandad by tha gaotachnical conauitant. nonparforatad pipa should ba Inatallad. SUBORAIN ^YPE-Subdraln typa ahould ba Aerylonltrila Butadiana Styrana (A.B.8.). Polyvinyl Chlorlda (PVC) or approvad aquivalant. Claaa 128, SOR 32.6 shouid ba uaad for maximum fin daptha of 38 faat. Claaa 200, SOR 21 ahould ba uaad for maximum nil daptha of 100 faat ROCK DISPOSAL DETAiL FINISH GRADE SLOPE FACE •OVERSIZE WINDROW QRANULAR SOIL (8.£.> 30} TO BC DENSIFIED IN PLACE BY FLOOOINQ DETAIL TYPICAL PROFILE ALONG WINDROW * 1) Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of.finish grade (or 2 feet beiow depth of lowest utility whichever is greater), and 15 feet horizontally of slope faces. 2) Rocks with maximum dimensions greater than 4 feet should not be utilized In fills. 3) Rock placement, flooding of granular soli, and fill placement should be observed by the} Qeotechnical consultant. ' 4) Maximum size and spacing of windrows should be in accordance with the above details] Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). 5) Rock should be placed in excavated trenches. Granular soil (S.E. greaterthan or equalj to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. UIGHTON AMD ASSOOATES, WC REQUIREMENTS FOR PAVING PROJECT: STATE FARM INSURANCE SERVICE CENTER Encxnitas, California (ENC) LOCATION: Ro^r^'^rn'''^''''^^ °^ intersection of Palomar Airoort Road and Palomar Oaks Way, Carlsbad, California DATE: ""^^ ^950 BACKGROUND INFORMATION: 1. 2. 3. maintenance criteria: «commenaations should be based on the foliowing design and Paving design life is 15 years Expected truck traffic is one 45.000 pound tandem axle tmck per dav ^rrr; rtrrof^^^^ r « as needed together extend the life of thrpav^HeSon p^t' ^^^^ T'''^ ''P'^' ^" ^^^^'^^ ^ ^o until after the tenth year. ^ expectancy. This should not be required EVALUATION AND RECOMMENDATIONS: fctck'fJe? ^"^^^'^^ ^° °- «^ following categories. free of detrim^ntai amint of Xstic 1^^^^^^^^^ T'l""^ sand-gravels and soils by moisture or frost They inlSa dLrln^^ T '"'^''^^ unaffected that are well gradS ^"'^ 9^=^^«'^- Particulariy those Califomia Bearing Ratio: 10+, R Value: 62+. California Bearing Ration: 5-9, R Value: 50-61 California Bearing Ratio: 2-4. R Value:-a&40- less than 25 2. Sub-base preparation required- -J^ Compaction to 2Q_ % ..ASTN HI'^-^V-Tfl . (Give test required) Scarify existing base to depth of 6". aerate, and recompact to 9^ Remove upper portion and replace with select material. SEE REVERSE SIDE 1 OF 2 3. Which of the following construction methods are common in your area and which in your opinion will' support the loads normally imposed upon parking lots and driveways? X Combination asphalt concrete and granular base course Full depth asphalt concrete Other (Specify) 4. What is the most common base course material used? Crushed stone Crushed gravel x Other (Specify) SEE BELOW Uncrushed gravel (Rough texture angular shaped) 5. Is an intrusion barrier (2* sand or stone screening) needed? Yes X No 6. What mix design is commonly used in your area? Mix designs per the Department of Public Works Green Book 7. Are parking lot underdrains acceptable? Yes PAVING SPECIRCATIONS Please specify the construction method most commonly used in your area, which in your opinion, will support the loads normally imposed on paricing lots and driveways. Break this specification down into base course material and wearing surfaces, both in quality, dimension and design mix. SEAL Signed ^ ^ Stan Helenschmidt, Chief Engineer/Manager Please include a completed copy of this form in the soil investigation report. GE 2064 4. Caltrans Class II Aggregate Base Aggregate should be compacted to a minimum of 95 percent relative compaction and conform to the following gradation requirements. Sieve Size 1" 3/4" No. 4 No. 30 No. 200 ^ '• C C r . ^^^Sv Percent Passing 100 87 - 100 30 - 60 5-35 0-12 2 OF 2 PAVEMENT SECTION DESIGN PROJECT DESCRIPTION : STATE FARM-CARLSBAD NO 8900827-01 PARKIN G AREA/DRIVEWAY DESIGN R-VALUE QF SUBGRADE ( R ) =» IS.O DESIGN TRAFFIC INDEX ( TI ) = 4.0 GRAVEL EQUIVALENT ( G.E. ) = 0.00-32 * 4.0 * ( 100. - 18.0 ) -t- .OC = 1.05 FEET RECOMMENDED PAVEMENT SECTION IS : 3.0 INCHES ASPHALTIC CONCRETE OVER 6.0 INCHES CALTRAN CLASS II AGGREGATE BASE