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Home My WebLink AboutUpdate to Geotechnical Investigation Proposed Carlsbad Car WashConstruction Testing & Engineering, Inc. Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering J Surveying February 18, 2020 Toyota Carlsbad RECORD COPY 5Xll--}f".'a ' Initial CTE Job No. 10-13214T Attention: Ms. Peggy Keleher 5424 Paseo Del Norte Carlsbad, California 92008 Telephone: (858) 679-1185 Via Email: pkelcher@toyotacarlsbad.com Subject: Reference: Ms. Keleher: Update to Geotechnical Investigation Proposed Carlsbad Car Wash 6010 A venida Encinas Carlsbad, California Geotechnical Investigation, Proposed Carlsbad Toyota Car Wash, 6010 A venida Encinas, Carlsbad, California, CTE Job No.: 10-13214T, dated September 16, 2016 RECEIVED MAR 2 0 2020 LAND DEVELOPMENT ENGINEERING As requested, Construction Testing & Engineering, Inc. (CTE) provides the following update to the Report of Geotechnical Investigation referenced above. The purpose of the update is to provide seismic parameters in accordance with current building code requirements based on the American Society of Civil Engineers (ASCE7-16) and the California Building Code (CBC) 2019. Based on nearby sea cliff exposures, regional geologic map relationships, previous soil borings and known subsurface conditions in the site vicinity, we anticipate dense to very dense Eocene Santiago Formation at a depth of less than 40 feet beneath the site. Therefore, Site Class C is considered to be appropriate for seismic evaluation. SEISMIC GROUND MOTION VALUES The seismic ground motion values listed in the table below were derived in accordance with the ASCE 7-16 Standard. This was accomplished by establishing the Site Class based on the soil properties at the site. Site coefficients and parameters were calculated using the SEAOC- OSHPD U.S. Seismic Design Maps application. These values are intended for the design of structures to resist the effects of earthquake ground motions based on the site coordinates of 33.1204° latitude and -117.3240° longitude, as underlain by soils corresponding to site Class C. 1441 Montiel Road, Suite 115 I Escondido, CA 92026 I Ph (760) 746-4955 I Fax (760) 746-9806 J www.cte-inc.net Update to Geotechnical Investigation Proposed Carlsbad Car Wash 6010 A venida Encinas, Carlsbad, California February 18, 2020 TABLE 1 SEISMIC GROUND MOTION VALUES 2019 CBC AND ASCE 7-16 PARAMETER VALUE Site Class C Mapped Spectral Response 1.119 Acceleration Parameter, Ss Mapped Spectral Response 0.402 Acceleration Parameter, S1 Seismic Coefficient, F. 1.2 Seismic Coefficient, Fv 1.5 MCE Spectral Response 1.343 Acceleration Parameter, SMs MCE Spectral Response 0.603 Acceleration Parameter, SM1 Design Spectral Response 0.895 Acceleration, Parameter Sos Design Spectral Response 0.402 Acceleration, Parameter S0 1 Peak Ground Acceleration PGAM 0.596 LIMITATIONS Page 2 CTE Job No. 10-13214T 2019 CBC/ASCE 7-16 REFERENCE ASCE 16, Chapter 20 Figure 1613.2. l (I) Figure 1613.2.1 (2) Table 1613.2.3 (I) Table 161 3.2.3 (2) Section I 613 .2.3 Section 1613.2.3 Section I 613 .2.5(1) Section 1613.2.5 (2) ASCE 16, Section 11.8.3 The update parameters herein are based on our review of the currently available design information, previous geotechnical investigations, and recent site observations. The anticipated conditions should be verified in the field during construction. Variations may exist and conditions not observed or described in the geotechnical reports may be encountered during construction. If conditions different from those described in the project geotechnical reports are encountered, this office should be notified and additional recommendations, if required, will be provided. The recommendations have been developed in order to reduce the potential adverse effects of soil expansion and settlement. However, even with the design and construction precautions, some post-construction movement and associated distress may occur. \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\l0-13214T\Ltr_Update (ASCE 7-16).doc Update to Geotecbnical Investigation Proposed Carlsbad Car Wash 6010 A venida Encinas, Carlsbad, California February 18, 2020 Page 3 CTE Job No. 10-13214T CTE appreciates this opportunity to be of service on this project. If you have any questions regarding this report, please do not hesitate to contact the undersigned. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. Dan T. Math, GE #2665 Principal Engineer AIB/DTM/JFL:ack Aaron J. Bee by, CEG #2603 Senior Engineering Geologist \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\l0-13214T\Ltr_Update (ASCE 7-16).doc Construction Testing & Engineering, Inc. Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying GEOTECHNICAL INVESTIGATION PROPOSED CARLSBAD TOYOTA CAR WASH 6010 AVENIDA ENCINAS CARLSBAD, CALIFORNIA CUP 2017-0009 GR 2019-0011 DWG 517-24 Prepared for: TOYOTA CARLSBAD MS. PEGGY KELCHER 5424 P ASEO DEL NORTE CARLSBAD, CALIFORNIA 92008 Prepared by: CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CALIFORNIA 92026 CTE JOB NO.: 10-13214T June 4, 2019 1441 Montiel Road, Suite 115 I Escondido, CA92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net -.. .. TABLE OF CONTENTS .. 1.0 INTRODUCTION AND SCOPE OF SERVICES ................................................................... I .. 1.1 Introduction ................................................................................................................... I 1.2 Scope of Services .......................................................................................................... I .. 2.0 SITE DESCRIPTION ............................................................................................................... 2 ... 3.0 FIELD INVESTIGATION AND LABORATORY TESTING ................................................ 2 -3. I Field Investigation ......................................................................................................... 2 3.2 Laboratory Testing ........................................................................................................ 3 ... 4.0 GEOLOGY ............................................................................................................................... 3 -4.1 General Setting .............................................................................................................. 3 4.2 Geologic Conditions ..................................................................................................... 3 4.2.1 Quaternary Undocumented Fill (unmapped) ................................................. 4 .. 4.2.2 Quaternary Old Paralic Deposits (Qop) ......................................................... 4 4.3 Groundwater Conditions ............................................................................................... 4 • 4.4 Geologic Hazards .......................................................................................................... 4 .. 4.4.1 Surface Fault Rupture .................................................................................... 5 4.4.2 Local and Regional Faulting .......................................................................... 5 4.4.3 Liquefaction and Seismic Settlement Evaluation .......................................... 6 4.4.4 Tsunamis and Seiche Evaluation ................................................................... 6 .. 4.4.5 Landsliding ..................................................................................................... 7 4.4.6 Compressible and Expansive Soils ................................................................ 7 -4.4.7 Corrosive Soils ............................................................................................... 7 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................... 9 5.1 General .......................................................................................................................... 9 .. 5.2 Site Preparation ............................................................................................................. 9 5.3 Site Excavation ........................................................................................................... I 0 -5.4 Fill Placement and Compaction .................................................................................. 11 5.5 Fill Materials ............................................................................................................... 11 • 5.6 Temporary Construction Slopes .................................................................................. 12 ... 5. 7 Foundations and Slab Recommendations ................................................................... 13 5.7.1 Foundations .................................................................................................. 13 .. 5.7.2 Foundation Settlement ................................................................................. 14 -5.7.3 Foundation Setback ...................................................................................... 14 5.7.4 Interior Concrete Slabs ................................................................................. 15 5.8 Seismic Design Criteria .............................................................................................. 16 5.9 Lateral Resistance and Earth Pressures ....................................................................... 17 .. 5.10 Exterior Flatwork ...................................................................................................... 19 5.11 Pavements ................................................................................................................. 19 -5.12 Drainage .................................................................................................................... 20 ... 5.13 Slopes ........................................................................................................................ 21 5.14 Plan Review .............................................................................................................. 22 -5 .15 Construction Observation ......................................................................................... 22 -6.0 LIMITATIONS OF INVESTIGATION ................................................................................. 23 - - -.. -• .. • .. .. .. .. .. • .. .. • .. .. .. .. .. -.. -.. - - - -- ---.. FIGURES FIGURE 1 FIGURE2 FIGURE3 FIGURE4 APPENDICES APPENDIX A APPENDIXB APPENDIXC APPENDIXD TABLE OF CONTENTS SITE LOCATION MAP GEOLOGIC/ EXPLORATION LOCATION MAP REGIONAL FAULT AND SEISMICITY MAP CONCEPTUAL RETAINING WALL DRAINAGE REFERENCES FIELD EXPLORATION METHODS LOGS LABORATORY METHODS AND RESULTS STANDARD GRADING SPECIFICATIONS - - .. • .. .. .. .. -.. -.. -.. - ---... --- ------- ---- Geotechnical Investigation Page I Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 CTE Job No.: 10-13214T 1.0 INTRODUCTION AND SCOPE OF SERVICES 1.1 Introduction This report presents the results of the geotechnical investigation, performed by Construction Testing and Engineering, Inc. (CTE), and provides preliminary conclusions and recommendations for the proposed improvements at the subject site located in Carlsbad, California. This investigation was performed in general accordance with the terms ofCTE proposal El 6111, dated June 15, 2016 . CTE understands that the proposed site improvements are to consist of a car wash structure, paved parking and flatwork, shade structures, associated utilities, landscaping, and ancillary improvements. Preliminary recommendations for excavations, fill placement, and foundation design for the proposed improvements are presented in this report. Reviewed references are provided in Appendix A. 1.2 Scope of Services The scope of services provided included: • Review of readily available geologic and geotechnical reports. • Coordination of utility mark-out and location. • Excavation of exploratory borings and soil sampling utilizing a truck-mounted drill rig. • Laboratory testing of selected soil samples. • Description of site geology and evaluation of potential geologic hazards. • Engineering and geologic analysis. • Preparation of this geotechnical investigation report. \\ESC _ SERVER\Projects\l 0-13000 to 10-13999 Projects\! 0-132 l 4T\Rpt_ Geotechnical.doc .. .. -.. -.. .. • .. .. .. -.. .. .. -,. .. ... ... ... ... - ... .. - "" -... -.. Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 2.0 SITE DESCRIPTION Page2 CTE Job No.: I0-13214T The project site is located at 6010 Avenida Encinas in Carlsbad, California (Figure I). The site is bounded by A venida Encinas to the southwest, Carlsbad Parts and Service Center to the southeast, and National University to the north. The project area generally descends to the southwest with approximate elevations ranging from approximately 60 feet ms! (above mean sea level) in the northeastern portion of the site to approximately 53 feet ms! in the southwestern portion of the site. 3.0 FIELD INVESTIGATION AND LABORATORY TESTING 3.1 Field Investigation CTE performed the field investigation on August 12, 2016. The field work consisted of a site reconnaissance and excavation of three exploratory borings. The maximum explored depth was approximately 20.0 feet below ground surface (bgs) in Boring B-1. Bulk samples were collected from the cuttings, and relatively undisturbed samples were collected by driving Standard Penetration Test (SPT) and Modified California (CAL) samplers. The Borings were advanced with a CME-75 truck-mounted drill rig equipped with eight-inch-diameter, hollow-stem augers. The approximate locations of the exploratory borings are presented on Figure 2 . The soils were logged in the field by a CTE Engineering Geologist and were visually classified in general accordance with the Unified Soil Classification System. The field descriptions have been modified, where appropriate, to reflect laboratory test results. Boring logs, including descriptions of the soils encountered, are included in Appendix B. The approximate locations of the borings are presented on Figure 2. \\ESC _SERVER\Projects\10-13000 to I 0-13999 Projects\) 0-132141'\Rpt_ Geotechnical.doc .. • -.. .. ... .. .. • .. .. .. • .. .. .. .. .. .. ... - -- --... ---- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 3.2 Laboratory Testing Page 3 CTE Job No.: 10-13214T Laboratory tests were conducted on selected soil samples for classification purposes, and to evaluate physical properties and engineering characteristics. Laboratory tests included: Gradation, Expansion Index (El), Resistance "R"-Value, Consolidation, and Chemical Characteristics. Test descriptions and laboratory test results for the selected soils are included in Appendix C . 4.0GEOLOGY 4.1 General Setting Carlsbad is located within the Peninsular Ranges physiographic province that is characterized by northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending regional faults. The greater San Diego Region can be further subdivided into the coastal plain area, a central mountain-valley area and the eastern mountain valley area. The project site is located within the coastal plain area that is characterized by Cretaceous, Tertiary, and Quaternary sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous crystalline rocks. 4.2 Geologic Conditions Based on the regional geologic map prepared by Kennedy and Tan (2005), the near surface geologic unit underlying the site consists of Quaternary Old Paralic Deposits, Unit 6-7. Based on the site explorations, Undocumented Fill was observed overlying the Quaternary Old Paralic Deposits. Descriptions of the geologic and soil units encountered are presented below. \\ESC _ SERVER\Projects\10-13000 to 10-13999 Projects\ 10-132141'\Rpt_ Geotechnical.doc .. .. .. .. .. .. .. - .. .. .. .. .. .. .. .. - - - - -.. ------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 4.2.1 Quaternary Undocumented Fill (unmapped) Page4 CTE Job No.: 10-13214T Where observed, the Quaternary Undocumented Fill generally consists ofloose to medium dense or stiff, brown, fine grained silty to clayey sand and sandy clay. This unit was found to extend to a depth of approximately 11 feet bgs in Boring B-1 during the investigation. The Undocumented Fill is anticipated to increase in thickness to the west and localized deeper fills may be encountered during grading . 4.2.2 Quaternary Old Paralic Deposits (Qop) Quaternary Old Paralic Deposits were found to be the underlying geologic unit at the site . Where observed, these materials generally consist of medium dense, reddish brown silty to clayey and poorly graded fine grained sand . 4.3 Groundwater Conditions Groundwater was not encountered in the borings that were advanced to a maximum explored depth of approximately 20 feet bgs. While groundwater conditions may vary, especially following periods of sustained precipitation or irrigation, it is not anticipated to affect the proposed construction activities or the completed improvements, if proper site drainage is designed, installed, and maintained as per the recommendations of the project civil engineer ofrecord. 4.4 Geologic Hazards Geologic hazards that were considered to have potential impacts to site development were evaluated based on field observations, literature review, and laboratory test results. It appears that the geologic hazards at the site are primarily limited to those caused by shaking from earthquake-generated \\ESC _ SERVER\Projects\10-13000 to I 0-13999 Projects\l0-l 32 l 4T\Rpt_ Geotechnical.doc ... -... .. ... ... .. .. --.. .. .. .. .. --.. .. ... .. ... .. ... ----... .. ------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 5 CTE Job No.: 10-13214T ground motions. Tbe following paragraphs discuss the geologic hazards considered and their potential risk to the site . 4.4.1 Surface Fault Rupture Based on the site reconnaissance and review of referenced literature, the site is not within a State of California-designated Alquist-Priolo Earthquake Fault Studies Zone or Local Special Studies Zone and no known active fault traces underlie, or project toward, the site . According to the California Division of Mines and Geology, a fault is active if it displays evidence of activity in the last 11,000 years (Hart and Bryant, revised 2007). Therefore, the potential for surface rupture from displacement or fault movement beneath the proposed improvements is considered to be low . 4.4.2 Local and Regional Faulting Tbe California Geological Survey (CGS) and the United States Geological Survey (USGS) broadly group faults as "Class A" or "Class B" (Cao, 2003; Frankel et al., 2002). Class A faults are generally identified based upon relatively well-defined paleoseismic activity, and a fault-slip rate of more than 5 millimeters per year (mm/yr). In contrast, Class B faults have comparatively less defined paleoseismic activity and are considered to have a fault-slip rate less than 5 mm/yr. The nearest known Class B fault is the Rose Canyon Fault, which is approximately 7 .0 kilometers west of the site (Blake, T.F., 2000). Tbe nearest known Class A fault is the Temecula segment of the Elsinore Fault, which is located approximately 40. 7 kilometers east of the site. \\ESC _ SERVER\Projects\10-13000 to 10-13999 Projects\l0-132 I 4T\Rpt_ Geotechnical.doc -.. -.. - -... .. .. .. .. .. .. .. .. .., .. -.. - --.. - .. --------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page6 CTE Job No.: 10-13214T The site could be subjected to significant shaking in the event of a major earthquake on any of the faults noted above or other faults in the southern California or northern Baja California area . 4.4.3 Liquefaction and Seismic Settlement Evaluation Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths during earthquake-induced shaking and behave like a liquid. This is due to loss of point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction potential varies with water level, soil type, material gradation, relative density, and probable intensity and duration of ground shaking. Seismic settlement can occur with or without liquefaction; it results from densification ofloose soils . The site is underlain at shallow depths by medium dense to dense Old Paralic Deposits. In addition, loose surficial soils within proposed improvement areas are to be overexcavated and compacted as engineered fill. Therefore, the potential for liquefaction or significant seismic settlement at the site is considered to be low. 4.4.4 Tsunamis and Seiche Evaluation According to State of California Emergency Management Agency mapping, the site is not located within a tsunami inundation zone based on distance from the coastline and elevation above sea level. Damage resulting from oscillatory waves (seiches) is considered unlikely due to the absence of nearby confined bodies of water. \\ESC _ SER VER\Projects\10-13000 to l 0-13999 Projects\1 0-I 32 l 4T\Rpt_ Geotechnical.doc .. .. .. .. -... ... -- - - - - - - - - - -.. ---- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 4.4.5 Landsliding Page7 CTE Job No.: 10-13214T According to mapping by Tan (1995), the site is considered only"Marginally Susceptible" to landsliding and no landslides are mapped in the site area. In addition, landslides or similar associated features were not observed during the recent field exploration. Therefore, landsliding is not considered to be a significant geologic hazard at the site. 4.4.6 Compressible and Expansive Soils Undocumented Fill Soils are considered to be potentially compressible. Therefore, these soils should be overexcavated to the depth of suitable material, processed, and placed as a properly compacted fill, as recommended herein. Based on field data and site observations the underlying Old Paralic Deposits are not considered to be subject to significant compressibility under the proposed loads. Based on observation and laboratory test results, soils at the site are generally anticipated to exhibit Very Low to Low expansion potential (Expansion Index of 50 or less). Therefore, expansive soils are not anticipated to present significant adverse impacts to site development. Additional evaluation of near-surface soils should be performed based on field observations during grading activities. 4.4.7 Corrosive Soils Chemical testing was performed to evaluate the potential effects that site soils may have on concrete foundations and various types of buried metallic utilities. Soil environments \\ESC_SERVER\Projects\10-13000 to l0-13999 Projects\10-132141\Rpt_ Geotechnical.doc .. .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. - - - - - --- - -.. Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 8 CTE Job No.: 10-13214T detrimental to concrete generally have elevated levels of soluble sulfates and/or pH levels less than 5.5. According to American Concrete Institute (ACI) Table 318 4.3.1, specific guidelines have been provided for concrete where concentrations of soluble sulfate (SO4) in soil exceed 0.1 percent by weight. These guidelines include low water: cement ratios, increased compressive strength, and specific cement type requirements . Based on the results of the Sulfate and pH testing performed, onsite soils are anticipated to generally have a negligible corrosion potential to Portland cement concrete improvements . A minimum resistivity value less than approximately 5,000 ohm-cm, and/or soluble chloride levels in excess of 200 ppm generally indicate a corrosive environment to buried metallic utilities and untreated conduits. Based on the obtained resistivity value of 1,890 ohm-cm, onsite soils are anticipated to have a severe corrosion potential for buried uncoated/unprotected metallic conduits. Based on these results, at a minimum, the use of buried plastic piping or conduits would appear logical and beneficial, where feasible. The results of the chemical tests performed are presented in the attached Appendix C. However, CTE does not practice corrosion engineering. Therefore, a corrosion engineer or other qualified consultant could be contacted if site specific corrosivity issues are of concern. \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_ Geotechnical.doc .. .. .. .. .. - ... .. .. .. .. .. .. .. .. .. ---- - .. .. --- "' -... Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 Page9 CTE Job No.: 10-13214T 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General CTE concludes that the proposed improvements at the site are feasible from a geotechnical standpoint, provided the recommendations in this report are incorporated into the design and construction of the project. Recommendations for the proposed earthwork and improvements are included in the following sections and Appendix D. However, recommendations in the text of this report supersede those presented in Appendix D should variations exist. These recommendations should either be evaluated as appropriate and/or updated during or following rough grading at the site . 5.2 Site Preparation Prior to grading, the site should be cleared of any existing building materials or improvements that are not to remain. Objectionable materials, such as construction debris and vegetation, not suitable for structural backfill should be properly disposed of offsite. In the area of the proposed structure existing soils should be excavated to a minimum depth of three feet below the bottom of proposed foundations, or to the depth of suitable material, whichever depth is greatest. Localized areas of loose and potentially compressible material could require overexcavation to deeper elevations, based on conditions encountered during grading. Overexcavations should extend at least five feet laterally beyond the limits of the proposed building, where feasible . \\ESC _ SERVER\Projects\l 0-13000 to 10-t 3999 Projects\! 0-132141\Rpt_ Geotechnical.doc .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. - ----- .. .. - - - -- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 10 CTE Job No.: 10-13214T Excavations in proposed pavement, flatwork, or other improvement areas should be conducted to a minimum depth of two feet below proposed or existing grades, or to suitable underlying materials, whichever depth is shallowest. Existing below-ground utilities should be redirected around the proposed structure where feasible . Existing utilities at an elevation to extend through the proposed footings should generally be sleeved and caulked to minimize the potential for moisture migration below the building slabs. Abandoned pipes exposed by grading should be securely capped to prevent moisture from migrating beneath foundation and slab soils or should be filled with minimum two-sack cement/sand slurry . A CTE geotechnical representative should observe the exposed ground surface at the overexcavation bottoms to evaluate the exposed conditions. The exposed sub grades to receive fill should be proof- rolled or scarified a minimum of nine inches, moisture conditioned to a minimum of three percent above optimum, and properly compacted prior to additional fill placement. 5.3 Site Excavation Generally, excavation of site materials may be accomplished with heavy-duty construction equipment under normal conditions. However, the Old Paralic Deposits may become increasingly difficult to excavate with depth. Materials also appear to be, at least locally, very granular and could be very sensitive to caving and/or erosion. \\ESC _ SER VER\Projects\10-13000 to I 0-13999 Projects\l 0-132141'\Rpt _ Geotechnical.doc - • .. .. .. -.. .. .. - .. .. .. --.. - - - - .. .. -.. ----- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 5.4 Fill Placement and Compaction Page 11 CTE Job No.: 10-13214T Granular fill and backfill should be compacted to a minimum relative compaction of90 percent at a moisture content of at least three percent above optimum, as evaluated by ASTM D 1557. The optimum lift thickness for fill soil will depend on the type of compaction equipment used . Generally, backfill should be placed in uniform, horizontal lifts not exceeding eight inches in loose thickness. Fill placement and compaction should be conducted in conformance with local ordinances . 5.5 Fill Materials Properly moisture-conditioned very low to low expansion potential soils derived from the on-site excavations are considered suitable for reuse on the site as compacted fill. If used, these materials should be screened of organics and materials generally greater than three inches in maximum dimension. Irreducible materials greater than three inches in maximum dimension should generally not be used in shallow fills (within three feet of proposed grades). In utility trenches, adequate bedding should surround pipes. Imported fill beneath structures, flatwork, and pavements should have an Expansion Index of 20 or less (ASTM D 4829). Imported fill soils for use in structural or slope areas should be evaluated by the geotechnical engineer before being imported to the site. Retaining wall backfill located within a 45-degree wedge extending up from the heel of the wall should consist of soil having an Expansion Index of 20 or less (ASTM D 4829) with less than 30 \\ESC _ SERVER\Projects\l 0-13000 to I 0-13999 Projects\10-132 l 4T\Rpt_ Geotechnical.doc Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 A venida Encinas, Carlsbad, California September 16, 2016 Page 12 CTE Job No.: 10-13214T percent passing the No. 200 sieve. The upper 12 to 18 inches of wall backfill could consist oflower permeability soils, in order to reduce surface water infiltration behind walls. The project structural engineer and/or architect should detail proper wall backdrains, including gravel drain zones, fills, filter fabric, and perforated drain pipes. However, a conceptual wall backdrain detail, which may not be suitable for use at the site, is provided as Figure 4. 5.6 Temporary Construction Slopes The following recommended slopes should be relatively stable against deep-seated failure, but may experience localized sloughing. On-site soils are considered Type B and Type C soils with recommended slope ratios as set forth in Table 5.6. However, due to the at least locally granular and erodible nature of the onsite soils, maximum 1.5: 1 temporary slopes are anticipated to be more reliable, and vertical excavations may not remain standing, even at shallow or minor heights. TABLE 5.6 RECOMMENDED TEMPORARY SLOPE RATIOS SOIL TYPE SLOPE RATIO MAXIMUM HEIGHT (Horizontal: vertical) B (Old Paralic Deposits) 1:1 (OR FLATTER) 10 Feet C (Undocumented Fill) 1.5:1 (OR FLATTER) 10 Feet \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_Geotechnical.doc .. .. • • .. .. .. .. .. ... .. .. -.. -.. - - - - - -... -------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 13 CTE Job No.: 10-13214T Actual field conditions and soil type designations must be verified by a "competent person" while excavations exist, according to Cal-OSHA regulations. In addition, the above sloping recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic, equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all unshored slopes . 5.7 Foundations and Slab Recommendations The following recommendations are for preliminary design purposes only. These recommendations should be reviewed after completion of earthwork to document that conditions exposed are as anticipated, and that the recommended structure design parameters are appropriate. 5.7.1 Foundations Following the preparatory grading recommended herein, continuous and isolated spread footings or deepened pier footings are anticipated to be suitable for use at this site. It is anticipated that building footings will be founded entirely in properly compacted fill with low to very low expansion potential. Foundation dimensions and reinforcement should be based on an allowable bearing value of 2,500 pounds per square foot for footings founded entirely upon properly placed compacted fill materials embedded a minimum of 24 inches below the lowest adjacent subgrade elevation. If utilized, continuous footings should be at least 15 inches wide; isolated footings \IESC _SERVER\Projects\10-13000 to 10-13999 Projects\10-13214T\Rpt_ Geotechnical.doc -... .. • -.. .. .. • .. .. -.. -.. -... - - - ---------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 14 CTE Job No.: 10-13214T should be at least 24 inches in least dimension. The above bearing values may be increased by one third for short duration loading which includes the effects of wind or seismic forces . Minimum reinforcement for continuous footings should consist of four No. 5 reinforcing bars; two placed near the top and two placed near the bottom or as per the project structural engineer. The structural engineer should design isolated footing reinforcement. Footing excavations should generally be maintained above optimum moisture content until concrete placement. 5. 7 .2 Foundation Settlement The maximum total settlement is expected to be on the order of one inch and the maximum differential settlement is expected to be on the order of 1/2 inch over a distance of approximately 40 feet. Due to the absence of a shallow groundwater table and the generally dense nature of underlying materials, dynamic settlement is not expected to adversely affect the proposed improvements. 5.7.3 Foundation Setback Footings for structures should be designed such that the horizontal distance from the face of adjacent slopes to the outer edge of the footing is at least 10 feet. In addition, footings should bear beneath a 1: 1 plane extended up from the nearest bottom edge of adjacent trenches and/or excavations. Deepening of affected footings may be a suitable means of attaining the prescribed setbacks. \IESC _ SERVER\Projectsll 0-13000 to 10-13999 Projects II 0-l 3214T\Rpt_ Geotechnical.doc --- • • - -.. .. • .. ... -.. - -... - - - - ---------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 5.7.4 Interior Concrete Slabs Page 15 CTE Job No.: 10-13214T Lightly loaded concrete slabs should be a minimum of 5.0 inches in thickness. Minimum slab reinforcement should consist of#4 reinforcing bars placed on maximum 18-inch centers, each way, at above mid-slab height, but with proper concrete cover. Subgrade materials should generally be maintained at above optimum moisture content until slab underlayment and concrete are placed . Slabs subjected to heavier loads may require thicker slab sections and/or increased reinforcement. A 120-pci subgrade modulus is considered suitable for elastic design of minimally embedded improvements such as slabs-on-grade. In moisture-sensitive floor areas, a suitable vapor retarder of at least 15-mil thickness (with all laps or penetrations sealed or taped) overlying a four-inch layer of consolidated crushed aggregate or gravel ( with SE of30 or more) should be installed, as per the 2013 CBC/Green Building Code. An optional maximum two-inch layer of similar material may be placed above the vapor retarder to help protect the membrane during steel and concrete placement. This recommended protection is generally considered typical in the industry. If proposed floor areas or coverings are considered especially sensitive to moisture emissions, additional recommendations from a specialty consultant could be obtained. CTE is not an expert at preventing moisture penetration through slabs. A qualified architect or other experienced professional should be contacted if moisture penetration is a more significant concern. \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\l0-13214T\Rpt_Geotechnical.doc Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 5.8 Seismic Design Criteria Page 16 CTE Job No.: 10-13214T The seismic ground motion values listed in the table below were derived in accordance with the ASCE 7-10 Standard and 2013 CBC. This was accomplished by establishing the Site Class based on the soil properties at the site, and then calculating the site coefficients and parameters using the United States Geological Survey Seismic Design Maps application using the site coordinates of 33 .1204 degrees latitude and -117 .3240 degrees longitude. These values are intended for the design of structures to resist the effects of earthquake ground motions. TABLE 5.9 SEISMIC GROUND MOTION VALUES PARAMETER VALUE CBC REFERENCE (2013) Site Class D ASCE 7, Chapter 20 Mapped Spectral Response I. 165 Figure 16 13.3.1 (!) Acceleration Parameter, Ss Mapped Spectral Response 0.449 Figure 1613.3.1 (2) Acceleration Parameter, S1 Seismic Coefficient, F • 1.034 Table 1613.3.3 (1) Seismic Coefficient, Fv 1.551 Table 1613.3.3 (2) MCE Spectral Response 1.205 Section 1613.3.3 Acceleration Parameter, SMs MCE Spectral Response 0.696 Section 1613.3.3 Acceleration Parameter, SM1 Design Spectral Response 0.803 Section 16 13.3.4 Acceleration, Parameter Sos Design Spectral Response 0.464 Section 1613.3.4 Acceleration, Parameter S01 Peak Ground Acceleration PGAM 0.484 ASCE 7, Section 11.8.3 \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_Geotechnical.doc I Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 A venida Encinas, Carlsbad, California September 16, 2016 5.9 Lateral Resistance and Earth Pressures Page 17 CTE Job No.: 10-13214T Lateral loads acting against retaining walls may be resisted by friction between the footings and the supporting compacted fill soil and/or Old Paralic Deposits or passive pressure acting against structures. If frictional resistance is used, an allowable coefficient of friction of 0.30 (total frictional resistance equals the coefficient of friction multiplied by the dead load) is recommended for concrete cast directly against compacted fill. A design passive resistance value of 250 pounds per square foot per foot of depth (with a maximum value of 2,000 pounds per square foot) may be used. The allowable lateral resistance can be taken as the sum of the frictional resistance and the passive resistance, provided the passive resistance does not exceed two-thirds of the total allowable resistance. If proposed, retaining walls up to approximately eight feet high and backfilled using granular soils may be designed using the equivalent fluid weights given below. TABLE5.l0 EQUIVALENT FLUID UNIT WEIGHTS (pounds per cubic foot) SLOPE BACKFILL WALL TYPE LEVEL BACKFILL 2:1 (HORIZONTAL: VERTICAL) CANTILEVER WALL 30 48 (YIELDING) RESTRAINED WALL 60 75 \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_Geotechnical.doc -.. -... .. .. - -.. .. -.. -... - --- - --- ------ Geotechnical Investigation Page 18 Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 CTE Job No.: 10-13214T Lateral pressures on cantilever retaining walls (yielding walls) due to earthquake motions may be calculated based on work by Seed and Whitman ( 1970). The total lateral thrust against a properly drained and backfilled cantilever retaining wall above the groundwater level can be expressed as: For non-yielding (or "restrained") walls, the total lateral thrust may be similarly calculated based on work by Wood (1973): Where PA= Static Active Thrust (determined using Table 5.9) PK= Static Restrained Wall Thrust (determined using Table 5.9) ~p AE = Dynamic Active Thrust Increment = (3/8) kb yH2 ~PKE = Dynamic Restrained Thrust Increment = kb yH2 kh = 2/3 Peak Ground Acceleration = 2/3 (PGAM) H = Total Height of the Wall y = Total Unit Weight of Soil::::: 135 pounds per cubic foot The increment of dynamic thrust in both cases should be distributed triangularly with a line of action located at H/3 above the bottom of the wall (SEAOC, 2013). These values assume non-expansive backfill and free-draining conditions. Measures should be taken to prevent moisture buildup behind all retaining walls. Drainage measures should include free- draining backfill materials and sloped, perforated drains. These drains should discharge to an appropriate off-site location. A general or conceptual detail for Retaining Wall Drainage, which may be appropriate for the subject site based on the review of the project structural engineer and architect, is attached as Figure 4. Waterproofing should be as specified by the project architect or the waterproofing specialty consultant. \\ESC _ SERVER\Projects\l 0-13000 to I 0-13999 Projects\! 0-l 3214T\Rpt_ Geotechnical.doc .. .. -• - -.. - -.. ... .. .. .. .. .. - - - - - -----.. -- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 60 IO A venida Encinas, Carlsbad, California September 16, 2016 5.10 Exterior Flatwork Page 19 CTE Job No.: 10-13214T To reduce the potential for cracking in exterior non-traffic flatwork areas caused by minor movement of subgrade soils and typical concrete shrinkage, it is recommended that such flatwork measure a minimum 5.0 inches thick and be installed with crack-control joints at appropriate spacing as designed by the project architect. Additionally, it is recommended that flatwork be installed with at least No. 4 reinforcing bars on maximum 18-inch centers, each way, at above mid-height of slab but with proper concrete cover, or other reinforcement per the project consultants. Doweling of flatwork joints at critical pathways or similar could also be beneficial in resisting minor subgrade movements . Subgrades should be prepared according to the earthwork recommendations previously given, before placing concrete. Positive drainage should be established and maintained next to all flatwork . Sub grade materials shall be maintained at, or be elevated to, above optimum moisture content prior to concrete placement. 5.11 Pavements Pavement sections provided are based on preliminary Resistance "R" -Value results, estimated traffic indices, and the assumption that the upper foot of compacted fill subgrade and overlying aggregate base materials are properly compacted to a minimum 95% relative compaction at a minimum of two percent above optimum moisture content (as per ASTM D 1557). Beneath proposed pavement areas, loose, clayey, or otherwise unsuitable soils are to be removed to the depth of competent underlying material as recommended in Section 5.2. R-V alue of subgrade material should be verified during grading and pavement sections may be modified as necessary. \\ESC _ SERVER\Projects\l 0-13000 to I 0-13999 Projects\! 0-l 32 I 4T\Rpt_ Geotechnical.doc Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 Page 20 CTE Job No.: 10-13214T TABLE 5.12 RECOMMENDED AC OR PCC PA YEMENI SECTION THICKNESSES Traffic Area Assumed Preliminary Asphalt Pavements Portland Cement Traffic Index Subgrade AC Ca!Trans Class II or Concrete "R"-Value Thickness Crushed Miscellaneous Pavements On (INCHES) Aggregate Base Subgrade Thickness (INCHES) (INCHES) Auto Parking 4.5 5 4.0 6.0 6.5 Areas Drive Areas 6.0 5 4.0 12.0 7.5 Asphalt paved areas should be designed, constructed, and maintained in accordance with, for example, the recommendations of the Asphalt Institute, or other widely recognized authority. Concrete paved areas should be designed and constructed in accordance with the recommendations of the American Concrete Institute or other widely recognized authority, particularly with regard to thickened edges, joints, and drainage. The Standard Specifications for Public Works construction ("Greenbook") or Caltrans Standard Specifications may be referenced for pavement materials specifications. 5 .12 Drainage Surface runoff should be collected and directed away from improvements by means of appropriate erosion-reducing devices, and positive drainage should be established around proposed improvements. Positive drainage should be directed away from improvements and slope areas at a minimum gradient of two percent for a distance of at least five feet. However, the project civil \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_Geotechnical.doc .. .. .. .. .. • .. .. .. .. .. - - -... ----- - .. -------- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 A venida Encinas, Carlsbad, California September 16, 2016 Page 21 CTE Job No.: 10-13214T engineer should evaluate the on-site drainage and make necessary provisions to keep surface water from affecting the site . Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes and improvements. However, it is understood that some agencies are encouraging the use of storm- water cleansing devices. Therefore, if storm water cleansing devices must be used, it is generally recommended that they be underlain by an impervious barrier and that the infiltrate be collected via subsurface piping and discharged off site. If infiltration must occur, water should infiltrate as far away from structural improvements as feasible. Additionally, any reconstructed slopes descending from infiltration basins should be equipped with subdrains to collect and discharge accumulated subsurface water (Appendix D contains general or typical details for internal fill slope drainage) . 5.13 Slopes Based on observed conditions and anticipated soil strength characteristics, cut and fill slopes, if proposed at the site, should be constructed at ratios of 2: 1 (horizontal: vertical) or flatter. These fill slope inclinations should exhibit factors of safety greater than 1.5. Although properly constructed slopes on this site should be grossly stable, the soils will be somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of slopes unless that water is confined to properly designed and constructed drainage facilities. Erosion-resistant vegetation should be maintained on the face of all slopes. Typically, soils along the top portion of a fill slope face will creep laterally. CTE recommends against building distress-sensitive hardscape \\ESC _SERVER\Projects\10-13000 to 10-13999 Projects\10-132141\Rpt_ Geotechnical.doc .. .. - • • -.. • ""' - • -.. -.. - - - - - -... -.. - ---- Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 Avenida Encinas, Carlsbad, California September 16, 2016 improvements within five feet of slope crests . 5.14 Plan Review Page 22 CTE Job No.: 10-13214T CTE should be authorized to review the project grading and foundation plans prior to commencement of earthwork to identify potential conflicts with the intent of the geotechnical recommendations. 5 .15 Construction Observation The recommendations provided in this report are based on preliminary design information for the proposed construction and the subsurface conditions observed in the explorations performed. The interpolated subsurface conditions should be checked in the field during construction to verify that conditions are as anticipated. Foundation recommendations may be revised upon completion of grading and as-built laboratory test results. Recommendations provided in this report are based on the understanding and assumption that CTE will provide the observation and testing services for the project. All earthwork should be observed and tested to verify that grading activities have been performed according to the recommendations contained within this report. CTE should evaluate all footing trenches before reinforcing steel placement. \\ESC _SERVER\Projects\l 0-13000 to 10-13999 Projects\10-13214T\Rpt_ Geotechnical.doc .. -.. - -.. .. .. • .. -.. .. -.. - - - .., - - - -... ------ Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 A venida Encinas, Carlsbad, California September 16, 2016 6.0 LIMITATIONS OF INVESTIGATION Page 23 CTE Job No.: 10-13214T The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been conducted according to current engineering practice and the standard of care exercised by reputable geotechnical consultants performing similar tasks in this area. No other warranty, expressed or implied, is made regarding the conclusions, recommendations and opinions expressed in this report . Variations may exist and conditions not observed or described in this report may be encountered during construction . The recommendations presented herein have been developed in order to help reduce the potential adverse effects of expansive soils and transitional bearing conditions. However, even with the design and construction precautions provided, some post-construction movement and associated distress should be anticipated. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. \\ESC _ SERVER\Projects\10-13000 to I 0-13999Projects\10-13214T\Rpt_ Geotechnical.doc Geotechnical Investigation Proposed Carlsbad Toyota Car Wash 6010 A venida Encinas, Carlsbad, California September 16, 2016 Page 24 CTE Job No.: 10-13214T CTE's conclusions and recommendations are based on an analysis of the observed conditions. If conditions different from those described in this report are encountered, this office should be notified and additional recommendations, if required, will be provided. The opportunity to be of service on this project is appreciated. If you have any questions regarding this report, please do not hesitate to contact the undersigned. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. Dan T. Math, GE #2665 Principal Engineer Aaron J. Beeby, CEG #2603 Project Geologist AJB/JFL/DTM:nri Jay F. Lynch, CEG #1890 Principal Engineering Geologist \\ESC_SERVER\Projects\10-13000 to 10-13999 Projects\10-132 141\Rpt_Geotechnical.doc .. --.. - 111 .. APPENDIX A -REFERENCES .. , .. .. "" .. .. .. -... -- , ... --- , ... ---... .. ..... -------- -.. - ... ... - - "' -... .. • . ,,. - - ..... ---... - - -------- REFERENCES 1. American Society for Civil Engineers, 2010, "Minimum Design Loads for Buildings and Other Structures," ASCE/SEI 7-10 . 2. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort," Volume 04.08 3. Blake, T.F., 2000, "EQFAULT," Version 3.00b, Thomas F. Blake Computer Services and Software. 4. California Building Code, 2013, "California Code of Regulations, Title 24, Part 2, Volume 2 of2," California Building Standards Commission, published by ICBO, June. 5. California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by Martin and Ross . 6. California Emergency Management Agency/California Geological Survey, "Tsunami Inundation Maps for Emergency Planning . 7. Frankel, A.D., Petersen, M.D., Mueller, C.S., Haller, K.M., Wheeler, R.L., Leyendecker, E.V., Wesson, R. L., Harmsen, S.C., Cramer, C.H., Perkins, D.M., Rukstales,K.S.,2002, Documentation for the 2002 update of the National Seismic Hazard Maps: U.S. Geological Survey Open-File Report 2002-420, 39p 8. Hart, Earl W., Revised 2007, "Fault-Rupture Hazard Zones in California, Alquist Priolo, Special Studies Zones Act of 1972," California Division of Mines and Geology, Special Publication 42. 9. Jennings, Charles W., 1994, "Fault Activity Map of California and Adjacent Areas" with Locations and Ages of Recent Volcanic Eruptions . 10. Kennedy, M.P. and Tan, S.S., 2008, "Geologic Map of the Oceanside 30' x 60' Quadrangle, California", California Geological Survey, Map No. 2, Plate 1 of 2. 11. Reichle, M., Bodin, P., and Brune, J., 1985, The June 1985 San Diego Bay Earthquake swarm [abs.]: EOS, v. 66, no. 46, p.952. 12. SEAOC, Blue Book-Seismic Design Recommendations, "Seismically Induced Lateral Earth Pressures on Retaining Structures and Basement Walls," Article 09.10.010, October 2013. 13. Seed, H.B., and R.V. Whitman, 1970, "Design of Earth Retaining Structures for Dynamic Loads," in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and Design of Earth-Retaining Structures, pp. 103-147, Ithaca, New York: Cornell University. - - -.. .. ... -.... - "' -.. - ""' - - ---.... - -.... -.. ------ 14. Simons, R.S., 1979, Instrumental Seismicity of the San Diego area, 1934-1978, in Abbott, P.L. and Elliott, W.J., eds., Earthquakes and other perils, San Diego region: San Diego Association of Geologists, prepared for Geological Society of America field trip, November 1979, p.101-105 . 15. Tan, S. S., and Giffen, D. G., 1995, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California: Encinitas Quadrangle, Landslide Hazard Identification Map No. 35", California Department of Conservation, Division of Mines and Geology, Open-File Report 95-04, State of California, Division of Mines and Geology, Sacramento, California. 16. Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05. Pasadena: California Institute of Technology. - -.. .. ... .. .. - -... .. ... ... .. -----,... - - -- ----- APPENDIXB EXPLORATION LOGS --- -.. -... - .. .... -.... ----- ---- - -.... ----- -- APPENDIXC LABORATORY METHODS AND RESULTS --- .. .. -.. - --- ---------------------- APPENDIXC LABORATORY METHODS AND RESULTS Laboratory Testing Program Laboratory tests were performed on representative soil samples to detect their relative engineering properties. Tests were performed following test methods of the American Society for Testing Materials or other accepted standards. The following presents a brief description of the various test methods used. Classification Soils were classified visually according to the Unified Soil Classification System. Visual classifications were supplemented by laboratory testing of selected samples according to ASTM D2487. The soil classifications are shown on the Exploration Logs in Appendix B. Particle-Size Analysis Particle-size analyses were performed on selected representative samples according to ASTM D 422. Expansion Index Expansion testing was performed on selected samples of the matrix of the on-site soils according to ASTMD4829. Consolidation To assess their compressibility and volume change behavior when loaded and wetted, relatively undisturbed samples ofrepresentative samples from the investigation were subject to consolidation tests in accordance with ASTM D 2435. Resistance "R" Value The resistance "R" -value was measured by the California Test. 301. The graphically determined "R" value at an exudation pressure of300 pounds per square inch is the value used for pavement section calculation. Chemical Analysis Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride content, pH, Corrosivity, and Resistivity. ---- --APPENDIXD ... STANDARD SPECIFICATIONS FOR GRADING ------------------------------