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Home My WebLink AboutMS 2019-0003; BMW OF CARLSBAD; GEOTECHNICAL INVESTIGATION REPORT; 2019-12-13 December 13, 2019 2 GMU Project 18-101-00 Geotechnical Investigation Report, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, Carlsbad, California Prepared For AUTONATION December 13, 2019 GMU Project No. 18-101-00 23241 Arroyo Vista Rancho Santa Margarita I CA 92688 949.888.6513 I FX: 949.888.1380 I www.gmugeo.com date 1 GMU Project XX AUTONATION 200 SW 1st Street, 14th Floor Fort Lauderdale, FL 33301 GMU PROJECT: 18-101-00 ATTENTION: Mr. Axay Patel SUBJECT: Geotechnical Investigation Report AutoNation BMW of Carlsbad 1050 & 1060 Auto Center Court City of Carlsbad, California Dear Mr. Patel: GMU is pleased to present this geotechnical report for the subject project which summarizes our data, conclusions, and recommendations. Please note that this report has not been prepared for the use by other parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. We appreciate the opportunity to work on this project. Please do not hesitate to contact the undersigned if you have any questions regarding any aspect of this report. Respectfully submitted, Nadim Sunna, MS, QSP, PE 84197 Senior Engineer DISTRIBUTION: Addressee: Electronic copy Commercial Development Resources (CDR) Attn: Mr. Royce Eklund (2 wet signed copies and electronic copy) SPARC + Attn: Mr. Cord McLean (Electronic copy) Dally & Associates Attn: Mr. Brian Ellestad (Electronic copy) 23241 Arroyo Vista Rancho Santa Margarita I CA 92688 FX: 949.888.1380 I www.gmugeo.com Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad date i GMU Project XX TABLE OF CONTENTS Description Page INTRODUCTION .......................................................................................................................... 1 PURPOSE ................................................................................................................................. 1 SCOPE ...................................................................................................................................... 1 LOCATION .............................................................................................................................. 2 SITE DESCRIPTION ..................................................................................................................... 2 TOPOGRAPHY AND PREVIOUS GRADING ...................................................................... 2 PROJECT DESCRIPTION ............................................................................................................. 3 SUBSURFACE EXPLORATION .................................................................................................. 3 GEOLOGIC FINDINGS ................................................................................................................ 4 REGIONAL GEOLOGIC SETTING ....................................................................................... 4 SUBSURFACE MATERIALS ................................................................................................. 4 Engineered Fill (Qafc) ....................................................................................................... 4 Santiago Formation (Tsa) .................................................................................................. 4 GROUNDWATER ................................................................................................................... 5 GEOLOGIC HAZARDS ................................................................................................................ 5 FAULTING AND SEISMICITY ............................................................................................. 5 LIQUEFACTION AND SEISMIC SETTLEMENT ................................................................ 5 Liquefaction ....................................................................................................................... 5 Secondary Seismic Hazards .............................................................................................. 5 LANDSLIDES .......................................................................................................................... 6 TSUNAMI, SEICHE, AND FLOODING ................................................................................ 6 GEOTECHNICAL ENGINEERING FINDINGS .......................................................................... 6 SOIL EXPANSION .................................................................................................................. 6 SOIL CORROSION ................................................................................................................. 6 PRELIMINARY INFILTRATION TESTING ......................................................................... 7 EXCAVATION CHARACTERISTICS ................................................................................... 8 Rippability ......................................................................................................................... 8 IN-SITU SOIL MOISTURE CONDITIONS ........................................................................... 8 CONCLUSIONS............................................................................................................................. 8 RECOMMENDATIONS ................................................................................................................ 9 GENERAL SITE PREPARATION AND GRADING ............................................................. 9 General .............................................................................................................................. 9 Clearing and Grubbing ...................................................................................................... 9 Corrective Grading ............................................................................................................ 9 Temporary Excavations ................................................................................................... 11 STRUCTURE SEISMIC DESIGN ......................................................................................... 11 Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 ii GMU Project 18-101-00 TABLE OF CONTENTS (continued) Description Page FOUNDATION DESIGN AND CONSTRUCTION ............................................................. 12 General ............................................................................................................................ 12 General Foundation Design Parameters .......................................................................... 12 Slab Subsection and Slab Design .................................................................................... 13 Foundation Design Parameters ........................................................................................ 14 Wall Design Parameters .................................................................................................. 14 STRUCTURAL CONCRETE ................................................................................................ 15 FERROUS METAL CORROSION PROTECTION .............................................................. 16 MOISTURE VAPOR TRANSMISSION ............................................................................... 16 Moisture Vapor Retarder ................................................................................................. 16 SURFACE DRAINAGE ......................................................................................................... 17 UTILITY TRENCH BACKFILL CONSIDERATIONS........................................................ 17 General ............................................................................................................................ 17 Pipe Bedding ................................................................................................................... 17 Trench Backfill ................................................................................................................ 18 ASPHALT CONCRETE PAVEMENT THICKNESS RECOMMENDATIONS ................. 18 Asphalt Pavement Design ............................................................................................... 18 CONCRETE PAVEMENT THICKNESS RECOMMENDATIONS .................................... 19 PERMEABLE PAVER DESIGN ........................................................................................... 20 Permeable Concrete Interlocking Vehicular Paver Design ............................................. 20 CONCRETE FLATWORK DESIGN ..................................................................................... 20 PLANTERS AND TREES ..................................................................................................... 21 BIORETENTION AREAS ..................................................................................................... 21 PLAN REVIEW / GEOTECHNICAL TESTING DURING GRADING / .................................. 22 FUTURE REPORT ................................................................................................................. 22 Plan Review ..................................................................................................................... 22 Geotechnical Testing ....................................................................................................... 22 Future Report ................................................................................................................... 22 CLOSURE .................................................................................................................................... 24 REFERENCES ............................................................................................................................. 25 PLATES Plate 1 -- Location Map Plate 2 -- Geotechnical Map Plate 3 -- Retaining Wall Construction Detail Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 iii GMU Project 18-101-00 TABLE OF CONTENTS (continued) APPENDICES APPENDIX A: APPENDIX B: APPENDIX C: APPENDIX D: Geotechnical Exploration Procedures and Drill Hole Logs, by GMU Geotechnical, Inc. Geotechnical Laboratory Procedures and Test Results by GMU Geotechnical, Inc. Infiltration Test Result TEMPORARY BACKCUT @ SECTION G-G APPENDIX E: RESPONSE TO COMMENTS INTRODUCTION PURPOSE This report presents the results of our geotechnical foundation investigation of soil and geologic conditions for the proposed 2-story dealership building development and site improvements, as shown on the reference (1) conceptual grading plans by CDR West, for the AutoNation BMW Carlsbad Dealership to be located at 1050/1060 Auto Center Court within Car Country Carlsbad in the City of Carlsbad. SCOPE The scope of our geotechnical foundation investigation along with future plan reviews, as outlined in our May 8, 2018 proposal, is as follows: 1.Reviewed and efficiently utilized data from the reference (2) geotechnical investigation report by others, and reference (3) as-graded and observation and testing report by others pertaining to the subject property, current plans and building sections, and anticipated building loading. 2.Staked seven (7) hollow stem auger drill holes, coordinated with AutoNation, and contacted Utility Underground Service Alert (USA/Dig Alert) in order to provide advance notification of the 7 subsurface drill holes planned within the AutoNation BMW Carlsbad Dealership project area. 3.Performed a field subsurface exploration program consisting of advancing one (1) hollow stem auger drill hole to a depth of approximately 50 feet, four (4) hollow stem auger drill hole to a depth of approximately 20 feet, and two hollow stem auger drill holes to a depth of approximately 5 feet in the planned bio-retention (infiltration) areas outside thedealership building and in adjacent parking lot areas. Logged the drill holes and obtainedbulk and drive soil samples for geotechnical laboratory testing. Infiltration tests were performed concurrently with the two shallow drill hole locations, which was coordinated with the project civil engineer. 4.Performed laboratory testing on soil samples obtained from the drill holes. Testingincluded moisture and density, particle size, Atterberg Limits, expansion, chemical, compaction, consolidation, direct shear strength, and R-value tests. 5.Interpreted and evaluated the newly acquired field and laboratory data and integratedwith the previously obtained existing data by others. Performed geotechnical engineeringdesign which included settlement analysis, liquefaction analysis, bearing capacity and Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 2 GMU Project 18-101-00 associated settlement, pavement design, and seismic parameters in accordance with the California Building Code (CBC) 2016 standards. 6. Supported the design processes by providing geotechnical design memos/e-mails with geotechnical design conclusions and recommendations for the proposed project. This included the following: • Foundation design and anticipated settlement of the dealership building. • Site preparation, building foundation excavation, and precise grading requirements. • Acceptability of the site soils for use as fill and backfill. • Infiltration results. • Site seismicity and seismic design parameters. • Lateral earth pressures and temporary excavation. • Liquefaction potential of the site soils. • Retaining wall/site wall design parameters. • Installation of underground utilities. • Flatwork design. • Asphalt pavement and concrete pavement designs. 7. Prepared and distributed this formal geotechnical foundation report for the BMW of Carlsbad Dealership containing our final geotechnical conclusions and recommendations to support the main project submittal and permitting process. LOCATION The site is located at 1050 and 1060 Auto Center Court in the City of Carlsbad, California. The site is bound by Auto Center Court on the south, Car County Drive on the east, Canyon Road on the north, and asphalt pavement and parking structure on the west. The general location of the project site is shown on Plate 1. SITE DESCRIPTION TOPOGRAPHY AND PREVIOUS GRADING The subject site is relatively flat, with local gentle northerly gradients from the corner of Auto Center Court and Car Country Drive towards Canyon Road. Currently, the site is occupied by a one-story, U-shaped building, asphalt concrete pavement, site walls, and planter areas. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 3 GMU Project 18-101-00 Previous geotechnical investigation for this site was completed in 1987 by Woodward-Clyde Consultants, which is listed as reference (2). Following the geotechnical investigation in 1987, the site was mass graded by Kleinfelder in 1988 in accordance with reference (3). PROJECT DESCRIPTION The subject project site is currently serving as an automotive dealer and repair complex surrounded by an asphalt concrete pavement parking lot and drives. We understand that the project will consist of the construction of a new BMW dealership with a 2-story building and rooftop parking. The second level of the building will be utilized for service. The structure will consist of a concrete columns and post-tensioned deck, and the front of the showroom will consist of steel-framed structure. It is also our understanding that the structure will be situated at-grade. In addition, we understand that the foundations for the proposed structure will be designed to account for one-level of future expansion. Based on our correspondence with the project structural engineer, the following building loads were provided for use in our analyses: Building Structural Loads Proposed Building Typical Interior Column Loads (kips) Typical Exterior Column Loads (kips) Two-Story Building – Current Design Dead : 375 Live : 152 Dead : 230 Live : 92 Future Addition Dead: 145 Live: 68 Dead: 90 Live: 40 Total Loads Dead: 520 Live: 220 Dead: 320 Live: 132 SUBSURFACE EXPLORATION GMU conducted a subsurface exploration program to evaluate the soil conditions below the proposed building and parking areas. A total of seven (7) hollow-stem-auger, truck-mounted drill holes were excavated to a maximum depth of 21.5 feet below the existing grade. The drill hole locations are shown on Plate 2 – Geotechnical Map. Drill hole logs are contained in Appendix A. The drill holes were logged by our Staff Geologist, and samples were collected in each of the drill holes for laboratory testing. Percolation testing was also performed in two (2) of the drill hole locations (DH-6 and DH-7). Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 4 GMU Project 18-101-00 LABORATORY TESTING Laboratory testing for the subject investigation was performed to characterize moisture and density, particle size distribution, Atterberg Limits, expansion index, maximum density, corrosion, direct shear, consolidation, and R-value. The results of our laboratory testing are summarized on Table B-1 and included within Appendix B – Laboratory Testing. GEOLOGIC FINDINGS REGIONAL GEOLOGIC SETTING The subject site is located within the coastal plain section of the Peninsular Ranges geomorphic province of California. This regional area of northern San Diego County generally consists of low eroded hills bisected by valleys filled with Quaternary alluvium. The site is underlain by the Tertiary-age Santiago Formation. Due to previous grading and development activity, this bedrock unit is locally overlain by a thin unit of artificial fill. SUBSURFACE MATERIALS Engineered Fill (Qafc) Engineered fill soils were encountered in all excavations at the site and consist of brown to dark brown, damp silty sands. The fills were placed as part of the previous grading operations and are estimated to be up to 8 feet in depth, with an average of 5 feet in depth. The fill soils largely possess low plasticity/expansion characteristics. Engineered fill soils were placed in 1988 under the observation of Kleinfelder (reference (3)). Santiago Formation (Tsa) Bedrock of the Santiago Formation underlies the site and was encountered under the fill in borings DH-1, DH-2, DH-3, DH-4, and DH-5. Where encountered, the bedrock consisted of brown to gray, damp to moist silty sandstone with interbeds of claystone, siltstone, and fine sandstone. Geologic structure was not observed in the samples collected; however, based on previous geotechnical reports and regional publications, structure within the bedrock is expected to be generally horizontal. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 5 GMU Project 18-101-00 GROUNDWATER Groundwater was not observed during our exploration to a maximum depth of 51.5 feet below the existing grade. Groundwater conditions may vary across the site due to stratigraphic and hydrologic conditions and may change over time as a consequence of seasonal and meteorological fluctuations, or activities by humans at this site and nearby sites. However, based on the above findings, groundwater is unlikely to impact the proposed development. GEOLOGIC HAZARDS FAULTING AND SEISMICITY The site is not located within an Alquist-Priolo Earthquake Fault Zone, and no known active faults are shown on the reviewed geologic maps crossing the site, however, the site is located in the seismically active region of Southern California. The nearest known active faults are the San Rose Canyon and Newport Inglewood fault systems, which are located approximately 4.5 miles from the site and capable of generating a maximum earthquake magnitude (Mw) of 6.9 and 7.5, respectively. Given the proximity of the site to these and numerous other active and potentially active faults, the site will likely be subject to earthquake ground motions in the future. A site PGAM of 0.48g was calculated for the site in conformance with the 2016 CBC. This PGAM is primarily dominated by earthquakes with a mean magnitude of 6.6 at a mean distance of 8.6 miles from the site using the USGS 2014 Interactive Deaggregation website. LIQUEFACTION AND SEISMIC SETTLEMENT Liquefaction Based on our review of Figure 3.5-3 of the Draft Program Environmental Impact Report for the Carlsbad General Plan Update, Chapter 3.5, the site is not located within a zone of potential liquefaction. In addition, based on the lack of shallow groundwater, relatively uniform soil stratum across the site, and our liquefaction analysis, it is our professional opinion that the liquefaction potential at the site is very low. Secondary Seismic Hazards Seismically induced dry sand settlement is the ground settlement due to densification of loose, dry, cohesionless soils during strong earthquake shaking. Based on our secondary seismic hazard Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 6 GMU Project 18-101-00 analysis, it is our professional opinion that the potential for seismically induced dry-sand settlement is low. LANDSLIDES Based on our review of available geologic maps, literature, topographic maps, aerial photographs, and our subsurface evaluation, no landslides or related features underlie or are adjacent to the subject site. Due to the relatively level nature of the site and surrounding areas, the potential for landslides to occur at the project site is considered negligible. TSUNAMI, SEICHE, AND FLOODING The site is located approximately 0.75 miles from the Pacific Ocean, however, it is not located within a tsunami inundation hazard zone in accordance with the County of San Diego Tsunami Inundation Map for Emergency Planning. The potential for the site to be adversely impacted by earthquake-induced seiches is considered to be negligible due to the lack of any significant enclosed bodies of water located in the vicinity of the site. The site is within an area of minimum flooding (Zone X) as defined by the Federal Emergency Management Agency (FEMA, 2012). GEOTECHNICAL ENGINEERING FINDINGS SOIL EXPANSION Based on our evaluation and experience with similar material types, the sandy soils encountered near the ground surface at the site exhibit a very low expansion potential. SOIL CORROSION Based on laboratory test results for pH, soluble chlorides, sulfate, and minimum resistivity of the site soils obtained during our subsurface investigation, the on-site soils should be considered to have the following: Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 7 GMU Project 18-101-00 • A negligible sulfate exposure to concrete per ACI 318-14, Table 19.3.1.1 • A high minimum resistivity indicating conditions that are moderately corrosive to ferrous metals. • A chloride content of up to 384 ppm (corrosive to ferrous metals). The laboratory testing program performed for this project does not address the potential for corrosion to copper piping. In this regard, a corrosion engineer should be consulted to perform more detailed testing and develop appropriate mitigation measures (if necessary). The above discussion is provided for general guidance in regards to the corrosiveness of the on-site soils to typical metal structures used for construction. Detailed corrosion testing and recommendations for protecting buried ferrous metal and/or copper elements are beyond our purview. If detailed recommendations are required, a corrosion engineer should be consulted to develop appropriate mitigation measures. PRELIMINARY INFILTRATION TESTING Two (2) preliminary infiltration tests were performed in general conformance with the County of San Diego Low Impact Development (LID) Handbook. The infiltration drill holes were excavated to depths ranging from 4 to 5 feet below the existing grade using a hollow-stem-auger, truck-mounted drill rig. The calculated unfactored infiltration rates are presented in the table below. The infiltration rates do not incorporate a factor of safety. Calculated Infiltration Rates Drill Hole Depth Below Finish Grade (feet) Unfactored Infiltration Rate (inch/hour) DH-6 5.0 0.02 DH-7 4.0 0.23 Based on our preliminary infiltration test result as discussed previously in this report and as presented in Appendix C, the two test locations showed inadequate infiltration rates within the upper 5 feet of the site soils. Also, due to the presence of engineered fill and dense to very dense formation, infiltration at the site is deemed not feasible. The preliminary percolation test hole locations are shown on the attached Geotechnical Map, Plate 2. The results of the infiltration testing are summarized in Appendix C of this report and site infiltration recommendations are presented later in this report. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 8 GMU Project 18-101-00 EXCAVATION CHARACTERISTICS Rippability The majority of the soil materials underlying the site can be excavated with scrapers and other conventional grading equipment. The bedrock is moderately hard and partially cemented, which yields difficult trenching conditions and may require heavy duty equipment. IN-SITU SOIL MOISTURE CONDITIONS Both the fill and formation soils are in damp to moist condition. In general, soils within the upper 10 feet have an average degree of saturation of less than 60%. It should be noted, however, that the moisture content within the upper several feet may vary depending on rainfall and the time of year in which grading occurs. CONCLUSIONS Based on our geotechnical findings, the following is a summary of our conclusions: 1. The project area is not underlain by any known active faults. 2. Groundwater is not expected to be encountered and is not anticipated to have a significant impact on the proposed development. 3. The site is not subject to liquefaction nor seismically induced dry sand settlement. 4. Site soils within the at-grade foundation influence zone are anticipated to have a very low expansion potential based on our recent laboratory test results and local experience. Recommendations for the proposed developments are based on a “very low to low” expansive condition. 5. Corrosion testing indicates that the on-site soils have a negligible sulfate exposure and are moderately corrosive to buried ferrous metals and reinforcing steel. Consequently, any metal exposed to the soil shall be protected. 6. Based on our percolation testing and calculated infiltration rates, the site soils in the upper 5 feet are deemed not feasible for infiltration of water. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 9 GMU Project 18-101-00 RECOMMENDATIONS GENERAL SITE PREPARATION AND GRADING General The following recommendations pertain to any required grading associated with the proposed improvements and corrective grading needed to support the proposed improvements. All site preparation and grading should be performed in accordance with the City of Carlsbad grading code requirements and the recommendations presented in this report. Clearing and Grubbing All significant organic material such as weeds, brush, tree branches, or roots, or construction debris such as old irrigation lines, asphalt concrete, and other decomposable material should be removed from the area to be graded. No rock or broken concrete greater than 6 inches in diameter should be utilized in the fills. Corrective Grading Corrective grading will serve to create a firm and workable platform for construction of the proposed developments such as new 2-story dealership and associated pavement and site flatwork. The fill material encountered during our subsurface investigation is competent for support of new foundations provided that remedial grading is performed in order to densify any disturbed soil that may be encountered during the grading operation. Based on our review of existing as-graded reports for the subject site, we understand that portion of the proposed car dealership building will be situated in engineered fill while the remaining portion will be situated in cut exposing Santiago Formation. For structures that will be found in both cut and fill areas, the cut portion of the building foundation shall be supported on at least 3 feet of compacted fill. The approximate limits of the cut/fill transition are provided on the attached Plate 2 – Geotechnical Map, however, the actual limits of the transition should be field verified during grading by the geotechnical engineer of record. It should be noted that the recommendations provided herein are based on our subsurface exploration and knowledge of the on-site geology. Actual removals may vary in configuration and volume based on observations of geologic materials and conditions encountered during grading. The bottom of all remedial grading removals should be observed by a GMU representative to verify the suitability of in-place soil prior to performing scarification and recompaction. Corrective grading recommendations are outlined below. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 10 GMU Project 18-101-00 Foundations Within Fill Portion/Slab on Grade: Grading recommendations for support of new foundations within existing engineered fill and slab on grade should consist of the following: o The bottom of the foundation/slab section should be scarified to a depth of at least 8 inches, moisture conditioned to 2% above optimum moisture content, and recompacted to at least 90% relative compaction. Foundations Within Cut Portion: Grading recommendations for support of new foundations within the cut portion should consist of the following: o The foundation should be excavated to a depth of at least 3 feet below the bottom of the footing. o The bottom of the foundation should then be scarified to a depth of at least 6 inches, moisture conditioned to 2% above optimum moisture content, and recompacted to at least 90% relative compaction. o Following the approval of the over-excavation bottom by a representative of GMU, the onsite material may be used as fill material to achieve the planned subgrade elevation. o The fill material should then be placed in 6- to- 8-inch-thick lifts, moisture conditioned to at least 2% above optimum moisture content, and compacted to achieve 90% relative compaction. Flatwork/Pavement Areas: Grading recommendations for the support of the asphalt and concrete pavement and flatwork should consist of the following: o The pavement/flatwork section should be excavated to the bottom of the pavement structural/flatwork section (i.e., bottom of the aggregate base). o The bottom of the excavation should then be scarified to a depth of at least 8 inches, moisture conditioned to least 2% above optimum moisture content, and recompacted to at least 90% relative compaction. o Following the approval of the over-excavation bottom by a representative of GMU, the onsite material may be used as fill material to achieve the planned subgrade elevation. o The fill material should then be placed in 6- to- 8-inch-thick lifts, moisture conditioned to at least 2% above optimum moisture content, and compacted to achieve 90% relative compaction. If the existing loose fill materials are found to be disturbed to depths greater than the proposed remedial grading, then the depth of over-excavation and re-compaction should be increased accordingly in local areas as recommended by a representative of GMU. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 11 GMU Project 18-101-00 Temporary Excavations Temporary excavations for demolitions, earthwork, footings, and utility trenches are expected. We anticipate that unsurcharged excavations with vertical side slopes less than 4 feet high will generally be stable, however, some sloughing of cohesionless sandy materials encountered near the existing grade at the site should be expected. Our recommendations for temporary excavations are as follows: • Temporary, unsurcharged excavation sides over 4 feet in height should be sloped no steeper than an inclination of 1H:1V (horizontal:vertical). • Where sloped excavations are created, the tops of the slopes should be barricaded so that vehicles and storage loads do no encroach within 10 feet of the tops of the excavated slopes. A greater setback may be necessary when considering heavy vehicles, such as concrete trucks and cranes. GMU should be advised of such heavy vehicle loadings so that specific setback requirements can be established. • If the temporary construction slopes are to be maintained during the rainy season, berms are recommended to be graded along the tops of the slopes in order to prevent runoff water from entering the excavation and eroding the slope faces. Our temporary excavation recommendations are provided only as minimum guidelines. All work associated with temporary excavations should meet the minimal requirements as set forth by CAL-OSHA. Temporary slope construction, maintenance, and safety are the responsibility of the contractor. STRUCTURE SEISMIC DESIGN No active or potentially active faults are known to cross the site, therefore, the potential for primary ground rupture due to faulting on-site is very low. However, the site will likely be subject to seismic shaking at some time in the future. Based on our field exploration and the site soil profile, the site should be designated as Site Class D based on the measured Standard Penetration Resistance within drill hole DH-3. The seismic design coefficients based on ASCE 7-10 and 2016 CBC are listed in Table 2 below. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 12 GMU Project 18-101-00 Table 2: 2016 CBC Site Categorization and Site Coefficients Categorization/Coefficient Design Value Site Class based on Soil Profile (ASCE 7, Table 20.3-1) D Short Period Spectral Acceleration Ss** 1.145 1-sec. Period Spectral Acceleration S1** 0.440 Site Coefficient Fa (Table 11.4-1)** 1.042 Site Coefficient Fv (Table 11.4-2)** 1.560 Short Period MCE* Spectral Acceleration SMS** 1.193 1-sec. Period MCE Spectral Acceleration SM1** 0.687 Short Period Design Spectral Acceleration SDS** 0.795 1-sec. Period Design Spectral Acceleration SD1** 0.458 MCE Peak Ground Acceleration (PGA) * 0.456 Site Coefficient FPGA (Table 11.8-1)** 1.044 MCE Peak Ground Acceleration (PGAM) * 0.476 Mean Contributing Magnitude to MCE Event 6.6 * MCE: Maximum Considered Earthquake ** Values Obtained from USGS Earthquake Hazards Program website are based on the ASCE7-10 and 2016 CBC and site coordinates of N33.1346o and W117.3242o. It should be recognized that much of southern California is subject to some level of damaging ground shaking as a result of movement along the major active (and potentially active) fault zones that characterize this region. Design utilizing the 2016 CBC is not meant to completely protect against damage or loss of function. Therefore, the preceding parameters should be considered as minimum design criteria. FOUNDATION DESIGN AND CONSTRUCTION General The criteria contained in the following section may be used for the design and construction of the proposed car dealership. Foundation design parameters are presented below. General Foundation Design Parameters o Bearing Material: Engineered Fill o Removal and Re-compaction Depth: 3 feet below bottom of footing for foundations found within the cut portion of the site. o Minimum Footing Size:  Width: 24 inches  Depth: 24 inches embedment below lowest adjacent soil grade (depth) Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 13 GMU Project 18-101-00 o Allowable Bearing Capacity: 3,500 psf for the minimum footing size given above.  May be increased by 250 psf for every footing width and 650 psf for every footing depth to a maximum allowable bearing pressure of 4,500 psf.  Above value may be increased by 1/3 for temporary loads such as wind or seismic o Settlement:  Static Settlement: • Total: 1.0 inch o Settlement is expected to occur during construction or shortly thereafter. o 0.7 inches will occur for the current development loading o 0.3 inches will occur for the future addition loading • Differential: 0.50 inches over a span of 40 feet o Lateral Foundation Resistance:  Allowable passive resistance: 300 psf/ft (disregard upper 6 inches, max 3,000 psf)  Allowable friction coefficient: 0.30  Above values may be combined without reduction and may be increased by 1/3 for temporary loads such as wind or seismic Slab Subsection and Slab Design Minimum Thickness: The minimum slab thickness shall be 6 inches. Minimum Slab Reinforcement: Minimum slab reinforcement shall not be less than No. 4 bars placed at 18 inches on center. Welded wire mesh is not recommended. Care should be taken to position the reinforcement bars in the center of the slab. Slab Subgrade: • The upper 12 inches of the on-site soils and subgrade soil should be moisture conditioned to 2% above the optimum moisture content and compacted to a minimum relative compaction of 90% in accordance with the latest version of ASTM D1557. • A 4-inch-thick section of compacted ¾-inch crushed rock shall be provided directly below the slab. • Place moisture vapor retarder per the Moisture Vapor Transmission section of this report. • Sand above the moisture retarder/barrier (i.e., directly below the slab) is not a geotechnical issue. This should be provided by the structural engineer of record based on the type of slab, potential for curling, etc. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 14 GMU Project 18-101-00 RETAINING WALL DESIGN CONSTRUCTION CRITERIA The following criterion is considered applicable to the design and construction of retaining walls at the subject site. The design assumes a maximum 6-foot-high retaining wall (i.e., from top of footing to top of retaining portion of wall) with level backfill conditions. In addition, the design assumes the use of on-site select backfill in accordance with Plate 3 – Retaining Wall Construction Detail. Foundation Design Parameters Minimum Foundation Width: 18 inches Minimum Foundation Depth: Depth below lowest adjacent grade to bottom of footing: o 18 inches Bearing Materials: Engineered fill o 3 feet of engineered fill below bottom of footing for foundations within the cut portion of the site. Allowable Bearing Capacity: 2,500 psf for footing on level ground o 1/3 increase for wind or seismic conditions Allowable Coefficient of Friction: 0.30 Unit Weight of Backfill: 125 pcf Allowable Passive Earth Pressure: 300 psf/ft of depth (static) o Disregard upper 6 inches o 1/3 increase for seismic conditions Wall Design Parameters Active Earth Pressure: 35 pcf – level backfill (Assumes the use of select soils in backfill zone) Weight of Backfill: 125 pcf Control/Construction Joints: As a minimum, maximum spacing of 15 feet and at angle points Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 15 GMU Project 18-101-00 Waterproofing: The back side of all retaining walls should be waterproofed down to the top of the foundation prior to placing subdrains or backfill. The design and selection of the waterproofing system is outside the scope of our report and is outside our purview. Concrete: 0.50 w/c ratio Type II/V cement (geotechnical perspective only). Wall Backfill and Drainage: See Retaining Wall Construction Detail Diagram and Notes (Plate 3) for backfill and drainage requirements. The unrestrained (active) values are applicable when the walls are designed and constructed as cantilevered walls allowing sufficient wall movement to mobilize active pressure conditions. This wall movement should not be less than 0.01 H (H = height of wall) for the unrestrained values to be applicable. Provided that the retaining walls have a maximum height of less than 6 feet, the current 2016 CBC indicates that the incorporation of seismic earth pressures is not required. STRUCTURAL CONCRETE Laboratory tests indicate that the onsite soils are classified as having a “negligible” sulfate exposure and “S0” sulfate exposure category per ACI 318-14, Table 19.3.1.1. However, due to the low to moderate soil resistivity and chloride contents obtained from our test result, the on-site soil is severely corrosive to ferrous metals such as reinforcing steel. On this basis, we recommend that a Type II/V cement with a maximum water to cement ratio of 0.50 be used for structural elements (i.e., foundations, walls, etc.). Utilization of CBC moderate sulfate level requirements will also serve to reduce the permeability of the concrete and help minimize the potential of water and/or vapor transmission through the concrete. Wet curing of the concrete per ACI Publication 308 is also recommended. Wet curing of the concrete per ACI Publication 308 is also recommended. The aforementioned recommendations in regards to concrete are made from a soils perspective only. Final concrete mix design is beyond our purview. All applicable codes, ordinances, regulations, and guidelines should be followed in regard to the designing a durable concrete with respect to the potential for sulfate exposure from the on-site soils and/or changes in the environment. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 16 GMU Project 18-101-00 FERROUS METAL CORROSION PROTECTION The results of the laboratory chemical tests performed on a sample of soil collected within the site indicate that the on-site soils are corrosive to ferrous metals. Consequently, metal structures which will be in direct contact with the soil (i.e., underground metal conduits, pipelines, metal sign posts, etc.) and/or in close proximity to the soil (wrought iron fencing, etc.) may be subject to corrosion. The use of special coatings or cathodic protection around buried metal structures has been shown to be beneficial in reducing corrosion potential. Additional provisions will be required to address high chloride contents of the soil per the 2016 CBC to protect the concrete reinforcement. The laboratory testing program performed for this project does not address the potential for corrosion to copper piping. In this regard, a corrosion engineer should be consulted to perform more detailed testing and develop appropriate mitigation measures (if necessary). The above discussion is provided for general guidance in regards to the corrosiveness of the on-site soils to typical metal structures used for construction. Detailed corrosion testing and recommendations for protecting buried ferrous metal and/or copper elements are beyond our purview. If detailed testing is required, a corrosion engineer should be consulted to perform the testing and develop appropriate mitigation measures. MOISTURE VAPOR TRANSMISSION Moisture Vapor Retarder A vapor retarder or barrier equivalent to Stego 15 Mil Class A should be utilized overtop of the required gravel/stone course. The retarder/barrier should be installed as follows: o Below moisture-sensitive flooring areas. o Installed per manufacture’s specifications as well as with all applicable recognized installation procedures such as ASTM E 1643-98. o Joints between the sheets and the openings for utility piping should be lapped and taped. If the barrier is not continuously placed across footings/ribs, the barrier should, as a minimum, be lapped into the sides of the footing/rib trenches down to the bottom of the trench. o Punctures in the vapor barrier should be repaired prior to concrete placement. The need for sand and/or the amount of sand above the moisture vapor retarder should be specified by the structural engineer. The selection of sand above the retarder is not a geotechnical engineering issue and is hence outside our purview. It should be noted that the moisture retarder is intended only to reduce moisture vapor transmissions from the soil beneath the concrete and is consistent with the current standard of the Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 17 GMU Project 18-101-00 industry in building construction in southern California. It is not intended to provide a “waterproof” or “vapor proof” barrier or reduce vapor transmission from sources above the retarder (i.e., concrete). The evaluation of water vapor from any source and its effect on any aspect of the proposed building space above the slab (i.e., floor covering applicability, mold growth, etc.) is outside our purview and the scope of this report. SURFACE DRAINAGE Surface drainage should be carefully controlled during and after grading to prevent ponding and uncontrolled runoff adjacent to the structures. Particular care will be required during grading to maintain slopes, swales, and other erosion control measures needed to direct runoff toward permanent surface drainage facilities. Positive drainage of at least 2% away from the perimeters of the structures and site pavements should be incorporated into the design. In addition, it is recommended that nuisance water be directed away from the perimeter of the structures by the use of area drains in adjacent landscape and flatwork areas and roof drains tied into the site storm drain system. UTILITY TRENCH BACKFILL CONSIDERATIONS General New utility line pipelines should be backfilled with both select bedding materials beneath and around the pipes and compacted soil above the pipe bedding. Recommendations for the types of the materials to be used and the proper placement of these materials are provided in the following sections. Pipe Bedding The pipe bedding materials should extend from at least 6 inches below the pipes to at least 12 inches above the crown of the pipes. Pipe bedding should consist of either clean sand with a sand equivalent (SE) of at least 30 or crushed rock. If crushed rock is used, it should consist of ¾-inch crushed rock that conforms to Table 200-1.2 of the 2018 “Greenbook.” Pipe bedding should also meet the minimum requirements of the City of Carlsbad. If the requirements of the County are more stringent, they should take precedence over the geotechnical recommendations. Sufficient laboratory testing should be performed to verify the bedding meets the minimum requirements of the Greenbook. Based on our subsurface exploration and knowledge of the onsite materials, the soils that will be excavated from the pipeline trenches will not meet the recommendations for pipe bedding materials; therefore, imported materials will be required for pipe bedding. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 18 GMU Project 18-101-00 Granular pipe bedding material having a sand equivalent of 30 or greater should be properly placed in thicknesses not exceeding 3 feet, and then sufficiently flooded or jetted in place. With proper techniques, flooding or jetting is not expected to have an adverse impact on existing site soils. Crushed rock, if used, should be capped with filter fabric (Mirafi 140N, or equivalent) to prevent the migration of fines into the rock. Trench Backfill All existing soil material within the limits of the pipeline alignment are considered suitable for use as trench backfill above the pipe bedding zone if care is taken to remove all significant organic and other decomposable debris, moisture condition the soil materials as necessary, and separate and selectively place and/or stockpile any inert materials larger than 6 inches in maximum diameter. Imported soils are not anticipated for backfill since the on-site soils are suitable. However, if imported soils are used, the soils should consist of clean, granular materials with physical and chemical characteristics similar to those described herein for on-site soils. Any imported soils to be used as backfill should be evaluated and approved by GMU prior to placement. Soils to be used as trench backfill should be moistened, dried, or blended as necessary to achieve a minimum of 2% over optimum moisture content for compaction, placed in loose lifts no greater than 8 inches thick, and mechanically compacted/densified to at least 90% relative compaction as determined by ASTM Test Method D 1557. No rock or broken concrete greater than 6 inches in maximum diameter should be utilized in the trench backfills. ASPHALT CONCRETE PAVEMENT THICKNESS RECOMMENDATIONS Asphalt Pavement Design Based on the R-value test results, as well as testing completed in the vicinity, an R-value of 50 was used for the design. The table below provides recommended minimum thicknesses for asphalt concrete (AC) and aggregate base sections for two traffic indices. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 19 GMU Project 18-101-00 Recommended Minimum AC and Base Section Thicknesses Location R-Value Traffic Index Asphalt Concrete (in.) Aggregate Base* (in.) Driveways Parking Stalls 50 50 5.5 4.0 4.0 3.0 4.0 4.0 * assumed R-Value = 78 Asphalt concrete pavement construction should be in accordance with the following recommendations: • The planned pavement structural sections should consist of aggregate base materials (AB) and asphalt concrete materials (AC) of a type meeting the minimum Caltrans and City of Carlsbad requirements. • The subgrade soils should be prepared in accordance with the Corrective Grading section of this report. • The AB and AC should be compacted to at least 95% relative compaction. CONCRETE PAVEMENT THICKNESS RECOMMENDATIONS It is anticipated that Portland Cement Concrete (PCC) pavement will be constructed as part of the drive way approaches. The table below provides minimum PCC pavement section constructed over properly prepared subgrade and AB section. Recommended Minimum PCC and Base Section Thicknesses Location R-Value Traffic Index PCC (in.) Aggregate Base* (in.) Driveways 50 6.0 6.0 4.0 * assumed R-Value = 78 Concrete pavement construction should be in accordance with the following recommendations: • The pavement structural sections should consist of aggregate base materials (AB) and Portland Cement Concrete (PCC). • The subgrade soils should be prepared in accordance with the Corrective Grading section of this report. • The AB should be compacted to at least 95% relative compaction. I I I Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 20 GMU Project 18-101-00 PERMEABLE PAVER DESIGN Permeable Concrete Interlocking Vehicular Paver Design We understand that permeable concrete interlocking vehicular pavers will be constructed as part of this project and will be utilize as additional measure to infiltrate stormwater into the site soils, while any overflow will be directed towards planter areas where they will be treated. Based on our understanding, we have developed the following general recommendations: • The soil subgrade below the permeable paver sections should only be cut to grade and should not be processed or compacted so that it remains permeable. A geotextile filter fabric, such as Mirafi 160N or equivalent, should be installed on the cut grade under the paver section. • In areas where the pavers are adjacent to hardscape, slopes, buildings, or curbs, it is recommended that an impermeable liner be placed on the exposed soil just below and at the edge of the vertical sides of the base course along the vertical edges of the hardscape, slopes, building or patio slabs, and curbs. • Construct the 80 mm permeable paver over 2-inches of bedding sand, also used for the joint and void filler between the pavers (ASTM No. 8 aggregate), over at least 6 inches of ¾-inch washed base course (ASTM No. 57 aggregate) as an open-graded base. o Pavers should be least 80 MM in thickness and have an aspect ratio of less than or equal to 3:1 (the length of the paver should be less 3 times or less the thickness of the paver) should then be placed over the compacted bedding sand. The pavers should be installed per the manufacture specifications. • The layers of No. 57 and No. 8 aggregate should be placed, moisture conditioned to at least optimum moisture, and lightly compacted using a static roller. Over-compaction of the materials will decrease their infiltration rates and storage capacities. CONCRETE FLATWORK DESIGN Due to the moderately expansive nature of the on-site soils, we recommend that the subgrade for the subject concrete flatwork be moisture conditioned to 2% over optimum to a depth of 12 inches below finish grade and compacted to 90% relative compaction. A 6-inch-thick section of Class 2 aggregate base (AB) or crushed miscellaneous base (CMB) should then be placed on the compacted subgrade soils, brought to optimum moisture condition, and compacted to 95% relative compaction prior to placement of flatwork reinforcing steel and concrete. For Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 21 GMU Project 18-101-00 flatwork concrete underlain by aggregate base, Type II/V cement with a maximum water/cement ratio of 0.50 may be used. Please refer to the Concrete Flatwork Table below for a summary of our flatwork recommendations: Description Subgrade Preparation (1) Aggregate Base (Class 2 or CMB) (2) Minimum Concrete Thickness Reinforcement(3) Expansion Joint Spacing (4) (Maximum) Concrete(5) Concrete Paving (flatwork/stair/curb adjacent) 2% over optimum to 12-inches at 90% relative compaction 6-inch- thick section at 95% relative compaction 5-inches No. 3 bars @ 18”o.c.b.w. and dowel into building and curb using 9-inch Speed Dowels @ 18"o.c 10-foot x 10- foot using 9-inch speed dowels with No. 3 bars @ 18" o.c. Type II/V (1) The moisture content and compaction of the subgrade must be verified by the geotechnical consultant prior to base placement. (2) For pedestrian usages only, S.E. 30 sand may be used instead of Aggregate Base or CMB. (3) Reinforcement to be placed in the middle of the recommended concrete section. (4) Control Joints: Suggested spacing of Pedestrian areas at 10’. (5) Final concrete mix design to be supplied by others. PLANTERS AND TREES Where new trees or large shrubs are to be located in close proximity of new concrete flatwork, rigid moisture/root barriers should be placed around the perimeter of the flatwork to at least 2 feet in depth in order to offer protection to the adjacent flatwork against potential root and moisture damage. Existing mature trees near flatwork areas should also incorporate a rigid moisture/root barrier placed at least 2 feet in depth below the top of the flatwork. BIORETENTION AREAS If bioretention area are incorporated into the design, we recommend that an impermeable liner be installed at the bottom and in the sides of all bioretention areas at the subject site to prevent lateral water migration into the adjacent structures and pavements. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 22 GMU Project 18-101-00 PLAN REVIEW / GEOTECHNICAL TESTING DURING GRADING / FUTURE REPORT Plan Review GMU should review the final construction plans (grading and foundation plans) to confirm that they are consistent with our recommendations provided in this report. Geotechnical Testing Geotechnical observation and testing should be performed by GMU during the following stages of precise grading and construction: • During site clearing and grubbing. • During removal of any buried irrigation lines or other subsurface structures. • During all phases of grading including over-excavation, temporary excavations, removals, scarification, ground preparation, moisture conditioning, proof-rolling, and placement and compaction of all fill materials. • During grading for the proposed car dealership building. • During pavement and flatwork section placement and compaction. • Foundation slab construction. • When any unusual conditions are encountered. Future Report If required, a report summarizing our construction observation/testing services will be prepared at project completion. LIMITATIONS All parties reviewing or utilizing this report should recognize that the findings, conclusions, and recommendations presented represent the results of our professional geological and geotechnical engineering efforts and judgments. Due to the inexact nature of the state of the art of these professions and the possible occurrence of undetected variables in subsurface conditions, we cannot guarantee that the conditions actually encountered during grading and site construction will be identical to those observed, sampled, and interpreted during our study, or that there are no unknown subsurface conditions which could have an adverse effect on the use of the property. We have exercised a degree of care comparable to the standard of practice presently maintained by other professionals in the fields of geotechnical engineering and engineering Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 23 GMU Project 18-101-00 geology, and believe that our findings present a reasonably representative description of geotechnical conditions and their probable influence on the grading and use of the property. Our conclusions and recommendations are based on the assumption that our firm will act as the geotechnical engineer of record during construction and grading of the project to observe the actual conditions exposed, to verify our design concepts and the grading contractor's general compliance with the project geotechnical specifications, and to provide our revised conclusions and recommendations should subsurface conditions differ significantly from those used as the basis for our conclusions and recommendations presented in this report. Since our conclusions and recommendations are based on a limited amount of current and previous geotechnical exploration and analysis, all parties should recognize the need for possible revisions to our conclusions and recommendations during grading of the project. It should be further noted that the recommendations presented herein are intended solely to minimize the effects of post-construction soil movements. Consequently, minor cracking and/or distortion of all on-site improvements should be anticipated. This report has not been prepared for the use by other parties or projects other than those named or described herein. This report may not contain sufficient information for other parties or other purposes. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 24 GMU Project 18-101-00 CLOSURE If you have any questions concerning our findings or recommendations, please do not hesitate to contact us and we will be happy to discuss them with you. The Plates and Appendices which complete this report are listed in the Table of Contents. Respectfully submitted, Nadim Sunna, M.Sc., P.E. 84197 Senior Engineer Lisa Bates, PG, CEG 2293 Associate Engineering Geologist David R. Atkinson Senior Engineer/Project Manager dra/18-101-00R (12-13-19) Mr. Axay Patel, AUTONATION Geotechnical Investigation Report – AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 25 GMU Project 18-101-00 REFERENCES SITE-SPECIFIC REFERENCES (1)BMW of Carlsbad Conceptual Grading Plan, SDP/CDP Submittal, prepared by Commercial Development Resources, dated November 4, 2019. (2)Woodward-Clyde Consultants, "Geotechnical Investigation, Car County Expansion, Carlsbad,California," Woodward-Clyde Consultants Project No. 8751256Y-S101, dated August 19, 1987. (3)Kleinfelder, "Report of Testing and Observation During Grading, Car County CarlsbadExpansion, Carlsbad, California," Kleinfelder Project No. 51-1380-01, dated August 4, 1988. TECHNICAL REFERENCES California Building Standards Commission and International Conference of Building Officials, 2016, 2016 California Building Code. Draft Program Environmental Impact Report for the Carlsbad General Plan Update, Chapter 3.5: Geology, Soils and Seismicity. FEMA, 2012, Flood Insurance Rate Map, San Diego County, California and Incorporated Areas, Map Number 06073C0764G, dated May 16. Idriss, I.M., and Boulanger, R.W., 2008, Soil Liquefaction During Earthquakes: Earthquake Engineering Research Institute. Ishihara, K., 1985, Stability of Natural Deposits During Earthquakes, Proceedings, 11th International Conference on Soil Mechanics and Foundation Engineering, pp. 321-376. Pradel, D., 1998, Procedure to Evaluate Earthquake-Induced Settlements in Dry Sandy Soils, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 124, No. 4, pgs. 364-368. Standard Specifications for Public Works Construction, by Public Works Standards, Inc., 2018, The Greenbook 2018 Edition. State of California, 2009, Tsunami Inundation Map for Emergency Planning, County of San Diego, Oceanside Quadrangle / San Luis Rey Quadrangle, dated June 1. U.S. Geological Survey, 2013a, 2014 Interactive De-aggregations Program; web site address: http://geohazards.usgs.gov/deaggint/2008/. U.S. Geological Survey, 2013b, U.S. Seismic Design Maps, web site address: http://earthquake.usgs.gov/hazards/designmaps/usdesign.php. Date: Project No.: Plate Location Map 18-101-00 December 13, 2019 1 00 800' PROJECT LOCATION 1050 AUTO CENTER DR CARLSBAD, CA 0 C: C: ol E ,5 0 z ,.: ID ~ ~ ~ ci ~ 0 ...J Q. ~ ~ 0 E C: 0 :g 0 .2 0 0 5 /ii (X) 5 "' ~ \ corlsbod Flower Fields --.____ ________ ---=----------------- c.tJ' ■ I it t • -, \ .:: ~ \ ~ <2., l iii Legolan~ California I") •I ' -~~~ FILLCUT FI L L C U T FILLCUTCAR C O U N T R Y D R CANNON RDAUTO CENTER CTDate:Project No.:PlateGeotechnical Map18-101-00December 13, 201920040'GEOTECHNICAL LEGEND DH-7APPROXIMATE LOCATION OFDH-1DH-3DH-4DH-5DH-6DH-7DH-2PROPOSED BORINGSAPPROXIMATE CUT/FILL LINE TO BE FIELDVERIFIEDI "' I 0 0 0 cii 3 " 0 0 I 0 'T <XI I 0 0 A I I I S~RS[)G-27. I E TOP OF WALL ELEVATION PER GRADING PLAN NATIVE SOIL CAP WATERPROOFING (see Notes 3 and 4) (see Note 6) Minimum NATIVE OR Width=2' SELECT SOIL BACKFILL SELECT GRANULAR BACKFILL MATERIAL (see Note 2) BACKCUT PER SOILS REPORT AND OSHA PROPOSED FINISH REQUIREMENTS GRADE ELEVATION TOP OF FOOTING ELEVATION PER GRADING PLAN BACK DRAIN (SEE NOTES 7 AND 8) FOOTING PER STRUCTURAL DETAILS RETAINING WALL DETAIL NOT TO SCALE 1. FINAL DETERMINATION OF THE MATERIAL TO BE USED FOR BACKFILL SHALL BE MADE BY GMU. 2. ALL SELECT BACKFILL TO WITHIN 1 TO 2 FEET OF FINAL GRADE SHOULD CONSIST OF FREE-DRAINING GRANULAR MATERIAL (I.E. SE 30 SAND, PEA GRAVEL, OR CRUSHED ROCK). CRUSHED ROCK, IF USED, SHOULD BE WRAPPED IN FILTER FABRIC (MIRAFI 140N OR EQUIVALENT) TO MINIMIZE THE POTENTIAL FOR MIGRATION OF FINES INTO THE ROCK. THE SELECT BACKFILL SHOULD BE MOISTURE CONDITIONED TO ACHIEVE OVER OPTIMUM MOISTURE CONTENT PER THE SOILS REPORT AND COMPACTED TO AT LEAST 90% RELATIVE COMPACTION AS DETERMINED BY ASTM TEST METHOD D 1557. 3. FINE-GRAINED NATIVE SOILS SHOULD BE USED TO CAP THE SELECT BACKFILL ZONE. 4. ALL NATIVE OR SELECT SOIL WALL BACKFILL SHOULD BE MOISTURE CONDITIONED AS NECESSARY TO OVER OPTIMUM MOISTURE CONTENT PER THE SOILS REPORT AND COMPACTED TO AT LEAST 90% RELATIVE COMPACTION AS DETERMINED BY ASTM TEST METHOD D 1557. 5. THE BACKSIDE OF THE WALLS SHOULD BE WATERPROOFED DOWN TO AND ACROSS THE TOP OF THE FOOTING. THE DESIGN AND SELECTION OF THE WATERPROOFING SYSTEM IS OUTSIDE OF THE PURVIEW OF GMU. 6. THE WATERPROOFING SYSTEM AND ANY DRAIN BOARDS SHOULD BE PROTECTED FROM DAMAGE BY CONSTRUCTION ACTIVITIES. THE TOP EDGE OF THE WATERPROOFING AND ANY DRAIN BOARDS SHOULD BE PROPERLY ADHERED TO THE WALL AND SEALED TO PREVENT THE POSSIBLE ACCUMULATION OF DEBRIS BETWEEN THE DRAINAGE/WATERPROOFING SYSTEM AND THE WALL. 7. THE BACKDRAIN SYSTEM SHOULD CONSIST OF 4" PERFORATED PIPE SURROUNDED BY AT LEAST ONE CUBIC FOOT OF 3/4"-1.5" OPEN GRADED GRAVEL WRAPPED IN MIRAFI 140 N FILTER FABRIC (OR EQUIVALENT). THE PERFORATED PIPE SHOULD CONSIST OF SDR-35 OR SCHEDULE 40 PVC PIPE (OR APPROVED EQUIVALENT) LAID ON AT LEAST 2" OF CRUSHED ROCK WITH THE PERFORATIONS LAID DOWN. THE BACKDRAIN GRADIENT SHOULD NOT BE LESS THAN 1% WHEN POSSIBLE. THE PERFORATED PIPE SHOULD OUTLET INTO AREA DRAINS OR OTHER SUITABLE OUTLET POINTS AT RUNS OF 200 FEET OR LESS, IF PRACTICAL. IF THE BACKDRAINS CANNOT BE OUTLETED BY GRAVITY FLOW, A SUMP PUMP SYSTEM WILL NEED TO BE DESIGNED AND CONSTRUCTED. REDUNDANT BACK-UP PUMPS OR COMPONENTS ARE RECOMMENDED. DESIGN OF THIS SYSTEM IS OUTSIDE OF THE PURVIEW OF GMU. 8. THE TIE-IN LOCATIONS FOR BACKDRAIN OUTLETS SHOULD BE SHOWN ON THE PRECISE GRADING, SITE WALL, AND/OR LANDSCAPE PLANS. RETAINING WALL CONSTRUCTION DETAIL PLATE 3 APPENDIX A Geotechnical Exploration Procedures and Drill Hole Logs by GMU Geotechnical, Inc. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report — AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 A-1 GMU Project 18-101-00 APPENDIX A GMU GEOTECHNICAL EXPLORATION PROCEDURES AND LOGS Our exploration at the subject site consisted of one (1) hollow-stem auger drill hole within the site to a maximum depth of 50 feet, four (4) hollow-stem auger drill hole within the site to a maximum depth of 20 feet, and two (2) hollow-stem auger drill hole within the site to a maximum depth of 5 feet in order to provide subsurface information for pavement design, continuous soil data for the dealership building foundation design, and percolation tests. The approximate locations of the drill holes are shown on Plate 2 – Geotechnical Map. Our drill holes were logged, and “undisturbed” samples were taken using a 3.0-inch outside-diameter drive sampler which contains a 2.416-inch-diameter brass sample sleeve 6 inches in length. In addition, blow counts recorded during sampling from the drive sampler are shown on the drill hole logs. Standard penetration testing (SPTs) were also taken in the rotary wash drill holes. Small bulk samples of the material were collected, and blow counts for each SPT and sleeve sample were recorded on the logs. Bulk samples of the soil materials were also collected from some of the drill holes. The logs of each drill hole are contained in this Appendix A, and the Legend to Logs is presented as Plate A-1 and A-2. The geologic and engineering field descriptions and classifications that appear on these logs are prepared according to Corps of Engineers and Bureau of Reclamation standards. Major soil classifications are prepared according to the Unified Soil Classification System as modified by ASTM Standard No. 2487. Since the descriptions and classifications that appear on the Log of Drill Hole are intended to be that which most accurately describe a given interval of a drill hole (frequently an interval of several feet), discrepancies do occur in the Unified Soil Classification System nomenclature between that interval and a particular sample in that interval. For example, an 8-foot-thick interval in a log may be identified as silty sand (SM) while one sample taken within the interval may have individually been identified as sandy silt (ML). This discrepancy is frequently allowed to remain to emphasize the occurrence of local textural variations in the interval. 1%3%5% 10%15% 20% LEGEND TO LOGS ASTM Designation: D 2487 (Based on Unified Soil Classification System) P8-11/16/2012 Plate A-2 MOISTURE CONTENT Dry- Very little or no moisture Damp- Some moisture but less than optimum Moist- Near optimum Very Moist- Above optimum Wet/Saturated- Contains free moisture The descriptive terminology of the logs is modified from current ASTM Standards to suit the purposes of this study SAMPLE SYMBOLS Undisturbed Sample(California Sample) Bulk Sample UnsuccessfulSampling Attempt SPT Sample 10: 10 Blows for 12-Inches Penetration6/4: 6 Blows Per 4-Inches PenetrationP: Push(13): Uncorrected Blow Counts ("N" Values)for 12-Inches Penetration- StandardPenetration Test (SPT) Undisturbed Sample(Shelby Tube) LEGEND TO LOGSASTM Designation: D 2487(Based on Unified Soil Classification System) P8-11/16/2012 Plate A-1 DS = Direct Shear HY = Hydrometer Test TC = Triaxial Compression Test UC = Unconfined Compression CN = Consolidation Test (T) = Time Rate EX = Expansion Test CP = Compaction Test PS = Particle Size Distribution EI = Expansion Index SE = Sand Equivalent Test AL = Atterberg Limits FC = Chemical Tests RV = Resistance Value SG = Specific Gravity SU = Sulfates CH = Chlorides MR = Minimum Resistivity pH (N) = Natural Undisturbed Sample (R) = Remolded Sample ADDITIONAL TESTS CS = Collapse Test/Swell-Settlement Well Graded Gravels and Gravel-Sand Mixtures,Little or No Fines. Poorly Graded Gravels and Gravel-Sand MixturesLittle or No Fines. Silty Gravels, Gravel-Sand-Silt Mixtures. Clayey Gravels, Gravel-Sand-Clay Mixtures. Well Graded Sands and Gravelly Sands, Little or No Fines. Poorly Graded Sands and Gravelly Sands, Little or No Fines. Silty Sands, Sand-Silt Mixtures. Clayey Sands, Sand-Clay Mixtures. Inorganic Silts, Very Fine Sands, Rock Flour, Silty orClayey Fine Sands or Clayey Silts With Slight Plasticity. Inorganic Clays of Low To Medium Plasticity,Gravelly Clays, Sandy Clays, Silty Clays, Lean Clays. Organic Silts and Organic Silty Clays of Low Plasticity Inorganic Silts, Micaceous or Diatomaceous Fine Sandyor Silty Soils, Elastic Silts. Inorganic Clays of High Plasticity, Fat Clays. Organic Clays of Medium To High Plasticity, Organic Silts. Peat and Other Highly Organic Soils. CleanGravels Gravels WithFines GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT CleanSands SandsWithFines FINE-GRAINED SOILS50% or More PasseThe No.200 Sieve Based on The Material Passing The 3-Inch(75mm) Sieve. Reference:ASTM Standard D2487 COARSE-GRAINED SOILSMore Than 50% RetainedOn No.200 Sieve Based on The MaterialPassing The 3-Inch (75mm) Sieve. Reference: ASTM Standard D2487 HIGHLY ORGANIC SOILS SANDSMore Than 50%of Coarse FractionPassesNo.4 Sieve GRAVELS50% or More ofCoarse FractionRetained onNo.4 Sieve SILTS AND CLAYS Liquid Limit 50% or Greater SILTS AND CLAYS Liquid Limit Less Than 50% MAJOR DIVISIONS TYPICAL NAMES SymbolGroup LetterThe descriptive terminology of the logs is modified from current ASTM Standards to suit the purposes of this study SOIL DENSITY/CONSISTENCY Consistency Field Test SPT (#blows/foot) Mod (#blows/foot) Very Soft Easily penetrated by thumb, exudes between fingers Soft Easily penetrated one inch by thumb, molded by fingers Firm Penetrated over 1/2 inch by thumb withmoderate effort Stiff Penetrated about 1/2 inch by thumb with great effort Very Stiff Readily indented by thumbnail Hard Indented with difficultybythumbnail FINE GRAINED Density Field Test SPT (#blows/foot) Mod (#blows/foot) Very Loose Easily penetrated with 0.5"rod pushed by hand Loose Easily penetrated with 0.5"rod pushed by hand Medium Dense Easily penetrated 1' with 0.5"rod driven by 5lb hammer Dense Dificult to penetrat 1' with 0.5"rod driven by5lb hammer Very Dense Penetrated few inches with 0.5"rod driven by 5lb hammer COARSE GRAINED <2 2-4 4-8 8-15 15-30 >30 <3 3-6 6-12 12-25 25-50 >50 <4 4-10 10-30 31-50 >50 <5 5-12 12-35 35-60 >60 BEDROCK HARDNESS Density Field Test SPT (#blows/foot) Soft Can be crushed by hand, soil like and structureless Moderately Hard Can be groovedwith fingernails, crumbles with hammer Hard Can't break byhand, can be grooved with knife Very Hard Scratches with knife, chips with hammerblows 1-30 30-50 50-100 >100 Sieve Size Grain Size Approximate Size >12">12"Largerthan a basketball 3-12"3-12"Fist-sized to basketball-sized Coarse 3/4-3"3/4-3"Thumb-sized to fist-sized Fine #4-3/4"0.19-0.75"Pea-sized to thumb-sized Coarse #10-#4 0.079-0.19"Rock-salt-sized to pea-sized Medium #40-#10 0.017-0.079"Sugar-sized to rock salt-sized Fine #200-#40 0.0029-0.017"Flour-sized to sugar-sized Fines passing #200 <0.0029"Flour-sized and smaller Description Boulders Cobbles Gravel Sand GRAIN SIZEGEOLOGIC NOMENCLATURE B = Bedding C = Contact J = Joint S = ShearF = Fracture Flt = Fault = Groundwater RS = Rupture Surface = Seepage MODIFIERS Trace FewSome Numerous Abundant 1% 1-5% 5-12% 12-20% >20% []] [!] []] []] []] Hd= ~~ -~= CE{ ~ ·r:r .• .. b.?. 5-?. 111 1111 ~ -_a_ --- 1%3%5% 10%15% 20% LEGEND TO LOGS P8-11/16/2012 Plate A-2 MOISTURE CONTENT Dry- Very little or no moisture Damp- Some moisture but less than optimum Moist- Near optimum Very Moist- Above optimum Wet/Saturated- Contains free moisture The descriptive terminology of the logs is modified from current ASTM Standards to suit the purposes of this study SAMPLE SYMBOLS Undisturbed Sample(California Sample) Bulk Sample UnsuccessfulSampling Attempt SPT Sample 10: 10 Blows for 12-Inches Penetration6/4: 6 Blows Per 4-Inches PenetrationP: Push(13): Uncorrected Blow Counts ("N" Values)for 12-Inches Penetration- StandardPenetration Test (SPT) Undisturbed Sample(Shelby Tube) LEGEND TO LOGSASTM Designation: D 2487(Based on Unified Soil Classification System) P8-11/16/2012 Plate A-1 DS = Direct Shear HY = Hydrometer Test TC = Triaxial Compression Test UC = Unconfined Compression CN = Consolidation Test (T) = Time Rate EX = Expansion Test CP = Compaction Test PS = Particle Size Distribution EI = Expansion Index SE = Sand Equivalent Test AL = Atterberg Limits FC = Chemical Tests RV = Resistance Value SG = Specific Gravity SU = Sulfates CH = Chlorides MR = Minimum Resistivity pH (N) = Natural Undisturbed Sample (R) = Remolded Sample ADDITIONAL TESTS CS = Collapse Test/Swell-Settlement Well Graded Gravels and Gravel-Sand Mixtures,Little or No Fines. Poorly Graded Gravels and Gravel-Sand MixturesLittle or No Fines. Silty Gravels, Gravel-Sand-Silt Mixtures. Clayey Gravels, Gravel-Sand-Clay Mixtures. Well Graded Sands and Gravelly Sands, Little or No Fines. Poorly Graded Sands and Gravelly Sands, Little or No Fines. Silty Sands, Sand-Silt Mixtures. Clayey Sands, Sand-Clay Mixtures. Inorganic Silts, Very Fine Sands, Rock Flour, Silty orClayey Fine Sands or Clayey Silts With Slight Plasticity. Inorganic Clays of Low To Medium Plasticity,Gravelly Clays, Sandy Clays, Silty Clays, Lean Clays. Organic Silts and Organic Silty Clays of Low Plasticity Inorganic Silts, Micaceous or Diatomaceous Fine Sandyor Silty Soils, Elastic Silts. Inorganic Clays of High Plasticity, Fat Clays. Organic Clays of Medium To High Plasticity, Organic Silts. Peat and Other Highly Organic Soils. CleanGravels Gravels WithFines GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT CleanSands SandsWithFines FINE-GRAINED SOILS50% or More PasseThe No.200 Sieve Based on The Material Passing The 3-Inch(75mm) Sieve. Reference:ASTM Standard D2487 COARSE-GRAINED SOILSMore Than 50% RetainedOn No.200 Sieve Based on The MaterialPassing The 3-Inch (75mm) Sieve. Reference: ASTM Standard D2487 HIGHLY ORGANIC SOILS SANDSMore Than 50%of Coarse FractionPassesNo.4 Sieve GRAVELS50% or More ofCoarse FractionRetained onNo.4 Sieve SILTS AND CLAYS Liquid Limit 50% or Greater SILTS AND CLAYS Liquid Limit Less Than 50% MAJOR DIVISIONSTYPICAL NAMES SymbolGroup LetterThe descriptive terminology of the logs is modified from current ASTM Standards to suit the purposes of this study SOIL DENSITY/CONSISTENCY Consistency Field Test SPT (#blows/foot) Mod (#blows/foot) Very Soft Easily penetrated by thumb, exudes between fingers Soft Easily penetrated one inch by thumb, molded by fingers Firm Penetrated over 1/2 inch by thumb with moderate effort Stiff Penetrated about 1/2 inch by thumb with great effort Very Stiff Readily indented by thumbnail Hard Indented with difficulty by thumbnail FINE GRAINED Density Field Test SPT (#blows/foot) Mod (#blows/foot) Very Loose Easily penetrated with 0.5" rod pushed by hand Loose Easily penetrated with 0.5" rod pushed by hand Medium Dense Easily penetrated 1' with 0.5" rod driven by 5lb hammer Dense Dificult to penetrat 1' with 0.5" rod driven by 5lb hammer Very Dense Penetrated few inches with 0.5" rod driven by 5lb hammer COARSE GRAINED <2 2-4 4-8 8-15 15-30 >30 <3 3-6 6-12 12-25 25-50 >50 <4 4-10 10-30 31-50 >50 <5 5-12 12-35 35-60 >60 BEDROCK HARDNESS Density Field Test SPT (#blows/foot) Soft Can be crushed by hand, soil like and structureless Moderately Hard Can be grooved with fingernails, crumbles with hammer Hard Can't break by hand, can be grooved with knife Very Hard Scratches with knife, chips with hammer blows 1-30 30-50 50-100 >100 Sieve Size Grain Size Approximate Size >12">12"Larger than a basketball 3-12"3-12"Fist-sized to basketball-sized Coarse 3/4-3"3/4-3"Thumb-sized to fist-sized Fine #4-3/4"0.19-0.75"Pea-sized to thumb-sized Coarse #10-#4 0.079-0.19"Rock-salt-sized to pea-sized Medium #40-#10 0.017-0.079"Sugar-sized to rock salt-sized Fine #200-#40 0.0029-0.017"Flour-sized to sugar-sized Fines passing #200 <0.0029"Flour-sized and smaller Description Boulders Cobbles Gravel Sand GRAIN SIZE GEOLOGIC NOMENCLATURE B = BeddingC = ContactJ = Joint S = ShearF = FractureFlt = Fault = Groundwater RS = Rupture Surface= Seepage MODIFIERS Trace Few Some Numerous Abundant 1% 1-5% 5-12% 12-20% >20% ASTM Designation: D 2487 (Based on Unified Soil Classification System) ru11 '-11..,ILI 5 107 13 15 15 6 50/4" 6 9 24 ASPHALT CONCRETE (approximately2.5 inches) CRUSHED AGGREGATE BASE(approximately 3 inches) SILTY SANDSTONE (SM); dark brown,damp, medium dense to dense,fine-grained sand SILTY SANDSTONE (SM); orange brown, damp, medium dense to dense,fine-grained sand POORLY GRADED SANDSTONE (SP);light brown to orange brown, very dense, fine grained sand with trace gravel grayish brown CLAYSTONE (CH); gray, moist to very moist, hard ASPHALT CRUSHED AGGREGATE BASE SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 103.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet21.5 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 95 90 85 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 2 5 10 15 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-1 Project Number: 18-101-00 Drill Hole DH-1 5 10 15 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19-= I -:.~·· . :··.: · . ...:..,..·, 11~-----~,>< I ?< ~-----~_>< .>< >< >< >< >< \.( ----------------------- ----------------------- E ~ ' ~ :s ,.~ .. '-IITIU ---------------- 8 10450(6") moist, trace yellow sand Total Depth: 21.5 feetNo Groundwater ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 2 of 2 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-1 Project Number: 18-101-00 Drill Hole DH-1DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19L ,--- ,.~ .. ..... '-II IU 13 8 114 100 21 33 50 16 35 50 22 50/2" ASPHALT CONCRETE (approximately2.5 inches) CRUSHED AGGREGATE BASE(approximately 3 inches) POORLY GRADED SANDSTONE (SP);dark brown, damp, dense to very dense,fine-grained sand brown SILTY SANDSTONE (SM); orange brown, moist, very dense, fine- to- mediumcoarse-grained sand, some gravel light gray, damp to moist, fine-grainedsand medium to coarse-grained sand. ASPHALT CRUSHED AGGREGATE BASE SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 105.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet21.5 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 95 90 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 2 5 10 15 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-2 Project Number: 18-101-00 Drill Hole DH-2 5 10 15 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19-= I .. ·. \"'======~-__JI -.--:- I T -·.:.,-:- ••••••••• .. · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . . ... .. . . · . . · ·.:-:: .· ·.:-:: .· ·.:-:: .· ·_::: 11~-----~,>< I ?< ~----~_>< .>< )< )< )< )< ____________________ )<"1------1---+---+---+----I - - ,.~ .. '-IITIU ---------------- 50(6")fine-grained sand Total Depth: 20.5 feetNo Groundwater ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 2 of 2 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-2 Project Number: 18-101-00 Drill Hole DH-2DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19:1 :· J: ~ ,.~. I ..... '-II IU 3 7 1079 116 15 27 50 11 17 19 17 32 45 ASPHALT CONCRETE (approximately2.5 inches) CRUSHED AGGREGATE BASE(approximately 3 inches) SILTY SAND (SM); brown, damp to moist,dense to very dense, fine-grained sand POORLY GRADED SANDSTONE with SILT (SP-SM); light brown with someyellow, moist, very dense, fine grainedsand POORLY GRADED SANDSTONE (SP);brown with some dark yellow, moist,dense dark brown, very dense, medium coarse-grained sand. ASPHALT CRUSHED AGGREGATE BASE ENGINEERED FILL (Qafc) SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 103.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet51.5 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 95 90 85 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 3 5 10 15 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-3 Project Number: 18-101-00 Drill Hole DH-3 5 10 15 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19-= I 1:.-.•:. , ... · :· ·-. 1·.-.•:. 1:---. .-: 1:.-.•:. , ... · :· ·-. 1·.-.•:. 1:---. .-: 11~------~,>< I ?< ~-----~_>< .>< - - -----------------------' :s 0 - ,.~ .. '-IITIU ---------------- 4 10 104 104 11 12 17 15 50/6" 5 9 10 15 26 50 7 13 17 light brown to brown, medium dense,fine-grained sand brown to dark brown light to dark brown with some black, dry todamp, very dense SILTY SANDSTONE (SM); moist, mediume dense, fine-grained sand gray with some yellow, slightly moist, verydense POORLY GRADED SANDSTONE (SP);gray with some yellow, damp, medium tocoarse-grained sand dark gray, damp, medium dense gray SILTY SANDSTONE (SM); dark gray,damp, very dense ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA 80 75 70 65 60 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 2 of 3 25 30 35 40 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-3 Project Number: 18-101-00 Drill Hole DH-3 25 30 35 40 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19E ~----------------~-+--+---+------,f--+-----1 ~ ~ -------.c -- - · . ...:..,.., -------------------+---+---+------,f---+------1 - ~-----------------+--+---+---+------,f---+------1 ,.~ .. '-IITIU ---------------- 12 10937 50 18 31 44 grayish yellowish brown, fine- to- mediumcoarse-grained sand Total Depth: 51.5 feet No Groundwater ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA 55 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 3 of 3 50 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-3 Project Number: 18-101-00 Drill Hole DH-3 50 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19-.. I'-'-'---'+---------+--+-------------------1--'1----+----+--+--I-----I ,.~ .. '-IITIU ---------------- 28 94 7 10 19 9 17 23 8 12 17 ASPHALT CONCRETE (approximately 3inches) CRUSHED AGGREGATE BASE(approximately 4 inches) SILTY SANDSTONE (SM); dark brown,damp, fine to medium coarse-grainedsand POORLY GRADED SANDSTONE (SP); light to orange brown, damp, mediumdense, fine- to- medium coarse-grainedsand SANDY CLAYSTONE (CL); gray, moist, very stiff, fine-grained sand SILTY SANDSTONE (SM); orangishbrown, moist, medium dense, mediumcoarse-grained sand ASPHALT CRUSHED AGGREGATE BASE SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 101.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet21.5 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 95 90 85 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 2 5 10 15 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-4 Project Number: 18-101-00 Drill Hole DH-4 5 10 15 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19. -::".-:''-=========~--__/' ···.: ···.· ~ ···.: ···.: ···.: ···.: .. ,~----------~, ~>( ~---------~' >< ~>( ------------------<=-"-+---+--+----I--+--- --------------------+--+--+--I--+--- - ~------------------+--+--+--I--+--- ,.~ .. '-IITIU ---------------- 13 12015 27 50 orangish brown with some yellow, verydense Total Depth: 21.5 feetNo Groundwater ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA 80 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 2 of 2 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-4 Project Number: 18-101-00 Drill Hole DH-4DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19- I--'---"-+-------+------+-- - - - - - - - - - - - - - -------+---+--+---+----I ,.~ .. '-IITIU ---------------- 7 4 124 114 21 33 50 7 12 14 50/5" ASPHALT CONCRETE (approximately 3inches) CRUSHED AGGREGATE BASE(approximately 4 inches) SILTY SAND (SM); brown, damp,fine-grained sand SILTY SANDSTONE (SM); dark brown, damp, very dense, medium grained sand,trace roots and gravel POORLY GRADED SANDSTONE (SP);brown to dark brown, damp, mediumdense to very dense, fine- to- medium coarse-grained sand, trace silt ASPHALT CRUSHED AGGREGATE BASE ENGINEERED FILL (Qafc) SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 102.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet21.5 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 95 90 85 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 2 5 10 15 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-5 Project Number: 18-101-00 Drill Hole DH-5 5 10 15 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19...... ...... ...... ...... ...... ,~-----~,~>( ~-----~'>< ~>( - - -----------------~-----' :s 0 ,.~ .. '-IITIU ---------------- 11 17 40light brown, very dense, fine to medium grained sandTotal Depth: 21.5 feetNo Groundwater ADDITIONALTESTSDRY UNITWEIGHT, pcfSAMPLEENGINEERING CLASSIFICATION AND DESCRIPTION ORIENTATION DATA GEOLOGICAL CLASSIFICATION AND DESCRIPTION GRAPHIC LOGDEPTH, feetMOISTURECONTENT, %DRIVINGWEIGHT, lbsNUMBEROF BLOWS / 6"ELEVATION, feetTEST DATASAMPLE DATA Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 2 of 2 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-5 Project Number: 18-101-00 Drill Hole DH-5DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/19\ I ,.~ .. '-IITIU ---------------- ASPHALT CONCRETE (approximately2.5 inches) CRUSHED AGGREGATE BASE(approximately 3 inches) SILTY SAND (SM); brown, damp,medium dense to dense, fine to mediumcoarse-grained sand Total Depth: 5 feetNo Groundwater ASPHALT CRUSHED AGGREGATE BASE ENGINEERED FILL (Qafc) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 101.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet5.0 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 1 5 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-6 Project Number: 18-101-00 Drill Hole DH-6 5 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/1911~-----~,>< ~----~' ::::::: .>< >< >< >< >< .>< ,.~ .. '-IITIU ---------------- ASPHALT CONCRETE (approximately2.5 inches) CRUSHED AGGREGATE BASE(approximately 3 inches) SILTY SANDSTONE (SM); dark brown,damp Total Depth: 5 feetNo Groundwater ASPHALT CRUSHED AGGREGATE BASE SANTIAGO FORMATION (Tsa) 5/29/18 ENGINEERING CLASSIFICATION AND DESCRIPTION MOISTURECONTENT, %GEOLOGICAL CLASSIFICATION AND DESCRIPTION CME 75 101.0 BD Approx. SurfaceElevation, ft MSL BULK, CAL, SPT ELEVATION, feetDEPTH, feet5.0 feet 8" Date(s)Drilled Driving Methodand Drop 2R DRILLING Remarks SAMPLE DATA ADDITIONALTESTSORIENTATION DATA GRAPHIC LOGTEST DATA SamplingMethod(s) DrillingContractor NOT ENCOUNTERED [] LoggedBy LB DrillingMethod Diameter(s)of Hole, inches Groundwater Depth[Elevation], feet Drill RigType NUMBEROF BLOWS / 6"SAMPLEDRIVINGWEIGHT, lbsDRY UNITWEIGHT, pcfCheckedBy Drill HoleBackfill 140 lb AUTO HAMMER NATIVE Total Depthof Drill HoleHollow Stem Auger 100 Project Location: 1050 & 1060 Auto Center Ct, Carlsbad, CA Sheet 1 of 1 5 Project: AUTONATION BMW of Carlsbad Log of Drill Hole DH-7 Project Number: 18-101-00 Drill Hole DH-7 5 DH_REV3 18-101-00.GPJ GMULAB.GPJ 12/12/1911~-----~,>< ~----~' ::::::: .>< >< >< >< >< .>< ,.~ .. '-IITIU ---------------- APPENDIX B Geotechnical Laboratory Procedures and Test Results by GMU Geotechnical, Inc. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report — AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 B-1 GMU Project 18-101-00 APPENDIX B GMU GEOTECHNICAL LABORATORY PROCEDURES AND TEST RESULTS MOISTURE AND DENSITY Field moisture content and in-place density were determined for each 6-inch sample sleeve of undisturbed soil material obtained from the drill holes. The field moisture content was determined in general accordance with ASTM Test Method D 2216 by obtaining one-half the moisture sample from each end of the 6-inch sleeve. The in-place dry density of the sample was determined by using the wet weight of the entire sample. At the same time the field moisture content and in-place density were determined, the soil material at each end of the sleeve was classified according to the Unified Soil Classification System. The results of the field moisture content and in-place density determinations are presented on the right-hand column of the Log of Drill Hole and are summarized on Table B-1. The results of the visual classifications were used for general reference. PARTICLE SIZE DISTRIBUTION As part of the engineering classification of the materials underlying the site, samples were tested to determine the distribution of particle sizes. The distribution was determined in general accordance with ASTM Test Method D 422 using U.S. Standard Sieve Openings 3", 1.5", 3/4, 3/8, and U.S. Standard Sieve Nos. 4, 10, 20, 40, 60, 100, and 200. In addition, on some samples a standard hydrometer test was performed to determine the distribution of particle sizes passing the No. 200 sieve (i.e., silt and clay-size particles). The results of the tests are contained in this Appendix B. Key distribution categories (% gravel; % sand, etc.) are contained on Table B-1. ATTERBERG LIMITS As part of the engineering classification of the soil material, samples of the on-site soil material were tested to determine relative plasticity. This relative plasticity is based on the Atterberg limits determined in general accordance with ASTM Test Method D 4318. The results of these tests are contained in this Appendix B and also Table B-1. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report — AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 B-2 GMU Project 18-101-00 EXPANSION TESTS To provide a standard definition of one-dimensional expansion, a test was performed on typical on-site materials in general accordance with ASTM Test Method D 4829. The result from this test procedure is reported as an “expansion index”. The results of this test are contained in this Appendix B and also Table B-1. CHEMICAL TESTS The corrosion potential of typical on-site materials under long-term contact with both metal and concrete was determined by chemical and electrical resistance tests. The soluble sulfate test for potential concrete corrosion was performed in general accordance with California Test Method 417, the minimum resistivity test for potential metal corrosion was performed in general accordance with California Test Method 643, and the concentration of soluble chlorides was determined in general accordance with California Test Method 422. The results of these tests are contained in this Appendix B and also Table B-1. COMPACTION TESTS Bulk sample representative of the on-site materials were tested to determine the maximum dry density and optimum moisture content of the soil. These compactive characteristics were determined in general accordance with ASTM Test Method D 1557. The results of this test are contained in this Appendix B and also Table B-1. CONSOLIDATION TESTS The one-dimensional consolidation properties of “undisturbed” samples were evaluated in general accordance with the provisions of ASTM Test Method D 2435. Sample diameter was 2.416 inches and sample height was 1.00 inch. Water was added during the test at various normal loads to evaluate the potential for hydro-collapse and to produce saturation during the remainder of the testing. Consolidation readings were taken regularly during each load increment until the change in sample height was less than approximately 0.0001 inch over a two-hour period. The graphic presentation of consolidation data is a representation of volume change in change in axial load. In addition, time rate tests were performed for select samples. The results of these tests are contained in this Appendix B. Mr. Axay Patel, AUTONATION Geotechnical Investigation Report — AutoNation BMW of Carlsbad, 1050/1060 Auto Center Court, Carlsbad December 13, 2019 B-3 GMU Project 18-101-00 DIRECT SHEAR STRENGTH TESTS Direct shear tests were performed on typical on-site materials. The general philosophy and procedure of the tests were in accord with ASTM Test Method D 3080 - “Direct Shear Tests for Soils Under Consolidated Drained Conditions”. The tests are single shear tests and are performed using a sample diameter of 2.416 inches and a height of 1.00 inch. The normal load is applied by a vertical dead load system. A constant rate of strain is applied to the upper one-half of the sample until failure occurs. Shear stress is monitored by a strain gauge-type precision load cell and deflection is measured with a digital dial indicator. This data is transferred electronically to data acquisition software which plots shear strength vs. deflection. The shear strength plots are then interpreted to determine either peak or ultimate shear strengths. Residual strengths were obtained through multiple shear box reversals. A strain rate compatible with the grain size distribution of the soils was utilized. The interpreted results of these tests are shown in this Appendix B. R-VALUE TESTS Bulk samples representative of the underlying on-site materials were tested to measure the response of a compacted sample to a vertically applied pressure under specific conditions. The R-value of a material is determined when the material is in a state of saturation such that water will be exuded from the compacted test specimen when a 16.8 kN load (2.07 MPa) is applied. The results from these test procedures are reported in this Appendix B. DH-1 0 103.0 Tsa SM 7.8 115 384 4720 DH-1 10 93.0 Tsa SP 4.7 107 23 DH-1 15 88.0 Tsa CH 53 25 28 DH-1 20 83.0 Tsa CH 8.4 104 37 DH-2 0 105.0 Tsa SM 0 90 10 117.0 11.0 DH-2 5 100.0 Tsa SM 13.4 114 78 DH-2 15 90.0 Tsa SM 7.6 100 31 DH-3 0 103.0 Qafc SM 0 78 22 0 DH-3 5 98.0 Tsa SP-SM 3.4 1079 -11 DH-3 15 88.0 Tsa SP 6.9 116 43 DH-3 25 78.0 Tsa SP 3.9 104 17 DH-3 35 68.0 Tsa SM 9.6 104 43 DH-3 45 58.0 Tsa SM 11.8 109 60 DH-4 0 101.0 Tsa SM 0 DH-4 10 91.0 Tsa CL 27.7 94 97 DH-4 20 81.0 Tsa SP 12.8 120 89 DH-5 5 97.0 Tsa SM 7.3 124 59 DH-5 15 87.0 Tsa SP 3.8 114 22 DH-6 0 101.0 Qafc SM 56 SUMMARY OF SOIL LABORATORY DATA TABLE B-1 USCS GroupSymbol PIPL Sample Information Boring Number In Situ Water Content,% In Situ Dry Unit Weight,pcf <2µ, % Elevation, feet Geologic Unit LL Maximum Dry Unit Weight,pcf Sand, %pHR-Value Chemical Test Results Expansion Index Min. Resistivity (ohm/cm) Chloride (ppm) Sulfate (ppm) Atterberg LimitsIn Situ Satur- ation,% Depth, feet Compaction <#200, % Gravel, % Sieve/Hydrometer Optimum Water Content,% Project No. 18-101-00 Project: AUTONATION BMW of CarlsbadGMU_TABLE_SOIL_LAB_DATA 18-101-00.GPJ FNC AB GWGN01.GDT 12/12/19,-~· · ..... '-II ILi 0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110 GRAVEL OPENING SILT CLAY DH-2 DH-3 COARSE 3" 1.5" COARSE MEDIUM FINE PARTICLE SIZE IN MILLIMETERSPERCENT FINER BY WEIGHT#10 U.S. STANDARD SIEVE NUMBERS SAND #20 #40 FINE 0.0 0.0 #4 #60 #1003/8" U.S. STANDARD SIEVE SILTY SANDSTONE (SM) SILTY SAND (SM) 3/4"#200 PARTICLE SIZE DISTRIBUTION Tsa Qafc Symbol LLBoringNumber PIDepth(feet)GeologicUnit Classification Project: AUTONATION BMW of Carlsbad Project No. 18-101-00GMU_GRAIN_SIZE 18-101-00.GPJ 12/12/19~ \ I\ \ I\ \ \ \ \ \ \ \ \ \ \ I \ \ 4 \ ' ,. \ ~ \ ""' • IJI r~• • '-IITIU ---------------- 0 10 20 30 40 50 60 0 20 40 60 80 100 PL 28 LL PI TestSymbolDepth(feet)GeologicUnit TsaDH-1 CLAYSTONE (CH)53 BoringNumber 25 Classification "A" LINE PLASTICITY INDEX (PI)LIQUID LIMIT (LL) CL or OL ML or OL MH or OH CH or OH CL-ML ATTERBERG LIMITS 15.0 Insitu WaterContent (%) Project: AUTONATION BMW of Carlsbad Project No. 18-101-00LIMITS 18-101-00.GPJ 12/12/19/ V' / V / / ~ / / / V / • ,.~ .. '-IITIU ------------- 80 85 90 95 100 105 110 115 120 125 130 135 140 0 10 20 30 40 50 MOISTURE CONTENT (%) SG=2.60 SG=2.70 11 DH-2 Symbol SILTY SANDSTONE (SM)Tsa ClassificationDRY DENSITY (pcf)OptimumMoisture Content, % MaximumDry Density,pcf Depth (feet) 0.0 Geologic Unit COMPACTION TEST DATA 117 Boring Number Project: AUTONATION BMW of Carlsbad Project No. 18-101-00DVTCOMP 18-101-00.GPJ 12/12/19\\ \ \ \\ \\ ~ ~\ \ • ,.--• \\ \ \ ~ \ ~ ~ ~ ~ ' ~ ' • r~• • '-IITIU -----------' 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 0 1,000 2,000 3,000 4,000 SAMPLE AND TEST DESCRIPTION SHEAR TEST DATA Sample Location: STRENGTH TYPE NORMAL STRESS (psf) STRENGTH PARAMETERS FRICTION ANGLE (degrees)SHEAR STRESS (psf)COHESION (psf) Notes: Strain Rate (in/min): DH-2 @ 5.0 ft Geologic Unit: Classification:SILTY SANDSTONE (SM) 0.005 Tsa Sample Preparation:Undisturbed Project: AUTONATION BMW of Carlsbad Project No. 18-101-00 258Peak Strength 35.0 GMU_DIRECT_SHEAR 18-101-00.GPJ GM&U.GDT 12/12/19Ultimate Strength 276 27.0 !-/ / / V / /0 V V v /. .. / ~ V .. / 0 ~ V ~ V • Ill r~• • '-IITIU -------------- 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 0 1,000 2,000 3,000 4,000 SAMPLE AND TEST DESCRIPTION SHEAR TEST DATA Sample Location: STRENGTH TYPE NORMAL STRESS (psf) STRENGTH PARAMETERS FRICTION ANGLE (degrees)SHEAR STRESS (psf)COHESION (psf) Notes: Strain Rate (in/min): DH-3 @ 5.0 ft Geologic Unit: Classification:POORLY GRADED SANDSTONE (SP-SM) 0.005 Sample saturated prior and during shearing Tsa Sample Preparation:Undisturbed Project: AUTONATION BMW of Carlsbad Project No. 18-101-00 450Peak Strength 34.0 GMU_DIRECT_SHEAR 18-101-00.GPJ GM&U.GDT 12/12/19Ultimate Strength 6 31.0• Ill r~• • '-IITIU -----------------' -4 -2 0 2 4 6 8 10 12 14 16100 1,000 10,000 W = water added % Hydro-Collapse 0.13 SITLY SANDSTONE (SM)DH-5 In Situ Boring Number Depth (feet) 5.0 Geologic Unit Tsa Symbol CONSOLIDATION TEST DATASTRAIN (%)STRESS (psf) W ClassificationIn Situ orRemoldedSample Project: AUTONATION BMW of Carlsbad Project No. 18-101-00GMU_CONSOL 18-101-00.GPJ GM&U.GDT 12/12/19. ----- ~ ---r------ • r~• • '-IITIU -----------------' APPENDIX C Infiltration Test Result Riverside/Orange County - Percolation Rate Conversion Porchet Method, aka Inverse Borehole Method Autonation - BMW Carlsbad 18-101-00 DH-6 4 inches 60.0 inches (min)(min)(ft)(ft)(in)(in)(in)(in)(in/hour) 1 8:21:00 AM 8:51:00 AM 30.0 30.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 2 8:51:00 AM 9:21:00 AM 30.0 60.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 3 9:21:00 AM 9:51:00 AM 30.0 90.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 4 9:51:00 AM 10:21:00 AM 30.0 120.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 5 10:21:00 AM 10:52:00 AM 31.0 151.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 6 10:53:00 AM 11:23:00 AM 30.0 181.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 7 11:23:00 AM 11:53:00 AM 30.0 211.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 8 11:53:00 AM 12:23:00 PM 30.0 241.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 9 12:23:00 PM 12:53:00 PM 30.0 271.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 10 12:53:00 PM 1:23:00 PM 30.0 301.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 11 1:23:00 PM 1:53:00 PM 30.0 331.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 12 1:53:00 PM 2:23:00 PM 30.0 361.0 2.65 2.66 28.20 28.08 0.12 28.14 0.02 0.02 Final Height of Water (Hf) ∆H Havg Infiltration Rate (It) Average Infiltration Rate (in/hour) End Time ∆t Total Time Initial Depth of Water (D0) Final Depth of Water (Df) Initial Hight of Water (H0) Project Name: Project Number: Test Hole Number: Test Hole Radius: Total Depth : Trial Start Time 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0Infiltration Rate (in/hour)Time (min) DH-6 Infiltration Rate vs. Time 28.07 28.13 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0Water level drop (in)Time (min) DH-6 Water Level Drop vs. Time & & & & & & & & & & ~ ~ ~ ~ ~ ~ ~ ~ Riverside/Orange County - Percolation Rate Conversion Porchet Method, aka Inverse Borehole Method Autonation - BMW Carlsbad 18-101-00 DH-7 4 inches 48.0 inches (min)(min)(ft)(ft)(in)(in)(in)(in)(in/hour) 1 8:15:00 AM 8:45:00 AM 30.0 30.0 1.70 1.91 27.60 25.08 2.52 26.34 0.36 2 8:45:00 AM 9:18:00 AM 33.0 63.0 1.70 1.87 27.60 25.56 2.04 26.58 0.26 3 9:18:00 AM 9:48:00 AM 30.0 93.0 1.70 1.90 27.60 25.20 2.40 26.40 0.34 4 9:48:00 AM 10:18:00 AM 30.0 123.0 1.70 1.90 27.60 25.20 2.40 26.40 0.34 5 10:18:00 AM 10:48:00 AM 30.0 153.0 1.70 1.89 27.60 25.32 2.28 26.46 0.32 6 10:50:00 AM 11:20:00 AM 30.0 183.0 1.70 1.88 27.60 25.44 2.16 26.52 0.30 7 11:20:00 AM 11:50:00 AM 30.0 213.0 1.70 1.90 27.60 25.20 2.40 26.40 0.34 8 11:50:00 AM 12:20:00 PM 30.0 243.0 1.70 1.86 27.60 25.68 1.92 26.64 0.27 9 12:20:00 PM 12:50:00 PM 30.0 273.0 1.70 1.86 27.60 25.68 1.92 26.64 0.27 10 12:50:00 PM 1:20:00 PM 30.0 303.0 1.70 1.84 27.60 25.92 1.68 26.76 0.23 11 1:20:00 PM 1:50:00 PM 30.0 333.0 1.70 1.85 27.60 25.80 1.80 26.70 0.25 12 1:50:00 PM 2:20:00 PM 30.0 363.0 1.70 1.83 27.60 26.04 1.56 26.82 0.22 0.23 Final Height of Water (Hf) ∆H Havg Infiltration Rate (It) Average Infiltration Rate (in/hour) End Time ∆t Total Time Initial Depth of Water (D0) Final Depth of Water (Df) Initial Hight of Water (H0) Project Name: Project Number: Test Hole Number: Test Hole Radius: Total Depth : Trial Start Time 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0Infiltration Rate (in/hour)Time (min) DH-7 Infiltration Rate vs. Time 25.00 25.20 25.40 25.60 25.80 26.00 26.20 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0Water level drop (in)Time (min) DH-7 Water Level Drop vs. Time .... . " r ............... ..... ~ ~ ~~ '-.... A ~ ~....-...... ~ APPENDIX D TEMPORAY BACKCUT @ SECTION G-G October 26, 2021 Mr. Patel AUTONATION 200 SW 1ST Street, 14th Floor Fort Lauderdale, FL 33301 GMU Project 18-101-00 Subject: Supplemental Section to Geotechnical Investigation Report: Grading and Temporary Excavation for Fire Water Line at Section G-G, Adjacent to Auto Center Court References: “Geotechnical Investigation Report, AutoNation BMW of Carlsbad, 1050 and 1060 Auto Center Court, Carlsbad California”, GMU Geotechnical Inc., dated December 13, 2019, (GMU Project Number 18-101-00) Precise Grading Plans, BMW of Carlsbad, CDR Retaining Wall Structural Plans, BMW of Carlsbad, GMU Structural Engineering, dated 8/11/2021, (GMU Structural Engineering Project Number 20-150-00) Dear Mr. Patel: Per our referenced report, temporary un-surcharged excavations over 4 feet in height may be sloped no steeper than an inclination of 1H:1V. This limitation in vertical excavation height may be exceeded in a maximum “trench” width of up to 2-feet, up to a maximum vertical height of 10 feet provided all other referenced constraints are maintained. Referenced constraints in our report consist of the following: • barricading the top of the temporary excavation so vehicle and storage loads do not encroach within 10-feet of the top of slope. A greater set-back may be necessary when considering heavy vehicles such as concrete trucks or cranes. GMU Geotechnical should be advised of such heavy vehicle loadings so that specific setback requirements can be established. • Temporary slopes are maintained during the rainy season, i.e. berms are provided to prevent runoff water from entering the excavation and eroding slope faces. Based on the referenced retaining wall structural plans a back-cut of 5’-11” will be required to complete construction of the retaining wall, detail 2, at section G-G, adjacent Auto Center Court. it is advised that this back-cut be graded per our report recommendations with a 4-foot vertical below ,..~ .. \Jll""'ILI 23241 Arroyo Vista Rancho Santa Margarita I CA 92688 FX: 949.888.1380 I www.gmugeo.com a 1:1 sloped cut along the length of the wall. This cut appears to fall within the property limits and will not encroach into the City’s right of way. Based on section G-G in the referenced precise grading plans it appears that an additional cut of 3 feet to 4 feet maximum will be required to install the proposed fire water line. This additional cut may be made in a “trench” within the back-cut excavation at no greater than a 2 foot width. Respectfully submitted, Matthew T. Farrington Project Engineer ,..~ .. \Jll""'ILI 23241 Arroyo Vista Rancho Santa Margarita I CA 92688 FX: 949.888.1380 I www.gmugeo.com APPENDIX E Response to Comments June 22, 2021 Mr. Cliff Powell AUTONATION 200 SW 1st Street, 14th Floor Fort Lauderdale, FL 33301 GMU Project 18-101-00 City Project ID: CDP 2019-0013 City GR No.: 2021-0005 Subject: Response to Review of Geotechnical Report AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California References: (1) NV5, Review of Geotechnical Report, Proposed Carlsbad BMW, 1050 and 1060 Auto Center Court, Carlsbad, California, NV5 Project No. 226816- 0000101.76, dated April 7, 2021. (2) GMU Geotechnical, “Report of Geotechnical Foundation Investigation, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California,” GMU Project No. 18-101-00, dated December 13, 2019. Dear Mr. Powell: GMU Geotechnical, Inc. has prepared this letter as response to the reference (1) City of Carlsbad review of our reference (2) geotechnical report. The comments provided by the City’s consultant NV5 and our responses are presented below. A copy of the review letter is attached to this response. Comment 1: The project geotechnical investigation report references CBC 2016 and presents geotechnical recommendations and seismic design parameters based on the 2016 California Building Code, which is outdated. Per the current building code, recommendations including seismic parameters should be based on the 2019 California Building Code. The project geotechnical consultant should issue an addendum report which references CBC 2019 and includes the updated geotechnical recommendations and seismic parameters in accordance with CBC 2019. 23241 Arroyo Vista Rancho Santa Margarita I CA 92688 949.888.6513 I FX: 949.888.1380 I www.gmugeo.com Mr. Cliff Powell, AUTONATION Response to Geotechnical Review Comments, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California June 22, 2021 2 GMU Project 18-101-00 Response 1: We have developed the following geotechnical recommendations in order to update the seismic parameters from the 2016 CBC to 2019 CBC. We recommend that the project structural engineer verify that their design considers the 2019 CBC seismic parameters as provided below. Based on the soil profile encountered during our exploration, evaluation, the estimated shear wave velocity based on the SPT values was determined to be 1,413 feet/sec, which designates the site as Site Class C. The seismic design coefficients based on ASCE 7-16 and 2019 CBC are listed in the table below, if needed. 2019 CBC Site Categorization and Site Coefficients Categorization/Coefficient Design Value Site Class per Soil Profile (ASCE 7-16, Table 20.3-1) C Short Period Spectral Acceleration Ss** 1.08 1-sec. Period Spectral Acceleration S1** 0.39 Site Coefficient Fa (Table 11.4-1)** 1.2 Site Coefficient Fv (Table 11.4-2)** 1.5 Short Period MCE* Spectral Acceleration SMS** 1.296 1-sec. Period MCE Spectral Acceleration SM1** 0.585 Short Period Design Spectral Acceleration SDS** 0.864 1-sec. Period Design Spectral Acceleration SD1** 0.39 MCE Peak Ground Acceleration (PGA) 0.477 Site Coefficient FPGA (Table 11.8-1)** 1.2 MCE Peak Ground Acceleration (PGAM) 0.573 * MCE: Maximum Considered Earthquake ** Values obtained from USGS Earthquake Hazards Program website are based on the ASCE 7-16 and 2019 CBC and site coordinates of N33.134445o and W117.324673o. It should be recognized that much of southern California is subject to some level of damaging ground shaking as a result of movement along the major active (and potentially active) fault zones that characterize this region. Design utilizing the 2019 CBC is not meant to completely protect against damage or loss of function. Therefore, the preceding parameters should be considered as minimum design criteria. Comment 2: The geotechnical report does not include a geologic map or graphical representation of a geologic cross section(s). The geologic cross sections should also depict the recommended remedial grading. Such graphics are a City requirement and are typically included in project geotechnical reports. Mr. Cliff Powell, AUTONATION Response to Geotechnical Review Comments, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California June 22, 2021 3 GMU Project 18-101-00 Response 2: We have prepared the attached Plate 2 – Geologic Map and Plate 3 – Geologic Section depicting the recommended remedial grading. Comment 3: The geotechnical report on Page 10, Flatwork/Pavement Areas, indicates the bottom of excavation (subgrade) should be scarified and compacted to 90% relative compaction. It should be noted that for pavements, subgrade is generally recommended to be compacted to 95% of the relative compaction. Response 3: We concur that generally if pavement is placed directly on subgrade, then the subgrade should be compacted to 95% relative compaction in accordance with Greenbook Section 301-1.3, however, since a base section is recommended below the AC section, then Greebook Section 301-1.3 allows the subgrade material to be compacted to 90% relative compaction. Comment 4: The geotechnical report on Page 16, Moisture Vapor Retarder, indicates the need for the sand above moisture barrier should be specified by the structural engineer. It should be noted that recent ACI standards no longer recommends the use of sand over a moisture barrier, and to compensate, a lower water cement ratio and improved curing methods are suggested. Response 4: We concur with this comment that sand above the moisture barrier is not a requirement and thus it is not recommended from a geotechnical standpoint. Additionally, wet curing per ACI 308 and the use of a maximum w/c ratio of 0.5 as mentioned on Page 15 of the report is recommended. Comment 5: The geotechnical report on Pages 18 and 19, Asphalt Concrete and Concrete Pavement Thickness Recommendations, pavement recommendation for parking stalls and driveways were provided. The consultant should verify if the recommended thicknesses are adequate for fire truck access and provide additional recommendations, if needed. Response 5: Based on our analysis, we note that the “Driveways” pavement section provided in our referenced report is adequate for support of occasional fire trucks. Mr. Cliff Powell, AUTONATION Response to Geotechnical Review Comments, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California June 22, 2021 4 GMU Project 18-101-00 Comment 6: The geotechnical report on Page 20, Permeable Paver Design, provides recommendation for a pavement section thickness. However, a traffic index associated with the pavement recommendation is not included. The consultant should verify where these permeable pavers will be used and if the recommended section is adequate for the anticipated traffic loads (fire trucks, light vehicles, etc.). The above noted report section also recommends impermeable liner for the pavers adjacent to hardscape, slopes, buildings or curbs, which we agree. However, the impact on other improvements such as utility trenches are not noted. The consultant should identify all existing and proposed improvements that could be impacted from pavers and include impermeable liner or appropriate recommendations. Response 6: The Permeable Pave Design as recommended in our referenced report is adequate for support of a TI of 5.5 and occasional fire truck loading. Based on our review of the precise grading plans, it appears that the new pavers are planned adjacent to curbs, hardscape, retaining walls and buildings. The pavers are planned with parking stalls and it appears that a fire water line will be crossing some of the parking stalls on southern side of the property. On this basis, trenches that are crossing the new permeable paver parking stalls should also be protected with an impermeable liner that is placed over and on the sides of the trenches to minimize water intrusion into the trenches. Please do not hesitate to contact the undersigned if you have any questions regarding this information. Respectfully submitted, GMU GEOTECHNICAL, INC. Matthew T. Farrington, MSc, PE 90349 Project Engineer Katie M. Farrington, MSc, PG, CEG 2611 Senior Engineering Geologist Mr. Cliff Powell, AUTONATION Response to Geotechnical Review Comments, AutoNation BMW of Carlsbad, 1050 & 1060 Auto Center Court, City of Carlsbad, California June 22, 2021 5 GMU Project 18-101-00 Submitted Via Email Attachments: City of Carlsbad Review Letter Plate 2 – Geologic Map Plate 3 – Geologic Section A-A’ NS/18-101-00 (06-22-2021) City of Carlsbad April 7, 2021 1635 Faraday Avenue Project No.: 226816-0000101.76 Carlsbad, California 92008 Attention: Mr. Emad Elias Subject: Review of Geotechnical Report Project: Proposed Carlsbad BMW 1050 and 1060 Auto Center Court Carlsbad, California City Project ID: CDP 2019-0013 City GR No.: 2021-0005 References: 1) “Geotechnical Investigation Report, AutoNation BMW of Carlsbad”, prepared by GMU, Project No. 18-101-00, dated December 13, 2019. 2) “Technical Guidelines for Geotechnical Reports”, issued by the City of Carlsbad, dated January 1993. 3) “CGS Note 41, Guidelines for Reviewing Geologic Reports”, prepared by the State of California, Department of Conservation, California Geological Survey, dated 2017. Dear Mr. Elias: As requested, NV5, West Inc. (NV5) has conducted a geotechnical review of the above-referenced geotechnical report (reference 1) for the proposed project located in Carlsbad, California. The purpose of the review was to provide an opinion on whether the geotechnical aspects of the project have been identified and appropriately addressed in the project geotechnical report. NV5’s geotechnical review is based on geotechnical information presented in the referenced geotechnical report, guidelines for geotechnical and geologic reports (references 2 and 3), and experience with the geotechnical conditions in the general site area. NV5 has not performed an independent geotechnical investigation at the project site and therefore does not offer or imply any guarantee or warranty as to future site performance. The opinions presented below are limited. Other consultants could arrive at different conclusions. This report presents a summary of the review. Review Summary Based on the review, it is NV5’s opinion that the referenced geotechnical report for the proposed project has generally identified and addressed a majority of the significant geotechnical factors affecting the site development as currently proposed. However, the report is not approved. Additional information is requested from the geotechnical consultant as discussed in the following comments. Comment 1 - The project geotechnical investigation report references CBC 2016 and presents geotechnical recommendations and seismic design parameters based on the 2016 California Building Code, which is outdated. Per the current building code, recommendations including seismic parameters should be based on NV 5 OFFICES NATIONWIDE I 5092 AVENUE OF SCIENCE, SUITE 200 SAN DIEGO, CA 92 I 28 WWW.NV5.COM OFFICE 858.385.0500 FAX 858.385.0400 CONSTRUCTION QUALITY ASSURANCE -INFRASTRUCTURE -ENERGY -PROGRAM MANAGEMENT -ENVIRONMENTAL Review of Geotechnical Report Project No.: 226816-0000101.76 Proposed BMW of Carlsbad 1050 and 1060 Auto Center Court Carlsbad, California the 2019 California Building Code. The project geotechnical consultant should issue an addendum report which references CBC 2019 and includes the updated geotechnical recommendations and seismic parameters in accordance with CBC 2019. Comment 2 - The geotechnical report does not include a geologic map or graphical representation of a geologic cross section(s). The geologic cross sections should also depict the recommended remedial grading. Such graphics are a City requirement and are typically included in project geotechnical reports. Comment 3 – The geotechnical report on Page 10, Flatwork/Pavement Areas, indicates the bottom of excavation (subgrade) should be scarified and compacted to 90% relative compaction. It should be noted that for pavements, subgrade is generally recommended to be compacted to 95% of the relative compaction. Comment 4 – The geotechnical report on Page 16, Moisture Vapor Retarder, indicates the need for the sand above moisture barrier should be specified by the structural engineer. It should be noted that recent ACI standards no longer recommends the use of sand over a moisture barrier, and to compensate, a lower water cement ratio and improved curing methods are suggested. Comment 5 – The geotechnical report on Pages 18 and 19, Asphalt Concrete and Concrete Pavement Thickness Recommendations, pavement recommendation for parking stalls and driveways were provided. The consultant should verify if the recommended thicknesses are adequate for fire truck access and provide additional recommendations, if needed. Comment 6 – The geotechnical report on Page 20, Permeable Paver Design, provides recommendation for a pavement section thickness. However, a traffic index associated with the pavement recommendation is not included. The consultant should verify where these permeable pavers will be used and if the recommended section is adequate for the anticipated traffic loads (fire trucks, light vehicles, etc.). The above noted report section also recommends impermeable liner for the pavers adjacent to hardscape, slopes, buildings or curbs, which we agree. However, the impact on other improvements such as utility trenches are not noted. The consultant should identify all existing and proposed improvements that could be impacted from pavers and include impermeable liner or appropriate recommendations. NV5 appreciates the opportunity to be of service to you on this project. If you have any questions regarding this report, please do not hesitate to contact our office. Respectfully submitted, NV5 West, Inc. Gene Custenborder, CEG 1319 Madan Chirumalla, PE, GE 3047 Senior Engineering Geologist Manager/ Principal Engineer GC/MC Distribution: (1) Addressee, via email - NIVIS OFFICES NATIONWIDE CONSTRUCTION QUALITY A SSURANCE -INFRASTRUCTURE ENGINEERING -MUNICIPAL OUTSOURCING -A SSET MANAGEMENT -ENVIRONMENTAL SERVICES FILLCUT FI L L C U T FILLCUTQafcTsaAA'TsaTsaTsaCAR C O U N T R Y D R CANNON RDAUTO CENTER CTDate:Project No.:PlateGeotechnical Map18-101-00June 23, 202120040'GEOTECHNICAL LEGEND DH-7APPROXIMATE LOCATION OFDH-1DH-3DH-4DH-5DH-6DH-7DH-2PROPOSED BORINGSAPPROXIMATE CUT/FILL FROM PREVIOUSGRADING LINE TO BE FIELD VERIFIEDQafTsaENGINEERED FILLSANTIAGO FORMATION BEDROCK,CIRCLED WHERE BURRIEDI "' I 0 0 0 cii 3 " 8 I 0 'T a:, a:, ~ c:,; z §, < "' Cl l-o, I0:?39£'G -----------0 0 19:J. "14rcl-/ ,q /103/Jqrc ~O Cf:liJ /103.,•"0 -~cl. r. ·,+. CLoA,vEw,4y A.urocc,v77:Acr -. 40DATUM ELEVGROUPSECTION40'Project Number 18-101-00A - A'SCALE: 1'' = 40'AA'80120160200240280320360400440480520120160408012080EXISTING GRADEP/LTD 21.5'DH-5Proj. ~48'QafcTsaDH-3Proj. ~30'TD 21.5'DH-4Proj. ~45'TsaTsaPROPOSEDGRADEREMEDIAL GRADINGP/LTD 51.5'APPROXIMATE LOCATION OF PROPOSED BUILDINGEXISTING GRADEDate:Project No.:PlateGeotechnical Section A-A'18-101-00June 23, 20213DRAWING: q: \2018\18-101-00\dwq\18101 OO_plate 2_qeo map.dwq PLOTTED: 6/23/2021 8: 27 PM BY: Matt Farrinqtan '' :JC: c: I ■I l