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HomeMy WebLinkAboutAMEND 2021-0004; DISTRIBUTE LOTS 13-15 SHELL BUILDING; GEOTECHNICAL REPORT; 2021-02-24DRAFT Ge<itechnical Evaluabon Prepared for: Amazon Logistics (AMZL) Prepared by: AECOM 1255 Broad Street -Suite 201 Clifton, NJ 07013 aecom.com Copyright© 2020 by AECOM Project reference: AMZL-MR-DGB6 Project numboc 60646117 All rights reserved, No part of this copyrighted work may be reproduced, distributed, or transmitted in any form or by any means without the prior written permission of AECOM, Prepared for: Amazon Logistics AECOM DRAFT Geotechnlcal Evaluation Table of Contents ProIect reference: AMZL-MR-DGB6 Project number: 60646117 Executive Summary ........................................................................................................ 1 1 Introduction ........................................................................................................... 2 1.1 General. ................................................................................................................ 2 1.2 Site Description & Proposed Development. .......................................................... 2 1.3 Objectives & Scope of Services ............................................................................ 2 1.4 Report Organization ............................................................................................. 3 2 Subsurface Conditions ......................................................................................... 4 2.1 General ................................................................................................................. 4 2.2 AECOM Subsurface Investigation Program .......................................................... 4 2.3 Laboratory Testing ................................................................................................ 4 2.4 Geologic Setting ................................................................................................... 5 2.5 Tectonic and Seismic Setting ................................................................................ 5 2.6 Generalized Subsurface Conditions ..................................................................... 6 2. 7 Geologic Hazards ................................................................................................. 7 2.8 Recommended Soil Parameters ........................................................................... 7 2.9 Groundwater Conditions ....................................................................................... 8 3 Foundation Design Recommendations ................................................................. 9 3.1 General ................................................................................................................. 9 3.2 Seismic Considerations ........................................................................................ 9 3.3 Foundation Recommendations ............................................................................. 9 3.4 Pavement Design Recommendations ................................................................ 1 O 4 Construction Recommendations ......................................................................... 11 4.1 General ................................................................................................................ 11 4.2 Excavation Considerations .................................................................................. 11 4.3 Temporary Groundwater Control ......................................................................... 11 4.4 Support of Adjacent Structures ........................................................................... 12 4.5 Subgrade Preparation ........................................................................................ 12 4.6 Backfill and Compaction Requirements .............................................................. 13 4. 7 Pre-Construction Condition Report and Monitoring ............................................ 13 4.8 Construction Inspection ...................................................................................... 14 5 Statement of Qualification and Limitations ......................................................... 15 6 References ......................................................................................................... 17 Prepared for: Amazon Logistics AECOM DRAFT Geotechnical Evaluation Tables Project refer~mce: AMZL·MR-DGB6 Project number: 60646117 Table 1: Characteristics of Nearby Faults ........................................................................ 6 Table 2: Recommended Geotechnical Engineering Parameters ..................................... 7 Table 3:Recommended Structure for Flexible Pavement .Error! Bookmark not defined. Table 4:Recommended Structure for Rigid Pavement.. .... Error! Bookmark not defined. Appendices Appendix A Project Site Location Plan Appendix B Boring Location Plan Appendix C Boring Logs Appendix D Laboratory Testing Results Appendix E Pavement Design Calculations Prepared for: Amazon Logistics AECOM DRAFT Geotechnical Report Executive Summary Project reference AMZL-MR-DGB6 Project number: 60646117 This Phase II Geotechnical report presents the results of a due diligence geotechnical investigation and recommendations for the construction of a canopy structure and new pavement. The Project site is located at 3266 Lionshead Ave, Carlsbad, California. The recommendations presented herein are in general accordance with the California Building Code 2019. A total of five borings were drilled to investigate the subsurface conditions of the project area. The test borings were drilled to a depth of 20.5 feet below existing grade. The subsurface conditions generally consist of approximately 5 feet of fill (Stratum 1 ), followed by a dense to very dense silty/clayey sand that extends to maximum drilling depth of 20.5 feet (Stratum 2). Groundwater was not encountered during the subsurface investigation. Based on the collective data from borings, the seismic site classification is Site Class "D". If the Risk Category is I, II, or 111, the Seismic Design Category is "D". Our analysis indicates that liquefaction does not need to be considered in the design. We recommend that the proposed structure be supported on shallow foundation bearing on the sand of Stratum 2 with a maximum bearing pressure of 1 ton per square foot (tsf). This report includes additional information regarding the subsurface conditions, foundation design recommendations, any additional recommendations pertaining to excavation considerations, temporary groundwater control, backfill and compaction requirements pre-construction condition documentation and monitoring and construction inspection and monitoring. Prepared for: Amazon Logistics AECOM 1 DRAFT Geotechoical Report Project reference: AMZL-MR-DGB6 Project number: 60646117 1 Introduction 1.1 General This report presents the results of a due diligence Phase II geotechnical investigation performed by AECOM USA, Inc. (AECOM) and geotechnical recommendations for design and construction of a canopy structure and rehabilitation of the parking area located at 3266 Lionshead Ave, Carlsbad, California. AECOM previously performed a Phase I desk study and provided a memo which presented conceptual recommendations based on existing data. This Phase II geotechnical evaluation report supersedes the previously provided memo. The geotechnical evaluations and recommendations presented herein are in general accordance with the California Building Code 2019 (Code). 1.2 Site Description & Proposed Development The project site is located at 3266 Lionshead Ave, Carlsbad, CA. The site location is shown in the site location plan, presented as Appendix A. The project involves modification to the existing site including constructing of a new canopy structure and rehabilitation of the parking area. 1.3 Objectives & Scope of Services The objectives of this investigation are to evaluate the subsurface conditions of the project area and to provide geotechnical recommendations to evaluate estimated costs for the design and construction tasks and site suitability for project development. In order to achieve these objectives, the following scope of work was performed: 1. Retained a subcontractor to drill five test borings; 2. Provided full-time on-site inspection of the test boring/drilling operations; 3. Performed engineering evaluations and prepared this Phase ll report which includes the following: a) A description of the subsurface investigation performed for this project; b) As-drilled test boring location plan; Prepared for: Amazon Logistics AECOM ' DRAFT Geotechnical Report Project reference: AMZL-MR-DGB6 ProJect number: 60646117 c) An overview of general site and geologic conditions; d) The results of engineering evaluations and recommendations including: ■ Foundation type, estimated capacity and bearing elevation: ■ Seismic site classification and liquefaction potential; e) Recommendations regarding construction related issues, including: ■ Excavation and temporary support of excavation considerations; ■ Subgrade preparation; ■ Backfill and compaction requirements; ■ Pre-construction condition surveys; ■ Construction monitoring recommendations; f) Appendices that include the site plan, boring location plan, boring logs, laboratory testing results and calculations. 1.4 Report Organization This report is divided into six sections. This section (Section 1) presents an overview of the project and work performed in the report. Section 2 includes a description of the subsurface investigation methods and results. Section 3 summarizes the engineering evaluations and the foundation design recommendations. Construction recommendations are included in Section 4. The limitations of this study are discussed in Section 5. Section 6 presents a list of references. Figures, boring logs, laboratory testing results, parameter development, and calculations are included in the Appendices. Prepared for: Amazon Logistics AECOM 3 DRAFT Geotechnical Evalua~on 2 Subsurface Conditions 2.1 General Project reference: AMZL-MR-DGB6 Project number: 60646117 This subsurface investigation included drilling two test borings and three pavement cores. The subsurface investigation also included a laboratory testing program to further identify soil and groundwater conditions at the site. Details of the subsurface investigation are described in the following sections. 2.2 AECOM Subsurface Investigation Program Five test borings were drilled on February 15, 2021. All test borings, LB-1, LB-2, PC-1, PC-2, and PC-3, were advanced to the depth of 20.5 feet below existing grade. Drilling of the borings was inspected on a full-time basis by AECOM Geologist (Emma J. Vierra) working under the direction of Dr. Assem Elsayed, P.E. of AECOM. The locations of the test borings are shown in the boring location plan contained in Appendix B. The boring logs are included in Appendix C. The borings were performed by Choice Drilling Inc. using a truck mounted, CME 75 drill rig. Soil samples were obtained using techniques and equipment in general accordance with the ASTM International (ASTM) Standard Specification D1586-Standard Penetration Test (SPT). The SPT consists of driving a 2 inch outside diameter (O.D.) split spoon sampler, with repeated blows of a 140-pound hammer free falling of a 30 inches distance. The standard penetration number (N- value) is quantified as the number of blows required to advance the sampler 12 inches after the initial 6 inches of penetration. The recovered split-spoon samples were placed in bags and labeled with the project name and number, boring number, sample number, SPT blow count, and quantity of recovery. 2.3 Laboratory Testing Laboratory testing was conducted by the AECOM Geotechnical Laboratory in Anaheim, CA, on representative soil samples to determine physical indices and engineering properties of the subsurface materials and to confirm field classifications. Tests performed included 12 sieve analyses, 11 Atterberg Limits tests, 12 moisture content tests and R-value test. The laboratory test results are included in Appendix D. Prepared for: Amazon Logistics AECOM ' DRAFT Gootechnical Evaluation 2.4 Geologic Setting Project reference: AMZL·MR-DGB6 Project number 60646117 The project site is in the Carlsbad area of San Diego and lies within the Peninsular Ranges geomorphic province. The Peninsular Ranges consist of a series of elongated northwest-trending mountain ranges with intervening valleys and structural basins located south of the Transverse Ranges and west of the Colorado Desert geomorphic provinces. The coastal plain sub-province runs parallel to the coastline and forms the western edge of the Peninsular Ranges in San Diego County. The project area is located in the central portion of the coastal range sub-province approximately 6 miles from the Pacific Ocean. The coastal plain is underlain by an eastward-thinning wedge of Tertiary and Quaternary age sedimentary deposits (both marine and nonmarine) that overlie crystalline bedrock and then onlap onto crystalline bedrock to the east of the project site. The coastal plain is characterized by gently dipping mesa surfaces incised by westerly trending drainages. The project site is underlain by Tertiary age sedimentary rocks of the Santiago Formation. The mid-Eocene age Santiago Formation is comprised of marine and non-marine deposits that extend to depths of greater than 100 feet below ground surtace (bgs) based on our interpretation of geologic mapping and field investigation. The Santiago Formation in the site area consist primarily of interbedded mudstone, siltstone, and sandstone. Relatively thin fill ranging to depths of 5 to 7 ½ feet bgs were encountered in the borings and consisted of clay with sands and gravels. 2.5 Tectonic and Seismic Setting The site is in a tectonically active region of North America influenced by the plate boundary interaction between the North American and Pacific lithospheric plates and characterized by numerous northwest-trending, predominantly right-lateral, strike-slip faults. Major southern California fault systems include the San Andreas, San Jacinto, Elsinore, and Imperial fault zones to the east and north; the Coronado Bank and Rose Canyon fault zones to the west; and the Agua Blanca and San Miguel fault zones to the south. The closest major active fault to the project area is the Rose Canyon fault zone located approximately 7 miles west of the site. Characteristics of nearby faults are presented in Table 1. Prepared for: Amazon Logistics AECOM 5 DRAFT Geotechn1cal Evaluation Table 1 • Characteristics of Nearby Faults Fault Name Fault Type Distance Rose Canyon fault zone Holocene-Active3,4 7 miles Coronado Bank fault zone Holocene-Active 25 miles Elsinore fault zone Holocene-Active 35 miles San Diego Trough fault zone Holocene-Active 38 miles San Jacinto fault zone Holocene-Active 47 miles San Andreas fault zone Holocene-Active 73 miles 1 Based on Earthquake Scenano Map, (USGS. 2020a} Project reference: AMZL-MR,DGB6 Project number: 60646117 Maximum Potential Intensity Magnitude1 (MMI') 7.0 6.5-7 7.4 6-6.5 7.8 6 7.3 5.5-6 7.8 5.5 8.2 5.5 2 -The ModtIed Mercalli intensity (MMI) scale measures severity of earthquakes. MMI 6 and greater shaking can cause structural damage. 3-Based on CGS. 2018 classification of Holocene-Actwe faults having surface displacement w1lh1n Holocene time (the last 11,700 years) and pre- Holocene laults whose recency of movement Is older than 11,700 years. 4 -Data from USGS, 2020b The faults discussed above are nearby known seismic sources mapped in the area. These faults and all the faults in the region and their characteristics are integrated into the seismic hazard models that predict shaking hazards. The output from these models is used by the pertinent building codes, such as the California Building Code, to evaluate the design level seismic acceleration at the site. 2.6 Generalized Subsurface Conditions The generalized strata descriptions provided below are based on our interpretation of the results of the subsurface investigations: Stratum 1 -Fill: This stratum was encountered in all borings and generally consists of Clay with Sand and Gravel. This layer was mostly hand cleared and blow counts are available only for LB- 2 and PC-3. The N-value in those two borings ranged from 8 to 13. The thickness of this stratum varies from 5 feet to 7.5 feet. Stratum 2 -Silty/Clayey Sand (SC/SM): This stratum was encountered below Stratum 1 in all borings. It generally consists of sand with varying amounts of silt and clay. The N value ranged from 8 to 120 bpf, with an average of 34 bpf, indicating loose to very dense soil. Prepared fore Amazon Logistics AECOM ' DRAFT Geotechnlcal Evaluation 2.7 Geologic Hazards Project reference: AMZL-MR-DGB6 Project number: 60646117 No active faults have been mapped through the project site and the site is not located within an Alquist-Priolo Earthquake fault zone as defined by the State of California (Hart and Bryant, 2007). Based on this information, the surface fault rupture displacement hazard at the site is considered low. Liquefaction is a phenomenon whereby saturated granular soils lose some of their shear strength due to increased pore water pressures, which may be induced by cyclic loading during an earthquake. Soil that is granular (for example, sand, gravel), and has a low relative density and is saturated (shallow groundwater) is susceptible to liquefaction if exposed to ground shaking. The secondary effects of liquefaction include loss of shear strength, settlement, soil boils, and lateral spreading. The site lies outside liquefaction hazard zones delineated by the City of Carlsbad and is underlain by geologically old deposits and a deep groundwater table. These materials are not susceptible to liquefaction, liquefaction-induced settlement at the ground surface or lateral spreading. The potential for liquefaction and liquefication related hazards at the site is very low. Design level geotechnical investigations should review and revise as necessary the preliminary geologic hazard evaluations presented here. 2.8 Recommended Soil Parameters Based on the results of the field investigation, the recommended geotechnical design parameters for each stratum are presented in Table 2. Table 2: Recommended Geotechnical Engineering Parameters. Unit Weight Friction Stratum Cohesion, Soil Soil Type of Soil, y Angle, t/> C Modulus, k No. (lbltt'J (lbltt'J (degree) {lb/in') 1 Fill 115 25 0 - 2 Silly/Clayey 120 31 0 90 Sand Prepared fo~ Amazon Logistics Strain Factor, e50 - - AECOM ' DRAFT Geotechnical Evaluation 2.9 Groundwater Conditions Project reference AMZL-MR-DGB6 Project number: 60646117 Groundwater was not encountered in any of the borings. Groundwater was not observed over an extended period of time; therefore, seasonal variations in the groundwater level are unknown. Perched water may be encountered within the fill material, due to increased Silty Clay content. Prepared for: Amazon Logistics AECOM ' DRAFT Geotechmcal Evaluation Project reference: AMZL-MR-DG86 Project numboc 60646 11 7 3 Foundation Design Recommendations 3.1 General This section of the report presents our geotechnical analyses and recommendations for the design of the proposed foundations below grade. The evaluations and recommendations are based on the results of the subsurface investigations performed for this project and our experience with other projects. 3.2 Seismic Considerations Based on the soil strata and the SPT N-values, the seismic site classification is Site Class "D". Therefore, in accordance with the 2019 Code, if the Risk Category is I, II, or Ill, the Seismic Design Category is "D". The appropriate Risk Category should be determined by the Architect or Structural Engineer. Liquefaction can potentially occur in submerged, poorly sorted, loosely packed, fine granular material subjected to dynamic loads. Based on the site and the relatively dense nature of the materials encountered during the subsurface investigation performed at this site, and no groundwater was encountered., the potential for damage due to liquefaction-induced seismic settlement and lateral spreading is low and is not considered in the foundation design. 3.3 Foundation Recommendations 3.3.1 Shallow Foundations Based on the subsurface investigation, undocumented fill extends to a depth of approximately 5 to 7.5 feet. Therefore, we recommend that the bottom of footing elevation should be at least 8 feet below grade. We recommend that the canopy be supported on a shallow foundation bearing on the Silty/Clayey Sand of Stratum 2 with a maximum allowable bearing capacity of 1 ton per square foot (tsf). If unsuitable bearing materials (e.g., organic soils, topsoil, loose soil, mud or fill such as concrete, brick, wood, debris, etc) are encountered at the bearing depth, the unsuitable material must be excavated until recommended bearing material is exposed (see section 4.5). The excavated Prepared for: Amazon Logistics AECOM 9 DRAFT Geotechnical Evaluation Project reference: AMZL-MR-DGB6 Project number: 60646117 material must be replaced with either lean concrete, gravel or compacted structural fill placed in a controlled manner (see section 4.6) or the foundation may be extended to the top of competent material. 3.3.2 Lateral Capacity A shallow foundation will resist the lateral load by the friction between the base of the footing and the supporting subgrade and also by passive resistance from the soils against the footing sides. The recommended coefficient of friction for shallow foundations bearing on silty/clayey sand of Stratum 2 is 0.25. Considering the anticipated depth of footing is minimal, passive resistance from soils should be ignored. The ultimate capacity should be estimated by applying frictional resistance to the foundation dead load. The allowable capacity should be determined by structural engineer applying an appropriate factor of safety. A minimum factor of safety of 1.5 is recommended. 3.4 Pavement Design Recommendations To be included. Prepared for-Amazon Logistics AECOM 10 DRAFT Gootechnical Evaluation Project reference: AMZL-MR-DGB6 Project number. 60646117 4 Construction Recommendations 4.1 General This section presents a discussion and recommendations regarding special geotechnical aspects of the proposed construction, which should be addressed in the project specifications and contract documents. 4.2 Excavation Considerations Local temporary soil excavations above and below the groundwater level can have cut slopes as steep as 1.5H:1V and 2H:1V, respectively, unless steeper slopes are approved by the support of excavation (SOE) engineer. The slopes of any excavations adjacent to the existing structures must be no steeper than 2H: 1V, unless approved by the SOE engineer. All vertical soil faces will require temporary support. If the bottom of the excavation will be above the groundwater elevation, a feasible support system may consist of drilled soldier piles and timber lagging. If the bottom of the excavation will be below the groundwater elevation, a feasible support system may consist of a sheet pile or secant pile wall, embedded sufficiently to provide groundwater "cutoff''. In any case, lateral restraints (e.g., anchors, rakers, bracing, etc.) must be provided as required. Measurements of vibration levels must be made in any adjacent structures during the installation of the support system (see Section 4. 7). The maximum allowable vibration levels must be established as part of the pre-construction condition survey of the adjacent structures. The design and construction of any slopes and/or temporary excavation support systems must be the responsibility of a licensed California Professional Engineer. All excavations and temporary support systems must conform to all applicable OSHA, local, and other applicable safety regulations. 4.3 Temporary Groundwater Control The groundwater level must be maintained below the bottom of the excavation so that the foundation bearing surface can be adequately prepared. Based on the borings, groundwater will Prepared for. Amazon Logistics AECOM " DRAFT Geotechnical Evalua~on Project reference: AMZL-MR-DGB6 Project number: 60646117 likely not be encountered within any excavations. Regardless, the contractor should be prepared to control runoff from precipitation by using sump pits and pumps. Discharge of water into the sewer system will likely require permits as required by local law. 4.4 Support of Adjacent Structures Support of adjacent structures is required at locations where a proposed excavation or building is within the influence zone of the foundation of an existing adjacent structure. The influence zone is defined as a line drawn diagonally downward, from the bottom of the foundation of the adjacent structure, toward the proposed excavation/structure, with a one to one (1 :1) slope (one vertical unit for every one horizontal unit). Support of the adjacent structures is necessary to avoid undermining their foundations during excavation and to avoid imposing lateral loads from the adjacent structure onto the foundation walls of the new structure. This is accomplished by transferring the foundation loads from their present bearing elevation to an elevation below the lowest excavation elevation of the proposed building. The extent of the required support system cannot be determined at present due to the limited information available regarding the elevations, locations, and bearing grades of foundations of the adjacent structures. It is recommended that information be collected regarding the type and depth of the foundations of any adjacent structures. This information should then be reviewed to determine underpinning needs and should be provided to the Contractor for the preparation of the foundation construction bid. The proposed underpinning system, as designed by the Contractor's engineer, should be reviewed and inspected by a qualified engineer during construction. 4.5 Subgrade Preparation Subgrade surfaces for slabs-on-grade, footings, mat slabs, and other foundation elements must be level and cleaned of loose soil, mud, and other deleterious material (such as concrete, brick, wood, paper, metallic objects, debris, etc.) that could have an adverse impact on the performance of the foundation element. If directed by the Special Inspector, the soil subgrade must be proof rolled with a minimum of 6 passes of a smooth drum roller with a minimum 1500 lb. static weight and minimum centrifugal force of 4,000 lbs., or similar approved equipment. Proof-rolling must not be performed when the subgrade is wet, muddy, or frozen. Any unstable areas encountered which cannot be stabilized by additional compaction should be excavated until competent material Prepared for: Amazon Logistics AECOM " DRAFT Geotechnical Evaluation Project reference: AMZL-MR-DGB6 Project number: 60646117 is encountered. Once competent material has been encountered, either the bottom of footing should be extended to bear on the competent material, or the over-excavated area should be backfilled with compacted structural fill or¾" stone (see Section 4.6). If concrete for the foundation element is not poured immediately after subgrade approval, a 4- inch thick layer of compacted coarse aggregate, commonly known as¾" gravel or crushed stone, and/or a "mud-slab" (i.e., 2 inches of lean concrete), must be placed on the approved subgrade so that the subgrade is properly protected from disturbance. Concrete for the footings, slabs or other foundation elements must not be poured if the subgrade is wet, muddy, or frozen. 4.6 Backfill and Compaction Requirements Select backfill or structural backfill must consist of granular soils free of cinder, brick, asphalt, ash, and other unsuitable materials. Such material should not contain any boulders or cobbles larger than 4 inches across and should have a fines content (material passing the No. 200 sieve) of less than 30 percent and a plasticity index less than 15. Materials proposed to be used as structural fill should be submitted to and approved by a licensed California Professional Engineer. If requested by the Special Inspector, the subgrade underneath the backfill should be satisfactorily prepared as specified in Section 4.5. All backfill should be placed in lifts no greater than 8 inches in loose thickness. We recommend that structural backfill or select backfill beneath proposed foundations be compacted to a minimum of 95% of the maximum dry density, as determined by ASTM 01557-88, Method C. Backfill placed beneath slabs-on-grade, behind below-grade walls, and underneath sidewalks should be compacted to a minimum of 90% of the maximum dry density. Backfill placed in landscaped areas should be compacted to a minimum of 85% of the maximum dry density. 4.7 Pre-Construction Condition Report and Monitoring If pile driving or excavation near existing structures is proposed, a pre-construction condition report of any adjacent structures should be performed for the protection of the building owner in the event of a future damage claim. The report must include detailed documentation and a photographic log of the existing condition of the adjacent structures. Based on the survey results, a monitoring program should be developed for the purpose of checking the performance of the adjacent structures or utilities and for monitoring construction procedures. This monitoring program should include, at a minimum, recommendations for the location of survey points to Prepared for: Ama~on Logistics AECOM n DRAFT Geotechnical Evaluation Project reference: AMZL-MR-DGB6 Project number: 60646117 monitor vertical and horizontal movements, locations for crack gauges, locations for monitoring vibrations during key construction activities, and groundwater monitoring wells if dewatering is performed. The monitoring program should also include threshold levels for allowable movements and vibrations, and the procedures to be implemented if the threshold levels are exceeded during construction. 4.8 Construction Inspection Our recommendations are contingent upon the proper review and observation during excavation and foundation construction operations by a geotechnical engineer familiar with the subsurface conditions and foundation design criteria. The geotechnical engineer's role should include the following: • Review and approval of contractor submittals related to foundation construction; • Observation and documentation of all phases of excavation and foundation construction; • Special inspection of underpinning and support of excavation; • Special inspection of foundation subgrades; • Special inspection of fill placement and compaction; and, • Monitoring of vibrations and review of monitoring data. Prepared for: Amazon Logistics AECOM " DRAFT Geotechnical Evaluation 5 Statement of Qualification and Limitations Project reference. AMZL-MR-DGB6 Project number: 60646117 The attached Report (the "Report") has been prepared by AECOM USA Ltd. (°'AECOM") for the benefit of the Client ("Client") in accordance with the agreement between AECOM and Client, including the scope of work detailed therein (the "Agreement"). The information, data, recommendations and conclusions contained in the Report (collectively, the "Information"): • is subject to the scope, schedule, and other constraints and limitations in the Agreement and the qualifications contained in the Report (the "Limitations"); • represents AECOM's professional judgement in light of the Limitations and industry standards for the preparation of similar reports; • may be based on information provided to AECOM which has not been independently verified; • has not been updated since the date of issuance of the Report and its accuracy is limited to the time period and circumstances in which it was collected, processed, made or issued; • must be read as a whole and sections thereof should not be read out of such context; • was prepared for the specific purposes described in the Report and the Agreement; and • in the case of subsurface, environmental or geotechnical conditions, may be based on limited testing and on the assumption that such conditions are uniform and not variable either geographically or over time. AECOM shall be entitled to rely upon the accuracy and completeness of information that was provided to it and has no obligation to update such information. AECOM accepts no responsibility for any events or circumstances that may have occurred since the date on which the Report was prepared and, in the case of subsurface, environmental or geotechnical conditions, is not responsible for any variability in such conditions, geographically or over time. AECOM agrees that the Report represents its professional judgement as described above and that the Information has been prepared for the specific purpose and use described in the Report and the Agreement, but AECOM makes no other representations, or any guarantees or warranties whatsoever, whether express or implied, with respect to the Report, the Information or any part thereof. Prepared for: Amazon Logistics AECOM " DRAFT Geotechnical Evaluation Project reference: AMZL-MR-DGB6 Project number: 60646117 Without in any way limiting the generality of the foregoing, any estimates or opinions regarding probable construction costs or construction schedule provided by AECOM represent AECOM's professional judgement in light of its experience and the knowledge and information available to it at the time of preparation. Since AECOM has no control over market or economic conditions, prices for construction labor, equipment or materials or bidding procedures, AECOM, its directors, officers and employees are not able to, nor do they, make any representations, warranties or guarantees whatsoever, whether express or implied, with respect to such estimates or opinions, or their variance from actual construction costs or schedules, and accept no responsibility for any loss or damage arising therefrom or in any way related thereto. Persons relying on such estimates or opinions do so at their own risk. Except (1) as agreed to in writing by AECOM and Client; (2) as required by-law; or (3) to the extent used by governmental reviewing agencies for the purpose of obtaining permits or approvals, the Report and the Information may be used and relied upon only by Client. AECOM accepts no responsibility, and denies any liability whatsoever, to parties other than Client who may obtain access to the Report or the Information for any injury, loss or damage suffered by such parties arising from their use of, reliance upon, or decisions or actions based on the Report or any of the Information ("improper use of the Report"), except to the extent those parties have obtained the prior written consent of AECOM to use and rely upon the Report and the Information. Any injury, loss or damages arising from improper use of the Report shall be borne by the party making such use. This Statement of Qualifications and Limitations is attached to and forms part of the Report and any use of the Report is subject to the terms hereof. Copyright© 2020 by AECOM Prepared for: Amazon Logistics AECOM " DRAFT Geotechnical Evaluation 6 References • California Building Code 2019 (CBC). Project reference: AMZL-MR-DGB6 Project number: 60646117 • USACE, Design of Foundations, Dated 15 January 1991. (EM 1110-2-2906). • CGS, 2020, Data Viewer, accessed December 2020: https://maps.conservation.ca.go_v/cgs/DataViewer/ • City of San Diego, 2020, The San Diego Seismic Safety Study, accessed December, 2020: https://www.sandiego.gov/development-services/zoning-maps/seismic-safety-study • USGS, 2020a, Earthquake Scenario Map (BSSC 2014), accessed December, 2020: https :/ /usgs. maps.a reg is. com/apps/webappviewer/index. html?id = 14d2f7 5c 7 c4f 4619936dac0 d14e1e468 • USGS, 2020b, Quaternary fault and fold database of the United States, accessed December, 2020: https. //earthquake .usgs.gov/cfu s1on/qfau lt/quer y main AB. cfrn?CF I 0=33968 3&CFTOKEN= d25e40e2380d1893-DE5B40D3-F385-GBD0-540373B551 F96612 AECOM " DRAFT Geotechrucal Evaluation Appendix C Log of Borings Project reference: AMZL-MR-0GB6 Project number. 60646117 AECOM .. Project: AMZL DGB6 Project Location: Carlsbad, CA Project Number: 60646117 Date(s) Drilled 2115/21 -2115/21 Drilling Method Hollow Stem Auger Ca~in Siz ype NIA Dnll Rig Type CME-75 Groundwater level Not Encountered and Date Measured Boring Location and Comments • Soll Samples Rock Coring -!:? € * ~ £ <ii &~ <ii > > a.-•.O .0 Cl) Q) &E 8 . 3: c: E 0 0 O.s1 c:o u 0 >,::> Cl) Q)-::> ::> Cl) 1-Z a:: a..e a::z a:: a:: 0 LE -2-BU K 5 4 B-2-1 1.5 6 7 5 B-2-, 1.5 8 14 10 4 B-2"' 1.5 6 9 15 9 B-2-< 1.5 11 9 PUSH B·2•! 0 3 20-B-2-E 1.5 4 4 25- 30 -Log of Boring LB-2 Sheet 1 of 1 Logged E. J. Vierra Afeproximate Surface By E evation (feet) - Drilling Choice Drilling Coordinates North: 33.134659 Contractor East: -117.232101 Drill Rig Operator -Total Depth 20 5 I Rock Depth Drilled (feet) • (feet) NIA Drill Bit 8" Bullet Sampler 2" Split Spoon Sampler Sizeffype Type(s) Hammer 140 lbs/30"/Auto leasing Hammer Core Barrel NIA IM/Drop u ~---,, Wt/Orop NIA Size/Type No. of Samples Dist.: 6 Undisl :0 Core lft\:0 ~ -e.,. .E .E c MATERIAL DESCRIPTION J 0 u J (.) "' REMARKS/ :c u Cl) '0 ~ C: a. '::i ~ ii: OTHER TESTS ~ Cl CG a, CT <.!l .3 J a: ~ ~ 4" Asphalt concrete over 12" of class 2AB Hand Auger to S feet ~ Fill-Moist, tanCCLAY with fine Gravel and fine to ~~ ~ coarse Sand ( L) ~~ ~ ) ,<'. ., ~ ~ Becomes mottled grass and browns (CL) :8 :1:•.~. Santiago Formation -Moist, medium dense, tan, Silty to ,,-:·,·~ Clayey fine SAND (SM/SC) ~ ;·; I?. ,, ';-:. ~ -~-: ;;, ... Moist, stiff, gray to tan Sandy CLAY (CL) with lenses of poorly cemented, bedded, sandstone. ~~·-· ; V •. I i:r . t~ ~ ·% ~~:·:.· j ~ r .... ~ .... 1 "" Moist, very stiff, dark brown. CLAY (CL) .. .' . . •,.; ~ >~ Shelby tube -no recovery ~ •. ;/ ·•. ~I Becomes medium and mottled (gray and dark brown) ~(CL) - Bottom of hole 20.5 feet -- --ASCOM Prnted: 2122/21 .. DRAFT Geotechnlcal Evaluation Project reference: AMZL-MR-OG86 Project number. 606461 1 7 Appendix D Laboratory Test Results (to be provided) AECOM ... DRAFT Geotechnical Evaluation Project reference: AMZL-MR-DGB6 Project number: 60646117 Appendix E Pavement Design Calculations (to be provided) AECOM