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Home My WebLink AboutCT 16-02; OCEAN CONDOMINIUMS; GEOTECHNICAL DESIGN REPORT OCEAN CONOMINIUMS; 2020-04-24301 Mission Avenue Suite 201 Oceanside California 92054 tel. 760.721.9990 fax. 760.721.9991 www.VisitTGI.com TGI Project No. 19.00911 Updated April 24, 2020 Prepared for: GEOTECHNICAL DESIGN REPORT PROPOSED OCEAN CONDOMINIUM PROJECT 2501 STATE STREET CARLSBAD, CALIFORNIA CT 16-02 / GR2019-0028 / DWG 519-5A Ocean 17 GP, LLC 234 Venture Street, Suite 100 San Marcos, CA 92078 Geotechnical Engineering Civil Engineering Environmental Site Assessment TAYLOR GROUP, INC.itg April 24, 2020 TGI Project No. 19.00911 Carlsbad 17 GP, LLC Attn: Mr. Richard Woolsey 234 Venture Street, Suite 100 San Marcos, California 92078 Subject: Geotechnical Design Report Proposed Ocean Condominium Project 2501 State Street, Carlsbad, California CT 16-02 / GR2019-0028 / DWG 519-5A Dear Mr. Woolsey: At your request, Taylor Group, Inc. (TGI) has performed a geotechnical investigation of the subject site. Based on the results of our investigation, we conclude that the site is suitable for the proposed development, provided the geotechnical recommendations presented in this report are followed during design and construction of the proposed improvements. If the recommendations presented in this report appear not to cover any specific feature of the proposed project, please contact TGI for any required additions, revisions or clarifications to the recommendations. TGI appreciates the opportunity to be of service to you. Please contact us if you have any questions regarding this report. Sincerely, TAYLOR GROUP, INC. Michael A. Cazeneuve Larry R. Taylor Senior Engineer Principal Engineer G.E. 3114 G.E. 2602 C.E.G. 2546 301 Mission Avenue Suite 201 Oceanside California 92054 tel: 760.721.9990 fax: 760.721.9991 www.visitTGI.com Table of Contents TOC 1 INTRODUCTION ........................................................................................................................................................ 1 1.1 GENERAL ........................................................................................................................................................ 1 1.2 SITE DESCRIPTION ........................................................................................................................................ 1 1.3 PROJECT DESCRIPTION ............................................................................................................................... 1 1.4 OBJECTIVE & SCOPE .................................................................................................................................... 2 1.5 PREVIOUS GEOTECHNICAL INVESTIGATION OF THE SUBJECT SITE ...................................................... 2 2 SUBSURFACE INVESTIGATION .............................................................................................................................. 4 2.1 EXPLORATORY BORINGS ............................................................................................................................. 4 2.2 EARTH MATERIALS ........................................................................................................................................ 4 2.2.1 Fill 4 2.2.2 Weathered Native Soils ............................................................................................................................ 5 2.2.3 Older Terrace Deposits ............................................................................................................................. 5 2.3 UNDERGROUND OBSTRUCTIONS ............................................................................................................... 5 2.4 GROUNDWATER AND CAVING ..................................................................................................................... 5 2.5 GEOTECHNICAL LABORATORY TESTING ................................................................................................... 5 3 REGIONAL GEOLOGY AND FAULTING ................................................................................................................... 7 3.1 REGIONAL GEOLOGIC SETTING .................................................................................................................. 7 3.2 FAULTING AND SEISMICITY .......................................................................................................................... 7 4 SEISMIC HAZARDS .................................................................................................................................................. 9 4.1 EARTHQUAKE FAULT RUPTURE HAZARD ................................................................................................... 9 4.2 GROUND SHAKING ........................................................................................................................................ 9 4.3 LIQUEFACTION .............................................................................................................................................. 9 4.4 SEISMICALLY-INDUCED SETTLEMENT ....................................................................................................... 9 4.5 LATERAL SPREADING ................................................................................................................................. 10 4.6 TSUNAMI HAZARD ....................................................................................................................................... 10 4.7 SEICHE HAZARD AND INUNDATION ........................................................................................................... 10 5 GEOTECHNICAL AND CLIMATIC CONSIDERATIONS .......................................................................................... 11 5.1 GEOTECHNICAL CONSIDERATIONS .......................................................................................................... 11 5.1.1 Expansive Soils ...................................................................................................................................... 11 5.1.2 Collapsible Soils/Hydroconsolidation ...................................................................................................... 11 5.1.3 Soil Corrosivity ........................................................................................................................................ 12 5.1.4 Landslides/Slope Stability ....................................................................................................................... 12 5.2 CLIMATIC HAZARDS .................................................................................................................................... 12 5.2.1 Flooding .................................................................................................................................................. 13 5.2.2 Sea-Level Rise ....................................................................................................................................... 13 6 CONCLUSIONS AND RECOMMENDATIONS ........................................................................................................ 14 6.1 PROPOSED CONDOMINIUM STRUCTURE................................................................................................. 15 6.2 PROPOSED PERMANENT SOLDIER PILE WALL ........................................................................................ 15 6.3 EARTHWORK RECOMMENDATIONS .......................................................................................................... 16 6.3.1 Demolition, Clearing, and Site Preparation, and Grading ....................................................................... 16 6.3.2 Remedial Grading ................................................................................................................................... 16 6.3.3 Subgrade Preparation ............................................................................................................................. 17 6.3.4 Acceptable Materials for Compacted Fill ................................................................................................ 17 6.3.5 Compaction ............................................................................................................................................ 17 6.3.6 Imported Fill ............................................................................................................................................ 18 6.3.7 Surface and Subsurface Drainage .......................................................................................................... 18 6.3.8 Carlsbad Opportunistic Beach Fill Program (COBFP) ............................................................................ 18 6.4 FOUNDATIONS AND FLOOR SLABS ........................................................................................................... 19 6.4.1 Conventional Foundations ...................................................................................................................... 19 6.4.2 Permanent Soldier Pile Foundation Design ............................................................................................ 20 6.4.3 Foundation Settlement ............................................................................................................................ 20 6.4.4 Foundations Observations ...................................................................................................................... 20 6.4.5 Floor Slabs on Grade .............................................................................................................................. 20 6.4.5a Interior Building Floor Slabs ....................................................................................................... 20 6.4.5b Exterior Concrete Flatwork, Hardscapes, and Walkways (Non-Trafficked) ................................ 20 Table of Contents TOC 6.4.5c Control Joints for Concrete Slabs ................................................................................................. 21 6.4.5dVapor Transmission Through Slabs .............................................................................................. 21 6.5 RETAINING WALLS ...................................................................................................................................... 22 6.5.1 Cantilever Retaining Walls ...................................................................................................................... 22 6.5.2 Restrained Retaining Walls .................................................................................................................... 22 6.5.3 Seismic Earth Pressure .......................................................................................................................... 22 6.5.4 Traffic Surcharge .................................................................................................................................... 22 6.5.5 Surcharge from Existing Structures ........................................................................................................ 23 6.5.6 Retaining Wall Drainage ......................................................................................................................... 23 6.5.7 Waterproofing ......................................................................................................................................... 23 6.5.8 Retaining Wall Backfill ............................................................................................................................ 24 6.5.9 Sump Pumps .......................................................................................................................................... 24 6.6 TEMPORARY EXCAVATIONS ...................................................................................................................... 24 6.6.1 Temporary Shoring ................................................................................................................................. 25 6.6.1a Installation of Soldier Piles ......................................................................................................... 26 6.6.1b Pre-Construction Survey ............................................................................................................ 27 6.6.1c Shoring Observations ................................................................................................................. 27 6.7 CONCRETE MIX CONSIDERATIONS ........................................................................................................... 27 6.8 SEISMIC DESIGN PARAMETERS ................................................................................................................ 27 6.9 STORM WATER MITIGATION BEST MANAGEMENT PRACTICES ............................................................. 28 6.10 PLAN REVIEW............................................................................................................................................... 28 6.11 CONSTRUCTION OBSERVATION AND TESTING ....................................................................................... 29 6.12 CHANGE OF ENGINEER OF RECORD ........................................................................................................ 29 7 LIMITATIONS ........................................................................................................................................................... 30 8 REFERENCES .......................................................................................................................................................... 31 TABLES Table 2.1. Summary of Exploratory Borings .............................................................................................................. 4 Table 2.2. Summary of Laboratory Testing ................................................................................................................ 6 Table 3.1. Nearby Active Regional Faults.................................................................................................................. 7 Table 6.1. Foundation Design Parameters .............................................................................................................. 19 Table 6.2. Temporary Shoring Design Parameters ................................................................................................. 25 Table 6.3. Soil Properties for Temporary Shoring Design ........................................................................................ 26 Table 6.4. Seismic Design Parameters ................................................................................................................... 28 FIGURES Figure 1. Site Location & Vicinity Figure 2a. Plot Plan Figure 2b. Survey Plan Figure 2c. Cross Sections A-A’ and B-B’ Figure 3. Local Geologic Map Figure 4. Map of Active Regional Faults Figure 5. FEMA Flood Insurance Rate Map Figure 6. Tsunami Inundation Map APPENDICES A. Boring Logs B. Laboratory Testing Data C. Seismic Design Parameter Information D. Earthwork Guidelines SUPPLEMENTAL APPENDIX Plot Plan, Boring Logs, and Lab Testing from Advanced Geotechnical Solutions, Inc., 2016 TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 1 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx INTRODUCTION 1.1 GENERAL This report presents the results of an investigation to provide geotechnical design and construction recommendations for a project consisting of a residential condominium project to be constructed at 2501 State Street in the City of Carlsbad, California (Figure 1). Taylor Group, Inc. (“TGI”) prepared this report for the exclusive use of Richard & Richard Construction Company, Inc. This work was performed in accordance with our Professional Services Agreement dated March 8, 2019. 1.2 SITE DESCRIPTION The project site (hereinafter “the Site”) is described as Assessor’s Parcel Number 155-200-10-00. The Site is bordered to the northeast by State Street, and to the southwest by the NCTD railroad right-of-way, which generally consists of undeveloped vacant land. The Site is bounded to the northwest by a commercial property developed with an existing 3-story commercial office building. It is bounded to the southeast by a 3-story multi-family residential condominium development. The Site is trapezoidal in shape with overall record dimensions of approximately 109 feet x 211 feet. The total area of the Site is approximately 21,223 square feet (0.49 acre). The Site is currently developed with a one-story commercial office building, asphalt paved parking lot, patio area and other related improvements including fencing, landscaping, vegetation, and walls. Vehicular access to the Site is and will be from the State Street. The Site is relatively level with mild slopes in varying directions at grades of about 1% to 5%, with about 5 feet of elevation difference across the eastern boundary of the Site along State Street. Elevations across the Site range between approximately 32 and 37 feet relative to mean sea level (MSL), based on NAVD88. An approximate 2 to 4 foot high slope descends offsite to the northwest at a gradient of approximately 2:1 (h:v). The condominium development located to the southeast of the Site is elevated approximately 4 feet above the existing average elevation of the Site. The grade changes are accommodated by an offsite retaining wall (with partially inclined backslope) located adjacent to the southeastern property line. The existing site conditions are shown on the enclosed Figure 2b – Survey Plan. The surrounding developments predominantly consist of multi-family residential and commercial related developments. 1.3 PROJECT DESCRIPTION Information regarding the proposed project was provided to TGI by the client. The proposed project will include demolition of the existing site structures and construction of a new 4-level multi-unit condominium development. In general, the lowest floor of the condominium structure will consist of vehicle parking, with limited mechanical, storage, trash, and lobby spaces. The upper floors are planned to be residential units. It is TGI’s understanding the proposed structure is currently planned to have a concrete slab-on-ground and conventional foundations at the ground floor, a reinforced concrete podium deck, and wood and/or steel framing for the upper floors. The lowest finished floor elevation for the structure is expected to range One TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 2 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx between approximately 31.5 and 33 feet relative to MSL. This corresponds to depths on the order of 2 to 5 feet below the existing site elevations. Therefore, the proposed parking level will be partially subterranean. The proposed project is shown on the enclosed Figure 2a – Plot Plan and Figure 2c – Cross Sections. Other miscellaneous site improvements such as site walls, landscapes, pavements, and hardscapes are also anticipated as part of the project. A new permanent soldier pile wall is planned along the easterly 90 feet of the southeastern property line, where the future site grades will extend approximately 4 to 5 feet below the bottom of the existing offsite retaining wall. The proposed soldier pile wall will support the existing offsite retaining wall and associated sloping backfill. The location of the soldier pile wall is noted on the enclosed Figure 2a – Plot Plan. Building wall loads are estimated to range between approximately 4 and 12 kips per lineal foot. Column loads are estimated to range between 250 and 500 kips. Grading will consist of the following: • Site preparations • Excavations on the order of 10 to 13 feet for removal and recompaction of existing unsuitable site soils • Lowering the existing site by as much as approximately 5 feet to achieve the proposed finished floor elevations 1.4 OBJECTIVE & SCOPE The primary objective of this investigation was to provide an evaluation of geotechnical conditions at the site and geotechnical design and construction recommendations for the project. To accomplish this objective, the following tasks were performed: • Visual geotechnical reconnaissance of the Site and vicinity; • Review of available published information and reports regarding geotechnical, geologic and seismic conditions; • Performance of a subsurface investigation consisting of excavating four exploratory borings to depths between approximately 16.25 and 20 feet below the ground surface. • Limited geotechnical laboratory testing of soil samples obtained from the borings; • Preliminary geotechnical engineering evaluation based on the available information and site- specific data, and; • Preparation of this report documenting the results, conclusions and recommendations of our investigation and evaluation. 1.5 PREVIOUS GEOTECHNICAL INVESTIGATION OF THE SUBJECT SITE A previous geotechnical investigation of the subject site was performed by Advanced Geotechnical Solutions, Inc. (AGS) in 2016. The results of the investigation were presented in the following report: • Preliminary Geotechnical Investigation, State Street Condominium Project, 2501 State Street, Carlsbad, California, dated March 30, 2016, Report No. 1602-03-B-2. The investigation addressed construction of a 4-story multi-family “Podium” type structure along with associated driveways and improvements. It was anticipated that the proposed structure would be constructed at or near the existing elevations onsite. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 3 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx Subsurface exploration included excavation of 3 borings to depths between 15.8 and 19.9 feet below the ground surface with a solid auger limited access tripod drill rig. The borings encountered existing undocumented fill to depths between approximately 8 and 10 feet below the ground surface. The fill soils were underlain by natural older terrace deposits (referred to as Old Paralic Deposits). The upper terrace deposits were reported to be weathered. Groundwater was not encountered to the maximum depth of exploration, although it was reported that groundwater may occur at elevations as shallow as 11 feet relative to MSL (or approximately 20 to 25 feet below the pad grade). Laboratory testing for the investigation included tests for moisture content, dry density, expansion character, maximum density, shear strength, consolidation, and corrosivity. The report includes recommendations for remedial grading and support of the proposed project on conventional spread footings. In general, it was recommended the undocumented fill and weathered Old Paralic Deposits be removed and recompacted as engineered fill for support of the proposed development. It was estimated that removal and recompaction depths would be on the order of 8 to 10 feet in depth for removal of the undocumented fill. Deeper removals were anticipated in some areas in order to remove the upper weathered terrace deposits. The plot plan, boring logs, and laboratory testing included in the investigation is provided in the enclosed Supplemental Appendix. Where appropriate, the results of subsurface exploration and testing are incorporated into this current investigation of the subject site. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 4 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx SUBSURFACE INVESTIGATION 2.1 EXPLORATORY BORINGS The site was explored by TGI on April 8 and 11, 2019 by excavating four exploratory borings. The borings were advanced to depths between approximately 16.25 and 20 feet using a truck mounted drilling machine equipped with 8-inch diameter hollow stem augers. The borings were generally located within the footprint of the planned structure. All excavation and sampling operations were performed under the supervision of a professional engineer experienced in the performance of geotechnical field investigations. TGI’s on-site personnel visually classified and logged the materials encountered in the exploratory borings and obtained relatively undisturbed samples and bulk samples at various depths for observation and laboratory testing. The boring locations are shown on the enclosed Figure 2a - Plot Plan, and the boring logs are included in Appendix A of this report. The boring depths and surface elevations are summarized in Table 2.1 below. Table 2.1 Summary of Exploratory Borings Boring No. Approx. Surface Elevation* (feet) Depth of Boring (feet) B1 34.5 20 B2 35.5 16.25 B3 35.3 20 B4 35.2 20 *Datum: NAVD88. Drive samples were obtained in the borings at various depths using a 3-inch O.D. by 2.5-inch I.D. ring-lined Modified California (Mod Cal) split spoon sampler. The sampler was driven using a 140-pound hammer dropped approximately 30 inches. The hammer system consisted of an automatic trip hammer. Samples obtained using the Mod Cal sampler were placed in plastic bags and then into 6-inch long PVC tubes. The ends of the tubes were then capped and taped. Bulk samples from selected depths were placed in plastic bags. 2.2 EARTH MATERIALS The field investigation performed by TGI encountered undocumented fill soils underlain by weathered native soils and Pleistocene age older terrace deposits. These geologic units are described in more detail below, in order from youngest to oldest. 2.2.1 Fill Undocumented fill soils were observed in the borings to depths between approximately 5 and 10 feet below the ground surface. The fill predominantly consists of sandy to silty clays, which are brown to medium brown and grayish brown in color, moist, firm, and occasionally include lenses, layers, and inclusions of silty sand and clayey sand. Occasional debris including asphalt, concrete, brick, wood, and plastic were also observed in the fill soils. Two TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 5 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 2.2.2 Weathered Native Soils Weathered native soils were encountered below the fill soils in all of the borings performed by TGI. These soils generally consist of highly weathered terrace deposits and/or residual natural soils. They were observed to extend to depths between approximately 10 to 13 feet below the ground surface. The weathered native soils consist of silty to clayey sands, sands, silts, and clays, which are light gray to dark gray, light brown to brown, and occasionally exhibit yellowish and/or orange staining. The weathered native soils are generally moist, medium dense or firm, and predominantly fine grained. 2.2.3 Older Terrace Deposits Older terrace deposits were observed below the weathered native soils at depths between 10 and 13 feet below the ground surface. The older terrace deposits were observed to consist of silty sands, which are light brown to brown, or light gray, slightly moist to very moist, and fine to coarse grained. The older terrace deposits are slightly to moderately weathered and occasionally exhibit partial degrees of cementation. 2.3 UNDERGROUND OBSTRUCTIONS Borings B1, B2, and B3 performed by TGI encountered a reinforced concrete slab below the surface asphalt pavement. The concrete slabs were on the order of 6-inches thick. A 4-inch thick concrete slab is also noted on boring log BA-3 in the geotechnical report by (AGS, 2016). 2.4 GROUNDWATER AND CAVING Groundwater was not observed in the borings on the Site to a maximum depth of 20 feet below the ground surface. Based on TGI’s experience in the vicinity of the site, groundwater is estimated to be at elevations on the order of 5 to 10 feet relative to MSL, or approximately 25 to 30 feet below the ground surface. Seasonal variation of groundwater level may occur, and shallower zones of perched groundwater may occasionally exist beneath the Site. Caving of the boreholes could not be directly observed during exploration because the boreholes were cased during drilling and caving was not possible. However, some of the subsurface soil conditions encountered during exploration were consistent with those where caving would be more likely to occur in shallow open excavations. This would include (but may not be limited to) areas where cohesionless sandy soils are present. 2.5 GEOTECHNICAL LABORATORY TESTING Samples that were obtained during the field investigation were transported to TGI’s lab for geotechnical laboratory testing. The laboratory testing program performed for this investigation included tests to evaluate TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 6 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx moisture content, dry density, expansion character, shear strength, consolidation, soil resistivity, corrosivity, and pH. The testing performed is summarized in the following Table 2.2. Table 2.2 Summary of Laboratory Testing Test Procedure Test Method Number of Tests Moisture Content / Dry Density ASTM D 2216 15 Expansion Index ASTM D 4829 2 Shear Strength ASTM D 3080 3 Consolidation ASTM 2435 2 Resistivity / pH ASTM / Caltrans 2 Sieve Analysis (-200 Sieve) ASTM D 422 3 Sulfate Caltrans 2 Tests were performed in general accordance with applicable ASTM and/or Caltrans procedures, or procedures generally accepted in geotechnical engineering practice. Laboratory testing results are included in Appendix B of this report. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 7 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx REGIONAL GEOLOGY AND FAULTING 3.1 REGIONAL GEOLOGIC SETTING The project site lies within the Peninsular Ranges geomorphic province, an extensive uplifted fault block that occupies the southwestern portion of California and extends southward into Baja California. The Site is located within the coastal plain portion of the Peninsular Range province. Topography in the Site vicinity is relatively flat and generally descends gradually toward the southwest. The Site area is underlain by sedimentary formations known as terrace deposits, which are Pleistocene in age (10,000 to 1.8 million years). A local geologic map indicating the site location is presented on Figure 3. The geologic structure of the area of investigation is dominated by a system of northwest trending faults including the San Clemente, Palos Verdes/Coronado Bank, Newport-Inglewood/Rose Canyon, Elsinore, and San Jacinto fault zones (see Figure 4). All of these faults are believed to have experienced historic or recent movement (within in the past 10,000 years). Movement along one or more of these faults or others is probable during the lifetime of the project. 3.2 FAULTING AND SEISMICITY Figure 4 presents a map illustrating the locations of known regional faults in relation to the study area location. The following table summarizes information on the nearby regional active faults. Table 3.1 Nearby Active Regional Faults Fault Approximate Distance From Study Area (km) Direction Maximum Credible Earthquake Newport-Inglewood Fault 3.4 SW 6.9 Rose Canyon Fault 3.4 SW 6.9 Coronado Banks Fault 31 SW 7.4 Elsinore Fault 37 NE 6.8 San Diego Trough Fault 47 SW >7.0 (?) San Jacinto Fault 75 NE 6.8 San Clemente Fault 87 SW >7.0 (?) San Andreas Fault 100 NE 7.4 The nearest known active faults are the southern extension of the Newport-Inglewood Fault and the northern extension of the Rose Canyon Fault, both of which are part of the Offshore Zone of Deformation located approximately 3.4 kilometers (2.1 miles) southwest of the study area in the Pacific Ocean. Other active faults located within approximately 50 km (30 miles) of the study area include the Coronado Bank Fault Zone, located approximately 31 km to the southwest, the Elsinore Fault, located approximately 37 km to the northeast, and the San Diego Trough Fault, located approximately 47 km to the southwest. Research (Rivero, et.al, 2000) has suggested that two blind thrust faults, the Thirtymile Bank thrust and the Oceanside thrust, might exist off the coast of Oceanside. These postulated thrust faults have little or no historical record. It has been suggested that the 1986 Oceanside earthquake (ML 5.3) ruptured as a small part of the Thirtymile Bank thrust. Three TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 8 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx The Thirtymile Bank thrust runs south from Santa Catalina Island, with the closest segment located approximately 60 km (37.3 miles) southwest from the study area. The Oceanside fault runs south from Laguna Beach in Orange County, with the closest segment located approximately 17 km (10.6 miles) southwest from the study area. Both extend south to San Diego and possibly beyond the U.S.-Mexico border. The postulated faults are thought to be capable of producing earthquake events with magnitudes up to Mw 7.6 if they are linked with other fault systems. Magnitude 7.4 events on the Thirtymile Bank Fault could have a minimum recurrence interval of about 2,100 years. The largest likely earthquake events on the Oceanside Fault could be on the order of magnitude 7.5 with a recurrence interval of 1,100 to 8,800 years. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 9 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx SEISMIC HAZARDS Southern California is a seismically active area and the Site, like virtually all of Southern California, is susceptible to earthquakes and earthquake related effects. In addition to damage caused directly by ground shaking and related ground failure, other hazards such as fires can easily start during and shortly after an earthquake. The following sections describe the relative level of risk associated with various earthquake related effects at the Site. 4.1 EARTHQUAKE FAULT RUPTURE HAZARD Based on a review of available current maps, and observations of the subject site, there are no known active or potentially active faults crossing the site. In addition, the Site is not located within a mapped Alquist- Priolo Earthquake Fault Zone. Based on these considerations, the risk of surface fault rupture occurring at the site is judged to be negligible. 4.2 GROUND SHAKING The Site may be subjected to strong ground motions during an earthquake on any of several known active fault systems, most specifically those identified in Section 3.2. Due to their close proximity to the site, the Rose Canyon and Newport Inglewood are believed to pose the most significant ground shaking hazard at the site. Based on recent fault parameters published by the CDMG, both the Newport-Inglewood and Rose Canyon faults are right lateral strike-slip faults and are considered to be capable of producing a Maximum Credible Earthquake (MCE) of magnitude 6.9. Based on the USGS U.S. Seismic Design Maps Tool the peak ground acceleration (PGA) corresponding to a 2% probability of being exceeded in 50 years in the area of the Site is on the order of 0.48g. 4.3 LIQUEFACTION When shaken strongly, unconsolidated sandy deposits that are saturated with water can liquefy and form a slurry as a result of an increase in pore pressure and a reduction in stress. This process is called "liquefaction." Slurries have little ability to support the weight of man-made structures or to resist flowing downslope, even on nearly flat ground. Liquefaction may result in sinking, tilt, distortion, or destruction of buildings and bridges, rupture of underground pipelines, and cracking and spreading of the ground surface. Based on the consistency of the future compacted fill and native older terrace deposits beneath the Site, the potential for liquefaction hazards to exist at the Site is judged to be negligible. 4.4 SEISMICALLY-INDUCED SETTLEMENT Seismically-induced settlement occurs when loose to medium dense deposits of partially saturated and saturated granular soils are densified as a result of strong ground shaking during an earthquake. Seismic settlement of foundations and the ground surface can result in significant property damage. Four TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 10 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx Based on the consistency of the future compacted fill and native older terrace deposits present beneath the Site, the potential for significant seismically induced settlement to occur at the Site is judged to be negligible. 4.5 LATERAL SPREADING Lateral spreading is a phenomenon that may occur during an earthquake event when the presence of a liquefied layer and gravity forces cause the ground to move laterally in a downslope direction. Liquefaction- induced lateral spreading can occur even on nearly flat ground and can result in tilting, distortion, or destruction of structures, rupture of underground pipelines, and cracking and spreading of the ground surface. Based on the consistency of the future compacted fill and native older terrace deposits beneath the Site, the potential for lateral spreading to occur at the Site is judged to be negligible. 4.6 TSUNAMI HAZARD Tsunamis are large, rapidly moving ocean waves triggered by a major disturbance of the ocean floor, which is usually caused by an earthquake but sometimes can be produced by a submarine landslide or a volcanic eruption. These events displace sea water and impulsively generate wave trains that can inundate low lying areas in proximity to the ocean. Review of the State of California Tsunami inundation map indicates the Site is located close to, but not within, a Tsunami inundation area. A copy of this map is included in the Appendix as Figure 6. In addition, the Site is currently situated at an elevation of approximately 35 feet above mean sea level, and the future planned finished floor elevation will be above an elevation of 30 feet. Based on these considerations, the potential for tsunami inundation at the Site is judged to be low. 4.7 SEICHE HAZARD AND INUNDATION A seiche is a wave in a body of water that may be caused by long-period earthquake ground motion or landslide. An earthquake induced seiche requires a form of resonance between the natural period of vibration of the body of water and the major periods of vibration in the seismic event. The subject site is located a few hundred feet from the edge of the Buena Vista Lagoon. Based on the site location and elevation relative to the lagoon, the seiche hazard is judged to be low. However, the potential for seiche to affect the subject site cannot be ruled out. No dams or dikes are located within the Site vicinity; therefore, flooding due to a dam or dike failure during an earthquake is not considered a potential hazard. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 11 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx GEOTECHNICAL AND CLIMATIC CONSIDERATIONS 5.1 GEOTECHNICAL CONSIDERATIONS 5.1.1 Expansive Soils Expansive soils pose a significant hazard to foundations for light buildings. Swelling clays derived from residual soils can exert large uplift pressures which can do considerable damage to lightly- loaded wood-frame structures. Expansive soils owe their characteristics to the presence of “active” clay minerals. As they get wet, the clay minerals absorb water molecules and expand; conversely, as they dry they shrink, leaving large voids in the soil. Swelling clays can control the behavior of virtually any type of soil if the percentage of clay is more than about 5 percent by weight. Soils with smectite clay minerals, such as montmorillonite, exhibit the most profound swelling properties. Expansive soils can damage foundations by uplift as they swell with moisture increases. Swelling soils lift up and crack lightly-loaded, continuous strip footings, and frequently cause distress in floor slabs. Because building loads vary on different portions of a structure's foundation, the resultant uplift will vary in different areas. The exterior corners of a uniformly-loaded rectangular slab foundation may only exert about one-fourth of the bearing pressure of that exerted at the central portion of the slab. As a result, the corners tend to be lifted up relative to the central portion. This phenomenon can be exacerbated by moisture differentials within soils at the edge of the slab. Such differential movement of the foundation can, in turn, cause distress to the framing of a structure. Potentially expansive soils can be identified in the lab by their plastic properties. Inorganic clays of high plasticity, generally those with liquid limits exceeding 50 percent and plasticity index over 30, usually have high inherent swelling capacity. Expansion of soils can also be measured in the lab directly, by immersing a remolded soil sample and measuring its volume change. Laboratory expansion index testing performed by TGI (ASTM D 4829) of the upper undocumented fill soils encountered in TGI’s borings indicates an expansion index (EI) between 112 and 192. Therefore, the soils are in the high to very high expansion category. Similar testing by (AGS, 2016) indicated an EI of 103 (high expansion category). Based on the high expansion character of the site soils, the recommendations provided herein are intended to mitigate the potential effects from expansive soils by removing them from the Site. 5.1.2 Collapsible Soils/Hydroconsolidation Hydroconsolidation, or soil collapse, typically occurs in soils that were recently (e.g., Holocene age) deposited in arid or semi-arid environments. Soils prone to collapse are commonly associated with poorly-compacted man-made fill, wind-laid sands and silts, and alluvial fan and mudflow sediments deposited during flash floods. The soil particles may be partially bonded by clay or silt, or chemically cemented with carbonates. When saturated, collapsible soils undergo a rearrangement of their grains and the water removes the cohesive (or cementing) material, resulting in often rapid and substantial settlement. An increase in surface water infiltration from irrigation, infiltration of surface Five TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 12 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx water or a rise in the ground-water table, combined with the weight of a structure, can initiate settlement. Settlement due to hydroconsolidation can cause foundations and walls to crack. Based on the consistency of engineered fill and older terrace deposits, and our local experience on numerous projects in the area, the potential for hydroconsolidation to occur at the Site is judged to be low. However, terrace deposits are occasionally slightly porous. Pore space within the soil structure could be susceptible to collapse when wetted. Therefore, the potential for hydroconsolication of the site soils cannot be ruled out. Consolidation testing (ASTM D 2435) of the site soils indicated a hydroconsolidation strain of 0.27 percent for a sample of the older terrace deposits. Similarly, the hydroconsolidation strain measured during testing of a sample of the weathered native soils was 0.55 percent. Provided the recommendations contained herein are implemented during design and construction of the proposed project, the potential for hydroconsolidation to affect the proposed development is judged to be low. 5.1.3 Soil Corrosivity Electrical resistivity testing of representative samples of the upper site soils (i.e. undocumented fill) indicates resistivities between approximately 270 and 290 ohms-cm (in a saturated condition). The measured resistivities are considered to be in the severely corrosive category. Soil pH was measured to be 8.0 to 8.1, or mildly alkaline. Two samples of the upper site soils (i.e. undocumented fill) were transported to the laboratory of Vinje & Middleton Engineering, Inc. for water-soluble sulfate content testing. The results indicate sulfate concentrations of 0.081% and 0.276% (or 810 ppm and 2,760 ppm, respectively). Soluble sulfate concentrations in soil greater than 0.2% (2,000 ppm) are generally considered to represent severe exposure and risk of external sulfate attack on concrete. The soluble sulfate test results are provided in the enclosed Appendix B. 5.1.4 Landslides/Slope Stability Landslides or slope failures are an abrupt movement of soil and/or bedrock downhill in response to gravity. Slope failures generally occur when the driving force induced by the weight of the earth materials within a slope exceeds the strength of those materials. Unstable slope conditions can arise from a number of natural and manmade causes, including increased moisture content, earthquakes, over steepening of the slope angle, and loading at the top of the slope. Slope failure can result in damage to property and injury or loss of life. There are no significant planned or existing slopes more than 5 feet high at the site, and based on our evaluation, no known landslides or slope failures exist on the site. 5.2 CLIMATIC HAZARDS Climatic hazards are extreme climatic/weather event(s) causing harm and damage to people, property, infrastructure and land uses. These may include both the direct (primary) impacts of the climate/weather event itself but also secondary hazards that are the result of such events, e.g., landslides that are 'triggered' by torrential rain. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 13 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 5.2.1 Flooding As shown on the FEMA Flood Insurance Rate Map for the area (Figure 5). The Site is located in an “X” zone, which indicates that the Site is not in a Special Flood Hazard Area. This designation implies that the Site is within an area that may be subject to shallow flooding with average depths of less than one foot. 5.2.2 Sea-Level Rise Rising sea levels caused by climate change are having profound effects on our coast and are changing coastal management planning and decision-making at all levels. Impacts from sea-level rise to the coastal zone include: flooding and inundation; increased coastal erosion; changes in supply, movement and distribution of sediment, and; saltwater intrusion into aquifers. The subject property may be most significantly impacted in the long term by increased flooding due to sea level rise. The inland extents of 100-year floods are likely to increase. Drainage systems that outlet close to sea level could become submerged, and inland areas may become flooded if outfall pipes back up with salt water. A variety of organizations and entities are working to quantify the effects of sea level rise and to address the effects from a policy and regulatory standpoint. The California Coastal Commission has recently prepared a draft guidance document to provide a framework for addressing sea-level rise in Local Coastal Programs and Coastal Development Permits. The draft CCC guidance includes projections included in a 2012 report by the National Research Council (NRC) Committee on Sea-Level Rise in California, Oregon and Washington. These projections, which the CCC believes “currently represents the best available science on the topic”, include predictions on a relatively localized. The predictions for the Los Angeles area that are included in the NRC report are summarized in the following table. Time Period Projected Sea-Level Rise Average Range 2000 – 2030 14.7 ± 5.0 cm 4.6 - 30.0 cm 2000 – 2050 28.4 ± 9.0 cm 12.7 - 60.8 cm 2000 – 2100 93.1 ± 24.9 cm 44.2 - 166.5 cm If these predictions are correct, then it can be estimated that sea-level could increase by 1.3 to 4.8 feet by 2090 (corresponding to a project life of approximately 75 years). This indicates that the project site will not be inundated as a result of sea level rise, but could become more susceptible to flooding due to rainfall events as a result of impacts on downstream storm drain systems. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 14 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx CONCLUSIONS AND RECOMMENDATIONS The results of TGI’s investigation and analysis indicate that the proposed development of the Site is feasible from a geotechnical engineering standpoint provided that the design recommendations provided in this report are followed. TGI’s investigation includes the following conclusions, recommendations, and key geotechnical considerations:  Between approximately 5 and 10 feet of existing undocumented fill soil was encountered during TGI’s exploration on the site. The existing fill soils in their present state are not considered to be suitable for support of foundations, floor slabs, or additional fill.  The existing fill soils predominantly consists of sandy to silty clays. The results of laboratory testing indicate the existing fill soils possess a high to very high expansion character. In addition, electrical resistivities of the fill soils were in the range that is considered severely corrosive to ferrous metals, and the water-soluble sulfate content was high enough to be considered severely aggressive for attack on concrete. Based on these considerations, it is recommended the existing fill soil materials not be re- used as compacted fill. It is recommended they be wasted from the site and select import fill be utilized where compacted fill is necessary. See Section 6.3.6 for discussion of recommended import soils.  Weathered natural soils were encountered below the undocumented fill to depths between 10 and 13 feet below the existing ground surface. In their present state, the weathered natural soils are not considered to be suitable for support of foundations, floor slabs, or additional fill. As discussed below, it is recommended these weathered natural soils be completely removed and recompacted during grading.  Older terrace deposits were encountered below the existing fill and weathered native soils to the maximum depth explored. The terrace deposits are suitable for support of foundations, floor slabs, and additional fill. The terrace deposits were encountered at depths between 10 and 13 feet below the ground surface during exploration on the site. This corresponds to elevations between approximately 22.5 and 24.5 feet relative to MSL.  As discussed in further detail in the following sections, it is recommended remedial grading be implemented in order to construct a compacted fill pad below the proposed condominium development. The recommended remedial grading includes: 1.) excavation and export of the expansive clay fill soils, 2.) additional removal and recompaction of the underlying weathered native soils, and 3.) import of select soils for use as compacted fill. Removal and recompaction to depths on the order of 10 to 13 feet are expected for the remedial grading operations.  An approximate 6-inch thick reinforced concrete slab should be expected to be encountered during grading throughout much of the site. The slab was encountered below the asphalt pavement in three of the borings performed by TGI. It is not known if the slab extends below the existing structures on the site.  Due to the anticipated excavation depths that will be required for removal and recompaction operations, and the proximity to the property lines and/or existing offsite structures, it is recommended shoring be utilized around the perimeter of the Site in order to maintain stable excavations during grading. Soldier piles and lagging are recommended for shoring. Shoring recommendations are provided in Section 6.6.1 of this report. Six TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 15 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx  Lagging boards (for temporary shoring) should not be buried during the removal and recompaction operation, and compacted fill should not be placed against the lagging. Lagging boards in the lower zone of excavation that will receive compacted fill should be completely removed prior to placement of loose lifts of fill and compaction.  A permanent soldier pile wall may be utilized along portions of the southern property line, as proposed. Recommendations for design and construction of the proposed soldier pile wall are provided in Section 6.2 below.  In order to further constrain the depth and distribution of undocumented fill, weathered native soils, and older terrace across the site, it is suggested additional subsurface explorations be performed near the southeast and southwest corners of the site. The results of the exploration would help constrain the anticipated removal depths during remedial grading and the anticipated shoring heights in those areas.  Groundwater was not encountered in the exploratory borings at the time of our field observations and is expected to be at a depths on the order of 25 to 30 feet below the existing ground surface (i.e. elevations between approximately 5 to 10 feet relative to MSL).  It is TGI’s opinion based on the findings of this investigation that, provided the recommendations included in this report are followed, the proposed development will have no adverse effect on the stability of the site or adjoining properties. The following sections provide detailed geotechnical design and construction recommendations for the project based on the current site assessment. If the recommendations appear not to cover any specific feature of the project, please contact TGI for any required additions, revisions or clarifications to the recommendations. 6.1 PROPOSED CONDOMINIUM STRUCTURE In order to provide uniform support for the proposed condominium structure, it is recommended the proposed structure be supported on conventional foundations bearing in a newly placed compacted fill pad. The fill pad may be comprised of the excavated and recompacted granular weathered native soils underlying the site, and select import soils complying with Section 6.3.6 of this report. The existing undocumented expansive fill soils underlying the site should be excavated and wasted from the site. The proposed floor slab-on-grade may also be supported on the newly placed fill pad. The recommended fill pad shall be constructed in accordance with the remedial grading recommendations provided in Section 6.3.2 below. Foundations and partial basement retaining walls may be designed in accordance with Sections 6.4 and 6.5, respectively. 6.2 PROPOSED PERMANENT SOLDIER PILE WALL The easterly 90 feet (approximate) of the southeastern property line is planned to consist of a permanent soldier pile wall. The wall will support the existing offsite retaining wall and associated backfill to the south of the site. Design of the proposed permanent soldier pile wall shall be based on the permanent design parameters provided herein for foundations and retaining walls. Specific foundation design parameters are provided in Section 6.4.2 for permanent soldier piles. The wall shall be designed for the permanent retaining wall pressures provided in Section 6.5. Permanent soldier piles shall be installed in general accordance with the recommendations and considerations of Section 6.6.1a – Installation of Soldier Piles. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 16 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx In the planned location, the permanent shoring wall will also serve as temporary shoring for the recommended remedial grading activities. It is recommended the wall designer specify the permanent construction materials that will be utilized for construction of the permanent soldier pile wall. This should include considerations for corrosion protection of buried steel and use of suitable permanent wall materials. 6.3 EARTHWORK RECOMMENDATIONS The following earthwork recommendations are provided for areas where fill or recompaction will be required for the project. This is expected to include the area of the proposed condominium structure, as well as areas to be finished with exterior concrete flatwork or pavements. Earthwork should be performed in accordance with the guidelines for earthwork summarized in the following sections and the Earthwork Guidelines provided in Appendix D of this report. 6.3.1 Demolition, Clearing, and Site Preparation, and Grading Demolition should include complete removal of any remaining elements of previous structures, foundations, concrete slabs, hardscape and underground piping systems. The Site should be cleared of all surface and subsurface deleterious materials including any pavements, buried utility and irrigation lines, fill soils, debris, trees, shrubs, vegetation and associated root systems. All such materials should be removed from the Site and properly disposed. An approximate 6-inch thick reinforced concrete slab should be expected to be encountered during grading throughout much of the site. The slab was encountered below the asphalt pavement in three of the borings performed by TGI. It is not known if the slab extends below the existing structures on the site. The slab should be completely removed during the grading operation. 6.3.2 Remedial Grading In order to provide uniform support for the proposed condominium structure, it is recommended the proposed structure be supported on conventional foundations bearing in a newly placed compacted fill pad. The proposed floor slab-on-grade may also be supported on the newly placed fill pad. The recommended fill pad shall be constructed in accordance with the following: • The existing undocumented fill soils consisting of expansive clay shall be completely excavated and wasted from the site. Based on the subsurface exploration performed by TGI, it is anticipated that the undocumented clayey fill soils will extend to depths between approximately 5 and 10 feet below the existing ground surface. • The weathered natural soils below the undocumented fill should then be removed until the underlying older terrace deposits are exposed at the bottom of the excavation. Based on the subsurface exploration performed by TGI, it is anticipated the older terrace deposits will be encountered at depths between approximately 10 and 13 feet below the ground surface. This would correspond to elevations between approximately 23 and 25 feet relative to MSL. • The subgrade at the bottom of the excavation should be observed and approved by TGI, then prepared as discussed in Section 6.3.3 below. • The excavated weathered natural soils may then be moisture conditioned and placed as newly compacted fill in accordance with these earthwork guidelines. All compacted fill should be compacted to a relative compaction of at least 90 percent as determined by TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 17 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx ASTM D1557. • Select import soils complying with Section 6.3.6 of this report shall then be placed as compacted fill up to the proposed subgrade elevation. • The compacted fill pad shall extend laterally beyond the edge of the perimeter foundations to the property lines, where feasible. The depth to competent terrace deposits should be expected to vary across the site. The remedial grading operation and construction of the recommended fill pad should be observed by a representative of the geotechnical engineer during construction. The bottom of all removals shall be observed and approved by a representative of the geotechnical engineer. Additional and/or deeper removals may be necessary in some areas of the site should existing unsuitable soils be encountered during grading. All compacted fill shall be observed and tested by a representative of the geotechnical engineer. All excavations shall be made in general accordance with Section 6.6 of this report. It is anticipated that the material encountered may be excavated using conventional earthmoving equipment, however, if concretions or cemented areas are encountered, they could require some heavy ripping. A bulking factor of 30% should be considered for material handling and stockpiling. The moisture content in the subgrade shall be maintained during construction to prevent drying of the soil in areas to be improved. 6.3.3 Subgrade Preparation Soil exposed at the bottom of excavations to receive structural fill should be scarified to a depth of at least 6 inches, moisture conditioned and compacted to relative compaction of at least 90 percent as determined by ASTM D1557. 6.3.4 Acceptable Materials for Compacted Fill It is recommended the existing expansive clay fill soils underlying the site not be re-used as compacted fill. It is recommended these existing clayey fill materials be excavated, removed from the site, and properly disposed. The weathered native soils underlying existing fill soils are considered to be satisfactory for re-use in compacted fill, provided any debris and/or deleterious materials (including roots and organic materials) are removed prior to placement of compacted fill. Import soils complying with the requirements of Section 6.3.6 may also be utilized as compacted fill on the Site. Materials larger than 6 inches in maximum dimension shall not be used in the fill. 6.3.5 Compaction Structural fill, backfill and subgrade soils should be compacted to a relative compaction of 90 percent or more as determined by ASTM D 1557. Prior to compaction, fill soils should be thoroughly mixed and moisture conditioned to bring the moisture content to within about 2 percent of the optimum moisture content and spread in uniform lifts of less than 8 inches (uncompacted thickness). TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 18 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.3.6 Imported Fill Any soil that is to be imported for use as structural fill shall meet the following specifications: o Expansion Index < 10 o Plasticity Index < 5 o No Organic Material o Less than 25 percent gravel larger than ¼ inch o Less than 15 percent rock larger than 2-1/2 inches o No rocks larger than 4 inches o Corrosivity characteristics suitable for the proposed construction materials o Design infiltration rate of at least 0.25 inch per hour In addition, import soils utilized in the building pad area shall meet the following minimum shear strength characteristics when compacted to a minimum of 90 percent of the maximum density as determined by ASTM D 1557: o Angle of Internal Friction (phi) = 33 degrees or greater o Cohesion = 50 psf or greater TGI shall be notified at least four working days in advance of importation in order to sample and test the proposed import material. No imported materials shall be delivered for use on site without prior sampling, testing, and evaluation by the geotechnical consultant. 6.3.7 Surface and Subsurface Drainage Final grading of the site must facilitate positive surface drainage away from foundations to prevent ponding of water. The minimum slope adjacent to structures should be 2 percent. We recommend the use of a sealed local area drain system around the perimeter of the structure to facilitate drainage, if possible. The discharge of downdrains from roof gutters and rooftop deck drains should be plumbed directly into an area drain system where possible. It is recognized that project’s storm water management requirements and design may be in conflict with the geotechnical recommendations. If infiltration devices are planned for the site, it is strongly recommended that site drainage and storm water BMP design should prevent ponding of water, infiltration, or saturation of soils adjacent to structure footings. 6.3.8 Carlsbad Opportunistic Beach Fill Program (COBFP) The City of Carlsbad encourages developers who plan to export soils from development sites to test the potential export soil material and evaluate if the soils are suitable for sand replenishment at local beaches. The proposed project will include export of the upper existing undocumented fill soils and import of select fill soil complying with Section 6.3.6 of this report. Based on the results of TGI’s site exploration and laboratory testing, the soils to be exported would not be suitable for beach replenishment materials. The export soils are expected to consist of clayey soils, with fines content (as defined by percent passing a #200 sieve) well in excess of 50 percent. In addition, the export soils are in the high to very high expansion character. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 19 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.4 FOUNDATIONS AND FLOOR SLABS The following sections discuss the foundation and floor slab recommendations for the project. These recommendations are based on the information obtained during our investigation and our current understanding of the proposed improvements. Furthermore, these recommendations assume that any import fill soils utilized on the site will comply with Section 6.3.6 above. 6.4.1 Conventional Foundations The proposed condominium development may be supported on conventional spread footings bearing in the newly placed compacted fill pad. Continuous footings and isolated pad footings may be designed using the design parameters and recommendations summarized in Table 6.1, below. Table 6.1. Foundation Design Parameters Parameter Continuous Footings Isolated column footings Minimum width 15 inches 24 inches X 24 inches Minimum depth below lowest adjacent grade 24 inches 24 inches Allowable bearing capacity 2,800 lb/ft2 3,000 lb/ft2 Increase in allowable bearing capacity per 12-inch increment of increased depth *800 lb/ft2 *800 lb/ft2 Increase in allowable bearing capacity per 12-inch increment of increased width *400 lb/ft2 *500 lb/ft2 Maximum allowable bearing capacity after depth and width increases applied 6,000 lb/ft2 Friction coefficient 0.35 Passive EFP for lateral resistance 390 lb/ft3 Ignore upper 6” unless confined by slab or pavement Reinforcing steel 4 – No. 4 bar top and bottom No. 4 bars at 12” top and bottom *Depth and width increases may be taken up to a maximum allowable bearing value of 6,000 lb/ft2 Lateral load resistance for conventional spread footings may be developed by a combination of passive resistance acting on footing walls and sliding resistance at the base of foundations. For passive resistance, a lateral pressure coefficient (Kp) of 3.25 or an equivalent fluid weight of 390 pcf may be used for design. The maximum passive resistance used for design should not exceed 3,900 psf. The uppermost 6 inches of soil should not be relied on for passive resistance unless confined by a slab or pavement. For sliding resistance, an allowable friction coefficient of 0.35 may be utilized with dead load forces for design of footings founded in new compacted fill. The equivalent fluid pressure, lateral pressure coefficient, and friction coefficient provided for lateral resistance are based on a safety factor of 1.0. The structural engineer shall utilize acceptable safety factors when utilizing these values for design. The provided values should not be increased for transient conditions such as seismic and/or wind forces. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 20 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.4.2 Permanent Soldier Pile Foundation Design Vertical capacities of soldier piles supporting the permanent soldier pile retaining wall may be computed using a skin friction of 500 psf for the portions of soldier piles permanently embedded in the older terrace deposits. Permanent soldier piles shall be at least 18 inches in diameter and spaced at least 2½ diameters on center. Lateral load resistance of the permanent soldier piles may be computed utilizing the lateral resistance values provided above for conventional foundations. Permanent soldier piles shall be installed in general accordance with the recommendations and considerations of Section 6.6.1a – Installation of Soldier Piles. 6.4.3 Foundation Settlement We estimate that the long-term settlement for conventional foundations designed using the above bearing pressures and anticipated building loads may be on the order of 0.75 inches, with differential settlements of less than 0.5 inches in 40 feet. Total and differential settlement of the proposed permanent soldier piles are estimated to be less than 0.5 and 0.25 inches, respectively. 6.4.4 Foundations Observations All foundations excavations should be observed and approved by a representative of the geotechnical engineer to verify that the foundations have been excavated into the recommended bearing materials. The observations should be made prior to placement of reinforcing steel. If necessary, foundations should be deepened to satisfactory materials. Prior to placement of reinforcement and concrete, all foundation excavations should be cleaned of loose soils. 6.4.5 Floor Slabs on Grade 6.4.5a Interior Building Floor Slabs Interior building floor slabs-on-grade (including the garage floor slab) should be at least 4- inches in thickness. TGI recommends building floor slabs be reinforced with a minimum of No. 3 steel reinforcing bars spaced 18 inches on center in both directions. Building floor slabs on grade may be cast over engineered fill materials placed in accordance with the Earthwork Recommendations provided in Sections 6.3 and 6.3.2 of this report. The slab section should be verified by the project structural engineer. 6.4.5b Exterior Concrete Flatwork, Hardscapes, and Walkways (Non-Trafficked) Exterior slabs for flatwork and walkways (not subject to vehicle traffic) should be at least 4 inches thick with minimum reinforcement consisting of No. 3 reinforcing bars spaced 18 inches on center in both directions. Exterior slabs within the area to undergo remedial grading may be cast directly over engineered fill materials placed in accordance with the Earthwork Recommendations provided in Section 6.3 and 6.3.2 of this report. It is recommended exterior slabs constructed beyond the area of remedial grading should be at least 4 inches thick with minimum reinforcement consisting of No. 3 bars spaced 18 inches on center in both directions. It is recommended the slabs be underlain by a minimum of 6-inches of class 2 miscellaneous base compacted to at least 95 percent of the maximum TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 21 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx density. Prior to placement of the base course in these areas, it is recommended the upper 12-inches of subgrade soils be removed and recompacted to at least 90 percent of the maximum density for support of the exterior slab sections. 6.4.5c Control Joints for Concrete Slabs All slabs should have control joints extending at least 25% of the slab thickness spaced at intervals of no more than 10 feet. Control joints should be constructed using grooving tools (in fresh concrete) or by saw cutting as soon as the concrete is hard enough that the edges abutting the cut don’t chip from the saw blade (generally 6-12 hours after finishing concrete). 6.4.5d Vapor Transmission Through Slabs It is normal for the soil moisture content beneath slabs-on-ground to increase over time. Concrete slabs are permeable and moisture beneath the slab will eventually penetrate through the slab unless protective measures are taken. Capillary break layers and vapor barriers are commonly placed below slabs to limit vapor transmission through floor slabs where moisture sensitive flooring will be present. Appropriate design considerations and construction methods can reduce the amount of moisture beneath the slab. Specification of these items is not a geotechnical issue and should be addressed on the foundation plans by the structural engineer or architect. We generally recommend that where moisture sensitive flooring is planned, the structural engineer or architect should consider specifying slab underlayment that is consistent with current recommendations and guidelines published by the American Concrete Institute (ACI) and Post-Tensioning Institute (PTI). Items that should be considered include the following: • Placement of a capillary break layer consisting of compacted clean concrete sand or ¾” crushed rock beneath slabs. • Placement of a plastic vapor retarder below the slab. • Whether the slab will be poured directly on the vapor retarder or on a layer of sand will be placed above the vapor retarder1. • Use of concrete admixtures, application of a curing compound and/or temporary covering of plastic sheeting to minimize the potential for differential drying and slab curl. 1 We suggest that slabs are poured directly on the vapor retarder. The slab designer should consider using a 15-mil plastic membrane meeting all criteria of Class A per ASTM E 1745. Example products meeting these requirements include Reef Industries “Griffolyn 15 Mil Green”, Stego Industries “Stego Wrap”, Raven Industries “Vapor Block 10, and W.R. Meadows “Perminator”. The vapor retarder should be installed in accordance with the manufacturer’s specifications, including overlapping and sealing of all penetrations and seams. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 22 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.5 RETAINING WALLS At this time retaining walls on the order of 3 to 5 feet in height are expected to be required for the proposed project. Retaining walls are anticipated in the following areas: • Around the partial basement of the proposed condominium structure. • Along the easterly 90 feet of the southern property line. This wall is anticipated to consist of a permanent soldier pile wall. • Miscellaneous retaining walls for ADA access ramps. All retaining walls associated with the planned improvements should be designed to resist lateral soil pressures and any additional existing or anticipated future surcharge loads. Retaining walls supported on conventional spread footings (i.e. the partial basement walls of the condominium structure and ADA ramp walls) may be designed in accordance with the allowable bearing values and design parameters provided in Section 6.4 of this report. Soldier pile foundations supporting the permanent solder pile wall may be designed using the skin friction and passive pressures provided in Section 6.4.2 of this report. All permanent retaining walls, including the permanent soldier pile wall, shall be designed to resist the lateral earth pressures indicated here for retaining walls. 6.5.1 Cantilever Retaining Walls Freestanding cantilever retaining walls (i.e. unrestrained) with uniform backfill should be analyzed and designed using an active earth pressure and an equivalent fluid pressure of 45 pcf. This value is valid for cantilever walls up to 5 feet in vertical height, with a level backslope extending behind the wall for a distance equal to or greater than the retained height of the wall. Cantilever walls with a maximum retained height of 5 feet supporting an inclined backslope with gradient of 2:1 (h:v), or flatter, may be designed using an active earth pressure and an equivalent fluid pressure of 60 pcf. 6.5.2 Restrained Retaining Walls Restrained retaining walls (braced to prevent deflection at the top of the wall) up to a maximum height of 5 feet shall be designed to resist a triangular distribution of “at-rest” earth pressure and an equivalent fluid pressure of 75 pcf. This value is valid for restrained walls with a level backslope extending behind the wall for a distance equal to or greater than the retained height of the wall. 6.5.3 Seismic Earth Pressure Although not anticipated at this time, retaining walls greater than 6 feet in height shall be designed to resist the additional earth pressure caused by seismic ground shaking. This firm should be notified if retaining walls of 6 feet in height (or higher) become part of the proposed project. Additional recommendations would be necessary. 6.5.4 Traffic Surcharge Where retaining walls will be within 10 feet of areas subject to vehicle traffic, the retaining walls should be designed to support the traffic surcharge. A uniform lateral pressure of 100 psf should be utilized in the design to accommodate normal street traffic. It is noted that higher surcharge TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 23 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx loads could result from heavy specialized traffic (i.e. cranes, heavy construction equipment, etc.). This office should be consulted if such traffic is anticipated. Additional surcharge recommendations would be necessary. 6.5.5 Surcharge from Existing Structures Additional active pressure should be added to the design where retaining walls would be surcharged by adjacent structures. Buildings and other structures (including the retaining wall and slope on the south side of the site) shall be considered surcharging where a 1:1 plane projected down and away from the bottom of the structure intersects the retaining wall. Where surcharge conditions are present, the wall designer shall incorporate an appropriate surcharge pressure into the retaining wall design. The surcharge pressure shall be based on suitable load estimates of the existing structure as determined by a qualified engineer. TGI can provide surcharge pressures if provided with suitable building loads. 6.5.6 Retaining Wall Drainage The retaining wall pressures provided herein are based on a drained condition and assume that a backdrainage system will be installed so that external hydrostatic forces do not develop behind the walls. If the retaining walls are not fitted with subdrainage systems, then the walls should be designed to support the lateral earth pressures indicated herein and the full hydrostatic pressure, using a water level at the ground surface. It is recommended retaining walls be equipped with a subdrain or weepholes covered with a minimum of 12 inches of gravel, with a compacted fill cap (or other seal) at the ground surface. Other geocomposite drainage / waterproofing systems may also be considered for the project. Some types of sudrainage systems and pipes are not accepted by various building officials and/or permitting agencies. It is recommended the subdrain system be cleared with the appropriate agencies prior to specifying and purchasing the system. All subdrain systems shall outlet to an acceptable location. It is TGI’s understanding the proposed permanent soldier pile wall planned at the southeast perimeter of the site will include an approximate 6-inch wide gravel pocket placed behind reinforced concrete lagging elements. The permanent lagging is planned to consist of 6-inch by 12-inch reinforced concrete cribbing. No seal is planned between the concrete lagging elements and subsurface water could weep between the cribbing. In addition, the gravel pocket will extend below the bottom of the lowest cribbing and provide a pathway for drainage into the gravel base below the pavers on the north side (lower side) of the proposed wall. From the geotechnical standpoint, it is TGI’s opinion this is adequate to provide back-drainage and prevent the potential build-up of hydrostatic forces. 6.5.7 Waterproofing It is recommended retaining walls be waterproofed. Specification of waterproofing is not a geotechnical issue and should be addressed on the plans by the structural engineer or architect. It is recommended a qualified professional should be consulted in order to recommend a product and/or method of retaining wall waterproofing. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 24 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.5.8 Retaining Wall Backfill If backfill of retaining walls is required, all backfill should be compacted to at least 90 percent of the maximum density in general accordance with the earthwork guidelines provided herein. The maximum density shall be determined by ASTM D1557. 6.5.9 Sump Pumps The recommended back drainage systems are intended to prevent building up of hydrostatic pressure behind retaining walls. The subdrains shall discharge to suitable locations. In the partial basement of the proposed structure, it is anticipated that a sump pump may be necessary to discharge any collected water. Groundwater was not encountered during exploration on the Site to a maximum depth of 20 feet below the ground surface. Based on information in TGI’s files for other projects in the immediate vicinity of the project site, groundwater is estimated to be at a depth of 25 to 30 feet below the ground surface. Therefore, a groundwater table is not expected to interact with the subdrain systems. However, water entering the subgrade from irrigation, precipitation, and other sources could potentially affect the retaining walls. Based on these considerations, the sump pumps would not be expected to pump groundwater, but it may be required to pump nuisance water from sources such as irrigation and/or precipitation. For design purposes, a minimum flow of 5 gallons per minute may be utilized in the design of sump systems. 6.6 TEMPORARY EXCAVATIONS Excavations on the order of 10 to 13 feet below the existing ground surface are anticipated for remedial grading operations and construction of the proposed project. Excavations on the site are expected to expose existing fill soils, weathered native soils, and terrace deposits. The clayey fill soils and terrace deposits are suitable for vertical excavations up to a maximum height of 5 feet, where not surcharged by adjacent traffic or existing structures. The cohesionless (sandy) weathered native soils are not suitable for vertical excavations. Surcharged excavations should be shored. Excavations greater than 5 feet in vertical height should be sloped or shored in accordance with the recommendations below. Adequate support for property lines, existing structures, and existing improvements shall be maintained at all times. In general, excavations exposing the clayey fill soils should be performed in accordance with Cal- OSHA requirements for Type B soils. Excavations exposing cohesionless (sandy) soils may be performed in accordance with Type C soils. Site safety and the stability of temporary excavations will be the contractor’s responsibility. Excavations for remedial grading operations will be in close proximity to the property lines and existing offsite structures around the perimeter of the Site. Due to the anticipated heights of the excavations, and the presence of offsite structures and improvements, it is recommended excavations around the perimeter of the Site be shored. Soldier piles and timber lagging are recommended for shoring. Shoring parameters are provided in the following section. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 25 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx Depending on the sequence of building construction and replacement of underground utilities along the northern portion of the Site, there may be sufficient space to utilize sloped excavations during grading and utility installation. Where sufficient space is available, temporary un-surcharged sloped excavations may be sloped in accordance with Cal-OSHA guidelines. The maximum vertical height of sloped excavations should not exceed 13 feet in height. Uniform sloped excavations do not have any vertical component. Sloped excavations with vertical cuts at the toe are not recommended. It is recommended all excavations shall be observed by a representative of the geotechnical engineer so that modifications of the excavations can be made if variations in the earth material conditions occur. 6.6.1 Temporary Shoring Based on the above, it is recommended excavations around the perimeter of the Site should be supported using a temporary shoring system. There may be sufficient space on the northern perimeter of the Site for sloped excavations. We recommend soldier beam and lagging type shoring. Due to the relatively shallow depth of the shoring system, it is recommended the soldier piles be designed as cantilevers. Design of temporary shoring shall be based on the fluid pressures in Table 6.2 or on the strength and unit weight parameters in Table 6.3. Additional active pressure should be added to the design where the shoring would be surcharged by adjacent traffic or structures. Traffic surcharge (including construction traffic) is provided in Table 6.2 below. Buildings and other structures (including the retaining wall and slope on the south side of the site) shall be considered surcharging where a 1:1 plane projected down and away from the bottom of the structure intersects the shoring bulkhead. Where surcharge conditions are present, the shoring engineer shall incorporate an appropriate surcharge pressure into the shoring design. The surcharge pressure shall be based on suitable load estimates of the existing structure as determined by a qualified engineer. TGI can provide surcharge pressures if provided with suitable building loads. Table 6.2. Temporary Shoring Design Parameters Parameter Value Active EFP (shoring up to 15 feet high) 45 lb/ft3 Allowable Passive EFP 390 lb/ft3 up to 3,900 psf maximum Traffic Surcharge 100 lb/ft2 Hydrostatic Pressure None Table 6.3. Soil Properties for Temporary Shoring Design Formational Material In-Situ Unit Weight (lbs/ft3) Dry Unit Weight (lbs/ft3) Phi Angle (Degrees) Cohesion (lbs/ft2) Existing Fill 124 105 27 1,075 Weathered Terrace Deposits 120 107 38 35 Terrace Deposits 130 115 37 105 Compacted Fill 124 113 33 50 TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 26 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx We recommend that soldier piles be wide-flanged beams (“W” sections) complying with the requirements of ASTM A 992 with a minimum yield strength of 36 ksi. Soldier beams for temporary shoring shall be set in drilled holes with a minimum diameter of 18 inches and shall be grouted to the cut depth using concrete with a compressive strength of at least 2,500 psi. The portion of the soldier pile above the cut depth may be backfilled with lean concrete. Piles should be spaced at least 2½ diameters on center. Timber lagging shall consist of pressure treated Douglas Fir or Hem-Fir grade marked #2 or better. Excavation and lagging shall be performed in lifts not to exceed 5 feet or as approved in the field by the Geotechnical Engineer. Lagging boards should not be buried during the removal and recompaction operation, and compacted fill should not be placed against the lagging. Lagging boards in the lower zone of excavation that will receive compacted fill should be completely removed prior to placement of loose lifts of fill and compaction. 6.6.1a Installation of Soldier Piles Where piles are closely spaced, it is recommended every other pile be drilled and filled with concrete. The concrete should be allowed to set at least 8 hours prior to drilling an adjacent pile shaft. This is intended to minimize the potential for caving (or blowout) between closely spaced piles. Placement of concrete should be performed with suitable equipment so that the concrete is not allowed to fall freely for a height of more than 5 feet. This is intended to prevent the falling concrete from hitting the sides of the drilled shaft and cause caving. Sandy (cohesionless) soils were encountered in the exploratory borings at depths between approximately 8 and 10 feet. Caving should be expected to occur in the sandy soils during drilling of soldier piles. Where caving occurs, it will be necessary to utilize casing or polymer drilling fluid to maintain open shafts during construction of soldier piles. If casing is used, the casing shall be carefully withdrawn so that the pile is not pulled apart as the casing is removed. The surface of the wet concrete should be kept at least 3 feet above the bottom of the casing as it is withdrawn. Groundwater was not encountered during exploration on the site to a maximum depth of 20 feet below the ground surface (or elevation 14.5 feet relative to MSL). In this area of Carlsbad, it is TGI’s opinion that groundwater likely occurs at an elevation of approximately 5 to 10 feet relative to MSL, or approximately 25 to 30 feet below the ground surface. Depending on the length of the soldier piles, groundwater may or may not be encountered in the drilled shafts. Should groundwater be encountered during drilling, caving should be expected to occur, and the measures indicated above should be implemented to mitigate the potential for caving. In addition, concrete for caissons placed below the groundwater level will require the use of a tremie and concrete shall be placed from the bottom up. A special concrete mix should be used for concrete to be placed below water. The design shall provide for concrete with a strength of 1,000 psi over the initial job specification. An admixture that reduces the problem of segregation of paste/aggregates and dilution of paste shall be included. The slump shall be commensurate to any research report for the admixture, provided that it shall also be the minimum for a reasonable consistency for placing when water is present. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 27 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.6.1b Pre-Construction Survey It is recommended a survey of the existing adjacent structures and site conditions be performed prior to installation of shoring and excavation. The survey would serve as a record of the existing conditions prior to excavation and could be relied upon in the event of any future disputes that may arise concerning the excavation. 6.6.1c Shoring Observations The installation of soldier piles and lagging shall be observed by a representative of the geotechnical engineer. The observations are made to ensure that geotechnical recommendations provided herein are implemented into the shoring system. In addition, the observations allow for modifications to be made should variations occur in the subsurface conditions. 6.7 CONCRETE MIX CONSIDERATIONS TGI recommends that concrete to be used for footings, permanent soldier piles, slabs, stem walls and other concrete on or below grade should meet the following minimum specifications: Avg. 28-day Compressive Strength: 4,500 psi Cement Type: Type V alkali-resistant cement Water-cementitious material ratio: 0.45 or less The site soils should be expected to be severely corrosive to metals. Care should be taken to ensure adequate concrete placement (using vibratory methods, where approved) and embedment of all reinforcing steel to reduce the potential for corrosion. 6.8 SEISMIC DESIGN PARAMETERS The proposed structure should be designed to resist earthquake loads in accordance with the minimum standards of the 2016 California Building Code (CBC). Seismic design parameters for the Site were evaluated using the USGS U.S. Seismic Design Maps Tool. Seismic design parameters were calculated based on the following input parameters: Site Location: Latitude = 33.164816 °N Longitude = 117.353682 °W Site Class: D (Stiff Soil) Seismic Risk Category: I/II/III Table 6.4 lists mapped, site modified and design spectral response accelerations for 0.2 second and 1 second periods. Program output including MCE, Site Modified and Design Response Spectrum data are included in Appendix C. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 28 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx Table 6.4. Seismic Design Parameters Period Mapped Spectral Response Acceleration Max. Spectral Response Acceleration Design Spectral Response Acceleration 0.2 Second SS = 1.165 g SMS = 1.204 g SDS = 0.803 g 1.0 Second S1 = 0.447 g SM1 = 0.694 g SD1 = 0.463 g 6.9 STORM WATER MITIGATION BEST MANAGEMENT PRACTICES The subject site is underlain by 5 to 10 feet of undocumented fill composed of highly to very highly expansive clay fill soils. These soils may also extend offsite and exist below adjacent properties. As discussed herein, TGI recommends that all the expansive soils be completely removed within the limits of the site and replaced with select import fill complying with Section 6.3.6. Select fill meeting the requirements of Section 6.3.6 may be expected to exhibit infiltration rates in the range of 0.25 to 2 inches/hour, whereas the clayey site soils are judged to have very low infiltration rates that would otherwise be unsuitable for infiltration-based BMPs. While the recommended import soils may possess favorable infiltration rates with respect to stormwater BMPs in general, it is TGI’s opinion that collection and transfer of stormwater runoff to limited areas for concentrated infiltration in volumes exceeding what would fall on the same area through natural precipitation or controlled irrigation could result in the following: • a perched water and saturated condition at the bottom of the select fill soils, and • vertical and lateral migration of subsurface waters, which could adversely impact onsite and adjacent offsite improvements through saturation and expansive soil related effects (i.e. expansion and contraction). Based on these considerations, the use of infiltration-based BMPs (such as infiltration basins, bioretention facilities, dry wells or storm water chambers) as pollutant control BMPs that are intended to infiltrate concentrated quantities of stormwater into the underlying soils are not recommended for the Site. Pollutant control BMPs at the site should be designed so that water is not allowed to percolate or infiltrate into the underlying site soils. This would be expected to include fully-lined biofiltration planters. However, it is TGI’s opinion the soil conditions at the Site following remedial grading will be suitable for low impact development (LID) site design BMPs (such as permeable pavers) used to retain runoff to a level equivalent to pervious ground and act as self-retaining areas. Where utilized, permeable paver sections not subject to vehicle traffic should consist of at least 3-inch thick pavers underlain by a minimum of 1-inch clean bedding sand placed above a minimum of 6-inches of open graded aggregate base. The thickness and gradation of the aggregate base should be specified by the engineer providing the LID design. It is anticipated the thickness and gradation will be dependent on the required storage capacity of the LID. 6.10 PLAN REVIEW TGI should review the final foundation plans, civil plans, shoring plans and specifications to evaluate conformance with the recommendations presented in this report and to assess whether additional analyses or recommendations are necessary based on the final design of planned improvements. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 29 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx 6.11 CONSTRUCTION OBSERVATION AND TESTING Soil and rock are highly variable materials. Subsurface conditions at a given site can vary spatially and can vary over time. While the geotechnical findings and recommendations presented in this report are based on interpretation and extrapolation of site-specific subsurface investigation, testing and analysis, it is not feasible to perform a geotechnical investigation that allows for assessment of all conditions that may be encountered during construction at any site. Consequently, observation and documentation of conditions encountered during grading is an integral and critical element of all earthwork projects. All earthwork associated with this project should be performed under the observation of a qualified geotechnical engineer and/or geologist from our office to assure that the recommendations presented in this report are followed, to verify that conditions encountered during construction are consistent with the design assumptions inherent in TGI’s recommendations and to identify the need for any additional or revised recommendations based on conditions encountered during construction. At this time, the following geotechnical observations and or tests are recommended during construction: • observation of drilled shoring pile shafts • observation during excavation to the subgrade bottom • observation of lagging installation • observation and approval of exposed subgrades prior to placement of fills • approval of imported fill with regard to the performance standards for LID stormwater BMPs per Section 6.9 of this report • observation and testing of all structural fill, including fill placed in the building pad, utility trenches, and any fill that will support surficial improvements such as exterior flatwork or pavement • observation of retaining wall subdrainage devices • observation and approval of all foundation excavations • observation and testing of base materials • observation of miscellaneous temporary excavations The preceding list is based on the anticipated construction activities on the subject site, as they relate to the geotechnical aspects of the proposed project. The list may or may not incorporate all geotechnical observations that will be necessary for the proposed project. Additional observations and testing may be required. 6.12 CHANGE OF ENGINEER OF RECORD If TGI is not retained as the geotechnical engineer of record during grading and/or future construction, then the new consultant will assume the responsibility as the geotechnical engineer of record. If that is the case, we recommend that the owner require that the new engineer of record thoroughly review the findings and recommendations of this report and notify the owner in writing as to their concurrence with such, or provide in writing any additional, revised or alternative recommendations that they believe are necessary based on their own professional opinions. TGI Project No. 19.00911 2501 State Street, Carlsbad, California Revised April 24, 2020 TAYLOR GROUP, INC. Page | 30 P:\00911 Ocean Condominiums\Geotechnical\Completed Reports\19.00911 Geotechnical Design Report_04242020.docx LIMITATIONS The findings, conclusions and recommendations presented in this report are based on various assumptions regarding the anticipated site improvements. TGI has reviewed conceptual plans for the proposed improvements at the time this report was prepared. If the improvements vary significantly from the stated assumptions presented herein, TGI should be consulted to update and modify, as needed, the conclusions and recommendations presented in this report. The subsurface conditions and engineering evaluation presented in this report were based on the results of a limited subsurface investigation. Subsurface conditions are, by their nature, uncertain and may vary from those documented in published reports and maps. The analysis and evaluation described in this report is limited. A more extensive geotechnical investigation performed at greater cost would provide more accurate and reliable information regarding subsurface conditions and geotechnical characteristics of the site. TGI’s evaluation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical engineering firms practicing in this or similar localities. The findings, recommendations and professional opinions presented in this report were developed in general accordance with generally accepted principles and practices of the geotechnical engineering profession at the time of the report preparation. TGI makes no other warranty, either expressed or implied, in fact or by law. The findings of this report are valid at the time the report was prepared. Changes in the condition of a property can and do occur with the passage of time as a result of natural processes or the work of man on the subject property or adjacent properties. Changes in applicable regulations, guidelines and standards of practice may also occur as a result of government action, legislation, and the broadening of knowledge. Consequently, the findings, conclusions and recommendations contained herein might be invalidated in whole or part by changes outside the control of TGI. Therefore, this report is subject to review and should not be relied on after a period of three (3) years. This report has been prepared for the exclusive use of the client and their consultants for this project. Any reliance by other parties upon the data, conclusions, opinions and recommendations presented herein is at such party’s sole risk. It is the responsibility of the client or their representative to ensure that the information and recommendations contained in this report are provided to the necessary design consultants for the project and are incorporated into the project plans. It is also the responsibility of the owners or their representative to ensure that contractors carry out the recommendations during construction. - - - §§§ - - - Seven REFERENCES Agnew, D. C., 2012, Tsunami history of San Diego, in Waiting for tsunami, coastal hazards of northern San Diego County, San Diego Association of Geologists, Cari Gomes, editor Advanced Geotechnical Solutions, Inc. (AGS), 2016, Preliminary Geotechnical Investigation, State Street Condominium Project, 2501 State Street, Carlsbad, California, dated March 30, 2016, Report No. 1602-03-B-2. California Department of Conservation, Division of Mines and Geology (2003), Fault Rupture Hazard Zones in California, Alquist-Priolo Special Studies Zone Act of 1972: California Division of Mines and Geology, Special Publication 42. California Geological Survey website, http://www.conservation.ca.gov/cgs/Pages/Index.aspx California Geological Survey (CGS), California Emergency Management Agency (CEMA), and University of Southern California (2009) Tsunami Inundation Map for Emergency Planning, State of California- Oceanside Quadrangle, 1:52,000 Scale, dated June 1, 2009. California Geological Survey (2008), The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) By 2007 Working Group on California Earthquake Probabilities, USGS Open File Report 2007-1437 CGS Special Report 203 SCEC Contribution #1138 California Seismic Safety Commission (2005), The Tsunami Threat to California, Findings and Recommendations on Tsunami Hazards and Risks, CSSC 05-03 Jennings, C. W. (1994), Fault Activity Map of California and Adjacent Areas: California Division of Mines and Geology, California Geologic Data Map Series. Kennedy, M.P. and Tan, S.S. compilers (2008), Geologic Map of the San Diego 30’X60’ Quadrangle, California, California Geological Survey, Regional Geologic Map No. 3, 1:100,000 scale. National Research Council (NRC), Committee on Sea Level Rise in California, Oregon, and Washington. (2012). Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future. National Academies Press, Washington, D.C. Rivero, C., Shaw, J.H. and Mueller, K., 2000, “Oceanside and Thirtymile Bank Blind trhursts: Implications for earthquake hazards in coastal southern California”, Geology, Vol. 8, No. 10, October 2000. Treiman, J.A. (1993), The Rose Canyon Fault Zone, Southern California, California Division of Mines and Geology, DMG Open-File Report 93-02. United States Geological Survey (2013), Open File report 2013-1170-M, California Geological Survey special report 229, Public Policy Issues associated with the SAFFR Tsunami scenario EIGHT FIGURES 2501 State Street Carlsbad, CA FIGURE 1. SITE LOCATION AND VICINITYTGI Project No. 19.00911 Drawn by: MC Checked by: MC Date: May 2019 Reference: USGS Topographic Maps, San Luis Rey 7.5 Minute Quadrangle, California, San Diego County, 2015 NORTH 2501 State Street, Carlsbad, California SUBJECT SITE FIGURE 2a. PLOT PLANReference:Preliminary Grading Plan Provided by Taylor Group, Inc.Project Name:Project Number:Location: Drawn by:Checked by:Richard & Richard Construction Company, Inc.19.009112501 State Street, Carlsbad, CAMCMCDate:Date:February 2020February 2020(UPDATED FEBRUARY 2020)LEGEND01020 40APPROXIMATE SCALE IN FEETNORTHApproximate Location and Number of Boring by TGI (this investigation)B4B4B3B2B1Approximate Location and Number of Boring by AGS (March 2016)BA-3BA-3BA-2BA-1Proposed Condominium DevelopmentProposed Permanent Soldier Pile WallAA'BB' FIGURE 2b. SURVEY PLANReference:Preliminary Grading Plan Provided by Taylor Group, Inc.Project Name:Project Number:Location: Drawn by:Checked by:Richard & Richard Construction Company, Inc.19.009112501 State Street, Carlsbad, CAMCMCDate:Date:February 2020February 2020(EXISTING SITE CONDITIONS)LEGEND01020 40APPROXIMATE SCALE IN FEETNORTHApproximate Location and Number of Boring by TGI (this investigation)B4B4B3B2B1Approximate Location and Number of Boring by AGS (March 2016)BA-3BA-3BA-2BA-1Proposed Permanent Soldier Pile WallAA'BB' FIGURE 2c. CROSS SECTIONS A-A' AND B-B'Project Name:Project Number:Location: Drawn by:Checked by:Richard & Richard Construction Company, Inc.19.009112501 State Street, Carlsbad, CAMCMCDate:Date:February 2020February 202001020 40APPROXIMATE SCALE IN FEETAA'Elevation in Feet010203040506070Elevation in Feet010203040506070B1BoringB3BoringB4BoringB2BoringB3AGS BoringPropertyLinePropertyLineSectionB-B'F.F.E. = 32.66F.F.E. = 32.48Proposed Condominium StructureTerrace DepositsWeathered Terrace DepositsUndocumented Fill????Newly CompactedFill PadShored ExcavationStateStreetEstimated High Groundwater ElevationBB'Elevation in Feet010203040506070Elevation in Feet010203040506070Estimated High Groundwater ElevationB2BoringBA-1BoringBA-2BoringPropertyLinePropertyLineSectionA-A'Existing Ground SurfaceExisting Ground SurfaceShored ExcavationNewly CompactedFill PadF.F.E. = 32.66Proposed Condominium Structure(E)Building????Terrace DepositsWeathered Terrace DepositsUndocumented Fill 2501 State Street, Carlsbad, California TGI Project No. 19.00911 Drawn by: MC Checked by: MC Date: May 2019 Reference: CDMG Open-File Report 96-02 NORTH FIGURE 3. LOCAL GEOLOGIC MAP SUBJECT SITE Scale in Feet 0 2,000 MAP UNITS 01020Scale (mi.)Source: Modified from base map from Scripp's Institute of OceanographySan Clemente FaultCatalina Escarpment FaultSan Pedro Basin FaultPalos V er d e s F a ult Oceanside FaultNewport-Ingle wood FaultSan Jacinto FaultElsinore FaultSan Di e g o Tr o u g h F a ult Corona d o B a n k F a ul t Rose Ca n y o n F a u l t FIGURE 4. MAP OF ACTIVE REGIONAL FAULTSNTGI Project No. 19.00911Drawn by: MCDate: June 2019Checked by: MCScale: as shownSource: Scripps InstituteProject SiteProject Site2501 State Street, Oceanside, CA FIGURE 5. FEMA FLOOD INSURANCE RATE MAP2501 State Street, Carlsbad, CaliforniaTGI Project No. 19.00911Drawn by: MCChecked by: MCDate: May 2019Reference: FEMASUBJECT SITE FIGURE 6. TSUNAMI INUNDATION MAP 2501 State Street, Carlsbad, California TGI Project No. 19.00911 Drawn by: MC Checked by: MC Date: May 2019 SUBJECT SITE Appendix A Boring Logs 2501 State Street Carlsbad, CA 100 100 100 100 100 100 56 100 GEOTECH BH COLUMNS 19.00911 OCEAN CONDOMINIUMS.GPJ GINT US LAB.GDT 6/4/1910-27- 50/4" 15-32- 50/4" 7-11-15 (26) 18-45- 50/2" light brown to brown, moist very dense, fine to coarse grained, partially cemented, slightly weathered TERRACE DEPOSITS: Silty Sand (SM), very light brown to light gray, moist to very moist, dense, fine to medium grained, moderate to highly weathered Sandy Silty Clay to Sandy Claeyey Silt (CL/ML), light gray to gray, moist, firm to stiff WEATHERED NATIVE SOIL: Silty Sand (SM), medium to dark gray with orange staining, moist, medium dense, fine grained Silty Sand (SM), brown, moist, medium dense, fine grained, mottled with brown to medium brown firm Sandy Clay (CL) inclusions UNDOCUMENTED FILL: Sandy Clay (CL), brown, moist, firm 6-inch Reinforced Concrete Slab 2-inch Asphalt Bottom of hole at 20.0 feet. MC 4-8-16 (24) MC MC End 20 feet, No Water, Fill to 5 feet MC MC BULK MC ATTERBERG LIMITS PLASTICITYINDEXPLASTICITYINDEX4-6-8 (14)PLASTICLIMITLIQUIDLIMIT0 5 10 15 20 25 MOISTURECONTENT (%)DRY UNIT WT.(pcf)POCKET PEN.(tsf)BLOWCOUNTS(N VALUE)RECOVERY %(RQD)PROJECT NUMBER 19.00911CLIENTR & R Construction Company, Inc. PROJECT NAME Ocean Condominiums PROJECT LOCATION 2501 State Street, Carlsbad, CADEPTH(ft)Boring Number B1 PAGE 1 OF 1 21 11 14 20106 115 112 FINES CONTENT(%)AT TIME OF DRILLING No Water SAMPLE TYPENUMBERMATERIAL DESCRIPTION GRAPHICLOGAT END OF DRILLING No Water AFTER DRILLING No Water DATE STARTED 4/11/19 GROUND WATER LEVELS: HOLE SIZE 8-inchGROUND ELEVATION 34.5* NOTES *Approximate Elevation (Datum: NAVD88) DRILLING CONTRACTOR Hamilton Drilling Corporation LOGGED BY CT COMPLETED 4/11/19 CHECKED BY MC DRILLING METHOD Hollow Stem Auger 100 100 100 100 100 100 100 18-38- 50/3"GEOTECH BH COLUMNS 19.00911 OCEAN CONDOMINIUMS.GPJ GINT US LAB.GDT 6/4/197-11-15 (26) 4-9-10 (19) 3-6-12 (18) Silty Sand to Sand (SM/SW), light to yellowish brown and orange brown, moist, medium dense, fine to medium grained WEATHERED NATIVE SOIL: Clayey to Silty Sand (SC/SM), brown to grayish brown, moist, dense, fine grained, some caliche filled veins Sandy to Silty Clay (CL), grayish brown, moist, firm, minor gravel and debris, mottled with Silty to Clayey Sand (SM/SC) inclusions that are brown, moist, medium dense, fine grained Clayey to Silty Sand (SC/SM), brown and grayish brown, moist, medium dense, fine grained UNDOCUMENTED FILL: Sandy Clay (CL), brown, moist, firm 6-inch Reinforced Concrete Slab 2-inch Asphalt TERRACE DEPOSITS: Silty Sand (SM), very light brown, slightly moist, very dense, fine to coarse grained, partially cemented End 16.25 feet, No Water, Fill to 7 feet MC BULK MC MC MC Sand (SP), light gray to light brown, slightly moist to moist, medium dense, fine grained MC 6-10-13 (23) Bottom of hole at 16.3 feet. MC ATTERBERG LIMITS PLASTICITYINDEX7-15-23 (38) 114 LIQUIDLIMIT0 5 10 15 20 25 MOISTURECONTENT (%)DRY UNIT WT.(pcf)POCKET PEN.(tsf)BLOWCOUNTS(N VALUE)RECOVERY %(RQD)PROJECT NUMBER 19.00911CLIENTR & R Construction Company, Inc. PROJECT NAME Ocean Condominiums PROJECT LOCATION 2501 State Street, Carlsbad, CADEPTH(ft)PLASTICLIMITBoring Number B2 PAGE 1 OF 1 PLASTICITYINDEX10 9 95 112 FINES CONTENT(%)11 115 22 AT END OF DRILLING No Water SAMPLE TYPENUMBERMATERIAL DESCRIPTION GRAPHICLOGAT TIME OF DRILLING No Water AFTER DRILLING No Water COMPLETED 4/11/19 HOLE SIZE 8-inchGROUND ELEVATION 35.5* NOTES *Approximate Elevation (Datum: NAVD88) LOGGED BY CT CHECKED BY MC GROUND WATER LEVELS: DATE STARTED 4/11/19 DRILLING CONTRACTOR Hamilton Drilling Corporation DRILLING METHOD Hollow Stem Auger 100 100 100 100 100 100 100 100 58 15-37- 50/5" 16-28- 50/5" 9-18-35 (53) 5-12-14 (26) 4-7-17 (24) 5-9-14 (23) 3-6-9 (15) 6-6-7 (13) 100 GEOTECH BH COLUMNS 19.00911 OCEAN CONDOMINIUMS.GPJ GINT US LAB.GDT 6/4/19TERRACE DEPOSITS: Silty Sand (SM), light orange brown to very light brown, slightly moist, very dense, fine to coarse grained, partially cemented Sand (SP), light brown to gray, slightly moist, medium dense, fine grained WEATHERED NATIVE SOIL: Silty to Clayey Sand (SM/SC), gray and brown, moist, medium dense, fine grained mottled with inclusions of grayish brown, fine grained, Silty Sand (SM), trace gravel trace wood and asphalt debris UNDOCUMENTED FILL: Sandy Clay (CL), brown to medium brown and grayish brown, moist, firm, trace brick debris (pebble sized) 6-inch Reinforced Concrete Slab 2.5-inch Asphalt End 20 feet, No Water, Fill to 9.5 feet Bottom of hole at 20.0 feet. MC MC MC MC MC BULK very light brown MC MC BULK MC PLASTICITYINDEXPLASTICITYINDEXMOISTURECONTENT (%)MATERIAL DESCRIPTION DRY UNIT WT.(pcf)DEPTH(ft)POCKET PEN.(tsf)BLOWCOUNTS(N VALUE)RECOVERY %(RQD)FINES CONTENT(%)SAMPLE TYPENUMBERPROJECT NUMBER 19.00911CLIENTR & R Construction Company, Inc. PROJECT NAME Ocean Condominiums PROJECT LOCATION 2501 State Street, Carlsbad, CA ATTERBERG LIMITS Boring Number B3 PAGE 1 OF 1 0 5 10 15 20 25 LIQUIDLIMITGRAPHICLOG102 100 18 PLASTICLIMITNOTES *Approximate Elevation (Datum: NAVD88) AT TIME OF DRILLING No Water AT END OF DRILLING No Water AFTER DRILLING No Water COMPLETED 4/11/19 GROUND WATER LEVELS: HOLE SIZE 8-inch 110 GROUND ELEVATION 35.3* 22 LOGGED BY CT CHECKED BY MC DRILLING METHOD Hollow Stem Auger 10 DATE STARTED 4/11/19 3 DRILLING CONTRACTOR Hamilton Drilling Corporation 100 100 100 100 100 100 100 100 79100 17-46- 50/5" 14-35- 50/5" 5-8-19 (27) 6-10-11 (21) 3-6-9 (15) 3-7-10 (17) 2-3-6 (9)GEOTECH BH COLUMNS 19.00911 OCEAN CONDOMINIUMS.GPJ GINT US LAB.GDT 6/4/193-3-5 (8) Bottom of hole at 20.0 feet. End 20 feet, No Water, Fill to 10 feet TERRACE DEPOSITS: Silty Sand (SM), very light brown to light gray, moist, dense to very dense, fine to coarse grained, slight clay binder, partially cemented, moderately weathered very light brown, slightly moist, very dense, slightly weathered WEATHERED NATIVE SOIL: Sand (SP), gray with faint orange staining, moist, medium dense, fine grained firm to stiff trace plastic debris, no Silty Sand inclusions observed UNDOCUMENTED FILL: Silty Sand (SM), brown, slightly moist, medium dense, fine to medium grained, minor gravel sized concrete debris Sandy Clay (CL), medium brown, moist, firm, mottled with occasional brown silty sand inclusions MC MC MC MC MC BULK MC MC MC MOISTURECONTENT (%)ATTERBERG LIMITS PLASTICITYINDEXPLASTICITYINDEXPLASTICLIMITDEPTH(ft)DRY UNIT WT.(pcf)POCKET PEN.(tsf)BLOWCOUNTS(N VALUE)RECOVERY %(RQD)FINES CONTENT(%)LIQUIDLIMITPROJECT NUMBER 19.00911CLIENTR & R Construction Company, Inc. PROJECT NAME Ocean Condominiums PROJECT LOCATION 2501 State Street, Carlsbad, CA Boring Number B4 PAGE 1 OF 1 0 5 10 15 20 25 12 25 119 17SAMPLE TYPENUMBER111 AT END OF DRILLING No Water MATERIAL DESCRIPTION GRAPHICLOGAT TIME OF DRILLING No Water AFTER DRILLING No Water COMPLETED 4/8/19 GROUND WATER LEVELS: DATE STARTED 4/8/19 HOLE SIZE 8-inch DRILLING CONTRACTOR Hamilton Drilling Corporation CHECKED BY MCLOGGED BY CT NOTES *Approximate Elevation (Datum: NAVD88) DRILLING METHOD Hollow Stem Auger GROUND ELEVATION 35.2* Appendix B Laboratory Testing Data 2501 State Street Carlsbad, CA Boring No. B2 Depth: 5'Peak: F =27.2o c = 1075 lb/ft2 Test Parameters: CU @ 0.002 in/min Sandy to Silty Clay (CL) Residual: F =22.1o c = 520 lb/ft2 Project: Ocean Condominiums Location: 2501 State Street, Carlsbad, California Project Number: 19.00911 Sample: Cal Mod. Ring (Field Moisture) gd=95.0 pcf w(i)=22.3% w(f)=22.3% Shear Strength Parameters: DIRECT SHEAR TEST 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress, kips/ft2Shear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0Shear Stress, kips/ft2Normal Stress, kips/ft2 Peak Shear Residual Shear ‐0.05 ‐0.04 ‐0.03 ‐0.02 ‐0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Displacement, inchShear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf Boring No. B3 Depth: 10'Peak: F =38.3o c = 35 lb/ft2 Test Parameters: CU @ 0.02 in/min Sand (SP) Residual: F =34.2o c = 0 lb/ft2 Project: Ocean Condominiums Location: 2501 State Street, Carlsbad, California Project Number: 19.00911 Sample: Cal Mod. Ring (Inundated) gd=102.4 pcf w(i)=3.4% w(f)=22.5% Shear Strength Parameters: DIRECT SHEAR TEST 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress, kips/ft2Shear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0Shear Stress, kips/ft2Normal Stress, kips/ft2 Peak Shear Residual Shear ‐0.05 ‐0.04 ‐0.03 ‐0.02 ‐0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Displacement, inchShear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf Boring No. B1 Depth: 15'Peak: F =37.1o c = 105 lb/ft2 Test Parameters: CU @ 0.02 in/min Silty Sand (SM) Residual: F =35.1o c = 20 lb/ft2 Project: Ocean Condominiums Location: 2501 State Street, Carlsbad, California Project Number: 19.00911 Sample: Cal Mod. Ring (Inundated) gd=111.8 pcf w(i)=11.2% w(f)=19.3% Shear Strength Parameters: DIRECT SHEAR TEST 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0.00 0.05 0.10 0.15 0.20 0.25 0.30Shear Stress, kips/ft2Shear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0Shear Stress, kips/ft2Normal Stress, kips/ft2 Peak Shear Residual Shear ‐0.05 ‐0.04 ‐0.03 ‐0.02 ‐0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30Vertical Displacement, inchShear Displacement, inch 1.0 ksf 2.0 ksf 4 ksf Boring No. B2 Sample: Cal. Mod. Ring Lined Sampler 112.0 pcf Depth: 9 Inundated at 2,000 psf 9.4 % Test: ASTM D 2435 Soil Type: Silty Sand to Sand (SM/SP) Project Name: Location: Project Number: Dry Density Moisture % CONSOLIDATION TEST Ocean Condominiums 2501 State Street, Carlsbad, California 19.00911 ‐2 0 2 4 6 8 10 12 100 1,000 10,000Percent Strain (%)Vertical Stress (psf) Percent Strain Vs. Vertical Stress Boring No. B4 Sample: Cal. Mod. Ring Lined Sampler 118.6 pcf Depth: 16 Inundated at 2,000 psf 11.5 % Test: ASTM D 2435 Soil Type: Silty Sand (SM) Project Name: Location: Project Number: Dry Density Moisture % CONSOLIDATION TEST Ocean Condominiums 2501 State Street, Carlsbad, California 19.00911 ‐2 0 2 4 6 8 10 12 100 1,000 10,000Percent Strain (%)Vertical Stress (psf) Percent Strain Vs. Vertical Stress Sample Identification *D100(mm) D60(mm) D30(mm) *D10(mm) Cc Cu %Gravel %Sand %< No.200 B1 @ 1-5' ----0.0 55.6 B3 @ 1-4' ----0.0 57.9 B4 @ 6-10' ----0.0 78.8 0 0 0 *Extrapolated where particle diameter is beyond sieve sizes utilized. Sample Identification SYM LL PL PI % Moisture B1 @ 1-5'CL/SM 20.6 B3 @ 1-4'CL/SM 18.3 B4 @ 6-10'CL 24.8 0 0 0 19.00911Project Number: GRAIN SIZE DISTRIBUTION (ASTM D 422) Sandy Clay Ocean Condominiums Classification Sandy Clay mixed with minor Silty Sand Sandy Clay mixed with minor Silty Sand 2501 State Street, Carlsbad, California Project Name: Location: 0 10 20 30 40 50 60 70 80 90 100 0.0010.0100.1001.00010.000100.0001000.000PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS 13/432 4 10 30 40 100 2003/84 50 SILT AND CLAYGRAVELCOBBLESSAND coarse medium fine U.S. SIEVE NUMBERU.S. SIEVE OPENING IN INCHES HYDROMETER coarse fine MOISTURE CONTENT(%)DEGREE OF SATUTATION(%)DRY DENSITY(lb/ft3)MOISTURE CONTENT(%)DEGREE OF SATUTATION(%)DRY DENSITY(lb/ft3)B-3 1-4' 9.1 44 107.6 28.8 105 96.3 0.1183 118.3 112112B-5 6-10' 10.1 47 105.6 36.8 110 88.0 0.1969 196.9 192192TESTS PERFORMED IN ACCORDANCE WITH ASTM D4829PROJECT:LOCATION:NUMBER:2501 State Street, Carlsbad, California19.00911Expansion Index Test ResultsCLASSIFICATION OF EXPANSION POTENTIALMEASURED EXPANSION OR(COLLAPSE)(inch)EI VALUE POTENTIAL EXPANSIONEXPANSION INDEX TEST RESULTSOcean Condominiums51-9091-130>130Very lowLowMediumHighVery high0-2021-50INITIAL CONDITIONS FINAL CONDITIONSEXPANSIONINDEXLOCATIONMEASUREDEI VALUEDEPTH(feet)EICORRECTED FOR S% Project Number: Project Name: Tested by: Date: Boring/Test Pit Number: Sample Number: Sample Depth (feet): Measurement No Total water added to dry soil 300 ml 400 ml 450 ml 500 ml 0.33 KW 0.26 KW 0.24 KW 0.26 KW Temperature (oC)26 oC 24.1 oC 24.0 oC 24.0 oC NOTES/CALCULATIONS: Rmin-15.5 = Rmin-T (24.5+t)/40 rmin-15.5 = Rmin-15.5 x C where: C= soil box constant = 1 cm Severely Corrosive 2,001 to 10,000 1,001 to 2,000 0 to 1,000 Greater than 10,000 Soil Resistivity in Ω-cm Corrosivity Category Mildly Corrosive Moderately Corrosive Corrosive Soil Resistivity and pH Data Sheet 1234 19.00911 Ocean Condominiums where: Rmin-T = resistance measures at test temperature t = test temperature in oC CT 1-5 feet (bulk sample) B3 Measured Resistance 0.24 KΩ 0.29 KΩ 290 Ω-cm 8.1 @ 23.8 oC Minimum Soil Resistance, Rmin-T Minimum Resistance corrected to 15.5oC,, R15.5 Minimum Soil Resistivity, rmin-15.5 Soil pH TAYLOR GROUP, INC. Project Number: Project Name: Tested by: Date: Boring/Test Pit Number: Sample Number: Sample Depth (feet): Measurement No Total water added to dry soil 300 ml 400 ml 450 ml 500 ml 0.35 KW 0.25 KW 0.22 KW 0.24 KW Temperature (oC)26 oC 24.9 oC 24.0 oC 24.0 oC NOTES/CALCULATIONS: Rmin-15.5 = Rmin-T (24.5+t)/40 rmin-15.5 = Rmin-15.5 x C where: C= soil box constant = 1 cm Severely Corrosive 2,001 to 10,000 1,001 to 2,000 0 to 1,000 Greater than 10,000 Soil Resistivity in Ω-cm Corrosivity Category Mildly Corrosive Moderately Corrosive Corrosive Soil Resistivity and pH Data Sheet 1234 19.00911 Ocean Condominiums where: Rmin-T = resistance measures at test temperature t = test temperature in oC CT 6-10 feet (bulk sample) B4 Measured Resistance 0.22 KΩ 0.27 KΩ 270 Ω-cm 8.0 @ 23.7 oC Minimum Soil Resistance, Rmin-T Minimum Resistance corrected to 15.5oC,, R15.5 Minimum Soil Resistivity, rmin-15.5 Soil pH TAYLOR GROUP, INC. Appendix C Seismic Design Parameter Information 2501 State Street Carlsbad, CA ASCE 7 Hazards Report Address: No Address at This Location Standard:ASCE/SEI 7-10 Risk Category:I Soil Class:D - Stiff Soil Elevation:35.43 ft (NAVD 88) Latitude: Longitude: 33.164816 -117.353682 Page 1 of 3https://asce7hazardtool.online/Wed Jun 05 2019 SS : 1.165 S1 : 0.447 Fa : 1.034 Fv : 1.553 SMS : 1.204 SM1 : 0.694 SDS : 0.803 SD1 : 0.463 TL : 8 PGA : 0.464 PGA M : 0.48 FPGA : 1.036 Ie : 1 Design Response Spectrum S (g) vs T(s)a MCE Response SpectrumR S (g) vs T(s)a Seismic Site Soil Class: Results: Seismic Design Category D - Stiff Soil D Data Accessed: Date Source: Wed Jun 05 2019 USGS Seismic Design Maps based on ASCE/SEI 7-10, incorporating Supplement 1 and errata of March 31, 2013, and ASCE/SEI 7-10 Table 1.5-2. Additional data for site-specific ground motion procedures in accordance with ASCE/SEI 7-10 Ch. 21 are available from USGS. 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Page 3 of 3https://asce7hazardtool.online/Wed Jun 05 2019 Appendix D Earthwork Guidelines 2501 State Street Carlsbad, CA TAYLOR GROUP, INC. Page D-1 Earthwork Guidelines EARTHWORK GUIDELINES 1.0 GENERAL These guidelines provide general procedures to be utilized in conjunction with the project grading plans during earthwork construction. These guidelines are a part of TGI’s geotechnical report. Where conflicts exist between these guidelines and the recommendations presented in the text of the geotechnical report, the recommendations presented in the text of the geotechnical report shall take precedence. 1. 1. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these guidelines and/or the recommendations of the geotechnical report. If, during the grading operations, geotechnical conditions are encountered which were not anticipated or described in the geotechnical report, the geotechnical consultant shall be notified immediately and additional recommendations, if applicable, may be provided. 1.2. It is the responsibility of the contractor to read and understand these guidelines as well as the geotechnical report and project grading plans. The contractor shall perform the grading operations in accordance with these guidelines, and shall be responsible for the quality of the finished product notwithstanding the fact that grading work will be observed and tested by the geotechnical consultant. The contractor shall not vary from these guidelines without prior recommendations by the geotechnical consultant and the approval of the client or the client's authorized representative. Recommendations by the geotechnical consultant and/or client shall not be considered to preclude requirements for approval by the jurisdictional agency prior to the execution of any changes. 1.3. It is the responsibility of the grading contractor to notify the geotechnical consultant and the jurisdictional agencies, as needed, prior to the start of work at the site and at any time that grading resumes after interruption. Each step of the grading operations shall be observed and documented by the geotechnical consultant and, where necessary, reviewed by the appropriate jurisdictional agency prior to proceeding with subsequent work. 1.4. A licensed land surveyor or civil engineer shall be retained, if required, to evaluate quantities of materials excavated during grading and/or to locate the limits of excavations. 1.5. An as-graded report should be prepared by the geotechnical consultant and signed by a Registered Engineer (and Certified Engineering Geologist if required). The as-graded report will document the geotechnical consultant’s observations, and field and laboratory test results, and provide conclusions regarding whether or not earthwork construction was performed in general accordance with the recommendations provided by the geotechnical consultant. Recommendations for foundation design, pavement design, subgrade treatment, etc., may also be included in the as-graded report. 2.0 DEFINITIONS The following definitions of terms are utilized in the remainder of these guidelines. CIVIL ENGINEER: The Registered Civil Engineer or consulting firm responsible for preparation of the grading plans and surveying, and evaluating as-graded topographic conditions CLIENT: The developer or a project-responsible authorized representative. The client has the responsibility of reviewing the findings and recommendations made by the geotechnical consultant and authorizing the contractor and/or other consultants to perform work and/or provide services. COLLUVIUM: Generally loose deposits, usually found on the face or near the base of slopes and brought there chiefly by gravity through downhill movement (see also Slopewash). TAYLOR GROUP, INC. Page D-2 Earthwork Guidelines COMPACTION: The densification of a fill by mechanical means. CONTRACTOR: A person or company under contract or otherwise retained by the client to perform demolition, grading, and other site improvements. DEBRIS: The products of clearing, grubbing, and/or demolition, or contaminated soil material unsuitable for reuse as compacted fill, and/or any other material so designated by the geotechnical consultant. ENGINEERED FILL: A fill which the geotechnical consultant or the consultant's representative has observed and/or tested during placement, enabling the consultant to conclude that the fill has been placed in substantial compliance with the recommendations of the geotechnical consultant and the governing agency requirements. ENGINEERING GEOLOGIST: A geologist registered by the state licensing agency who applies geologic knowledge and principles to the exploration and evaluation of naturally occurring rock and soil, as related to the design of civil works. EROSION: The wearing away of the ground surface as a result of the movement of wind, water, and/or ice. EXCAVATION: The mechanical removal of earth materials. EXISTING GRADE: The ground surface configuration prior to grading. Also referred to as original grade. FILL: Any deposit of soil, rock, soil-rock blends, or other similar materials placed by man. FINISH GRADE: The as-graded ground surface elevation that conforms to the grading plans. GEOFABRIC: An engineering textile utilized in geotechnical applications such as subgrade stabilization and filtering. GEOTECHNICAL CONSULTANT: The geotechnical engineering and engineering geology consulting firm retained to provide technical services for the project. For the purpose of these guidelines, observations by the geotechnical consultant include observations by the geotechnical engineer, engineering geologist and other persons employed by and responsible to the geotechnical consultant. GEOTECHNICAL ENGINEER: A licensed civil engineer and geotechnical engineer, registered by the state licensing agency, who applies scientific methods, engineering principles, and professional experience to the acquisition, interpretation, and use of knowledge of materials of the earth's crust to the resolution of engineering problems. Geotechnical engineering encompasses many of the engineering aspects of soil mechanics, rock mechanics, geology, geophysics, hydrology, and related sciences. GRADING: Any operation consisting of excavation, filling, or combinations thereof and associated operations. LANDSLIDE DEPOSITS: Material, often porous and of low density, produced from instability of natural or manmade slopes. OPTIMUM MOISTURE: The moisture content that is considered optimum to compaction operations as obtained by ASTM D-1557 or other standard test method recommended by the geotechnical engineer. RELATIVE COMPACTION: The degree of compaction (expressed as a percentage) of a material as compared to the dry density obtained from ASTM D 1557 or other standard test method recommended by the geotechnical engineer. ROUGH GRADE: The ground surface configuration at which time the surface elevations approximately conform to the approved rough grading plan. SITE: The particular parcel of land where grading is being performed. SLOPE: An inclined ground surface, the steepness of which is generally specified as a TAYLOR GROUP, INC. Page D-3 Earthwork Guidelines ratio of horizontal units to vertical units. SLOPE WASH: Soil and/or rock material that has been transported down a slope by gravity assisted by the action of water not confined to channels (see also Colluvium). SLOUGH: Loose, uncompacted fill material generated during grading operations. SOIL: Naturally occurring and manmade deposits of sand, silt, clay, etc., or combinations thereof SUBDRAIN: Generally, a pipe-and-gravel or similar drainage system placed beneath a fill along the alignment of buried canyons or former drainage channels. TAILINGS: Non-engineered fill which accumulates on or adjacent to equipment haul roads or disposed in an uncompacted state in connection with mining and quarry operations. TERRACE: A relatively level bench constructed on the face of a graded slope surface for drainage and maintenance purposes TGI: Taylor Group, Inc. TOPSOIL: The upper zone of soil or bedrock materials, which is usually dark in color, loose, and contains organic materials. 3.0 OBLIGATIONS OF PARTIES The parties involved in the projects earthwork activities shall be responsible as outlined in the following sections. 3.1. The client is ultimately responsible for the aspects of the project. The client or the client's authorized representative has a responsibility to review the findings and recommendations of the geotechnical consultant. The client shall authorize the contractor and/or other consultants to perform work and/or provide services. During grading the client or the client's authorized representative shall remain on site or remain reasonably accessible to the concerned parties to make the decisions that may be needed to maintain the flow of the project. 3.2. The contractor is responsible for the safety of the project and satisfactory completion of grading and other associated operations, including, but not limited to, earthwork in accordance with the project plans, specifications, and jurisdictional agency requirements. During grading, the contractor or the contractor's authorized representative shall remain on site. The contractor shall further remain accessible during non-working hours times, including at night and during days off. 3.3. The geotechnical consultant shall provide observation and testing services and shall make evaluations to advise the client on geotechnical matters. The geotechnical consultant shall report findings and recommendations to the client or the client's authorized representative. 3.4. Prior to proceeding with any grading operations, the geotechnical consultant shall be notified two working days in advance to schedule the needed observation and testing services. 3.4.1. Prior to any significant expansion or reduction in the grading operation the geotechnical consultant shall be provided with two working days notice to make appropriate adjustments in scheduling of on-site personnel. 3.4.2. Between phases of grading operations, the geotechnical consultant shall be provided with two working days notice in advance of commencement of additional grading operations. TAYLOR GROUP, INC. Page D-4 Earthwork Guidelines 4.0 SITE PREPARATION Site preparation shall be performed in accordance with the recommendations presented in the following sections. 4.1. The client, prior to any site preparation or grading, shall arrange and attend a pre-grading meeting between the grading contractor, the design engineer, the geotechnical consultant, and representatives of appropriate governing authorities, as well as any other involved parties. The parties shall be given two working days notice. 4.2. Clearing and grubbing shall consist of the substantial removal of vegetation, brush, grass, wood, stumps, trees, tree roots greater than 1/2-inch in diameter, and other deleterious materials from the areas to be graded. Clearing and grubbing shall extend to the outside of the proposed excavation and fill areas. 4.3. Demolition in the areas to be graded shall include removal of building structures, foundations, reservoirs, utilities (including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, etc.), and other manmade surface and subsurface improvements, and the backfilling of mining shafts, tunnels and surface depressions. Demolition of utilities shall include capping or rerouting of pipelines at the project perimeter, and abandonment of wells in accordance with the requirements of the governing authorities and the recommendations of the geotechnical consultant at the time of demolition. 4.4. The debris generated during clearing, grubbing and/or demolition operations shall be removed from areas to be graded and disposed of off site at a legal dump site. Clearing, grubbing, and demolition operations shall be performed under the observation of the geotechnical consultant. 4.5 The ground surface beneath proposed fill areas shall be stripped of loose or unsuitable soil. These soils may be used as compacted fill provided they are generally free of organic or other deleterious materials and evaluated for use by the geotechnical consultant. The resulting surface shall be evaluated by the geotechnical consultant prior to proceeding. The cleared, natural ground surface shall be scarified to a depth of approximately 8 inches, moisture conditioned, and compacted in accordance with the guidelines presented in Section 6 of these guidelines. 5.0 REMOVALS AND EXCAVATIONS Removals and excavations shall be performed as recommended in the following sections. 5.1. Removals 5.1.1. Materials which are considered unsuitable shall be excavated under the observation of the geotechnical consultant in accordance with the recommendations contained herein. Unsuitable materials include, but are not necessarily limited to: dry, loose, soft, wet, organic and compressible soils; fractured, weathered and soft bedrock; and undocumented or otherwise deleterious fill materials. 5.1.2. Materials deemed by the geotechnical consultant to be unsatisfactory due to moisture conditions shall be excavated in accordance with the recommendations of the geotechnical consultant, watered or dried as needed, and mixed to generally uniform moisture content in accordance with the guidelines presented in Section 6 of this document. 5.2. Excavations 5.2.1 Temporary excavations in firm fill or natural materials may be made with vertical side slopes not more than 5 feet high or deep unless otherwise recommended by the geotechnical engineer. Unless otherwise stated in the geotechnical report, any excavation deeper than 5 feet shall be shored or laid back at a 1:1 inclination or flatter, depending on material type, if construction workers are to enter the excavation. TAYLOR GROUP, INC. Page D-5 Earthwork Guidelines 6.0 COMPACTED FILL Fill shall be constructed as specified below or by other methods recommended by the geotechnical consultant. Unless otherwise specified, fill soils shall be compacted to 90 percent or greater relative compaction, as evaluated in accordance with ASTM Test Method D1557 or other standard test method recommended by the geotechnical engineer. 6.1. Prior to placement of compacted fill, the contractor shall request an evaluation of the exposed ground surface by the geotechnical consultant. Unless otherwise recommended, the exposed ground surface shall then be scarified to a depth of approximately 8 inches and watered or dried, as needed, to achieve generally uniform moisture conditions at or near the optimum moisture content. The scarified materials shall then be compacted to 90 percent or greater relative compaction. The evaluation of compaction by the geotechnical consultant shall not be considered to preclude any requirements for observation or approval by governing agencies. It is the contractor's responsibility to notify the geotechnical consultant and the appropriate governing agency when project areas are ready for observation, and to provide reasonable time for that review. 6.2. Excavated on-site materials which are in general compliance with the recommendations of the geotechnical consultant may be utilized as compacted fill provided they are generally free of organic or other deleterious materials and do not contain rock fragments greater than 6 inches in dimension. During grading, the contractor may encounter soil types other than those analyzed during the preliminary geotechnical study. The geotechnical consultant shall be consulted to evaluate the suitability of any such soils for use as compacted fill. 6.3. Where imported materials are to be used on site, the geotechnical consultant shall be notified three working days in advance of importation in order that it may sample and test the materials from the proposed borrow sites. No imported materials shall be delivered for use on site without prior sampling, testing, and evaluation by the geotechnical consultant. 6.4. Soils imported for on-site use shall preferably have very low to low expansion potential (based on ASTM D4829 test procedures). Lots on which expansive soils may be exposed at grade shall be undercut 4 feet or more and capped with very low to low expansion potential fill. In the event expansive soils are present near the ground surface, special design and construction considerations shall be utilized in general accordance with the recommendations of the geotechnical consultant. 6.5 Fill materials shall be moisture conditioned to near optimum moisture content prior to placement. The optimum moisture content will vary with material type and other factors. Moisture conditioning of fill soils shall be generally uniform in the soil mass. 6.6. Prior to placement of additional compacted fill material following a delay in the grading operations, the exposed surface of previously compacted fill shall be prepared to receive fill. Preparation may include removal and/or scarification, moisture conditioning, and recompaction. 6.7. Compacted fill shall be placed in horizontal lifts of approximately 8 inches in loose thickness. Prior to compaction, each lift shall be watered or dried as needed to achieve near optimum moisture condition, mixed, and then compacted by mechanical methods, using sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other appropriate compacting rollers, to the specified relative compaction. Successive lifts shall be treated in a like manner until the desired finished grades are achieved. 6.8. Fill shall be tested in the field by the geotechnical consultant for evaluation of general compliance with the recommended relative compaction and moisture conditions. Field density testing shall conform to current standardized test methods such as ASTM D 1556 (Sand Cone method), ASTM D 2937 (Drive-Cylinder method), and/or ASTM D 6938 (Nuclear Gauge method). Generally, one test shall be provided for approximately every 2 vertical feet of fill placed, or for approximately every 1000 cubic yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill TAYLOR GROUP, INC. Page D-6 Earthwork Guidelines found to be out of conformance with the grading recommendations shall be removed, moisture conditioned, and compacted or otherwise handled to accomplish general compliance with the grading recommendations. 6.9. The contractor shall assist the geotechnical consultant by excavating suitable test pits for removal evaluation and/or for testing of compacted fill. 6.10. At the request of the geotechnical consultant, the contractor shall "shut down" or restrict grading equipment from operating in the area being tested to provide adequate testing time and safety for the field technician. 6.11. The geotechnical consultant shall maintain a map with the approximate locations of field density tests. Unless the client provides for surveying of the test locations, the locations shown by the geotechnical consultant will be estimated. The geotechnical consultant shall not be held responsible for the accuracy of the horizontal or vertical location or elevations. 6.12 Grading operations shall be performed under the observation of the geotechnical consultant. Testing and evaluation by the geotechnical consultant does not preclude the need for approval by or other requirements of the jurisdictional agencies. 6.13. Fill materials shall not be placed, spread or compacted during unfavorable weather conditions. When work is interrupted by heavy rains, the filling operation shall not be resumed until tests indicate that moisture content and density of the fill meet the project guidelines. Re-grading of the near-surface soil may be needed to achieve the specified moisture content and density. 6.14. Upon completion of grading and termination of observation by the geotechnical consultant, no further filling or excavating, including that planned for footings, foundations, retaining walls or other features, shall be performed without the involvement of the geotechnical consultant. 6.15. Fill placed in areas not previously viewed and evaluated by the geotechnical consultant may have to be removed and recompacted at the contractor's expense. The depth and extent of removal of the unobserved and undocumented fill will be decided based upon review of the field conditions by the geotechnical consultant. 6.16. Off-site fill shall be treated in the same manner as recommended in these guidelines for on-site fills. Off-site fill subdrains temporarily terminated (up gradient) shall be surveyed for future locating and connection. 7.0 OVERSIZED MATERIAL Oversized material shall be placed in accordance with the following recommendations. 7.1. During the course of grading operations, rocks or similar irreducible materials greater than 6 inches in dimension (oversized material) may be generated. These materials shall not be placed within the compacted fill unless placed in general accordance with the recommendations of the geotechnical consultant. Where oversized rock (greater than 6 inches in dimension) or similar irreducible material is generated during grading, it is recommended, where practical, to waste such material off site. 7.2. Rocks 6 inches in dimension and smaller may be utilized within the compacted fill, provided they are placed in such a manner that there is no nesting of rock. Fill shall be placed and compacted over and around the rock. The amount of rock greater than 3/4-inch in dimension shall generally not exceed 40 percent of the total dry weight of the fill mass, unless the fill is specially designed and constructed as a "rock fill." TAYLOR GROUP, INC. Page D-7 Earthwork Guidelines 8.0 TRENCH BACKFILL The following sections provide recommendations for backfilling of trenches. 8.1. Trench backfill shall be placed in accordance with local agency requirements and the recommendations of the geotechnical report. In general, trench backfill shall consist of granular soils (bedding) extending from the trench bottom to 1 or more feet above the pipe. On-site or imported fill which has been evaluated by the geotechnical consultant may generally be used above the granular backfill. The cover soils directly in contact with the pipe shall be classified as having a very low expansion potential, in accordance with ASTM D 4829, and shall contain no rocks or chunks of hard soil larger than 3/4-inch in diameter. 8.2 Trench backfill shall, unless otherwise recommended, be compacted by mechanical means to 90 percent or greater relative compaction as evaluated in accordance with ASTM D 1557 or other standard test method recommended by the geotechnical engineer. Backfill soils shall be placed in loose lifts 8-inches thick or thinner, moisture conditioned, and compacted in accordance with the recommendations of Section 6 of these guidelines. The backfill shall be tested by the geotechnical consultant at vertical intervals of approximately 2 feet of backfill placed and at spacing along the trench of approximately 100 feet in the same lift. 8.3. Jetting or flooding is generally not recommended for densification of trench backfill and shall not be done unless approved by the geotechnical engineer. Jetting or flooding may only be allowed if trench backfill soils are sufficiently free-draining and provisions have been made for adequate dissipation of the water utilized in the jetting or flooding process. 8.4. If it is decided that jetting may be utilized, granular material with a sand equivalent greater than 30 shall be used for backfilling in the areas to be jetted. Jetting shall generally be considered for trenches 2 feet or narrower in width and 4 feet or shallower in depth. Following jetting operations, trench backfill shall be mechanically compacted to the specified compaction to finish grade. 8.5. Trench backfill which underlies the zone of influence of foundations shall be mechanically compacted to 90 percent or greater relative compaction, as evaluated in accordance with ASTM D 1557 or other standard test method recommended by the geotechnical engineer. The zone of influence of the foundations is generally defined as the zone defined by a 1:1 downward projection from the inner and outer edges of the foundation. 8.6. Trench backfill beneath slab areas shall be compacted by mechanical means to a relative compaction of 90 percent or greater relative compaction, as evaluated in accordance with ASTM D 1557 or other standard test method recommended by the geotechnical engineer. For minor interior trenches less than 3 feet deep, density testing may be omitted or spot testing may be performed, as deemed appropriate by the geotechnical consultant. 8.7. When compacting soil in close proximity to utilities, care shall be taken by the grading contractor so that mechanical methods used to compact the soils do not damage the utilities. If the utility contractors indicate that it is undesirable to use compaction equipment in close proximity to a buried conduit, then the grading contractor may elect to use light mechanical compaction equipment or, with the approval of the geotechnical consultant, cover the conduit with clean granular material. These granular materials shall be jetted in place to the top of the conduit in accordance with the recommendations of Section 8.4 prior to initiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate, upon review by the geotechnical consultant and the utility contractor, at the time of construction. 8.8 Clean granular backfill and/or bedding materials are not recommended for use in trenches on slopes unless provisions are made for a drainage system to mitigate the potential for buildup of seepage forces or piping of backfill materials. 8.9. The contractor shall exercise the specified safety precautions, in accordance with OSHA Trench Safety Regulations, while conducting trenching operations. Such precautions include shoring or laying back trench excavations at 1: 1 or flatter, depending on material type, for trenches in TAYLOR GROUP, INC. Page D-8 Earthwork Guidelines excess of 5 feet in depth. The geotechnical consultant is not responsible for the safety of trench operations or stability of the trenches. 9.0 DRAINAGE The following sections provide recommendations pertaining to site drainage. 9.1. Roof, pad, and slope drainage shall be directed away from slopes and structures to suitable discharge areas by non-erodible devices (e.g., gutters, downspouts, concrete swales, etc.). 9.2. Positive drainage adjacent to structures shall be established and maintained. Positive drainage may be accomplished by providing drainage away from the foundations of the structure at a gradient of 2 percent or steeper for a distance of 5 feet or more outside the building perimeter, further maintained by a graded swale leading to an appropriate outlet, in accordance with the recommendations of the project civil engineer and/or landscape architect. 9.3. Surface drainage on the site shall be provided so that water is not permitted to pond. A gradient of 2 percent or steeper shall be maintained over the pad area and drainage patterns shall be established to remove water from the site to an appropriate outlet. 9.4. Care shall be taken by the contractor during finish grading to preserve any berms, drainage terraces, interceptor swales or other drainage devices of a permanent nature on or adjacent to the property. Drainage patterns established at the time of finish grading shall be maintained for the life of the project. Property owners shall be made very clearly aware that altering drainage patterns may be detrimental to slope stability and foundation performance. 10.0 SITE PROTECTION The site shall be protected as outlined in the following sections. 10.1. Protection of the site during the period of grading shall be the responsibility of the contractor unless other provisions are made in writing and agreed upon among the concerned parties. Completion of a portion of the project shall not be considered to preclude that portion or adjacent areas from the need for site protection, until such time as the project is finished as agreed upon by the geotechnical consultant, the client, and the regulatory agency. 10.2. The contractor is responsible for the stability of temporary excavations. Recommendations by the geotechnical consultant pertaining to temporary excavations are made in consideration of stability of the finished project and, therefore, shall not be considered to preclude the responsibilities of the contractor. Recommendations by the geotechnical consultant shall also not be considered to preclude more restrictive requirements by the applicable regulatory agencies. 10.3. Precautions shall be taken during the performance of site clearing, excavation, and grading to protect the site from flooding, ponding, or inundation by surface runoff. Temporary provisions shall be made during the rainy season so that surface runoff is away from and off the working site. Where low areas cannot be avoided, pumps shall be provided to remove water as needed during periods of rainfall. 10.4. During periods of rainfall, plastic sheeting shall be used as needed to reduce the potential for unprotected slopes to become saturated. Where needed, the contractor shall install check dams, desilting basins, riprap, sandbags or other appropriate devices or methods to reduce erosion and provide the recommended conditions during inclement weather. 10.5. During periods of rainfall, the geotechnical consultant shall be kept informed by the contractor of the nature of remedial or precautionary work being performed on site (e.g., pumping, placement of sandbags or plastic sheeting, other labor, dozing, etc.). TAYLOR GROUP, INC. Page D-9 Earthwork Guidelines 10.6. Following periods of rainfall, the contractor shall contact the geotechnical consultant and arrange a walk-over of the site in order to visually assess rain-related damage. The geotechnical consultant may also recommend excavation and testing in order to aid in the evaluation. At the request of the geotechnical consultant, the contractor shall make excavations in order to aid in evaluation of the extent of rain-related damage. 10.7. Rain- or irrigation-related damage shall be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress, and other adverse conditions noted by the geotechnical consultant. Soil adversely affected shall be classified as "Unsuitable Material" and shall be subject to overexcavafion and replacement with compacted fill or to other remedial grading as recommended by the geotechnical consultant. 10.8. Relatively level areas where saturated soils and/or erosion gullies exist to depths greater than 1 foot shall be overexcavated to competent materials as evaluated by the geotechnical consultant. Where adverse conditions extend to less than 1 foot in depth, saturated and/or eroded materials may be processed in-place. Overexcavated or in-place processed materials shall be moisture conditioned and compacted in accordance with the recommendations provided in Section 6. If the desired results are not achieved, the affected materials shall be overexcavated, moisture conditioned, and compacted until the specifications are met. 10.9 During construction, the contractor shall grade the site to provide positive drainage away from structures and to keep water from ponding adjacent to structures. Water shall not be allowed to damage adjacent properties. Positive drainage shall be maintained by the contractor until permanent drainage and erosion reducing devices are installed in accordance with project plans. Supplemental Appendix Plot Plan, Boring Logs, and Lab Testing from Advanced Geotechnical Solutions, Inc., 2016 2501 State Street Carlsbad, CA -\-- BA-2 0-8' afu 8-16.5' Qop TD= 16.5' NoGW No Caving BA-3 0-10'afu 10-15.8' Qop TD= 15.8' NoGW l· ,h_ •• ~~ {' I. >' ' I I . . . . . ti / •··• • > ,.,,f,s,,/ .afu .. {Qop} EX BLDG. (36.5 FF) BA-1 0-9' afu 9-19.9' Qop TD= 19.9' NoGW 20 10 0 LEGEND PROPERTY LINE -fr.-- RIGHT OF WAY LINE -R/W· - STREET CENTERLINE -i-- PROP. BUILDING OUTLINE PZZZZJ PROP. CONCRETE I . . : I ~----;-;~~= PROP. PERVIOUS PAVER ~QP.$~J4,~ Geotechnical legend: BA-2G afu Qop Approximate location of Exploratory Boring Geologic Contact (Queried where uncertain, dotted where buried) Artificial Fill -Undocumented Old Paraiic Deposits (Bracketed where buried) Plate 1 Geologic Map and Exploration location Plan ADVANCED GEOTECliNICAl SOLUTIONS, INC. Project: P/\,'IJ 1602-03 20 SCALE: 1 "=20' Report: 1602-03-B-2 40 Date: March 2016 60 u, :E :::::, C oca z Cl) :e (.) 0 Oc z Check By Drawn By 0 0 DW Scale 1" = 20' Job Number 149417 PREPARED BY: NAME: 1--w w a: I-- (/) w ~ I-- (/) ,..... 0 LO C\I MICHAEL BAKER INTERNATIONAL ADDRESS: 5050 AVENIDA ENCINAS SUITE 260 CARLSBAD, CALIFORNIA 92008 (760) 476-9193 CONTACT: DAVID WIENER M icf:lael Baker INTERNATIONAL 5050 Avenida Encinas, Suite 260 Carlsbad, CA 92008 Phone: (760) 476-9193 MBAKERINTL.COM SHEET TITLE: PRELIMINARY CIVIL SITE PLAN REVISION 1: ORIGINAL DATE: 3/4/2016 --'-'------ SHEET C-1 N D:'. w z w 3: D -0 I 0.. (/) I ,..._ -ST ~ / > __J D / D z <( .7 D D <( ~ (/) 0 D z 0 (.) 1-w w ~ (/) w l- e" (/)I r--v -Ol ST / >"' <( 0 ;;;- :r: I I I I I .,. 0 "' g <ri S! (!) g BORING NUMBER BA-1 PAGE 1 OF 1 ADVANCED GEOTECH.'1/ICAL SOLUTIONS, INC. CLIENT Soil Retention PROJECT NAME 2501 State Street PROJECT NUMBER_1.,_,6:.::0=2....,-0'-"3'---------------PROJECT LOCATION_C=-a=r'-"ls,.,,b=a=d,_C=A'-'-------------- DATE STARTED_,2=/2=3=/1.,_,6:...._ __ _ COMPLETED _,2=/=23=/__,__16=-------GROUND ELEVATION-'3"""6"""ft~--- GROUND WATER LEVELS: HOLE SIZE _,6:...._ _____ _ DRILLING CONTRACTOR.-'N'-'-a=t"""iv=e....,D"-'n=·ll=in=g'----------- DRILLING METHOD_T.:...:n"'· :.::o=d _____________ _ AT TIME OF DRILLING_-_--____________ _ 15 CH GP SC CHECKED BY ....,J"-A""C'-----AT END OF DRILLING_-_-_____________ _ AFTER DRILLING ________________ _ LU a. ~ffi MATERIAL DESCRIPTION LUal _j:::? a. ::J :::?z <t: (/) BU MC @6 ft. Drilling slightly harder. (/) w 3:: f-::J 0Z.J _j ::J <t: mo> 06 7-10-10 (20) ~ ~ ~ ~ w ~ z o:::~ t:9 ::J f-0 z (J f-z ~ ::J -9, (/)LU -f-0::: & oz :::?O ::J f-0 0 <t: (/) 108 15.4 76 --------------------------~~--1------4 @8 ft. SANDY CLAY, brown to grayish brown, moist, stiff. MC 12-17-34 109 18_3 93 1---0-ld_P_a_r_a_li_c _D_e_p_o_si-ts-/Q_o_p_) ___________ _... (51 ) SAND, fine to medium grained, brown to olive brown, moist, dense. @12 ft. SAND, medium to coarse grained, light gray to light olive gray, moist, dense. @14 ft. SANDY GRAVEL, gray, subrounded, up to 3" , diameter, dense. _________________ f SAND with CLAY and SILT, fine to coarse grained, light yellow to light yellowish brown, slightly moist, very dense. MC 15-18-24 109 13.0 65 (42) MC 50/6" 102 10.7 45 f-z LU f-z 0~ 0 ~ (/) LU z u::: (/) f-(/) LU f- 0::: LU I 6 CHEM, El CONSOL (!) z ii: 0 al Cl) (!) <(L.,. __________________________________________________ __, I I I .., a.. C) <Ji C) 0 -' C) z ii: 0 a, M c;> N 0 <D 5 <( a, Cl) -' a:: <( u z 0 i= z w ,-w a:: -' 5 Cl) M ~ 0 <D <D I[ ::; -' :i: 9, a.. 0 ~ Cl) w 0 S2 u ~ a:: w Cl) ;l i..i M "' ~ <D 5i I ~ ,- 0 C) ai :5 I Cl) :::, ~ Cl) ,-z (5 I ' ;!: 0 N 0 M oi M > I C) 0 -' C) z ii: 0 a, Cl) C) <( BORING NUMBER BA-2 ADVANCED GEOTECIINlrAL SOLUTIONS, INC. CLIENT Soil Retention PROJECT NAME 2501 State Street PAGE 1 OF 1 PROJECTNUMBER_1~6~0~2--=0~3 _____________ _ PROJECT LOCATION....:C,,,,a,::.rl.:.::sc:ecba,,.,d~C,.,_A_,__ ___________ _ DATESTARTED....,2~/2~3~/1~6'-----COMPLETED ~2=n=3~/1~6 __ _ GROUND ELEVATION....,3,:..:,5:...:ft_,__ __ _ HOLE SIZE ~6~------ DRILLING CONTRACTOR_,N-"a""'t'"'iv--"'e-=D=-'-n:..::·11.!!.in,.,,g~---------GROUND WATER LEVELS: DRILLING METHOD_T:...:.n""· c:::O:::..d _____________ _ AT TIME OF DRILLING_-_-____________ _ LOGGED BY ....,P....:Wc..:..M=------CHECKED BY ~J~A=C~---AT END OF DRILLING ______________ _ NOTES ____________________ _ AFTER DRILLING ________________ _ z (.) 0 I ~~ :i: c, (/) f-~ (.) <( ¢:: a. ¢:: a.o >~ w~ r?. _J (/) w 0 :::i _J (.9 w 35 0 SM GP CH 30 5 SP 25 10 SC 20 15 MATERIAL DESCRIPTION Artificial Fill -Undocumented (afu) I SIL TY to CLAYEY SAND, fine to medium grained, brown, / I wet, loose. ___________________ / @0.5 ft. GRAVEL, angular, approx. 1/2" diameter. @3 ft. CLAY with trace SAND, grayish brown, wet, soft; hole is caving. @4.5 Slightly harder drilling. Old Paralic Deposits (Qop) SAND, fine to medium grained, grayish brown, medium dense. w a. (/) w i: ffi 3: f-:::i wa:i 0z_1 _J~ _J :::i <( a. :::i mo> ~z (.) ~ <( (/) --------------------------1-~----~ SAND with CLAY and SILT, fine to coarse grained, light greenish gray to light olive, moist, dense. MC 13-37- 50/4" _ ......... __ ......_......._..___ .......... __ @16 ft. Light yellowish brown. MC 50/6" TD= 16.5 ft. NoGW ~ ~ ~ ~ UJ ~ z Q'.f-t: 'ti' 0 :::>z ~ f-w z a. ~f-r?. :::i~ ~ oz :::i ~o ~ 0 (.) (/) 116 14.0 84 102 11.3 47 f-z w f-z 0~ (.) e..., (/) w z u:: (/) f-(/) w f-a: w I b DS I I I I BORING NUMBER BA-3 PAGE 1 OF 1 AD\IANCEO GEOTECHNICAL SOLUTIONS, INC. CLIENT Soil Retention PROJECT NAME 2501 State Street PROJECTNUMBER_1~6=0=2-~0~3 _____________ _ PROJECT LOCATION_C=a=r..,_,ls=b=a=-d'-'C"-'A'-'-------------- DATESTARTED~2~n=3~/1~6=----COMPLETED ~2_/2_3_/1_6 __ _ GROUND ELEVATION 35 ft -----HOLE SIZE ....:6=------- DRILLING CONTRACTOR~N~a=t~iv~e~D~ri~lli~ng~---------GROUND WATER LEVELS: DRILLING METHOD_T~n~· ~o~d _____________ _ AT TIME OF DRILLING_-_-____________ _ CHECKED BY~J~A~C ___ _ AT END OF DRILLING_-_-_____________ _ AFTER DRILLING ________________ _ MATERIAL DESCRIPTION w ~ a.. (/) w ~ffi 3: 1--:::, !=c;::-wm 0Z..J z (..) ..J ~ ..J:::, <{ :::, -9: a..:::, mo> ~z ()~ >- <{ et: (/) 0 ~ w ~ ~ et:~ z :::, 1--0 1--Z i== (/)UJ <{ -1--et: oz :::, ~o 1--() <{ 1--z UJ 1--z~ 0~ ()~ (/) UJ z u:: ~ (/) UJ l- o:: w I l-o §l--"""--+-..,.__ ..... _____ +-_C_o-re-d-th-ro_u_g_h_5_"_A_s_p_ha-l-t;_o_v-er_4_"_c_o_n_cr-e-te_;_o_ve_r_2_"_S_a_n_d_; ---lf----+------+---+--+----1----1,-------i ~ _ over 2" Asphalt. _________________ / .............. ---1 (/) g Artificial Fill -Undocumented (afu) ~ \ SIL TY SAND with CLAY, fine to medium grained, brown, ( ~ \ slightly moist, medium dense. ___________ J BU m @2 ft. CLAYEY SAND, fine to medium grained, brown, 9 moist, medium dense. g ---------------------------,.------15 < m Cl) ...J 0:: <'l z 0 ~ ~ 25 10 0:: ...J 5 Cl) M ~ "' <O Ii: :::; ...J :f 20 15 SP SC @5 ft. SANDY CLAY, fine to medium grained sand, brown, moist, very stiff; trace white, angular gravel to 1/4" diameter. Old Paralic Deposits (Qop) SAND, fine to medium grained, brownish gray with slight orange staining, slightly moist, medium dense . SAND with some CLAY and SILT, fine to coarse grained, yellowish brown, slightly moist. MC 13-13•18 104 20.0 88 (31) MC 20-21-31 108 4.4 22 (52) MAX, DS-R OS ~ @15 ft. Slightly moist, very dense. ~1---L--....L.£...4..L.J"1..-_----1_....:T::..D_=_15-.-8.::.ft __ ....:._ ___ :...._ __________ _.L_...__.....,_ ___ ,___,__---''-----'----'------1 MC 32-50/4" 96 10.9 39 CONSOL ~ NoGW 0 S2 u ~ 0:: w Cl) ::::, ;:; ti Cl iri ~ Cl) ::::, 0 >-Cl) >-z c5 ;! 0 N g cri S! 8 ...J Cl z ii 0 m Cl) Cl <L------------------------------------------------------' ... .. ------ - - -- - -- "" • -- ---... - ""' • -• -.. ADVANCED GEOTECHNICAL SOLUTIONS, INC. DRY DENSITY AND MOISTURE CONTENT -ASTM D2166 Project Name: 2501 State Street Location: Carlsbad, CA Project No: 1602-03 ------- Sample Date: 2/23/16 Submittal Date: 2/29/16 Test Date: 3/2/16 Boring No. BA-1 BA-1 BA-1 Depth (ft) 4' 8' 12' Moisture 15.4 18.3 13.0 Content(%) Dry Density 108.3 109.4 108.6 (pcf) By: PWM By: PWM By: HM BA-1 BA-2 16' 12' 10.7 14.0 102.3 115.5 BA-2 BA-3 16' 5' 11.3 20.0 101.6 103.8 BA-3 BA-3 10' 15' 4.4 10.9 107.9 95.5 ... --... - - - - -• -.. - --.. ... • .. • --- ADVANCED GEOTECHNICAL SOLUTIONS, INC. EXPANSION INDEX -ASTM D4829 Project Name: 2501 State Street Location: Carlsbad, CA File No: 1602-03 Date: 3/6/16 Excavation: BA-1 -------- Depth: 0-3' -------- Des c rip ti on: Grayish Brown Sandy Clay By: H-M Expansion Index -ASTM D4829 Initial Dry Density (pcf): 103.4 Initial Moisture Content(%): 12.0 Initial Saturation (%): 51.5 Final Dry Density (pcf): 106.3 Final Moisture Content(%): 21.5 Final Saturation (%): 92.3 Expansion Index: 103 Potential Expansion: High ASTM 04829 -Table 5.3 Expansion Index Potential Expansion 0-20 Very Low 21 -50 Low 51 -90 Medium 91 -130 High >130 Very High ,.., - - - - - - ·-----.. • ---• ---- ADVANCED GEOTECHNICAL SOLUTIONS, INC. MAXIMUM DENSITY -ASTM D1557 Excavation: BA-3 ---------Depth: 1-4' --------- Project Name: 2501 State Street Location: Carlsbad, CA Project No.: 1602-03 Des c rip ti on: Dark Brown Clayey Sand ---------Date: 2/26/2016 135,0 130,0 Ci:" 8,_ 125.0 -~ "' C ~ 120,0 ~ C 115.0 110.0 105.0 Test Number Dry Density (pcf) Moisture Content(%) Method 1 113.3 9.9 A 2 118.6 12.5 Max Density By: H-M 3 118.0 14.5 4 112.1 15.8 -+--Test Curve Zero Air Voids Curves -----SG=2.6 ---SG=2.7 100.0 ._ ____ .. ____ ....,..,_ ____ ... ____ ...,. _____ ,... ____ __ 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Moisture(%) Maximum Density 119.0 pcf Optimum Moisture 13.5 % ----- -- .. - , ... ... - - .. - --- - .. • .. • ---- ADVANCED GEOTECHNICAL SOLUTIONS, INC . DIRECT SHEAR -ASTM D3080 Project Name: 2501 State St. -----------Excavation: BA-2 -------- Location: Carlsbad, CA Depth: 12' ------- Project No.: 1502-03 -----------Sample Type: Undisturbed Date: 3/4/16 By: HM Samples Tested 1 2 3 Method: Drained Normal Stress (psf) 1000 2000 4000 Consolidation: Yes Maximum Shear Stress (psf) 1392 2436 3504 Saturation: Yes Ultimate Shear Stress (psf) 792 1356 2640 Shearing Rate (in/min): 0.04 Initial Moisture Content(%) 14.0 14.0 14.0 Initial Dry Density (pcf) 108.7 105.4 105.6 Friction Angle, phi (deg) Cohesion (psf) Peak 34 750 Ultimate 32 150 4000 3500 3000 ~ 2500 ~ "' "' Qj 2000 ... ... VI ... RI Qj .J::. 1500 VI 1000 / V / ., ., , ., / ., V ., 1r / ., j ]" ( V ., ., / ., ., / ., ., / ., , ., vr ., ~ or ., 0 Peak .,,. ~ --:/ ., -Peak Jr' ., D Ultimate 500 ., -. ---Ultimate ., 0 ., I I I .. 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Shear Stress v. Displacement 4000 ....... --------'---------, -----2000 3500 +----,-,-,,-.------------! ... ,/· ":/ t.·········· ······ ... _ 3000 -----------"'-----'t; ····-.... -;' 2500 +--,--~.,.,-=-,----- VI f., ' --1000 t 2000 -1--......,' .;...' ___ ',,,,_ _______ ----i C,I) } '' m 1500 +-...," .... · _______ ,....;.'----==--------1 .c ,'f~ --- "' 1000 -f-L-¥'-----___;::.....::::-----------1 500 /..( N .. ............... 4000 Normal Stress (psf) _0.02 .J-_______ :::;,_ ___ --1 5 5 0.01 +--_.,.....,_..,,.... _______ --I +' Ill E o.oo -tc,s-,=~--------------1 .E ~-0.01 --------------! iii :e-0.02 ------------- Cl> >_0_03 0.00 0.10 0.20 0.30 0.40 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Displacement (in) Displacement (in) -... -- .. .. - - ---- - .. • -• .. -... --- ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM D3080 Project Name: 2501 State St. Excavation: BA-3 --------Location: Carlsbad, CA Depth: 10' -------- Project No.: _1_6_02_-_0_3 ______ _ Sam p I e Type: Undisturbed Date: 3/5/16 By: HM Samples Tested 1 2 3 Method: Drained Normal Stress (psf} 1000 2000 4000 Consolidation: Yes ----Maximum Shear Stress (psf) 960 1404 2688 Saturation: Yes ----Ultimate Shear Stress (psf) 708 1356 2196 Shearing Rate (in/min): 0.04 ----Initial Moisture Content (%) 4.4 4.4 4.4 Initial Dry Density (pcf} 103.0 104.0 101.9 Friction Angle, phi (deg) Cohesion (psf) Peak 31 300 Ultimate 28 175 t;:" "' C. 3500 3000 2500 °;' 2000 "' QI ... .... Ill Ri 1500 QI .c Ill 1000 500 0 V. .;, ,,, V:,,, -,,, .. / / ,,, ,,, ~ I ,,, ,,, ,,, / ,,, ,,, V,,, ,,, a,,, / / / ,,, . ,,, ,,, V ,,, .-/ .,, ,,, .. "'[ J ,,, ,,, ,,, ,,, ,,, 0 Peak - --Peak D Ultimate - ---Ultimate I I 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Normal Stress {psf) Shear Stress v. Displacement 3000 -,---------"--------, . ········,., 2500 -------~...,.--................. 4000 ·•·• ....... , ! 2000 --------------2000 "' "' --1000 ~ 1500 --------------------1 "' ---------... '" l 1000 -t-1----:::::::::::==::::---------, 111 500 ..,...),..,,/(_,. _-___________ --1 N' 0 -1-l ....................... _.,_ ........ _.__ ............... ..__._...__ ......... ""' 0.00 0.10 0.20 0.30 0.40 Displacement (in) Vertical Deformation v. Displacement 0.03 ---------'------ _0.02 t---------=:::====--i :§. ~···························· I 0.01 -----/ .. -.... -.... -..... .,,.····""··· -"'--_-_-_ -__ -_-_-_----1 E 0.00 -k:----,""""'"----.,........;;;._-----1 ... ~~------.E ~-0.Dl +--------------1 ia :e-0.02 +--------------1 GJ ·····•••·••••·••· 4000 >-0.03 -----2000 --1000 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Displacement (in) ------- --.. .. .. - ..... --- ---.. ----- ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM D3080 Project Name: 2501 State St. ------------Location: Carlsbad, CA Project No.: 1602-03 ------------Date: 3/6/16 Samples Tested 1 2 Normal Stress (psf} 1000 2000 3 4000 Excavation: BA-3 --------Depth: 1-4' ....;_...;__ _____ _ Sample Type: Remolded to 90% By: HM Method: Drained Consolidation: Yes Maximum Shear Stress (osf) 936 1536 1992 Saturation: Yes ----Ultimate Shear Stress (psf} 912 1524 1980 Shearing Rate (in/min): _.....;0.....;.0_4_ Initial Moisture Content(%) 13.5 13.5 13.5 Initial Dry Density (pcf} 106.2 106.2 106.2 Friction Angle, phi (deg) Cohesion (psf) Peak 23 550 Ultimate 22 500 3500 3000 2500 ~ '; 2000 Ill Qj ... ti la 1500 ,r, ~ ~ ... ........-:: ~ =------ ~ ... ~--·~ ... Qj ..c VI ~ ~ ~ ... i, 1000 500 0 Peak -~ t -v---Peak ... D Ultimate - ---Ultimate 0 I I ' 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Shear Stress v. Displacement 2500 -----------------, ;;:- "' a. 2000 -1-------... -.... -.... -.... -. .. ---..... -·· .. ··· ';;;' 1500 -1--------=---~ ~ / .,., ... - ................. 4000 -----2000 --1000 t;, ! ,/ I 1000 t1-_;.\i1:r-:, ============-----, 500 i•v 0.00 0.10 0.20 0.30 0.40 Displacement (in) Normal Stress (psf) Vertical Deformation v. Displacement 0.03 -------------, -0.02 +-------------1 :§. 5 0.01 +-------------1 1 0.00 .L ........... -=-.. -... "" . .-:-== .. :-=.-:-.=~.=---.:=::.=:: -= .... -= .. :-= ... --:=._=_=_=_~-I ~-0.01 -t--------------i "iii "f-0.02 -t--------------i cu ................. 4000 >_0_03 -----2000 --1000 -0.04 +'-...... __ ....... __ ......... -+-'" ........ -+-'" ....... --+-" ....... ""' 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Displacement (in) - • -- ----- - --- - - - -- • --- • --- ADVANCED GEOTECHNICAL SOLUTIONS, INC. CONSOLIDATION -ASTM D2435 Excavation: BA-1 Project Name: 2501 State Street Location: Carlsbad, CA Project No: 1602-03 --------Depth: 12' --------Des c rip ti on: -----------------Date: 3/2/2016 By: HM -~ 0 -C 0 .. cu 'C 0 II) C 0 0 0.1 1 0 -~"-- -1 -2 -3 -4 -* -5 Test Description: Water Content, w Void Ratio, e Saturation, S Dry Density (pcf) Wet Density (pcf) ~-... * Consolidation-Pressure Curve Normal Pressure (ksf) 1 10 i I ..... ..... ~\.. ~-water added ·~ ... ... ... i I ~ , ... . --* * ~ ... .~ • .. I ~ I Before Test After Test 13.0% 19.6% 0.70 0.64 50% 83% 99.2 102.8 112.0 122.9 100 I i ! 7 - - -- - .... - .... • -.... - --.. .. • ... • --.. --- ADVANCED GEOTECHNICAL SOLUTIONS, INC. CONSOLIDATION -ASTM D2435 Excavation: BA-3 Project Name: 2501 State Street Location: Carlsbad, CA Project No: 1602-03 ---------Depth: 15' ---------Des c rip ti on: ------------------Date: 3/2/2016 By: HM -~ 0 -C 0 .:; ca "C 0 ti) C 0 0 0.1 1 0 >--.. -1 :=-.. -2 -3 ,....._. Consolidation-Pressure Curve Normal Pressure (ksf) 1 10 ~ "' ~-.... i I -I .... water added , '-I -,. ' -I i ~ -.... ... ' ,. ,. " ~ ,. ~ ~ i t-• \: I I I 100 I ' I I -4 +-----+--+---+--+--+--t-----+--++----+--+----+---+--+----+---1--+-a---+-----+-+-+---+--t-+-1 i I I I -5 Test Description: Before Test After Test Water Content, w 10.9% 15.1% Void Ratio, e 0.46 0.45 Saturation, S 64% 92% Dry Density (pcf) 115.2 116.5 Wet Density (pcf) 127.7 134.1 -.. -- ANAHEIM TEST LAB, INC 3008 ORANGE A VENUE SANT A ANA, CALIFORNIA 92707 PHONE (714) 549-7267 Advanced Geotechnical Solutions, Inc -2842 Walnut Avenue, Suite C-1 ,. Tustin, CA 92780 • Attn: Sean Donovan • J.N.: 1602-03 _ Project: 2501 State Street Carlsbad ---- PH ,_ BA-1 @0-3' 7.7 - .. -.. • -.. --- ANALYTICAL REPORT CORROSION SERIES SUMMARY OF DAT A SOLUBLE SULFATES per CA. 417 ppm 148 SOLUBLE CHLORIDES per CA. 422 ppm 74 DATE: 03/07 /16 P.O. NO.: Verbal LAB NO.: B-9160 SPECIFICATION: CA-417 /422/643 MATERIAL: Soil MIN. RESISTIVITY per CA. 643 ohm-cm 1,300 WES BRIDGER CHEMIST