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HomeMy WebLinkAboutSDP 2019-0012; RAF PACIFICA GROUP FUSION; REPORT GEOTECHNICAL UPDATE; 2019-11-05Report Geotechnical Update fu ·sion Site Improvements 1950 Camino Vida Roble, Carlsbad Airport Center, Carlsbad, California RAF Pacifica Group-Real Estate Fund IV, LLC 315 South Coast Highway 101 , Suite V-12 Encinitas, CA 92024 NOVA Project 2019195 November 5, 2019 ·RECEIVED MAY 21 2020 LAND DEVELOPMENT E C. ~-=:-. G 4373 Viewridge Avenue, Suite 8 San Diego, California 92123 858.292.7575 24632 San Juan Avenue, Su ite 100 Dana Point, CA 92629 949.388.7710 www.usa-nova.com GEOTECHNICAL MATERIALS SPECIAL INSPECTION CIVIL SURVEY SBE RAF Pacifica Group-Real Estate Fund IV, LLC Mr. Jim Jacob, Director of Development November 5, 2019 NOVA Project 2019195 315 South Coast Highway 101 , Suite V-12 Encinitas, CA 92024 Subject: Report Geotechnical Update fu·sion Site Improvements 1950 Camino Vida Roble, Carlsbad, California Dear Mr. Jacob: The above-referenced update geotechnical report is attached hereto. The work reported herein was completed by NOVA Services, Inc. (NOVA) for RAF Pacifica Group-Real Estate Fund IV, LLC, in accordance with NOVA's proposal dated September 25, 2019, as authorized on September 30, 2019. NOVA appreciates the opportunity to be of service to RAF Pacifica Group-Real Estate Fund IV, LLC. Should you have any questions regarding this report or other matters, please do not hesitate to call. Sincerely, NOVA Services, Inc. ct Manager ohn F. O'Brien, PE, GE rincipal Geotechnical Engineer 4373 Viewridge Avenue, Suite B San Diego, CA 92123 P: 858.292.7575 ryan Miller-Hicks PG, CEG Senior Engineering Geologist Hillary A. Price Project Geologist www.usa-nova.com 24632 San Juan Avenue, Suite 100 Dana Point, CA 92629 P: 949.388.7710 Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 Report Geotechnical Update fu.sion Site Improvements 1950 Camino Vida Roble, Carlsbad, California Table of Contents November 5, 2019 1.0 INTRODUCTION ................................................................................ 1 1.1 Terms of Reference ............................................................................................. 1 1.2 Geotechnical Work by Others ............................................................................ 1 1.3 Objectives, Scope, and Limitations of This Work ............................................. 2 1.3.1 Objectives .................................................................................................................................. 2 1.3.2 Scope ........................................................................................................................................ 2 1.3.3 Limitations ................................................................................................................................. 3 1.3.4 Understood Use of This Report ................................................................................................. 3 1.4 Related Assessment by NOVA ........................................................................... 3 1.5 Organization of this Report ................................................................................ 4 2.0 PROJECT INFORMATION ................................................................ 5 2.1 Site Description ................................................................................................... 5 2.2 Planned Site Improvements ............................................................................... 5 2.2.1 General ...................................................................................................................................... 5 2.2.2 Potential for Earthwork .............................................................................................................. 6 2.2.3 Stormwater ................................................................................................................................ 7 3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING ..... 8 3.1 Overview .............................................................................................................. 8 3.2 Engineering Borings by NOVA ........................................................................... 9 3.2.1 General ...................................................................................................................................... 9 3.2.2 Logging and Sampling .............................................................................................................. 9 3.2.3 Closure ...................................................................................................................................... 9 3.3 Percolation Testing ........................................................................................... 10 3. 3.1 General .................................................................................................................................... 10 3.3.2 3.3.3 3.3.4 3.3.5 Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Drilling ..................................................................................................................................... 10 Conversion to Percolation Well ............................................................................................... 11 Percolation Testing .................................................................................................................. 11 Closure .................................................................................................................................... 11 3.4 Laboratory Testing ............................................................................................ 11 3.4.1 General .................................................................................................................................... 11 3.4.2 Index ........................................................................................................................................ 12 3.4.3 Maximum Density and Optimum Moisture .............................................................................. 12 3.4.4 Expansion Potential ................................................................................................................ 12 3. 4. 5 Plasticity .................................................................................................................................. 12 3.4 .6 Chemical Testing ..................................................................................................................... 13 4.0 SITE CONDITIONS .......................................................................... 14 4.1 Geology .............................................................................................................. 14 4.2 Site-Specific Conditions ................................................................................... 15 4.2.1 Surface .................................................................................................................................... 15 4.2.2 Subsurface .............................................................................................................................. 15 4.2.3 Groundwater ............................................................................................................................ 16 4.2.4 Surface Water ......................................................................................................................... 16 5.0 REVIEW OF GEOLOGIC, SOIL, AND SITING HAZARDS .............. 17 5.1 Overview ............................................................................................................ 17 5.2 Geologic Hazards .............................................................................................. 17 5.2.1 Strong Ground Motion ............................................................................................................. 17 5.2.2 Fault Rupture ........................................................................................................................... 17 5.2.3 Landslide ................................................................................................................................. 17 5.3 Soil Hazards ....................................................................................................... 19 5.3.1 Embankment Stability ............................................................................................................. 19 5.3.2 Seismic .................................................................................................................................... 20 5.3.3 Expansive Soil ......................................................................................................................... 20 5.3.4 Hydro-Collapsible Soils ........................................................................................................... 21 5.4 Siting Hazards ................................................................................................... 21 5.4.1 Flood ....................................................................................................................................... 21 5.4.2 Tsunami ................................................................................................................................... 21 5.4.3 Seiche ..................................................................................................................................... 22 6.0 EARTHWORK AND FOUNDATIONS .............................................. 23 6.1 Overview ............................................................................................................ 23 6.1.1 Review of Site Hazards ........................................................................................................... 23 6.1.2 Effect on Adjacent Properties .................................................................................................. 23 6.1. 3 Review and Surveillance ......................................................................................................... 23 Page ii of vi 6.2 Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Seismic Design Parameters ............................................................................. 23 6.3 Corrosivity and Sulfates ................................................................................... 24 6.3.1 General. ................................................................................................................................... 24 6.3.2 Metals ...................................................................................................................................... 24 6.3.3 Sulfate Attack .......................................................................................................................... 25 6.3.4 Limitations ............................................................................................................................... 26 6.4 Earthwork ........................................................................................................... 26 6.4.1 Standards for Earthwork ......................................................................................................... 26 6.4.2 Site Preparation ....................................................................................................................... 26 6.4.3 Fill ............................................................................................................................................ 27 6.4.4 Foundation Preparation ........................................................................................................... 27 6.5 Shallow Foundations ........................................................................................ 28 6.5.1 General .................................................................................................................................... 28 6.5.2 Bearing Unit ............................................................................................................................. 28 6.5.3 Minimum Dimensions and Reinforcing ................................................................................... 28 6.5.4 Allowable Contact Stress ........................................................................................................ 28 6.5.5 Lateral Resistance ................................................................................................................... 29 6.5.6 Settlement ............................................................................................................................... 29 6.5.7 Footing Construction and Inspection ....................................................................................... 29 6.5.8 Ground Supported Slabs ......................................................................................................... 29 6.6 Capillary Break and Underslab Vapor Retarder .............................................. 30 6.6.1 Industry Design Guide ............................................................................................................. 30 6.6.2 Capillary Break and Vapor Membrane .................................................................................... 30 6.7 Walls ................................................................................................................... 31 6.7.1 Shallow Foundations ............................................................................................................... 31 6.7.2 Lateral Earth Pressures .......................................................................................................... 31 6.7.3 Foundation Uplift ..................................................................................................................... 31 6.7.4 Seismic Increment.. ................................................................................................................. 31 6.7.5 Resistance to Lateral Loads .................................................................................................... 31 6.7.6 Wall Drainage .......................................................................................................................... 32 6.8 Unbraced Slopes ............................................................................................... 32 7.0 STORMWATER INFILTRATION ...................................................... 33 7 .1 General ............................................................................................................... 33 7 .2 Infiltration Rates ................................................................................................ 33 7.2.1 General. ................................................................................................................................... 33 7.2.2 Design Infiltration Rate ............................................................................................................ 33 7.3 Review of Geotechnical Feasibility Criteria .................................................... 34 7.3.1 Overview ................................................................................................................................. 34 7.3.2 Soil and Geologic Conditions .................................................................................................. 34 7.3.3 Settlement and Volume Change ............................................................................................. 34 Page iii of vi Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 7.3.4 7.3.5 7.3.6 7.3.7 Slope Stability .......................................................................................................................... 34 7.4 8.0 8.1 8.2 Utilities ..................................................................................................................................... 34 Groundwater Mounding ........................................................................................................... 35 Other Factors .......................................................................................................................... 35 Suitability of the Site for Stormwater Infiltration ............................................ 35 REFERENCES ................................................................................. 36 Site Specific ....................................................................................................... 36 Design ................................................................................................................ 36 Plates Plate 1 Subsurface Investigation Map List of Appendices Appendix A Use of the Geotechnical Report Appendix B Logs of NOVA's Borings Appendix C Records of the Laboratory Testing Appendix D Infiltration Feasibility Documents List of Tables Table 3-1 . Abstract of the Engineering Borings Table 3-2. Abstract of the Percolation Testing Table 3-3. Abstract of the Gradation Testing Table 3-4. Summary of Testing to Determine Expansion Index Table 3-5. Summary of Testing to Determine Atterberg Limits Table 3-6. Abstract of Chemical Testing Table 6-1 . Seismic Design Parameters, ASCE 7-16 Table 6-2. Summary of Corrosivity Testing Table 6-3. Soil Resistivity and Corrosion Potential Table 6-4. Exposure Categories and Requirements for Water-Soluble Sulfates Table 6-5. Wall Lateral Loads from Soil Table 7-1 . Infiltration Rates Determined by Percolation Testing Page iv of vi Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 List of Figures Figure 1-1 . Vicinity Map Figure 2-1 . Site Limits and Location Figure 2-2. Proposed Site Improvements (Gray Shaded Area) Figure 3-1 . Location of Engineering and Percolation Test Borings Figure 3-2. Drilling Operations, October 3, 2019 Figure 4-1 . Geologic Mapping of the Site Vicinity Figure 4-2. Unit 2 Santiago Formation Figure 5-1 . Faulting in the Site Vicinity Figure 5-2. Landslide Susceptibility Mapping of the Site Area Figure 5-3. Flood Mapping of the Site Area Figure 6-1 . Sawed Contraction Joint Page v of vi November 5, 2019 Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 1.0 INTRODUCTION 1.1 Terms of Reference This report presents a geotechnical update for site improvements to an existing developed commercial lot located at 1950 Camino Vida Roble in Carlsbad, California. The site improvements are a project known to Nova as "fu ·sion." The work reported herein was completed by NOVA Services, Inc. (NOVA) for RAF Pacifica Group-Real Estate Fund IV, LLC, in accordance with the scope of work detailed in NOVA's proposal dated September 25, 2019, as authorized on September 30, 2019. Figure 1-1 provides a graphic that depicts the site vicinity. [iliJ PALOM.t.R AIRPORT_IIO t L )M• IAIII \ ~hi• 'f • .... ,.,. CD'n"1l,.VIII)' , ... POINSETTIA LN Figure 1-1. Vicinity Map 1.2 Geotechnical Work by Others :., "' ... ex 0 z j $ ... ... The site was previously investigated by GeoSoils, Inc. (reference, Preliminary Geotechnical Evaluation, Carlsbad Airport Center, Unit II, Lot 33 & 34, Carlsbad, California, GeoSoils, Inc., W.O. 1840-SC, July 13, 1995). Subsurface information developed for that project has been reviewed by NOVA and employed in this work. 1.3 1.3.1 Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 Objectives, Scope, and Limitations of This Work Objectives November 5, 2019 The objectives of the work reported herein by NOVA are twofold, as described below. 1. Objective 1, Geotechnical. Develop subsurface information sufficient to provide recommendations for foundation-related design and construction and improvements. 2. Objective 2, Stormwater. Conduct percolation testing in accordance with the requirements of the City of Carlsbad sufficient to assist in the design of permanent stormwater infiltration Best Management Practices ('BMPs'). 1.3.2 Scope To accomplish the above objective, NOVA undertook the task-based scope of work described below. 1. Task 1, Pre-Mobilization Activities. Prior to initiating any fieldwork, NOVA undertook the series of subtasks described below. a. Subtask 1-1, Background Review. Reviewed publicly available geologic and geotechnical reports, and records to establish the geologic and seismic setting of the site. b. Subtask 1-2, Utility Clearance. Contacted underground service alert (USA) and a private utility locator to determine the presence of underground utilities at locations planned for engineering borings and infiltration testing. c. Subtask 1-3, Coordination for Site Access. Coordinated to obtain access for the subsurface exploration. d. Subtask 1-4, Subcontracting. NOVA retained a specialty contractor to conduct the drilling required for the geotechnical investigation. 2. Task 2, Subsurface Exploration. A NOVA geologist directed a geotechnical-focused subsurface exploration that included the subtasks listed below. o Subtask 2-1, Engineering Boring. Five (5) engineering boring were completed under the surveillance of a NOVA geologist who logged the borings. o Subtask 2-2, Sampling and In Situ Testing. The engineering borings were sampled and tested utilizing both (i) Standard Penetration Test ('SPT', after ASTM D 1586) and (ii) the California Modified Sampler, after ASTM D 3550. o Subtask 2-3, Percolation Testing. Two (2) auger borings were drilled and sampled within 50 feet of a proposed biofiltration basin. Thereafter percolation testing was conducted in accordance with the City of Carlsbad BMP Design Manual, February 16, 2016 edition. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 o Subtask 2-4, Closure. Following completion of each boring, the borings were backfilled and closed per DEH requirements. 2. Task 3, Laboratory Testing. Samples recovered by Subtask 2 were returned to NOVA's geotechnical laboratory for review. Limited scope laboratory testing was completed on representative samples. 3. Task 4, Engineering Evaluations. The findings of Tasks 1-3 were utilized to support geotechnical-related evaluations of requirements for foundations, earthwork, and pavements. 4. Task 5, Reporting. Submittal of this report completes NOVA's scope of work. 1. 3. 3 Limitations The construction recommendations included in this report are not final. Geotechnical and geologic studies are characterized by uncertainty. These recommendations are developed by NOVA using judgment and opinion, based upon the limited information available from the test borings. NOVA can finalize its recommendations only by observing actual subsurface conditions revealed during construction. NOVA cannot assume responsibility or liability for the report's recommendations if NOVA does not perform construction observation. This report does not address any environmental assessment or investigation for the presence or absence of hazardous or toxic materials in the soil, groundwater, or surface water within or beyond the site. Appendix A to this report provides important additional guidance regarding the use and limitations of this report. This information should be reviewed by all users of the report 1. 3. 4 Understood Use of This Report NOVA expects that the findings and recommendations provided herein will be utilized by RAF Pacifica Group-Real Estate Fund IV, LLC and its Design Team in decision-making regarding design and construction. NOVA's recommendations are based on its current understanding and assumptions regarding project development. Effective use of this report by the Design Team should include review by NOVA of the final design. Such review is important for both (i) conformance with the recommendations provided herein, and (ii) consistency with NOVA's understanding of the planned development. 1.4 Related Assessment by NOVA This investigation is the second geotechnical-related assessment by NOVA of the mezzanine addition located at 1950 Camino Vida Roble, Carlsbad Airport Center, in Carlsbad California. The findings of a geotechnical update for the mezzanine addition were reported by NOVA on September 20, 2019 (reference, Report, Geotechnical Update, Mezzanine Addition, 1950 Camino Vida Roble, Carlsbad, California, NOVA Services Inc., Project 2019195, September 20, 2019). 1.5 Geotechnical Update Report fu-sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Organization of this Report The remained of this report is organized as abstracted below. • Section 2 reviews available project information. • Section 3 describes the field investigation and laboratory testing. • Section 4 describes the surface and subsurface conditions. • Section 5 reviews geologic, soil, and siting-related hazards common to this area of California, considering each for its potential to affect construction and long-term use of the development. • Section 6 provides recommendations for earthwork and foundation design. • Section 7 provides recommendations for development of stormwater infiltration BMPs. • Section 8 lists the principal references utilized in the development of the report. Figures and tables are embedded in the text of the report at the point which they are referenced. Plate 1, provided immediately following the text of this report, shows the location of field work in larger scale. The report is supported by five appendices: • Appendix A presents guidance regarding the use and limitations of this report. • Appendix B presents logs of NOVA's borings. • Appendix C provides records of laboratory testing. • Appendix D provides records related to development of stormwater infiltration criteria. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 2.0 PROJECT INFORMATION 2.1 Site Description The subject property is nominally located at 1950 Camino Vida Roble in the City of Carlsbad supports a commercial building with associated site improvements. The site is located northeast of the intersection of Camino Vida Roble, which bounds the property to the south, and Kellogg Avenue, bounding the property to the west. The property is surrounded by commercial and residential development. Palomar Airport lies to the northeast. The location and limits of the property are depicted on Figure 2-1 . Figure 2-1. Site Location and Limits (source: adapted from Google Earth 2019) 2.2 Planned Site Improvements 2. 2. 1 General NOVA's understanding of current planning for the site improvements is based upon review of plans submitted for Minor Site Development Plan approval and Minor Planned Unit Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Development approval that were developed by SCA Architecture (reference, fu·sion, 1950 Camino Vida Roble, Carlsbad, California 92008, RAF Pacifica Group, SCA Architecture, Job No. 18034.S02, September 13, 2019, hereinafter 'SCA 2019'). The referenced plans (SCA 2019) indicate that a number of surface improvements are proposed. In addition , a biofiltration basin for stormwater treatment and disposal is proposed. Figure 2-2 indicates the proposed area of improvements, comprising approximately 1.3 acres. Improvements will include: • New drive aisle • Concrete screen walls • Concrete ramps and walkways • Retaining walls • Shade structures • Amphitheater with seating • Biofiltration (BMP) basin LW••HrMO.IIIG --'fW-11)« co,,,p'ff,J,0-'J •l'IJ~ll'i# "" ~--7"'!,r Ea.-lDWn IU-C--l'Cl 'C•I". EXISnllG STRUCTURE TOREMA/11 .,_ ---<W<Mr COIi>.,_ , ..... -,.. ... ~ -°':':.:::.~•;-------,, I ~.:!:! ---:-J I ~J I :1:':~~-- ...... l(flllNI ~1«1).1< Figure 2-2. Proposed Site Improvements (Gray Shaded Area) (Source: SCA 2019) 2.2.2 Potential for Earthwork Development of the site will include demolition of the existing trees, flatwork, and pavement as well as removal or relocation of existing utilities. The majority of earthwork for this project will include cutting to achieve planned grades and constructing and backfilling retaining walls. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Based on review of SCA 2019 it appears that earthwork will be limited to making cuts of up to 7 feet and minor fills of up to 3 feet. 2.2.3 Stormwater The Minor Site Development Plan prepared by Pasco Laret Suiter & Associates (PLSA 2019) indicates a new BMP Basin in the southern portion of the site. 3.0 3.1 Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 SUBSURFACE EXPLORATION AND LABORATORY TESTING Overview The subsurface exploration was completed on October 3, 2019. The work included the drilling and sampling of five (5) engineering borings (referenced as 'B-1' through 'B-5') and two (2) percolation tests ('P-1 ' and 'P-2'). The engineering borings were completed by a specialty subcontractor working under the surveillance of a NOVA geologist. Figure 3-1 presents a plan view of the site improvements indicating the location of the subsurface exploration by NOVA. Plate 1, provided immediately following the text of this report, shows the location of this work in larger scale. : ~ j ·-., . . =---- ~- F B-2 ,.. -~ • u -L.~ Q;,f ' Ts;, L ~);' \1,> TH.,, ~ T r,f\lAt\ t-• KEY TO SYMBOLS P-2 E9 LOCATION OF PERCOLATION TEST BORING B-5 8 LOCATION OF GEOTECHNICAL BORING Figure 3-1. Location of Engineering and Percolation Test Borings The remainder of this section provides detail regarding the engineering borings (Section 3.2), percolation testing (Section 3.3), and related laboratory testing (Section 3.4). Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 3.2 3.2. 1 Engineering Borings by NOVA General November 5, 2019 Five (5) engineering borings were advanced by a truck-mounted drilling rig utilizing hollow stem auger drilling equipment, drilled under the surveillance of a NOVA geologist at the locations depicted on Figure 3-1. The boring locations were determined in the field by the geologist who measured distances from existing site features. Figure 3-2 (following page) depicts the drilling on October 3, 2019. Table 3-1 provides an abstract of the engineering borings. Table 3-1. Abstract of the Engineering Boring Approximate Total Depth Elevation at Depth to Boring Below Reference Ground Surface Ground Completion Formation Elevation (feet, msl) Surface (feet) (feet, msl) (feet) 8-1 264.5 20 244.5 5 8-2 253.5 20 233.5 3 8-3 249 15.5 233.5 4 8-4 249.5 20 229.5 5 8-5 241 20 221 15 Note: The referenced geologic formation is Santiago Formation (Tsa) 3. 2. 2 Logging and Sampling The geologist directed sampling and maintained a log of the subsurface materials that were encountered. Both disturbed and relatively undisturbed samples were recovered from the borings as described below. 1. The Modified California sampler ('ring sampler', after ASTM D 3550) was driven using a 140-pound hammer falling for 30-inches with a total penetration of 18-inches, recording blow counts for each 6-inches of penetration. 2. The Standard Penetration Test sampler ('SPT', after ASTM D 1586) was driven in the same manner as the ring sampler, recording blow counts in the same fashion. SPT blow counts for the final 12-inches of penetration comprise the SPT 'N' value, an index of soil strength and compressibility. 3. Bulk samples were recovered from the near subsurface. 3. 2. 3 Closure On completion, the borings were backfilled with soil cuttings. The area was cleaned and left as close to the original condition as practical. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Figure 3-2. Drilling Operations, October 3, 2019 3.3 Percolation Testing 3. 3. 1 General NOVA directed the excavation and construction of two (2) percolation test wells following the recommendations for percolation testing presented in the City of Carlsbad BMP Design Manual, February 16, 2016 edition. The percolation test locations were located within the proposed biobasin area and are shown on Figure 3-1. 3.3.2 Drilling The borings were drilled with an 8-inch hollow stem auger to a depth of 17 to 18 feet bgs, the proposed bottom of basin elevation. Field measurements were taken to confirm that the boring was excavated to approximately 8-inches in diameter. The boring was logged by a NOVA geologist, who observed and recorded exposed soil cuttings and the boring conditions. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 3.3.3 Conversion to Percolation Well Once the boring was drilled to the desired depth, the boring was converted to a percolation test well by placing an approximately 2-inch layer of ¾-inch gravel on the bottom, then extending 3- inch diameter Schedule 40 perforated PVC pipe to the ground surface. The ¾-inch gravel was used to partially fill the annular space around the perforated pipe below the existing finish grade to minimize the potential of soil caving. 3.3.4 Percolation Testing The percolation test well was pre-soaked by filling the hole with water to at least five times the hole's radius. In the test well, the pre-soak water did not percolate at least 6-inches into the soil unit within 25 minutes; therefore, the hole was filled to the ground surface elevation and testing commenced the following day, within a 26-hour window. Water levels were then recorded every 30 minutes for 6 hours, or until the water percolation stabilized after each reading (minimum of 12 readings). At the beginning of each half-hour test period, the water level was filled to approximately the same starting water level of the previous tests in order to maintain a near-constant head during the entire testing period. Table 3-2 abstracts the indications of the percolation testing. Table 3-2. Abstract of the Percolation Testing Boring Approximate Total Approximate Percolation Subsurface Elevation Depth Percolation Test Rate (in/hr) 2 Unit (feet, msl) (feet) Elev. (feet, msl) Tested1 P-1 240 17 223 2.16 Tsa P-2 241 18 223 2.40 Tsa Notes: 1. The referenced geologic unit is Santiago Formation (Tsa). 2. This table addresses percolation rates only. Section 7 addresses design infiltration rates. 3.3.5 Closure At the conclusion of the percolation testing , the PVC pipe was removed and the resulting hole was backfilled with soil cuttings and patched to match the existing surfacing. 3.4 Laboratory Testing 3.4. 1 General Soil samples recovered from the engineering borings were transferred to NOVA's geotechnical laboratory where a geotechnical engineer reviewed the soil samples and the field logs. Representative soil samples were selected and tested in NOVA's materials laboratory to check visual classifications and to determine pertinent engineering properties. The laboratory program included visual classifications of all soil samples as well as index and expansion potential testing in general accordance with ASTM standards. Records of the geotechnical laboratory testing are provided in Appendix C. 3.4.2 Index Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 The visual classifications were further evaluated by performing grain size and expansivity tests. The index testing may be used to estimate a variety of soil characteristics and physical properties. Table 3-3 provides an abstract of this testing. Table 3-3. Abstract of the Gradation Testing Depth Passing Classification Boring (feet) Soil Description #200 After ASTM D 2487 8-3 10-15 Tsa: Gray and orange brown sandy 71 ML siltstone 8-4 0-5 Fill: Grayish brown Clayey sand 40 SC with gravel 8-4 5-10 Tsa: Yellow to orange brown 47 SC-SM clayey-silt sandstone P-2 13-15 Tsa: Dark gray and black claystone 44 SC-CL Notes: 1. 'Passing #200' percent by weight passing the U.S.# 200 sieve (0.074 mm}, after ASTM 06913. 2. 'Tsa' indicates 'Santiago Formation', the near surface geologic unit at this site 3.4.3 Maximum Density and Optimum Moisture A single sample of the fill soil was tested to determine its moisture-density relationship after ASTM D 1557 (the 'modified Proctor'). This testing indicated an optimum dry density (ydry) of ydry = 121 lb/ft3 at an optimum moisture content (w) of w = 10 percent. 3. 4. 4 Expansion Potential Tests were completed to assess the potential for behavior as an expansive soil. The results of testing to determine Expansion Index after ASTM D4829 are tabulated on Table 3-4. Table 3-4. Summary of Testing to Determine Expansion Index Boring Depth Expansion Expansion (feet) Index Potential 8-2 0-2 44 Low 8-4 5 -10 10 Very Low 3. 4. 5 Plasticity Several tests were conducted to determine the plasticity of soils potentially dominated by cohesive soil behavior. The results of testing to determine Atterberg Limits after ASTM D4318 are tabulated on Table 3-5 (following page). Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Table 3-5. Summary of Testing to Determine Atterberg Limits Boring Depth Liquid Plasticity Soil (feet) Limit Index Classification B-2 0-2 34 7 ML B-4 5 -10 31 11 CL P-1 13 -18 40 22 CL 3.4. 6 Chemical Testing Resistivity, sulfate content, and chloride contents were determined to estimate the potential corrosivity of the soils. These chemical tests were performed on a representative sample of the near surface soils by Clarkson Laboratory and Supply, Inc. Table 3-6 abstracts the chemical testing . Indications of this testing are discussed in more detail in Section 6.3. Table 3-6. Abstract of Chemical Testing Sample Ref Resistivity Sulfates Chlorides pH Boring Depth (Ohm-cm) ppm % ppm % (feet) B-4 0-5 7.9 280 2640 0.264 140 0.014 B-4 5-10 7.6 320 2400 0.240 410 0.041 4.1 Geology Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 4.0 SITE CONDITIONS The site is located in the western San Diego County portion of the Peninsular Ranges Geomorphic Province. This geomorphic province encompasses an area that extends approximately 900 miles from the Transverse Ranges and the Los Angeles Basin south to the southern tip of Baja California (Norris and Webb, 1990). The province varies in width from approximately 30 to 100 miles. In general, the province consists of rugged mountains and coastal terraces underlain mostly by Jurassic metavolcanic and metasedimentary rocks, and Cretaceous igneous rocks of the southern California batholith. The coastal terraces are composed of marine and nonmarine sediments of primarily Cenozoic Age. Rocks in the San Diego embayment are gently folded and faulted Eocene marine, lagoonal and nonmarine rocks. The regional surface topography is characterized geomorphically by eroded and dissected mesa terrain. The site is mapped to be underlain by Santiago Formation sedimentary bedrock. Figure 4-1 reproduces geologic mapping of the site area). KEY TO SYMBOLS • METASEDIMENTARY & METAVOlCANIC ROCKS UNDIVIDED VERY OLD PARALIC Ovop• DEPOSITS. UNIT 10 SANTIAGO FORMATION YOUNG ALLUVIAL Oya FLOOD-PLAIN DEPOSITS VERY OLD PARALIC Qvop ' DEPOSITS. UNIT 11 Figure 4-1 . Geologic Mapping of the Site Vicinity 4.2 4.2.1 Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 Site-Specific Conditions Surface November 5, 2019 The project site is located to the east of the existing building and is currently occupied by parking stalls and landscaping areas. Elevations across the project site range from about +279 feet mean sea level (msl) along the northern portion to about +250 msl along the southern portion. 4.2.2 Subsurface For the purposes of this report, the subsurface may be generalized to occur as the sequence of soil and rock described below. 1. Unit 1, Fill. As encountered in the borings, much of the site is underlain by artificial fill (Qaf) of variable thickness. This soil unit occurs as clayey sand with gravel, and is of medium dense to dense consistency 2. Unit 2, Santiago Formation. The site is entirely underlain by the Eocene-aged Santiago Formation (geologic map symbol: Tsa) consisting of marine silty sandstone and clayey siltstone. The unit is of relatively higher strength and low compressibility. The Santiago Formation is known to extend well beyond the depths explored in the borings. Figure 4-2 provides a photograph of a representative sample of this formation. Figure 4-2. Unit 2 Santiago Formation 4.2.3 Groundwater Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Groundwater was not encountered in either of the borings by NOVA or in the test trenches reported in GeoSoils 1995. Groundwater likely first occurs at depths greater than 30 feet below ground surface. Infiltrating storm water from prolonged wet periods can 'perch' atop localized zones of lower permeability soil that exist above the static groundwater level. Localized perched groundwater conditions may also develop once site development is complete and landscape irrigation commences. 4.2.4 Surface Water NOVA did not observe any evidence of seeps, springs, surface staining, or eroded areas that would suggest the recent problems with surface water on the site. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 5.0 REVIEW OF GEOLOGIC, SOIL, AND SITING HAZARDS 5.1 Overview This section provides review of geologic, soils, and siting-related hazards common to this region of California, considering each for its potential to affect the planned construction. The review provided in this section shows that the primary geologic and seismic hazard during the life of the tenant improvements is the expectation of moderate-to-severe ground shaking in response to either a local moderate or more distant large-magnitude earthquake. While there is no risk of liquefaction or related seismic phenomena, strong ground motion could affect the site. 5.2 Geologic Hazards 5. 2. 1 Strong Ground Motion The site is not located within a currently designated Alquist-Priolo Earthquake Zone (Hart and Bryant, 2007). No known active faults are mapped onsite. The nearest known active fault is the Rose Canyon fault system, located offshore approximately 7 miles west of the site. This system has the potential to be a source of strong ground motion. The site may be subjected to a Magnitude 7 or greater seismic event at the Rose Canyon Fault, with a corresponding risk-based Peak Ground Acceleration (PGAm) of PGAm = 0.52 g. 5. 2. 2 Fault Rupture There are no known active faults on or near the site. The potential for surface rupture at the site is thus considered low. Shallow ground rupture due to shaking from distant seismic events is not considered a significant hazard, although it is a possibility at any site. Figure 5-1 (following page) maps faulting in the site vicinity, from which it can be seen that there are no active or potentially active faults in the site vicinity. Because of this, the potential for surface rupture at the site is considered very low. 5. 2. 3 Landslide As used herein, 'landslide' describes downslope displacement of a mass of rock, soil, and/or debris by sliding, flowing, or falling. Such mass earth movements are greater than about 10 feet thick and larger than 300 feet across. Landslides typically include cohesive block glides and disrupted slumps that are formed by translation or rotation of the slope materials along one or more slip surfaces. These mass displacements can also include similarly larger-scale, but more narrowly confined modes of mass wasting such as 'mud flows' and 'debris flows'. The causes of classic landslides start with a preexisting condition -characteristically, a plane of weak soil or rock inherent within the rock or soil mass. Thereafter, movement may be precipitated by earthquakes, wet weather, and changes to the structure or loading conditions on a slope (e.g., by erosion, cutting, filling, release of water from broken pipes, etc.). S21 Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 NEWPORT-INGLEWOOD-ROSE CANYON FAULT ZONE Figure 5-1. Faulting in the Site Vicinity Geologic reconnaissance and review of aerial photography indicated no evidence of active or dormant landsliding. Clues to landslide hazards can also be obtained by review of mapping that depicts both historic landslides and landslide-prone topography. Figure 5-2 (following page) reproduces such mapping for the site area. The mapping indicates that the site is in an area judged to be 'generally susceptible' to landsliding. In consideration of the shallow existing ground slopes and proposed grades at the project, NOVA considers the landslide hazard at the site to be 'negligible' for the site and the surrounding areas. The proposed development will not affect the landslide hazard characterization. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 . ,/ /E D 3-1 ( ~-. _.'~' . f :P ~. .. ....>-_ ... ·"-. _,,,,, . RELATIVE LANCSUOE SUSCEPTIBILITY AAEAS --...... t I -----lncilwelftO·UWIOIIIOe So~----+ ~........__.. Figure 5-2. Landslide Susceptibility Mapping of the Site Area 5.3 Soil Hazards 5. 3. 1 Embankment Stability ' , , As used herein, 'embankment stability' is intended to mean the safety of localized natural or man-made embankments against failure. Unlike landslides described above, embankment stability can include smaller scale slope failures such as erosion-related washouts and more subtle, less evident processes such as soil creep. No new slopes are planned as part of the site improvements. I I I 5.3.2 Seismic Liquefaction Geotechnical Update Report fu-sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 'Liquefaction' refers to the loss of soil strength during a seismic event. The phenomenon is observed in areas that include geologically 'younger' soils (i.e., soils of Holocene age), shallow water table (less than about 60 feet in depth), and cohesionless (i.e., sandy and silty) soils of looser consistency. The seismic ground motions increase soil water pressures, decreasing grain-to-grain contact among the soil particles, which causes the soils to lose strength. Resistance of a soil mass to liquefaction increases with increasing density, plasticity (associated with clay-sized particles), geologic age, cementation, and stress history. The stiff/dense, cemented and geologically 'older' subsurface units at this site have no potential for liquefaction. Seismically Induced Settlement Apart from liquefaction, a strong seismic event can induce settlement within loose to moderately dense, unsaturated granular soils. The cohesionless, cemented soils of Unit 2 are sufficiently dense and finer-grained that these soils will not be prone to seismic settlement. Lateral Spreading Lateral spreading is a phenomenon in which large blocks of intact, non-liquefied soil move downslope on a liquefied soil layer. Lateral spreading is often a regional event. For lateral spreading to occur, a liquefiable soil zone must be laterally continuous and unconstrained, free to move along sloping ground. Due to the absence of a potential for liquefaction, there is no potential for lateral spreading. 5. 3. 3 Expansive Soil Expansive soils are characterized by their ability to undergo significant volume changes (shrinking or swelling) due to variations in moisture content. These volume changes can be damaging to structures. Nationally, the value of property damage caused by expansive soils is exceeded only by that caused by termites. As is discussed in Section 3, the Unit 1 soils have been characterized by testing to determine Expansion Index ('El', after ASTM D 4829). El has been adopted by the California Building Code ('CBC', Section 1803.5.3) for characterization of expansive soils. The listing on the following page tabulates the qualitative descriptors of expansion potential based upon El. Laboratory testing of the fill indicates these soils possess Low expansive potential after ASTM D4829 (El= 44). Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad , California NOVA Project 2019195 November 5, 2019 Table 5.1. Descriptors of Expansive Soil after ASTM D 4829 Expansion Index Expansion Potential, Expansion ('El'), ASTM D 4829 ASTM D 4829 Classification, 2013 CBC 0 to 20 Very Low Non-Expansive 21 to 50 Low 51 to 90 Medium Expansive 91 to 130 High >130 Very high 5. 3. 4 Hydro-Collapsible Soils Hydro-collapsible soils are common in the arid climates of the western United States in specific depositional environments -principally in areas of young alluvial fans, debris flow sediments, dune sands, and loess (wind-blown sediment) deposits. These soils are characterized by low in situ density, low moisture contents, and relatively high unwetted strength. The soil grains of hydro-collapsible soils were initially deposited in a loose state (i.e., high initial 'void ratio') and thereafter lightly bonded by water sensitive binding agents (e.g., clay particles, low-grade cementation, etc.). While relatively strong in a dry state, the introduction of water into these soils causes the binding agents to fail. Destruction of the bonds/binding causes relatively rapid densification and volume loss (collapse) of the soil. This change is manifested at the ground surface as subsidence or settlement. Ground settlements from the wetting can be damaging to structures and civil works. The geologic age and depositional history of the Unit 2 soils are such that these soils are not potentially hydro-collapsible. 5.4 Siting Hazards 5.4.1 Flood The site is not located within a FEMA-designated flood zone and is designated as Flood "Zone X" (FEMA, 2006). Zone X is an "Area of 500-year flood: areas of 100-year flood with average depths of less than 1 foot or with drainage areas Jess than 1 square mile; and areas protected by levees from 100-year flood'. 5.4. 2 Tsunami Tsunami ('tidal wave') describes a series of fast-moving, long-period ocean waves caused by earthquakes or volcanic eruptions. The elevation and distance of the site from the ocean preclude this threat. 5. 4. 3 Seiche Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Figure 5-3. Flood Mapping of the Site Area Seiches are standing waves that develop in an enclosed or partially enclosed body of water such as lakes or reservoirs. Harbors or inlets can also develop seiches. They are most commonly caused by wind and atmospheric pressure changes. Seiches can also result from seismic events and tsunamis. The site is not located near a body of water that could generate a seiche. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 6.0 EARTHWORK AND FOUNDATIONS 6.1 Overview 6. 1. 1 Review of Site Hazards Section 5 provides review of geologic, soil and siting-related hazards that may affect the planned development. The primary hazard identified by that review is that the site is at risk for moderate-to-severe ground shaking in response to large-magnitude earthquakes during the lifetime of the planned development. This circumstance is common to all civil works in this area of California. While strong ground motion could affect the site, there is no risk of liquefaction or related seismic phenomena. Section 6.2 provides seismic design parameters. Section 6.4 addresses maintenance of the site groundform in development of new construction. 6. 1. 2 Effect on Adjacent Properties The proposed development is suitable for its site and not affect the structural integrity of adjacent properties or existing public improvements and street right-of-ways located adjacent to the site if the recommendations of this report are incorporated into project design. 6. 1. 3 Review and Surveillance The subsections following provide geotechnical recommendations for the planned development as it is now understood. NOVA should review the grading plan, foundation plan, and geotechnical-related specifications as they become available to confirm that the recommendations presented in this report have been incorporated into the plans prepared for the project. All earthwork related to site and foundation preparation should be completed under the observation of NOVA, the Geotechnical Engineer of Record (GEOR) for this work. 6.2 Seismic Design Parameters The Site Class has been determined from ASCE 7, Table 20.3-1. Based on estimated average N-values in the upper 100 feet of the soil/rock profile, the site corresponds to a Site Class C. Table 6-1 (following page) provides seismic design parameters for the site in accordance with 2019 CBC and mapped spectral acceleration parameters. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad , California NOVA Project 2019195 November 5, 2019 Table 6-1. Seismic Design Parameters, ASCE 7-10 Parameter Value Site Soil Class C Site Latitude (decimal degrees) 33.122538 Site Longitude (decimal degrees) -117.282928 Site Coefficient, Fa 1.2 Site Coefficient, Fv 1.5 Mapped Short Period Spectral Acceleration, Ss 0.997 Mapped One-Second Period Spectral Acceleration, s·1 0.363 Short Period Spectral Acceleration Adjusted For Site Class, SMs 1.196 g One-Second Period Spectral Acceleration Adjusted For Site 0.544 g Design Short Period Spectral Acceleration, Sos 0.798 g Design One-Second Period Spectral Acceleration, S01 0.363 g Source: ASCE 7 Hazard Tool, found at: https://asce7hazardtool.online/ 6.3 Corrosivity and Sulfates 6. 3. 1 General Electrical resistivity, chloride content, and pH level are all indicators of the soil's tendency to corrode ferrous metals. Water-soluble sulfates are used as an index of the potential for sulfate attack to concrete. These chemical tests were performed on a representative sample of the near-surface soils. The results of the testing to assess corrosion potential are tabulated in Table 6-2. Records of the testing are provided in Appendix C. Table 6-2. Summary of Corrosivity Testing Parameter Units B-4@0-5' B-4@5-10' pH standard 7.9 7.6 Resistivity O-cm 280 320 Water-Soluble Chloride ppm 140 410 Water-Soluble Sulfate ppm 2,640 2,400 6.3.2 Metals Caltrans considers a soil to be corrosive to embedded metals if one or more of the following conditions exist for representative soil and/or water samples taken at the site: • chloride concentration is 500 parts per million (ppm) or greater; • sulfate concentration is 2,000 ppm (0.2%) or greater; or, • the pH is 5.5 or less. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Based on the Caltrans criteria, the site soils would be considered 'corrosive' to embedded metals. Appendix C provides records of the chemical testing that include estimates of the life expectancy of buried metal culverts of varying gauge. In addition to the above parameters, the risk of soil corrosivity buried metals is considered by determination of electrical resistivity (p). Soil resistivity may be used to express the corrosivity of soil only in unsaturated soils. Corrosion of buried metal is an electrochemical process in which the amount of metal loss due to corrosion is directly proportional to the flow of DC electrical current from the metal into the soil. As the resistivity of the soil decreases, the corrosivity generally increases. A common qualitative correlation (cited in Romanoff 1989, NACE 2007) between soil resistivity and corrosivity to ferrous metals is tabulated below. Table 6-3. Soil Resistivity and Corrosion Potential Minimum Soil Qualitative Corrosion Resistivity (O-cm) Potential 0 to 2,000 Severe 2,000 to 10,000 Moderate 10,000 to 30,000 Mild Over 30,000 Not Likely Despite the relatively benign environment for corrosivity indicated by pH , the resistivity testing suggests that design should consider that the soils may be severely corrosive to embedded ferrous metals. Typical recommendations for mitigation of such corrosion potential in embedded ferrous metals include: • a high-quality protective coating such as an 18-mil plastic tape, extruded polyethylene, coal tar enamel, or Portland cement mortar; • electrical isolation from above grade ferrous metals and other dissimilar metals by means of dielectric fittings in utilities and exposed metal structures breaking grade; and, • steel and wire reinforcement within concrete having contact with the site soils should have at least 2-inches of concrete cover. If extremely sensitive ferrous metals are expected to be placed in contact with the site soils, it may be desirable to consult a corrosion specialist regarding choosing the construction materials and/or protection design for the objects of concern. 6. 3. 3 Sulfate Attack As shown in Table 6-2, the soil sample tested indicated water-soluble sulfate (SQ4) content of 2,640 parts per million ('ppm,' 0.264% by weight). With SQ4 > 0.20 percent by weight, the American Concrete Institute (ACI) 318-08 considers a soil to have severe potential (S2) for sulfate attack. NOVA recommends the use of Type V cement Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 Table 6-4 reproduces the Exposure Categories considered by ACI. Table 6-4. Exposure Categories and Requirements for Water-Soluble Sulfates Exposure Water-Soluble Cement Type Max Water-Min.fc Class Sulfate (SQ4) In Category (ASTM C150) Cement Ratio (psi) Soil Not Aoolicable so SQ4 < 0.10 --- Moderate S1 0.10 s SQ4 < 0.20 II 0.50 4,000 Severe S2 0.20 s SQ4 s 2.00 V 0.45 4,500 Very severe S3 SQ4 > 2.0 V + pozzolan 0.45 4,500 Adapted from : ACI 318-08, Building Code Requirements for Structural Concrete 6. 3. 4 Limitations Testing to determine several chemical parameters that indicate a potential for soils to be corrosive to or attack construction materials are traditionally completed by the Geotechnical Engineer, comparing testing results with a variety of indices regarding corrosion potential. NOVA does not practice in the field of corrosion protection, since this is not specifically a geotechnical issue. Should you require more information, a specialty corrosion consultant should be retained to address these issues. 6.4 Earthwork 6. 4. 1 Standards for Earthwork As is noted in Section 2, no structural or final civil-related design information is available at this time. Earthwork should be performed in accordance with Section 300 of the most recent approved edition of the "Standard Specifications for Public Works Construction" and "Regional Supplement Amendments." 6.4.2 Site Preparation Establish Erosion and Sedimentation Control Construction-related erosion and sedimentation must be controlled in accordance with Best Management Practices and City of San Diego requirements. These controls should be established at the outset of site disturbance. Clearing and Grubbing Before proceeding with construction, all vegetation, root systems, topsoil, refuse, and other deleterious non-soil materials should be stripped from construction areas. Any existing underground utilities within the footprint of the proposed structures should be grouted in place or removed . Clearing, including the removal of any abandoned utilities, should be extended a minimum of 5 feet beyond the building and pavement limits. Stripped materials consisting of vegetation and organic materials should be hauled away from the site, or used in landscaping non-structural areas. 6.4.3 Fill Materials Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 All soils placed as fill within the upper 3 feet beneath the base of foundations/floor slabs and upper 2 feet below the base of pavements and flatwork should be 'Select' fill. Select Fill should be a mineral soil free of organics and regulated constituents, conforming to the following: ■ at least 40 % by weight finer than ¼-inches; ■ maximum particle size of 6-inches; and ■ Expansion Index ('El,' after ASTM D 4829) of El< 50. The fill observed within NOVA borings will meet the above criteria. Any clayey soils encountered during grading should be removed and replaced with approved soil. Placement All Select Fill should be moisture conditioned to at least 2% above the optimum moisture then placed to 90% relative compaction after ASTM D 1557 (the modified Proctor) using equipment appropriate to the soil type. Lift thicknesses affect the ability of the compaction equipment to fully densify the soil. For most larger scale compaction equipment, this requirement will limit loose lift thickness to about 10-inches. Hand-operated equipment as may be used around utilities will be limited to about 4-inches. 6.4.4 Foundation Preparation New Improvements Existing Unit 1 fill to 3 feet outside the limits of new improvements the design should be prepared using the stepwise procedure described below. 1. Step 1, Excavate and Stage. The upper 2 feet beneath the base of foundations/ floor slabs should be removed and staged for later replacement. All material over 6-inches should be removed from the fill. 2. Step 2, Scarify/Moisture Condition. The surface exposed by Step 1 should be scarified to a depth of 12-inches, moisture conditioned to above the optimum moisture, then compacted to at least 90% relative compaction after ASTM D1557. 3. Step 3, Replacement. The soils staged by Step 1 should be moisture conditioned to 2% above the optimum moisture content and replaced at 90% relative compaction after ASTM D 1557. Pavement Subgrades Subgrades for new pavements, including areas extending to 2 feet outside the limits of new pavements, should be prepared as described below. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 1. Step 1, Excavate and Stage. The upper 12-inches of soil below the base course level should be removed and staged for later replacement. 2. Step 2, Scarify/Moisture Condition. The surface exposed by Step 1 should be scarified to a depth of 12-inches, moisture conditioned to above the optimum moisture, then compacted to at least 90% relative compaction after ASTM D1557. 3. Step 3, Replacement. The soils staged by Step 1 should be moisture conditioned to 2% above the optimum moisture content and replaced at 95% relative compaction after ASTM D 1557. Flatwork Non-structural areas outside of building pads that include sidewalks and other flatwork, etc., should be over-excavated a minimum of 12-inches below the design subgrade and be replaced as moisture conditioned, properly densified fill. 6.5 Shallow Foundations 6.5.1 General The tenant improvements may be supported on shallow foundations. The following subsections provide recommendations for these foundations. 6. 5. 2 Bearing Unit Spread or continuous footings can be used to support the new improvements following earthwork to prepare foundations as described in Section 6.4. Foundations should bear entirely on Santiago Formation or new engineered fill. Cut and fill transitions within foundations should be avoided. 6. 5. 3 Minimum Dimensions and Reinforcing Continuous footings should be at least 24-inches wide and have a minimum embedment of 24- inches below lowest adjacent grade. Isolated square or rectangular footings should be a minimum of 36-inches wide. Foundations for the building should be embedded at least 24- inches below surrounding grade. It is recommended that all foundation elements, including any grade beams, be reinforced top and bottom. The actual reinforcement should be designed by the Structural Engineer. 6. 5. 4 Allowable Contact Stress Continuous and isolated footings constructed as described in the preceding sections may be designed using an allowable (net) contact stress of 2,500 pounds per square foot (psf). An allowable increase of 500 psf for each additional 12-inches in depth may be utilized, if desired. In no case should the maximum allowable contact stress should be greater than 3,500 psf. The maximum bearing value applies to combined dead and sustained live loads (DL + LL). The Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 allowable bearing pressure may be increased by ½ when considering transient live loads, including seismic and wind forces. 6. 5. 5 Lateral Resistance Resistance to lateral loads will be provided by a combination of (i) friction between the Unit 1 soils and foundation interface, and (ii) passive pressure acting against the vertical portion of the footings. Passive pressure may be calculated at 200 psf per foot of depth. A frictional coefficient of 0.35 may be used. No reduction is necessary when combining frictional and passive resistance. 6. 5. 6 Settlement Structures supported on shallow foundations as recommended above will settle less than 0.5- inch, with about 80% of this settlement occurring during the construction period. The differential settlement between adjacent columns is estimated on the order of 0.5-inch over a horizontal distance of 40 feet. The estimated seismic settlement (on the order of 0.5-inch or less, as is discussed in Section 5) would occur in addition to this movement. 6.5. 7 Footing Construction and Inspection Foundation excavations should be cleaned of loose material and observed by a qualified Geotechnical Engineer or Engineering Geologist prior to placing steel or concrete to verify soil conditions exposed at the base of the excavations. 6. 5. 8 Ground Supported Slabs The ground level slab of the garage may employ conventional on-grade (ground-supported) slab, designed using a modulus of subgrade reaction (k) of 90 pounds per cubic inch (i.e., k = 90 pci). The actual slab thickness and reinforcement should be designed by the Structural Engineer. NOVA recommends the slab be a minimum 5-inches thick, reinforced by at least #3 bars placed at 16-inches on center each way within the middle third of the slabs by supporting the steel on chairs or concrete blocks ("dobies"). Minor cracking of concrete after curing due to drying and shrinkage is normal. Cracking is aggravated by a variety of factors, including high water/cement ratio, high concrete temperature at the time of placement, small nominal aggregate size, and rapid moisture loss due during curing. The use of low-slump concrete or low water/cement ratios can reduce the potential for shrinkage cracking. To reduce the potential for excessive cracking, concrete slabs-on-grade should be provided with construction or 'weakened plane' joints at frequent intervals. Joints should be laid out to form approximately square panels and never exceeding a length to width ratio of 1.5 to 1. Proper joint spacing and depth are essential to effective control of random cracking. Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness. Joint spacing that is greater than 15 feet should include the use of load transfer devices (dowels or diamond plates). Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad , California NOVA Project 2019195 November 5, 2019 Contraction/control joints should be established to a depth of ¼ the slab thickness, as depicted in Figure 6-1 . rSawcut -------~ ~ • • • ., ·• • • 1°/4 D minJ •• . . . ... .., . . . . -·-.. . . . -•.• .. Induced crack ~ Sawed contraction joint Figure 6-1. Sawed Contraction Joint 6.6 Capillary Break and Underslab Vapor Retarder 6. 6. 1 Industry Design Guide NOVA recommends that any moisture barrier be designed in accordance with ACI Publication 302.1 R-15, "Guide to Concrete Floor and Slab Construction." 6.6.2 Capillary Break and Vapor Membrane General Ground-supported slabs that support moisture-sensitive floor coverings or equipment may be protected by an underslab moisture barrier. Such barriers normally include two components, as described below. 1. Capillary Break. A "capillary break" consisting of a 4-inch thick layer of compacted, well-graded gravel or crushed stone should be placed below the floor slab. This porous fill should be clean coarse sand or sound, durable gravel with not more than 5% coarser than the 1-inch sieve or more than 10% finer than the No. 4 sieve, such as AASHTO Coarse Aggregate No. 57. 2. Vapor Membrane. A minimum 15-mil polyethylene membrane, or similarly-rated vapor barrier, should be placed over the porous fill to preclude floor dampness. Membranes set below floor slabs should be rugged enough to withstand construction. NOVA recommends that a minimum 15 mil low permeance vapor membrane be used. For example, Carlisle-CCW produces the Blackline 400® underslab, vapor and air barrier, a 15-mil low-density polyethylene (LOPE) rated at 0.012 perms after ASTM E 96. Limitations of This Recommendation Recommendations for moisture barriers are traditionally included with geotechnical foundation recommendations, though these requirements are primarily the responsibility of the Structural Engineer or Architect. NOVA does not practice in the field of moisture vapor transmission evaluation, since this is not specifically a geotechnical issue. A Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 specialty consultant would provide recommendations for mitigation of potential adverse impact of moisture vapor transmission on various components of the structures, as deemed appropriate. 6.7 Walls 6. 7. 1 Shallow Foundations Continuous shallow foundations for retaining walls should be developed on ground prepared in accordance with the criteria provided in Section 6.4. Continuous shallow foundations may be designed to the criteria provided in Section 6.5. 6. 7. 2 Lateral Earth Pressures Lateral earth pressures for wall design are provided on Table 6-5 as equivalent fluid weights, in psf/foot of wall height or pounds per cubic foot (pcf). These values do not contain a factor of safety. Table 6-5. Wall Lateral Loads from Soil Equivalent Fluid Density (pcf) for Loading Condition Approved 'Native' Backfill Notes Notes A, 8 Level Backfill Active (wall movement allowed) 35 "At Rest" (no wall movement) 65 'Passive" (wall movement toward the soils) 260 Note A: 'Native means site-sourced soil with El < 50 after ASTM D4546. Note B: Assumes wall includes appropriate drainage. 6. 7. 3 Foundation Uplift 2:1 Backfill Sloping Upwards 60 100 220 A soil unit weight of 125 pcf may be assumed for calculating the weight of soil over the wall footing. 6. 7.4 Seismic Increment The seismic load increment should be calculated as a uniform 11 H psf (with H the height of the wall in feet). 6. 7. 5 Resistance to Lateral Loads Lateral loads to wall foundations will be resisted by a combination of frictional and passive resistance as described below. • Frictional Resistance. A coefficient of friction of 0.35 between the soil and base of the footing. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 • Passive Resistance. Passive soil pressure against the face of footings or shear keys will accumulate at an equivalent fluid weight of 200 pounds per cubic foot (pcf). Ignore the upper 12-inches of material in areas not protected by floor slabs or pavement. 6. 7. 6 Wall Drainage The above recommendations assume a wall drainage panel or a properly compacted granular free-draining backfill material. If wall drainage cannot be insured, design for wall pressures should include allowance for hydrostatic buildup. 6.8 Unbraced Slopes Temporary slopes may be required for excavations during grading. All temporary excavations should comply with local safety ordinances. The safety of all excavations is solely the responsibility of the Contractor and should be evaluated during construction as the excavation progresses. Based on the data interpreted from the borings, the design of temporary slopes may assume California Occupational Safety and Health Administration (Cal/OSHA) Soil Type C for planning purposes. Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 7.0 STORMWATER INFILTRATION 7.1 General Percolation testing for design of stormwater infiltration BMPs was completed after guidance contained in the City of Carlsbad BMP Design Manual, February 16, 2016 edition (hereafter, 'the BMP Manual'). Section 3.3 provides a description of the field work undertaken to complete the testing. Figure 3- 1 depicts the location of the testing. This section provides the results of that testing and related recommendations for management of stormwater in conformance with the BMP Manual. As is well-established by the BMP Manual, the feasibility of stormwater infiltration is principally dependent on geotechnical and hydrogeologic conditions at the project site. This section provides NOVA's assessment of the feasibility of stormwater infiltration BMPs utilizing the information developed by the field exploration described in Section 3.3, as well as other elements of the site assessment. 7 .2 Infiltration Rates 7. 2. 1 General A tabulation of the percolation rates determined by the field testing is provided in Section 3.3. The percolation rate of a soil profile is not the same as its infiltration rate ('I'). Therefore, the measured/calculated field percolation rate was converted to an estimated infiltration rate utilizing the Porchet Method in accordance with guidance contained in the BMP Manual. Table 7-1 provides a summary of the infiltration rates determined by the percolation testing. Table 7-1. Infiltration Rates Determined by Percolation Testing Approximate Depth of Boring Ground Elevation Test (feet, msl) (feet) P-1 +240 17 P-2 +241 18 Notes: 'F' indicates 'Factor of Safety' 7.2.2 Design Infiltration Rate Approximate Infiltration Design Test Elevation Rate Infiltration Rate (feet, msl) (in/hour) (in/hour, F=2*) +223 0.08 0.04 +223 0.05 0.03 In consideration of the nature and variability of infiltration materials, as well as the natural tendency of infiltration structures to become less efficient with time, the infiltration rates measured in the testing should be modified to use at least a factor of safety (F) of F=2 for preliminary design purposes. The measured infiltration rates range from I = 0.04 to I = 0.03 (no infiltration) inches per hour using a preliminary factor of safety (F) of F = 2, as is indicated on Table 7-1 . As may be seen by review of Table 7-1 , measured infiltration rates are less than 0.05-inches per hour. Based on the requirements of the BMP Manual and the results of this design infiltration investigation, no infiltration feasible at P-1 and P-2. Geotechnical Update Report fu-sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 7.3 7.3.1 Review of Geotechnical Feasibility Criteria OveNiew November 5, 2019 Section C.2 of Appendix C of the BMP Manual provides seven factors should be considered by the project geotechnical professional while assessing the feasibility of infiltration related to geotechnical conditions. These factors are listed below. • C.2.1 Soil and Geologic Conditions • C.2.2 Settlement and Volume Change • C.2.3 Slope Stability • C.2.4 Utility Considerations • C.2.5 Groundwater Mounding • C.2.6 Retaining Walls and Foundations • C.2.7 Other Factors The above geotechnical feasibility criteria are reviewed in the following subsections. 7. 3. 2 Soil and Geologic Conditions The soil borings and percolation tests borings completed for this assessment disclose the sequence of artificial fill and rock described below. 1. Unit 1, Undocumented Fill. As encountered in the borings, much of the site is underlain by artificial fill (Qaf) of variable thickness. This soil unit occurs as clayey and silty sand with gravel, and is of medium dense to dense consistency. 2. Unit 2, Santiago Formation. The site is entirely underlain by the Eocene-aged Santiago Formation (geologic map symbol: Tsa) comprised of marine silty sandstone and clayey siltstone. The unit is of relatively higher strength and low compressibility. The Santiago Formation is known to extend well beyond the depths explored in the borings. 7.3.3 Settlement and Volume Change The soils at the tested infiltration locations are of sufficient density that saturation will not affect settlement by soil collapse. The Unit 2 have low expansion potential. 7. 3. 4 Slope Stability Infiltration of water has the potential to result in an increased risk of slope failure of slopes. As such, BMPs should not be sited within 50 feet of a slope. 7. 3. 5 Utilities Infiltration has the potential to damage subsurface utilities and/or underground utilizes may pose geotechnical hazards in themselves when infiltrated was is introduced. Stormwater infiltration BMPs should not be sited within 10 feet of underground utilities. BMPs should not be located within 10 feet of underground utilities. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 7.3.6 Groundwater Mounding Stormwater infiltration will result in damaging ground water mounding during wet periods. Mounded water will be damaging to utilities, pavements, flat work, and foundations, all of which will be established on soils with medium expansion potential. 7. 3. 7 Other Factors NOVA knows of no other geotechnical or site design factors that could affect stormwater infiltration BMPs. However, the complete design is not known at this point. Risk factors could arise (for example, the proximity of BMPs to retaining walls) in review of the final design. 7.4 Suitability of the Site for Stormwater Infiltration It is the judgment of NOVA that based on the referenced BMP Manual that the site is not suitable for development of stormwater BM P's due to the factors listed below. 1. Factor 1, Low Design Infiltration Rate. The average design infiltration rate determined from the two site-specific percolation tests is less than 0.05-inches per hour. The low vertical permeability (kv) of the Unit 2 Santiago Formation -on the order of kv ~ 10-7 cm/sec or less -precludes stormwater infiltration. 2. Factor 2, Widespread Low Permeability Formation Soil/Rock. The site is entirely underlain by lower permeability Unit 2 Santiago Formation. This unit would be located at the base of any stormwater infiltration BMPs. As shown by the percolation/infiltration testing this geologic unit will not percolate stormwater. In consideration of the above factors, it is NOVA's judgment that the site is not suitable for stormwater infiltration BMPs. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 8.0 REFERENCES 8.1 Site Specific fu·sion, 1950 Camino Vida Roble, Carlsbad, California 92008, RAF Pacifica Group, SCA Architecture, Job No. 18034.S02, September 13, 2019. 8.2 Design American Concrete Institute, 2002, Building Code Requirements for Structural Concrete, ACI 318-02. American Concrete Institute, 2015, Guide to Concrete Floor and Slab Construction, ACI 302.1 R- 15. ASCE, Minimum Design Load for Buildings and Other Structures, ASCE 7-10. APWA, 2015 Standard Specifications for Public Works Construction ('Greenbook'). California Code of Regulations, Title 24, 2019 California Building Standards Code. California Department of Conservation, Division of Mines and Geology, 1996, DMG Open File Report, 96-02, Geologic Maps of Northwest Part of San Diego County California. California Department of Transportation (Caltrans), 2003, Corrosion Guidelines, Version 1.0, available at http://www.dot.ca.gov/hq/esc/ttsb/corrosion/pdf/2012-11-19-Corrosion- Guidelines. pdf. California Department of Water Resources, Water Data Library: found at http://www.water.ca.gov/waterdatalibrary/. California Division of Mines and Geology (CDMG), 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117 A. California Geological Survey (CGS), 2007, Geologic Map of The Oceanside 30' x 60' Quadrangle, California. Scale 1:100,000. Plate 1 of 2. GSI, Inc., 1995, Preliminary Geotechnical Evaluation, Carlsbad Airport Center, Unit II, Lot 33 & 34, Carlsbad, California, Geosoils, Inc., W.O. 1840-SC, July 14, 1995. Hart, E.W. and Bryant, W. A., 1997, Fault-Rupture Hazard Zones In California, California Department of Conservation, Division of Mines and Geology, Special Publication 42. Jennings, C. W., 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Map Sheet No. 6. Structural Engineers Association of California, Seismic Design Recommendations, Tilt up Buildings, SEAOC Blue Book, Article 9.02.010, September 2008. Tan, S. and Giffen, G., California Department of Conservation, Division of Mines and Geology, 1995, DMG Open File Report, 95-04, Landslide Hazards In The Northern Part Of The San Diego Metropolitan Area, San Diego County, California. USGS, Earthquake Hazards Program, Seismic Design Maps & Tools, accessed July 2018 at: http:! /earthquake. usgs. gov /hazards/designmaps/. Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 PLATES ) I I I I I 7UREMAIP/ '.., ~---1 ma1TC} (2961 Fl./ J 0 1G :Ii IN I 2541 re 12$J.6FL -~3FS) i ~ -~T, ; 1/~ / / EXJSnNa 1CTPVCCL-'5C f' PUBUC 'NITER t.WN ro BE 't _,.. ,,,,, CONVERTED 1D PRfVJI.TF / / HRlSER\l!Cf UNI. I i KEY TO SYMBOLS FILL .,. (2&6TC} (2!160Fl) \... EXISTING Pl'.R/(/1/Glt) _,N ~H~¥N@ 7521 FS, 8 EXISTING SOC 0 RNSETOGWJE 2!11/RIII !2480/E, -EXJSrlNG SO INLET iOREJ,1,,4,JN (148 f ro, (2484/E ~ EXISTING FIRE lfflJRANT TO RFMAJ/v 2!i0.l/ll:OU1 !252.24 FS.• ;!l!NJ (25a.3 TC} /2561/FL) r isiOFS ~-, • f- .,. EXISTING PIIR/Orv(J lt) REMNN UMITOF/>£ GRJ//DN/0 O\/!'RLAY Ji ~EXIST ~-~-. ~ '' < 1"'""~i'"'.·r--1-r-• 21/2.0FS _/ 252.leFS (25217FS) 2'619FS I FIRE EMERGENCY ACCESS~ /20'/INWOTHJ 25216FS -" " C !:}(/ST/HG soco TO BE RELOCATED '2~2Rll,IJ (2'31 IE, EXISTING STRUCTURE TO REMAIN PLAN VIEW -PRELIMINARY GRADING PLAN s~ , , 3!l HORJZONT,IJ. P-1 E9 LOCATION OF PERCOLATION TEST BORING Qaf Tsa SANTIAGO FORMATION B-6 8 LOCATION OF GEOTECHNICAL BORING m.llFS - 2521BFS 25Z1BFS _J I EXIST1'1G 16' PVC PRIVATE STORM ORNN TO REt.WN EXIST1NGSD ~ C.O TO REMAIN /24'.BRH,/ ~0/E EJ(ISTING 10 PVC CL-l!ll} - PUBllC MTER AWN TO BE CON'1iRTliD TO PRWATE FIRE SERVICE LINE EXIST1NGSD CC 10REMAJN 1231 t RIM1 (23C DIE. I 2421/TC- 2424FL ,,-EXISTING SD CO ro REMAIN / (26/UltiR/II). / 2416/EINIIORTH. 2S42 2530 1 24951F 2501W (2516 7W} (25D.67W} 2,maw V .1r-.......__ ---:,t ------ 124136TC) (24085FL) 2,00 re !231/5FL1 / /2389 TCJ ~ ,,../ !238BFL, / I PASCO LARET SUITE~ & A880CIATES CIWIL-♦~l'Ual-♦IMD-1111 .... .....,W. ...... _....,ca__ ,.--.au11awi,11r r ••- 244 0 IE IN EAST (2411 IE OUT) EXISTII/GSD CO )t)REMAJN (230.84 RIM, (122 0 IE) :~:;~@ 235.BIEOUT EXiSTING SD INLET ro BE REMOVED CONNECT 16 SD TO / EXISTINGSD/NtET" /223.D R/Mj, 217.D IE IN (216.7/EOUTi -EXISTINGSD coroREMNN /234 0 Rl!IJ. (22B 2 IE) DAit l'IVMIIDc 111,.-,'!0!1 fsim' I I CITY OF CARLSBAD 11 silEffll L...!..J IIIJIOR sm DEmDPIIIIIT PWf L..!...J RAF PACIFICA GROUP FUSION I.,.. tr .. I !Owl BY: =----1 _"'fillli...-""• u...,_,,...,,----r,z1511l"',,.-...--= ~~ .....111,.__ Ji\ ---NOVA 4373 VIEWRIDGE AVENUE, SUITE B SAN DIEGO, CALIFORNIA 858-292-7575 858-292-7570 (FAX) WWW.USA-NOVA.COM w w <( ...J _J m co z 0 0 a: cc a: 0 <( <( LL C 0 _J --<( > > 0 0 0 z z 0 --<( ~ ~ co <( <( Cl) (.) 0 _J 0 0 a: LO L() <( 0, 0) 0 ,-T""" PROJECT NO: DATE: DRAWN BY: 2019195 OCT2019 DTJ REVIEWED BY: JOB 0 SUBSURFACE INVESTIGATION MAP 60' PLATE 1 120' Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 APPENDIX A USE OF THE GEOTECHNICAL REPORT Im ortant Information About Your Geotechnical Engineering Report Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. The following information is provided to help you manage your risks. Geotechnical Services Are Performed for Specific Purposes, Persons, and Projects Geotechnical engineers structure their services to meet the specific needs of their clients. A geotechnical engineering study conducted for a civil engi- neer may not fulfill the needs of a construction contractor or even another civil engineer. Because each geotechnical engineering study is unique, each geotechnical engineering report is unique, prepared solely for the client. No one except you should rely on your geotechnical engineering report without first conferring with the geotechnical engineer who prepared it And no one -not even you -should apply the report for any purpose or project except the one originally contemplated. Read the Full Report Serious problems have occurred because those relying on a geotechnical engineering report did not read it all. Do not rely on an executive summary. Do not read selected elements only. A Geotechnical Engineering Report Is Based on A Unique Set of Project-Specific Factors Geotechnical engineers consider a number of unique, project-specific fac- tors when establishing the scope of a study Typical factors include: the client's goals, objectives, and risk management preferences the general nature of the structure involved, its size, and configuration; the location of the structure on the site: and other planned or existing site improvements, such as access roads, parking lots, and underground utilities. Unless the geotechnical engineer who conducted the study specifically indicates oth- erwise, do not rely on a geotechnical engineering report that was: • not prepared for you, • not prepared for your project, • not prepared for the specific site explored, or • completed before important project changes were made. Typical changes that can erode the reliability of an existing geotechnical engineering report include those that affect: • the function of the proposed structure, as when it's changed from a parking garage to an office building, or from a light industrial plant to a refrigerated warehouse, • elevation, configuration, location, orientation, or weight of the proposed structure, • composition of the design team, or • project ownership. As a general rule, always inform your geotechnical engineer of project changes-even minor ones-and request an assessment of their impact Geotechnical engineers cannot accept responsibility or liability for problems that occur because their reports do not consider developments of which they were not informed Subsurface Conditions Can Change A geotechnical engineering report is based on conditions that existed at the time the study was performed. Do not rely on a geotechnical engineer- ing report whose adequacy may have been affected by: the passage of time by man-made events, such as construction on or adjacent to the site or by natural events, such as floods, earthquakes, or groundwater fluctua- tions. Always contact the geotechnical engineer before applying the report to determine if it is still reliable. A minor amount of additional testing or analysis could prevent major problems. Most Geotechnical Findings Are Professional Opinions Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. Geotechnical engi- neers review field and laboratory data and then apply their professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ-sometimes significantly- from those indicated in your report. Retaining the geotechnical engineer who developed your report to provide construction observation is the most effective method of managing the risks associated with unanticipated conditions. A Report's Recommendations Are Not Final Do not overrely on the construction recommendations included in your report. Those recommendations are not final. because geotechnical engi- neers develop them principally from judgment and opinion. Geotechnical engineers can finalize their recommendations only by observing actual subsurface conditions revealed during construction. The geotechnical engineer who developed your report cannot assume responsibility or liability for the report's recommendations if that engineer does not perform construction observation. A Geotechnical Engineering Report Is Subject to Misinterpretation Other design team members' misinterpretation of geotechnical engineering reports has resulted in costly problems. Lower that risk by having your geo- technical engineer confer with appropriate members of the design team after submitting the report. Also retain your geotechnical engineer to review perti- nent elements of the design team's plans and specifications. Contractors can also misinterpret a geotcchnical engineering report Reduce that risk by having your geotechnical engineer participate in prebid and preconstruction conferences, and by providing construction observation. Do Not Redraw the Engineer's Logs Geotechnical engineers prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical engineering report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give con- tractors the complete geotechnical engineering report, but preface it with a clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited encourage them to confer with the geotechnical engineer who prepared the report (a modest fee may be required) and/or to conduct additional study to obtain the specific types of information they need or prefer. A prebid conference can also be valuable. Be sure contrac- tors have sumcient time to perform additional study. Only then might you be in a position to give contractors the best information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Read Responsibility Provisions Closely Some clients, design professionals, and contractors do not recognize that geotechnical engineering is far less exact than other engineering disci- plines. This lack of understanding has created unrealistic expectations that have led to disappointments, claims, and disputes. To help reduce the risk of such outcomes, geotechnical engineers commonly include a variety of explanatory provisions in their reports. Sometimes labeled "limitations" many of these provisions indicate where geotechnical engineers· responsi- bilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely Ask questions. Your geotechnical engineer should respond fully and frankly. Geoenvironmental Concerns Are Not Covered The equipment. techniques, and personnel used to perform a geoenviron- mental study differ significantly from those used to perform a geotechnical study. For that reason, a geotechnical engineering report does not usually relate any geoenvironmental findings, conclusions, or recommendations: e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated environmental problems have led to numerous project failures. If you have not yet obtained your own geoen- vironmental information, ask your geotechnical consultant for risk man- agement guidance. Do not rely on an environmental report prepared for someone else. Obtain Professional Assistance To Deal with Mold Diverse strategies can be applied during building design, construction, operation, and maintenance to prevent significant amounts of mold from growing on indoor surfaces. To be effective, all such strategies should be devised for the express purpose of mold prevention, integrated into a com- prehensive plan, and executed with diligent oversight by a professional mold prevention consultant. Because just a small amount of water or moisture can lead to the development of severe mold infestations, a num- ber of mold prevention strategies focus on keeping building surfaces dry. While groundwater, water infiltration, and similar issues may have been addressed as part of the geotechnical engineering study whose findings are conveyed in this report, the geotechnical engineer in charge of this project is not a mold prevention consultant: none of the services per- formed in connection with the geotechnical engineer's study were designed or conducted for the purpose of mold preven- tion. Proper implementation of the recommendations conveyed in this report will not of itself be sufficient to prevent mold from growing in or on the structure involved. Rely, on Your ASFE-Member Geotechncial Engineer for Additional Assistance Membership in ASFE/ThE: Best People on Earth exposes geotechnical engineers to a wide array of risk management techniques that can be of genuine benefit for everyone involved with a construction project. Confer with you ASFE-member geotechnical engineer for more information. A5FE The Best People ID larlh 8811 Colesville Road/Suite G106, Silver Spring, MD 20910 Telephone 301/565-2733 Facsimile 301/589-2017 e-mail info@asfe.org wwwasfe.org Copyright 2004 by ASFE, Inc. Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with ASFE's specific written permission Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of ASFE, and only for purposes of scholarly research or book review Only members of ASFE may use this document as a complement to or as an element of a geotechnical engineering report. Any other firm, individual, or other entity that so uses this document without being an ASFE member could be commiting negligent or intentional (fraudulent) misrepresentation IIGER06045 OM Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 APPENDIX B LOGS OF BORINGS November 5, 2019 BORING LOG 8-1 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_7_5 __________ _ EXCAVATION DESCRIPTION: 8-INCH DIAMETER AUGER BORING GPS COORD.: _N_/_A ___________ _ GROUNDWATER DEPTH: w -' a.. CJ ~ cli t=' 0 <( U) !:::, __J U) <( g I-d1n a.. U) -' u ::i 0~ <( u UJ- SC ML SM GROUNDWATER NOT ENCOUNTERED ELEVATION: _±_26_4_,5_FT_M_S_L _______ _ U) w I u z U) --;- 3: ~ 0 a: -' w [Il a.. 50/5" SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) FILL (Qaf): CLAYEY SAND; LIGHT OLIVE GRAY, DAMP, MEDIUM DENSE, FINE TO MEDIUM GRAINED SANTIAGO FORMATION (Tsa): SANDY SILTSTONE; DARK GRAY, MOIST, HARD 63 SIL TY SANDSTONE; DARK GRAY, MOIST, VERY DENSE, FINE GRAINED 50/3" 80 50/5" BORING TERMINATED AT 20 FT. NO GROUND WA TEA. NO CAVING. KEY TO SYMBOLS >-a: 0 ~ a: 0 [Il :5 GROUNDWATER / STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY CR MD OS El AL SA RV CN SE SPT SAMPLE ( ASTM D1586) GEOLOGIC CONT ACT LOGGED BY: GAN DATE: NOV 2019 CAL. MOD. SAMPLE {ASTM D3550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 CORROSIVITY MAXIMUM DENSITY DIRECT SHEAR EXPANSION INDEX ATTERBERG LIMITS SIEVE ANALYSIS RESISTANCE VALUE CONSOLIDATION SAND EQUIVALENT REMARKS ,,, NOVA APPENDIX B.1 BORING LOG 8-2 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_7_5 __________ _ EXCAVATION DESCRIPTION: 8-INCH DIAMETER AUGER BORING GPS COORD.: NIA GROUNDWATER DEPTH: UJ _J CL ~ ui i=' <t Cf) ~ Cf) <t r-den CL Cf) _J (.) ::i -Cf) <t 0::::, (.) Cf)~ ------------- GROUNDWATER NOT ENCOUNTERED ELEVATION: ± 253.5 FT MSL Cf) UJ I (.) z Cf)~ 3: ~ O cc _J UJ CD CL ------------- SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) 6 INCHES OF CONCRETE OVER 2 INCHES OF AGGREGATE BASE >-cc 0 r-<t cc 0 CD <t _J CR MD OS El AL SA RV CN SE SC FILL (Oaf): CLAYEY SAND; YELLOW-BROWN, DAMP, MEDIUM DENSE, FINE TO MEDIUM El 44 LOW GRAINED AL ML SM 42 50/1" 50/4" SANTIAGO FORMATION (Tsa): SANDY SILTSTONE; DARK GRAY, MOIST, HARD, FINE TO MEDIUM GRAINED SIL TY SANDSTONE; DARK GRAY. MOIST, VERY DENSE, FINE GRAINED 5013., LIGHT GRAY, VERY DENSE 5013" DARK GRAY BORING TERM/NA TED AT 20 FT. NO GROUNDWATER. NO CAVING. KEY TO SYMBOLS GROUNDWATER /STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY SPT SAMPLE ( ASTM 01586) GEOLOGIC CONTACT LOGGED BY: GAN DATE: NOV 2019 CAL. MOD. SAMPLE (ASTM 03550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 CORROSIVITY MAXIMUM DENSITY DIRECT SHEAR EXPANSION INDEX ATTERBERG LIMITS SIEVE ANALYSIS RESISTANCE VALUE CONSOLIDATION SAND EQUIVALENT REMARKS APPENDIX B.2 BORING LOG B-3 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_7_5 __________ _ EXCAVATION DESCRIPTION: 8-INCH DIAMETER AUGER BORING GPS COORD.: _N_/_A ___________ _ GROUNDWATER DEPTH: w _J CL ('.) ~ CJi i=' 0 <t: (/) !:=.. -' (/) <t: g I-den CL (/) ::J _J u <t: 0~ u C/J- SC ML GROUNDWATER NOT ENCOUNTERED ELEVATION: _±_2_49_FT_M_S_L ________ _ (/) w I u z (/)~ ~~ 0 a: _J w CD CL 40 50/6" 50/6" SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) FILL (Oaf): CLAYEY SAND; YELLOW BROWN, DRY, DENSE, FINE TO MEDIUM GRAINED, SCATTERED GRAVEL SANTIAGO FORMATION (Tsa): SANDY SILTSTONE WITH CLAY; MEDIUM BROWN WITH YELLOW AND DARK ORANGE OX/DA TION, MOIST, HARD 50/6" LIGHT GRAY, PART/ALLY CEMENTED WITH CONCRETIONARY MINERALIZATION BORING TERM/NA TED AT 15.5 FT. NO GROUNDWATER ENCOUNTERED. NO CAVING KEY TO SYMBOLS >-a: ~ a: 0 CD :5 SA GROUNDWATER /STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY CR MD DS El AL SA RV CN SE SPT SAMPLE ( ASTM D1586) GEOLOGIC CONT ACT LOGGED BY: GAN DATE: NOV 2019 CAL. MOD. SAMPLE (ASTM D3550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 CORROSIVITY MAXIMUM DENSITY DIRECT SHEAR EXPANSION INDEX ATTERBERG LIMITS SIEVE ANALYSIS RESISTANCE VALUE CONSOLIDATION SAND EQUIVALENT REMARKS APPENDIX B.3 BORING LOG B-4 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_7_5 __________ _ CR CORROSIVITY MD MAXIMUM DENSITY OS DIRECT SHEAR EXCAVATION DESCRIPTION: 8-INCH DIAMETER AUGER BORING GPS COORD.: NIA El EXPANSION INDEX AL ATTERBERG LIMITS -------------SA SIEVE ANALYSIS RV RESISTANCE VALUE GROUNDWATER DEPTH: GROUNDWATER NOT ENCOUNTERED ELEVATION: --'+=----=-24'--"9'--".5-'-F--'-T-"M"'S=L _______ _ CN CONSOLIDATION i=' ~ UJ -' a.. ::i: ct (/) I-a.. (/) :::i ct (.) cr.i (/) ct den -' (.) 0~ (/)- SC (/) UJ J: (.) z (/)~ 3:~ 0 a: -' UJ co a.. SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) FILL (Qaf): CLAYEY SAND; YELLOW BROWN, DRY, VERY DENSE, FINE TO MEDIUM GRAINED, SCATTERED GRAVEL SC-SM SANTIAGO FORMATION (Tsa): CLA YEY-S/L TY SANDSTONE; MEDIUM BROWN WITH 50/6" YELLOW AND DARK ORANGE OX/DA TION, MOIST, VERY DENSE, FINE TO MEDIUM GRAINED 52 50/5" PALE ORANGE MOTTLED WITH GRAY 36 MEDIUM BROWN WITH DARK ORANGE OX/DA TION, TRACE GYPSUM DARK BROWN WITH DARK YELLOW OX/DA TION ALONG BEDDING 50/5" BORING TERMINATED AT 20.0 FT. NO GROUNDWATER. NO CAVING. KEY TO SYMBOLS GROUNDWATER / STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY SPT SAMPLE ( ASTM D1586) GEOLOGIC CONTACT LOGGED BY: GAN DATE: CR MD SA RV CR SE SAND EQUIVALENT REMARKS El 10 VERY LOW AL SA NOV 2019 CAL. MOD. SAMPLE (ASTM D3550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 APPENDIX B.4 BORING LOG 8-5 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_9_5 __________ _ CR CORROSIVITY MD MAXIMUM DENSITY DS DIRECT SHEAR EXCAVATION DESCRIPTION: _B_-I_N_C_H_D_IA_M_E_TE_R_A_U_G_E_R_B_O_R_IN_G ___ GPS COORD.: _N-'---/A ___________ _ El EXPANSION INDEX AL ATTERBERG LIMITS SA SIEVE ANALYSIS RV RESISTANCE VALUE GROUNDWATER DEPTH: GROUNDWATER NOT ENCOUNTERED ELEVATION: ~+~24_1_FT_M_S_L ________ _ CN CONSOLIDATION SE SAND EQUIVALENT w _J Cf) w a. w ('.) _J ~ Cl) I SOIL DESCRIPTION f=' a. <( (.) 0 ~ Cf) Cf) z !:=. _J <( SUMMARY OF SUBSURFACE CONDITIONS ,2 <( I-den Cf)~ I Cf) a. (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) I-I Cf) ~~ CL ::s:: _J (.) a. < _J :::i -en 0 a: w a: ::J <( o::J -'W Cl ('.) CD (.) Cf)_ CD a. REMARKS 4 INCHES OF ASPHALT CONCRETE OVER 9 INCHES OF AGGREGATE BASE SC FILL (Qaf): CLAYEY SAND; YELLOW BROWN, DAMP, MEDIUM DENSE, FINE GRAINED YELLOW BROWN AND LIGHT GRAY ~ ~~ 100~ SC-CL 13 CONTAINS SOME CLAY 25 48 42 DARK GRAY AND BLACK, MOIST SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE-SANDY CLA YSTONE WITH SILT; YELLOW BROWN MOTTLED WITH GRAY AND DARK ORANGE OXIDE STAINING, MOIST, DENSE-HARD, FINE GRAINED ORANGE BROWN, MEDIUM DENSE BORING TERMINATED AT 20 FT. NO GROUNDWATER ENCOUNTERED. NO CAVING. KEY TO SYMBOLS GROUNDWATER / STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY SPT SAMPLE ( ASTM D1586) GEOLOGIC CONT ACT LOGGED BY: GAN DATE: 19.5% 107.Bpcf NOV 2019 CAL. MOD. SAMPLE (ASTM 03550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 APPENDIX B.5 PERCOLATION BORING LOG P-1 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C_M_E_9_5 __________ _ EXCAVATION DESCRIPTION: _B_-_IN_C_H_D_IA_M_E_TE_R_A_U_G_E_R_B_O_R_IN_G ___ GPS COORD.: -'N-'--/---'A ___________ _ GROUNDWATER DEPTH: i=' ~ I l-e,_ w Cl g (.) :i: Q._ <( cc CJ w _.J w c,_ _.J ~ c,_ <( ~ Cl) <( I-C/) c,_ :5 ~ :::> <( CXl (.) Cl) Cl) <( den _.J (.) -Cl) 0:::, Cl)_ SC SC-CL GROUNDWATER NOT ENCOUNTERED ELEVATION: -'+~24_;0_F_T_M_;S~L ________ _ Cl) w I (.) z Cl)~ 3: -0 a: _.Jw CXl c,_ SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) 3 INCHES OF ASPHALT CONCRETE OVER 9 INCHES OF AGGREGATE BASE FILL (Qaf): CLAYEY SAND; YELLOW BROWN, DAMP, MEDIUM DENSE, FINE GRAINED YELLOW BROWN WITH WHITE MOTTLING SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE-SANDY CLA YSTONE WITH SILT; DARK GRAY AND BLACK, MOIST, MEDIUM DENSE-FIRM, FINE TO MEDIUM GRAINED BORING TERM/NA TED AT 17 FT AND CONVERTED TO A PERGOLA TION WELL. KEY TO SYMBOLS >-a: ~ a: 0 CXl <( _.J GROUNDWATER / STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY CR MD DS El AL SA RV CN SE SPT SAMPLE ( ASTM D1586) GEOLOGIC CONTACT LOGGED BY: GAN DATE: NOV 2019 CAL. MOD. SAMPLE (ASTM D3550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO.: 2019195 CORROSIVITY MAXIMUM DENSITY DIRECT SHEAR EXPANSION INDEX ATTERBERG LIMITS SIEVE ANALYSIS RESISTANCE VALUE CONSOLIDATION SAND EQUIVALENT REMARKS ,,, NOVA APPENDIX B.6 PERCOLATION BORING LOG P-2 LAB TEST ABBREVIATIONS DATE EXCAVATED: OCTOBER 3, 2019 EQUIPMENT: _C'----M---'E=---9=---5 __________ _ EXCAVATION DESCRIPTION: 8-INCH DIAMETER AUGER BORING GPS COORD.: _N_/A ___________ _ GROUNDWATER DEPTH: t=' ~ I l-a._ w 0 8 _J g :r: a._ <( a: Cl w ...J w a._ ...J ~ a._ <l'. ~ (/) <l'. I-r/) a._ :i ~ :J <l'. co (.) SC SC-CL GROUNDWATER NOT ENCOUNTERED ELEVATION: _±_24_1_FT_M_S_L ________ _ (/) w I (.) z (/) -;- 3: ~ oa:: ...JW co a._ SOIL DESCRIPTION SUMMARY OF SUBSURFACE CONDITIONS (USCS; COLOR, MOISTURE, DENSITY, GRAIN SIZE, OTHER) 3 INCHES OF ASPHALT CONCRETE OVER 8 INCHES OF AGGREGATE BASE FILL (Qaf): CLAYEY SANO; YELLOW BROWN, DAMP, MEDIUM DENSE, FINE GRAINED SANTIAGO FORMATION (Tsa): CLAYEY SANDSTONE-SANDY CLA YSTONE WITH SILT; DARK GRAY, MOIST, MEDIUM DENSE-FIRM, FINE TO MEDIUM GRAINED LIGHT GRAYISH ORANGE BORING TERMINATED AT 18 FT ANO CONVERTED TOA PERCOLATION WELL. KEY TO SYMBOLS >-a: ~ a: 0 co s AL SA GROUNDWATER / STABILIZED # ERRONEOUS BLOW COUNT FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA BULK SAMPLE * NO SAMPLE RECOVERY CR MD DS El AL SA RV CN SE SPT SAMPLE ( ASTM D1586) GEOLOGIC CONTACT LOGGED BY: GAN DATE: NOV 2019 CAL. MOD. SAMPLE (ASTM D3550) SOIL TYPE CHANGE REVIEWED BY: BMH PROJECT NO .: 2019195 CORROSIVITY MAXIMUM DENSITY DIRECT SHEAR EXPANSION INDEX ATTERBERG LIMITS SIEVE ANALYSIS RESISTANCE VALUE CONSOLIDATION SAND EQUIVALENT REMARKS APPENDIX B.7 Geotechnical Update Report fu·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 November 5, 2019 APPENDIX C RECORDS OF LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (ASTM) test methods or suggested procedures. Brief descriptions of the tests performed are presented below: • CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifications are in accordance with the Unified Soils Classification System and are presented on the exploration logs in Appendix B. • MAXIMUM DENSITY AND OPTIMUM MOISTURE CONTENT (ASTM D 1557 METHOD A,B,C): The maximum dry density and optimum moisture content of typical soils were determined in the laboratory in accordance with ASTM Standard Test O 1557. Method A. Method B. Method C. • DENSITY OF SOIL IN PLACE (ASTM D2937): In-place moisture contents and dry densities were determined for representative soil samples. This information was an aid to classification and permitted recognition of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the in-place moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the exploration logs presented in Appendix B. • EXPANSION INDEX (ASTM D 4829): The expansion index of selected materials was evaluated in general accordance with ASTM O 4829. Specimens were molded under a specified compactive energy at approximately 50 percent saturation (plus or minus 1 percent). The prepared 1-inch thich by 4-inch diameter specimens were loaded with a surcharge of 144 pounds per square foot and were inundated with tap water. Readings of volumetric swell were made for a period of 24 hours. • ATTERBERG LIMITS (ASTM D 4318): Tests were performed on selected representative fine-grained soil samples to evaluate the liquid limit, plastic limit, and plasticity index in general accordance with ASTM O 4318. These test results were utilized to evaluate the soil classification in accordance with the Unified Soil Classification System. • CHEMICAL TEST (CAL. TEST METHOD 417,422,643): Soil PH, and minimum resistivity tests were performed on a representative soil sample in general accordance with test method CT 643. The sulfate and chloride content of the selected sample were evaluated in general accordance with CT 417 and CT 422, respectively. • GRADATION ANALYSIS (ASTM C 136 and/or ASTM D422): Tests were performed on selected representative soil samples in general accordance with ASTM 0422. The grain size distributions of selected samples were determined in accordance with ASTM C 136 and/or ASTM 0422. The results of the tests are summarized on Appendix C.3 through Appendix C.6. 4373 VIEWRIDGE AVENUE, SUITE 8 SAN DIEGO, CALIFORNIA PHONE: 858-292-7575 FAX: 858-292-7570 BY:CLS LAB TEST SUMMARY FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA DATE: NOV 2019 PROJECT: 2010195 APPENDIX: C.1 I I I I I I I I j I I I f • I I I I I Maximum Dry Density and Optimum Moisture Content (ASTM D1557) Sample Location 8-4 Sample Location 8-5 8-5 Sample Location B-2 B-4 P-1 Sample Sample Depth Location (ft.) 8-4 8-4 0-5 5 -10 4373 VIEWRIDGE AVENUE, SUITE B SAN DIEGO, CALIFORNIA Sample Depth (ft.) 0-5 Soil Description Yellow Brown Clayey Sand Maximum Dry Density (pcf) 121.2 Optimum Moisture Content (%) 10.0 Density of Soil in Place (ASTM D2937) Sample Moisture Depth (ft) Soil Description (%) 5 -6.5 Yellow Brown Clayey Sand 12.3 10 -11.5 Dark Gray and Black Clayey Sand 19.5 Atterberg Limits (ASTM D4318) Sample Depth Liquid Plastic Plasticity (ft.) Limit, LL Limit, PL Index, Pl 0-2 34 27 7 5-10 31 20 11 13 -18 40 18 22 Expansion Index (ASTM D4829) Sample Location 8-2 8-4 Sample Depth (ft.) 0-2 5 -10 Expansion Index 44 10 Expansion Potential Low Very Low Chemical (Cal. Test Method 417,422,643) pH 7.9 7.6 Resistivity (Ohm-cm) 280 320 Sulfate Content (ppm) (%) 2640 2400 0.264 0.240 Dry Density (pcf) 100.9 107.8 uses (% Finer than No. 40) ML CL CL Chloride Content (ppm) (%) 140 410 0.014 0.041 LAB TEST RESULTS BY:CLS FU.SION SITE IMPROVEMENTS 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA DATE: NOV 2019 PROJECT: 2019195 APPENDIX: C.2 iPHONE: 858-292-7575 FAX: 858-292-7570 [ ~ Size (Inches/ >< ~ ✓ Hydrometer Analysis ' U.S. Standard Sieve Sizes ,,..._ ✓ 0 0 ~ 0 0 ~ 0 "1 !!: ~ ee .., <Xl "' "' N ~"' ~"' ci ci ci ci ci ci ci 100.0 --z z z z z z z -I ... ► -1--;-I I I I I I I -· .. : I I I I I I I ,._ ,a I I 90.0 I I I I I I I I I I I I I I r--' I I I I I I I '+, I I I I I I I I I I I I I I I ' I 80.0 I I I I I I I \ I I I I I I I I I I I I I I I I I Cl 70.0 -I I I I I I I C: 11 I I ,~ -, -~- ~ "iii I I I I I I I I Ill I I I I I I I I "' I I I I I I I I Q. 60.0 I, ' ' ' ' ' ' -I I I I I I I I C: I I I I I I I I CII u I I I I I I I I [ ... I I I I I I I I CII 50.0 Q. I I I I I I I I I I I I I I I I I I I I I I I I 40.0 I I I I I I I I [ I I I I I I I I I I I I I I I I I I I I I I I I 30.0 I I I I I I I I I I I I I I I I [ I I I I I I I I I I I I I I I I 20.0 I I I I I I I I I I I I I I I I I I I I I I I I 10.0 I I I I I I I I [ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0.0 100 10 1 0.1 0.01 0.001 [ Grain Size (mm) [ Gravel Sand Silt or Clay Coarse I Fine Coarse! Medium Fine [ Sample Location: B-3 [ Depth (ft): 10-15 uses Soil Type: ML Passing No. 200 (%): 71 [ [ '~\ GRADATION ANALYSIS TEST RESULTS ,._ FU.SION SITE IMPROVEMENTS [ NOVA 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA 4373 VIEWRIDGE AVENUE, SUITE B SAN DIEGO, CALIFORNIA BY:CLS DATE: NOV 2019 PROJECT: 2019195 APPENDIX: C.3 [ PHONE: 858-292-7575 FAX: 858-292-7570 0, [ [ [ <E------Size (Inches) -J '-J Hydrometer Analysis -, ' U.S. Standard Sieve Sizes , ' , 0 ~ 0 0 0 ""! ~ ~ ..,. a, .., "' N :,t 0 0 0 0 0 0 ~ ~"' ~ "' 100.0 --z z z z z z ,.. -I"' .... I ,.._,_ I I I I I I ~ '1~ I I I I I I I -! I I 90.0 I I I I I I I I I I I I I I I I I I I ~ I I I I I I I \ I I I I I I I \ I I 80.0 I I I I I , I I I I I I I I I I I I I I \ I I Cl 70.0 I I I I I -1-:-I -~ ~ i---r,-,-I ~ -~ ~ -~ C: \ "iii I I I I I I I VI I I I I I I I ftl I I I I I I : \ I D. 60.0 1, 1, I I 1, ' ' 'E I I I I I I I \ I GI I I I I I I I \ I (,) I I I I I I I ' ... I I I I I I I ' I I GI 50.0 D. I I I I I I I I I I I I I I I I \ I I I I I I I I I 40.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 30.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I 20.0 I I I I I I I I I I I I I I I I I I I I I I 10.0 I I I I I I I C I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0.0 100 10 1 0.1 0.01 0.001 [ Grain Size (mm) Gravel Sa nd [ Silt or Clay Coarse I Fine Coarse! Medium Fine [ Sample Location: B-4 I Depth (ft): [ 0-5 USCS Soil Type: SM I Passing No. 200 (%): 40 [ I [ '~\ GRADATION ANALYSIS TEST RESULTS I .R FU.SION SITE IMPROVEMENTS [ NOVA 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA 4373 VIEWRIDGE AVENUE, SUITE B I SAN DIEGO, CALIFORNIA C BY:CLS DATE: NOV 2019 PROJECT: 20191 95 APPENDIX: C.4 PHONE: 858-292-7575 FAX: 858-292-7570 n - [ [ <E---Size (Inches) --3►::::: --Hydrometer Analysis ~ [ U.S. Standard Sieve Sizes ,,~ , 0 0 ~ 0 0 ~ 0 "< :!!: ~ !!:! .., ct) (') "' N ~ ~ (') (') 0 ~ 0 0 0 0 0 100.0 z z z z z -... i-,1-, [ I I I I I r----I I I I I I I I 'I I I I I I I I I \ I I 90.0 I I I I I I --\ I I I I I I I I I I I I I I I I \ I I I I I I I I I I [ I I I I I I I I 80.0 -1---~ 1--1----I-I ---1--1 ,_ ~ \-1 - I I I I I I \ I I I I I I I I ~ I I I I I I I I Cl 70.0 I I I I I I I C: [ "iii I I I I I I I\ I "' I I I I I I I \ I cu I I I I I I I \ I c.. 60.0 I, I, ' ' I, ' ' ' "E I I I I I I I I QI I I I I I I I I [ u I I I I I I I I ... I I I I I I I 1,, QI 50.0 c.. I I I I I I I I I I I I I I I I I I I I I I 40.0 I I I I I I I I [ II II I I II I I l I I I I I I I I I I I I I I I I I I I I I I I I 30.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 20.0 I I I I I I I I I I I I I I I I I I I I I I I I 10.0 I I I I I I I I I I I I I I I I I I I I I I I: I I I I I I I I I I I I I I I I 0.0 100 10 1 0.1 0.01 0.001 Grain Size (mm) Gravel Sand Silt or Clay Coarse Fine Coarse Medium Fine Sample Location: 8-4 [ Depth (ft): 5-10 USCS Soil Type: SC-SM Passing No. 200 (%): 47 [ [ '~\ GRADATION ANALYSIS TEST RESULTS l■~ FU.SION SITE IMPROVEMENTS NOVA 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA 4373 VIEWRIDGE AVENUE, SUITE B SAN DIEGO, CALIFORNIA BY:CLS DATE: NOV 2019 PROJECT: 2019195 APPENDIX: C.5 PHONE: 858-292-7575 FAX: 858-292-7570 [ [ <E--Size (Inches) ~::: U.S. Standard Sieve Sizes ' , Hydrometer Analysis ' , ' , 0 ~ 0 ~ 0 ~ :,;!: ;! CD ..,. CD .., "' ~ ~ .., ;;; g ci ci ci ci ci 100.0 z z z z z --• I I I I I I I I I I I I I I I I I I I I 90.0 I I I I I I I I I I I I I I I I I I I I I I I I I ' I I I I I I I I I 80.0 ~ I I I I I \ I I I I I I I I I I I I I I I I Cl 70.0 I I I I I I I C: I ·1 I I' ·u; I I I I I I I Cl) I I I I I I I ra I I I I I ,,, I I Q. 60.0 1, c I I I I I I ' I I I I I I I I I Cl) I I I I I ,. I I u ... I I I I I ' I I Cl) 50.0 Q. I I I I I --+-I I I I I I I I I I I I 40.0 I I I I I I I 11 I I I I I I 11 I I I I I I I I I I I I I I I I I I I I I 30.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I 20.0 I I I I I I I I I I I I I I I I I I I I I 10.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0.0 100 10 1 0.1 0.01 0.001 Grain Size (mm) I Gravel Sand Silt or Clay Coarse I Fine Coarse! Medium Fine Sample Location: P-2 I Depth (ft): i 13-18 uses Soil Type: SC-CL Passing No. 200 (%): 44 I [ '~\ GRADATION ANALYSIS TEST RESULTS .R FU.SION SITE IMPROVEMENTS NOVA 1950 CAMINO VIDA ROBLE CARLSBAD, CALIFORNIA 4373 VIEWRIDGE AVENUE, SUITE B SAN DIEGO, CALIFORNIA BY:CLS DATE: NOV 2019 PROJECT: 2019195 APPENDIX: C.6 PHONE: 858-292-7575 FAX: 858-292-7570 Geotechnical Update Report fu ·sion Site Improvements, 1950 Camino Vida Roble, Carlsbad, California NOVA Project 2019195 APPENDIX D INFILTRATION FEASIBILITY DOCUMENTS November 5, 2019 Appendix I: Forms and Checklists ► \ I ,-_:. .... • -,_ •; 1-• - : Categorization of Infiltration Feasi}?ility Form 1-8 ,, , Condition ( r • ..,_ -• '... -• _•__ ~• Part 1 -Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Yes No X The infiltration rate of the existing soils for location P-1 based on the on-site infiltration study was calculated to be less than 0.5 inches p er hour (P-1=0.03 inches per hour) after apply ing a minimum factor of safety (F) of F=2. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Q uestion shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: No. See Criterion 1. X Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 1-3 February 2016 Appendix I: Forms and Checklists , ' -: i -•----=-. --. . -. -..,.. • ; -::.,: ~~ --'T. .. ~ . --~.. 9"t"'i :: .. Form 1-8 Page 2 of 4· ; · -·. 1- ,.... .. • • -• .... ! _.. Criteri a 3 Screening Question Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Water contamination was not evaluated by NOVA Services. Yes No Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: The potential for water balance was not evaluated by NOVA Services. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 Result * If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration If any answer from row 1-4 is "No", infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a "full infiltration" design. Proceed to Part 2 Proceed to Part 2 *To be completed usmg gathered site 1nformat1on and best professional Judgment cons1denng the definition of i\IBP 1n the MS4 Permit. Additional testing and/ or studies may be required by the City to substantiate findings. 1-4 February 2016 Appendix I: Forms and Checklists Part 2 -Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria 5 Screening Question Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Yes No X The infiltration rate of the existing soils for location P-1 based on the on-site infiltration study was calculated to be less than 0.5 inches per hour (P-1 =0. 03 inches per hour) after applying a minimum factor of safety (F) of F=2. These widespread very low permeability soils and geologic conditions do not allow for infiltration in any appreciable rate or volume. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: C2. I A geologic investigation was performed at the subject site. X C2.2 Settlement and volume change due to water infiltration is possible due to the expansive soils underlying the site. C2.3 Infiltration has the potential to cause slope failures. BMPs are to be sited a minimum of 50 feet away from any slope or the BMP design should implement an impermeable liner. C2. 4 BMPs are to be sited a minimum of 10 feet away from all underground utilities. C2. 5 Stormwater infiltration can result in damaging ground water mounding during wet periods. Due to the low infiltration rates, this site is at a high risk. C2. 6 Infiltration has the potential to increase lateral pressure and reduce soil strength which can impact foundations and retaining walls. BMPs are to be sited a minimum of IO feet away from any foundations or retaining walls. C2. 7 Other Factors: Based on the low infiltration rates, high risk for groundwater mounding, and clayey soils underlying the site, infiltration is not feasible. 1-5 February 2016 Appendix I: Forms and Checklists ---~ -... -":..-' . Form _1-:8 P~ge 4 of 4 _ . .. .. . ,. . {, Criteria 7 Screening Question Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Water contamination was not evaluated by NOVA Services. Yes No Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: The potential for water balance was not evaluated by NOVA Services. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. Part 2 Result* If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration. If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. No Infiltration *To be completed using gathered site information and best professional judgment constdenng the defininon of MEP m the MS4 Permit. Additional testing and/ or studies may be required by the City to substantiate findings. 1-6 February 2016