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Geotechnical Engineering Report HDR VA Stockton – Off-Site Utilities Veterans Administration Project French Camp, California

Prepared for:

HDR Architecture, Inc. c/o Allegiance Group, LLC Attn: Connie Latour 1500 D Street Vancouver, Washington 98663

September 2015 PBS Project No. 21595.017

Allegiance Project No. 201422

September 23, 2015

HDR VA Stockton – Off-Site Utilities Veterans Administration Project French Camp, California

Prepared for: HDR Architecture, Inc. c/o Allegiance Group, LLC Attn: Connie Latour 1500 D StreetVancouver, Washington 98663

Prepared by:

Ryan White, PE (CA), GE (OR) Senior Project Engineer

Reviewed by:

Arlan H. Rippe, PE (OR), GE (OR), D.GE Senior Geotechnical Consultant

This document was prepared for use only by the Client, only for the purposes stated, and within a reasonable time from issuance,but in no event later than three years from the date of the report. Non-commercial, educational, and scientific use of this report by regulatory agencies is regarded as a “fair use” and not a violation of copyright. Regulatory agencies may make additional copies of this document for internal use. Copies may also be made available to the public as required by law. The reprint must acknowledgethe copyright and indicate that permission to reprint has been received.

9/30/17

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Geotechnical Engineering Report HDR VA Stockton – Off-Site Utilities French Camp, California

PBS Project No. 21595.017

Allegiance Project No. 201422 September 23, 2015

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TABLE OF CONTENTS

1.0 INTRODUCTION ......................................................................................................................... 1 1.1 General ................................................................................................................................ 1 1.2 Project Understanding .......................................................................................................... 1 1.3 Field Explorations ................................................................................................................. 1 1.4 Laboratory Testing ............................................................................................................... 1

2.0 SITE CONDITIONS ..................................................................................................................... 1 2.1 Surface Description .............................................................................................................. 1 2.2 Geologic Setting ................................................................................................................... 1 2.3 Subsurface ........................................................................................................................... 2

2.3.1 Field Explorations ........................................................................................................... 2 2.3.2 Subsurface Conditions ................................................................................................... 2 2.3.3 Groundwater ................................................................................................................... 3

3.0 CONCLUSIONS AND RECOMMENDATIONS ........................................................................... 3 3.1 Discussion ............................................................................................................................ 3

4.0 CONSTRUCTION CONSIDERATIONS ...................................................................................... 3 4.1 Site Preparation ................................................................................................................... 3

4.1.1 Wet-Weather/Wet-Soil Conditions .................................................................................. 3 4.2 Groundwater Control ............................................................................................................ 4 4.3 Excavation ............................................................................................................................ 4 4.4 Structural Fill ........................................................................................................................ 4

4.4.1 Imported Granular Material ............................................................................................ 5 4.4.2 Trench Backfill ................................................................................................................ 5 4.4.3 Stabilization Material ...................................................................................................... 5 4.4.4 Pavement Base Aggregate ............................................................................................ 5

5.0 CONSTRUCTION OBSERVATIONS .......................................................................................... 6 6.0 LIMITATIONS .............................................................................................................................. 6 7.0 REFERENCES ............................................................................................................................ 7




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SUPPORTING DATA

Figures

Figure 1 Vicinity Map Figure 2 Site Plan

Appendix A – Field Explorations

Table A-1 Terminology Used to Describe Soil Table A-2 Key to Test Pit and Boring Log Symbols Figures A1-A6 Logs for Borings B-1 through B-6

Appendix B – Laboratory Tests

Figure B1 Atterberg Limits Test Results Figure B2 Particle-Size Analysis




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1.0 INTRODUCTION

1.1 General This report presents the results of the Allegiance Group, LLC (Allegiance), supported by PBS Engineering and Environmental Inc. (PBS), geotechnical explorations for the proposed water and sewer lines for the VA French Camp site located in Stockton, California. A Vicinity Map is provided on Figure 1.

1.2 Project Understanding Allegiance understands that the project will include construction of new sanitary sewer and water lines to provide service to the French Camp VA facility. The approximate alignments are shown on Figure 2, Site Plan. The new sanitary sewer will be installed in the right-of-way (ROW) of French Camp Road, heading east, starting at the intersection of Wolfe Road and Manthey Road, where it will extend approximately 2,000 feet south to the VA site. The sanitary line will be installed to depths of up to 25 to 30 feet below the existing ground surface (bgs). The water line will be installed within the ROW for Yettner Road, starting approximately 1,800 feet west of the intersection with Manthey Road and extending approximately 1,300 feet south from that same intersection. The proposed new water line will be installed to a depth of 5 to 6 feet bgs. 1.3 Field Explorations Six borings were drilled to depths between 21.5 and 41.5 feet bgs at the approximate locations shown on Figure 2. The borings were advanced by Woodward Drilling of Rio Vista, California, using a truck-mounted drill rig and hollow-stem auger techniques. 1.4 Laboratory Testing Laboratory tests included natural moisture contents, grain-size (sieve) analyses, and Atterberg limits testing on selected samples. Results are included on the boring logs presented in Appendix A. Detailed laboratory test results are included in Appendix B.

2.0 SITE CONDITIONS

2.1 Surface Description The proposed sewer and water lines will be constructed along French Camp, Manthey, and Yettner Roads in Stockton and unincorporated San Joaquin County, California. The area is essentially flat-lying at an elevation of approximately 13 to 17 feet above mean sea level (AMSL), with a very gentle slope to the northeast, toward the San Joaquin River. A housing subdivision is north of the project area. The rest of the area is predominantly agricultural with related farm buildings. The VA facility is located south of the project area. 2.2 Geologic Setting The subject property is located within the Central Valley of California. The Central Valley is bounded by the Southern Coast Range to the west and the Sierra Nevada Range to the east; the mountain ranges were elevated by accretion, faulting, and volcanic processes. Subsequent erosion of the ranges has filled the valley with thick deposits of alluvium. The Central Valley comprises the Sacramento Valley to the north and the San Joaquin Valley to the south; the two valleys are separated by the Sacramento-San Joaquin River Delta. The site is located near the southern extent of the Sacramento-San Joaquin River Delta. The San Joaquin River is approximately 2 miles west of the site.




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The project site geology is mapped as Pleistocene-age Modesto Formation (Atwater, 1982). Atwater describes the Modesto Formation as consisting of aeolian, loose sands and alluvial loose sand and silt. Geologic mapping by Bartow (1991) suggests that the Modesto Formation in the vicinity of the site is roughly 300 feet thick and lies atop the Great Valley sequence. The Great Valley sequence is described as Tertiary- to Jurassic-age sedimentary rock, serpentinite, and blueschist. 2.3 Subsurface

2.3.1 Field Explorations Six borings were drilled to depths between 21.5 and 41.5 feet bgs at the approximate locations shown on Figure 2. The borings were advanced by Woodward Drilling of Rio Vista, California, using a truck-mounted drill rig. Hollow-stem auger methods were used for all borings. The subsurface materials encountered were logged and field classified in general accordance with the Manual-Visual Classification Method (ASTM D 2488). In the borings, in-situ standard penetration tests (SPT, ASTM D 1586) were performed at regular 5.0- and 10.0-foot intervals in B-1 and penetration testing using a Modified California (CalMod) sampler (2.5-inch O.D.; 2.0-inch I.D.) was completed at the remainder of the sample locations. Consistencies and relative densities were based on equivalent SPT N-values developed by multiplying the field N-values for the CalMod sampler by 0.64. The N-values reported on the logs in Appendix A are the uncorrected field blow counts. Disturbed soil samples were collected using a split-spoon sampler and packaged in moisture-tight bags. The borings were backfilled with grout in accordance with local regulations. San Joaquin County Environmental Health Department personnel waived observation of the grout backfill. The soil samples were re-examined in the laboratory to supplement field classifications. Interpreted boring logs are provided in Appendix A. 2.3.2 Subsurface Conditions In general, subsurface conditions encountered in the borings consist of alluvium (silt, sand, and clay) to the termination depth in all of the borings. A summary of the encountered units is described below. PAVEMENT SECTION:

Where borings were advanced through existing asphalt concrete (AC) pavement (B-3 through B-6), the AC ranged from 5 to 7 inches thick and was underlain by 12 to 18 inches of crushed rock base course (CRBC) in B-3 and B-4, and 5 to 6 inches of CRBC at B-5 and B-6.

DISTURBED GROUND:

Where borings were advanced adjacent to the existing roadway and pavement surfacing (B-1 and B-2), the ground surface was disturbed from adjacent agricultural use and consisted of dry, very loose to loose, brown, silty fine sand to a depth of approximately 3 feet bgs.

ALLUVIUM: The alluvium consists of alternating layers of coarse-grained

and fine-grained soils. The course-grained alluvium consists of very loose to dense, fine sand with silt to medium sand. The




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fine-grained alluvium ranges from medium stiff to hard clay to fine, sandy silt. The sands encountered were typically fine-grained, with some medium-grained sand.

2.3.3 Groundwater Groundwater was not measured directly due to the need to backfill the borings while the augers were extruded. Groundwater was interpreted at depths of 24 to 28 feet bgs in the borings based on the observation of free-moisture in the samples at or below those depths. Perched groundwater was typically encountered where sandy soils overlaid less permeable, clayey soils, and did not appear to represent regional groundwater based on the moisture of the underlying soils. Based on mapping completed as part of the California Statewide Groundwater Elevation Monitoring (CASGEM) program between the spring of 2011 and 2015, groundwater depths along French Camp road in the vicinity of the project area are shown as generally between depths of 15 and 25 feet bgs. Monitoring occurs twice per year, during the spring and fall. The depths are generally shallower at the west end of the project, becoming deeper to the east.

3.0 CONCLUSIONS AND RECOMMENDATIONS

3.1 Discussion Subsurface explorations encountered along the proposed utility alignments generally consist of clay, silt, and sand to the proposed depth of excavation. These soils were generally stiff to hard where fine-grained soils were encountered and loose to medium dense where granular soils were encountered. These materials are relatively easily excavated using conventional earthwork equipment. Groundwater was observed at depths below about 24 feet at the time of exploration. This depth could vary along the alignment and in response to season, weather, irrigation, and pumping in the vicinity of the proposed project. Consideration should be given to controlling groundwater, which will probably be encountered during construction. Excavation below groundwater where sandy soils are present could result in flowing conditions and should be avoided. Conventional shoring, including slide rail or similar systems, is well suited for use in maintaining soil support during excavation of the proposed trenches. Due to the location of the trenches in the existing roadway ROW, open-excavation techniques are not likely feasible.

4.0 CONSTRUCTION CONSIDERATIONS

4.1 Site Preparation Preparation for construction of off-site utilities will likely include saw cutting through the existing pavement section and removal of the pavement and associated aggregate base rock within a minimum of 2 feet from the edge of new trench excavations. Materials generated during demolition of existing pavement sections should be transported off-site or stockpiled in areas designated by the Owner.

4.1.1 Wet-Weather/Wet-Soil Conditions Due to the presence of silt and clay or soils containing silt and clay, trafficability on the near-surface soils may be difficult during or after extended wet periods, or when the




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moisture content of the surface soil is more than a few percentage points above optimum. Soils that have been disturbed during site preparation activities, or soft or loose zones, should be removed and replaced with stabilization material. Protection of the subgrade is the responsibility of the contractor. Construction of granular haul roads may help reduce further damage to the pavement and disturbance of site soils. The thickness of the granular material for haul roads and staging areas will depend on the amount and type of construction traffic. The actual thickness of haul roads and staging areas should be based on the contractors’ approach to site development, and the amount and type of construction traffic. The stabilization material should be placed in one lift over the prepared, undisturbed subgrade and compacted using a smooth-drum, non-vibratory roller. Additionally, a geotextile fabric should be placed as a barrier between the subgrade and stabilization material. The geotextile should meet the Standard Specifications, State of California, Department of Transportation – 2010 (Caltrans 2010) 88-1.02O – Subgrade Enhancement Geotextile. The geotextile should be installed in conformance with Caltrans 19-8 – Subgrade Enhancement Geotextile.

4.2 Groundwater Control It is possible that utility trench excavations may extend into groundwater. We recommend that the type and design of the dewatering system be the responsibility of the contractor, who is in the best position to choose a system that fits the overall plan of operation.

4.3 Excavation Our understanding is that the new sewer and water lines will be constructed in the existing road ROW to depths of 5 to 6 feet for the water line and 25 to 30 feet bgs for the sanitary sewer. Therefore, open excavation techniques are not likely feasible and some form of shoring will likely be used to support the soil and overlying roadway. Use of temporary shoring is recommended for cuts extending below groundwater seepage or if vertical walls are desired for cuts deeper than four feet. Please note that groundwater was observed in the sand layers at a depth of 26 feet bgs in most of the explorations at the time of exploration. If shoring or dewatering is used, the type and design of the shoring and dewatering systems should be the responsibility of the contractor and should be made in accordance with applicable Occupational Safety and Health Administration and State regulations. Subsurface conditions at the project site consist of predominately alluvial deposits of clay, silt, and sand to the proposed excavation depths. Excavations in these soil-types can be accomplished with conventional earthwork equipment. 4.4 Structural Fill Fills should be placed over subgrade that has been prepared in conformance with the Site Preparation and Wet-Weather/Wet-Soil Conditions sections of this report. A wide range of material may be used as structural fill; however, all material used should be free of organic matter or other unsuitable materials and should meet the specifications provided in the Caltrans 2010, depending on the application. A brief characterization of some of the acceptable materials and our recommendations for their use as structural fill is provided below.




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4.4.1 Imported Granular Material Imported granular material used during periods of wet weather or for haul roads, staging areas, etc., should be pit or quarry run rock, crushed rock, or crushed gravel and sand, and should meet the specifications provided in Caltrans 19-7– Borrow Material. However, the imported granular material should also be fairly well graded between coarse and fine and have less than 5 percent by weight passing the US Standard No. 200 Sieve. Imported granular material should be placed in lifts with a maximum uncompacted thickness of 8 to 12 inches and be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557 (modified Proctor). During the wet season or when wet subgrade conditions exist, the initial lift should be approximately 18 inches in uncompacted thickness and should be compacted by rolling with a smooth-drum roller without using vibratory action. Where imported granular material is placed over soft-soil subgrades, we recommend a geotextile be placed as a barrier between the subgrade and imported granular material. Depending on site conditions, the geotextile should meet Caltrans 88-1.02O–Subgrade Enhancement Geotextile. The geotextile should be installed in conformance with Caltrans 19-8-Subgrade Enhancement Geotextile. 4.4.2 Trench Backfill Trench backfill placed beneath, adjacent to, and for at least 1 foot above utility lines (i.e., the pipe zone), should consist of well-graded granular material with a maximum particle size of 1 ½ inches and less than 10 percent by weight passing the US Standard No. 200 Sieve, and should meet the standards prescribed by Caltrans Division VII, Drainage, for the type of pipe specified. The pipe zone backfill should be compacted to at least 90 percent of the maximum dry density, as determined by ASTM D 1557, or as required by the pipe manufacturer or local jurisdiction. The remainder of the trench backfill should consist of well-graded granular material with a maximum particle size of 2 ½ inches, less than 10 percent by weight passing the US Standard No. 200 Sieve, and should meet the requirements for specific surface loading or other criteria of the backfill zone. This material should be compacted to at least 92 percent of the maximum dry density, as determined by ASTM D 1557, or as required by the pipe manufacturer or local jurisdiction. The upper 3 feet of the trench backfill should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM D 1557. 4.4.3 Stabilization Material Stabilization rock should consist of imported granular material that is well-graded, angular, crushed rock consisting of 4- or 6-inch-minus material with less than 2 percent passing the US Standard No. 4 Sieve. The material should be free of organic matter and other deleterious material. 4.4.4 Pavement Base Aggregate Imported granular material used as aggregate base course (base-rock) along roadway alignments should be relatively clean, crushed rock or crushed gravel and sand that is




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fairly well-graded between coarse and fine. The base aggregate should meet the gradation defined in Caltrans 26-Aggregate Bases, depending upon application. The base aggregate should be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557.

5.0 CONSTRUCTION OBSERVATIONS

Satisfactory earthwork performance depends on the quality of construction. Sufficient observation of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. We recommend that a qualified geotechnical representative be retained to observe general excavation, trench backfill placement and compaction, temporary shoring, and subgrades and aggregate base course for pavements. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. This is important since variable material is present throughout the site. Recognition of changed conditions requires experience; therefore, a geotechnical engineer or their representative should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipated. 6.0 LIMITATIONS

This report has been prepared for the exclusive use of the addressee, and their architects and engineers, for aiding in the design and construction of the proposed development and is not to be relied upon by other parties. It is not to be photographed, photocopied, or similarly reproduced, in total or in part, without express written consent of the Client and Allegiance. It is the addressee's responsibility to provide this report to the appropriate design professionals, building officials, and contractors to assure correct implementation of the recommendations. The opinions, comments, and conclusions presented in this report are based upon information derived from our literature review, field explorations, and laboratory testing. Conditions between, or beyond, our explorations may vary from those encountered. If soil, rock, or groundwater conditions encountered during construction differ from those described herein, the Client is responsible for ensuring that Allegiance is notified immediately so that we may reevaluate the recommendations of this report. Unanticipated soil and rock conditions and seasonal soil moisture and groundwater variations are commonly encountered and cannot be fully determined by merely taking soil samples or borings. Such variations may result in changes to our recommendations and may require additional funds for expenses to attain a properly constructed project. Therefore, we recommend a contingency fund to accommodate such potential extra costs. The scope of services for this subsurface exploration and geotechnical report did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site. If there is a substantial lapse of time between the submission of this report and the start of work at the site, if conditions change due to natural causes or construction operations at or adjacent to the site, or if the basic project scheme is significantly modified from that assumed, this report should be reviewed to determine the applicability of the conclusions and recommendations presented herein. Land use, site conditions (both on- and off-site), or other factors may change over time and could materially affect our findings. Therefore, this report should not be relied upon after three years from its issue, or in the event that the site conditions change.




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7.0 REFERENCES

Atwater, Brian F., (1982). Geologic maps of the Sacramento – San Joaquin Delta, California, US

Geological Survey Miscellaneous field studies Map 1401, Sheet 17 of 21 sheets. Bartow, J. Alan (1991). The Cenozoic Evolution of the San Joaquin Valley, California, U. S.

Geological Survey Professional Paper 1501, 40 pp, 2 pl. Caltrans (2010). Standard Specifications, State of California, Business, Transportation and Housing

Agency, Department of Transportation.

FIGURES

VICINITY MAPFIGURE

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APPENDIX A Field Exploraitons




A-1

APPENDIX A – FIELD EXPLORATIONS A1.0 GENERAL

Allegiance explored subsurface conditions at the project site by advancing six borings on March 9 and 10, 2015. The approximate locations of the explorations, designated B-1 through B-6, are shown on Figure 2. The procedures and techniques used to advance the borings, collect samples, and other field techniques are described in detail in the following paragraphs. Unless otherwise noted, all soil sampling and classification procedures followed applicable ASTM standards. A2.0 Borings

A2.1 Drilling

The borings were advanced to depths of about 21.5 to 41.5 feet bgs using hollow stem auger techniques with a truck-mounted drill rig provided and operated by Woodward Drilling of Rio Vista, California. The borings were observed by a member of the Allegiance geotechnical engineering staff, who maintained a detailed log of the subsurface conditions and materials encountered during the course of the work. A2.2 Sampling

Disturbed soil samples were taken in the borings at selected depth intervals. The samples were obtained using both a standard two-inch outside diameter (OD), split-spoon (SS) sampler and a Modified California (CalMod) sampler following procedures prescribed for the Standard Penetration Test (SPT). Using the SPT, the sampler is driven 18 inches into the soil using a 140-pound hammer dropped 30 inches. The number of blows required to drive the sampler the last 12 inches is defined as the standard penetration resistance (N-value). The N-value provides a measure of the relative density of granular soils such as sands and gravels, and the consistency of cohesive soils such as clays and plastic silts. N-values for the CalMod sampler can be converted to equivalent SPT N-values by multiplying them by 0.64. The disturbed soil samples were examined by the Allegiance geotechnical engineering staff member and then sealed in plastic bags for further examination and physical testing in a soils laboratory. A2.3 Boring Logs

The logs in the attached Appendix A, Field Explorations, show the various types of materials that were encountered in the borings and the depths where the materials and/or characteristics of these materials changed, although the changes may be gradual. Where material types and descriptions changed between samples, the contacts were interpreted. The types of samples taken during drilling, along with their sample identification number, are shown to the right of the classification of materials. The N-value, natural water (moisture) contents, and Atterberg Limits are shown further to the right. Groundwater interpretations and the dates of the observations are plotted in the column to the right. The groundwater observations are only for the dates shown and probably vary from time to time during the year.

A4.0 MATERIAL DESCRIPTION

Initially, soil samples were classified visually in the field. Consistency, color, relative moisture, degree of plasticity, and other distinguishing characteristics of the soil samples were noted. Afterward, the samples were re-examined, various standard classification tests were conducted, and the field classifications were modified where necessary. The terminology used in the soil classifications and other modifiers are defined in Table A-1 - Terminology Used to Describe Soil.

Table A-1

Terminology Used to Describe Soil 1 of 2

Soil Descriptions Soils exist in mixtures with varying proportions of components. The predominant soil, i.e., greater than 50 percent based upon total dry weight, is the primary soil type and is capitalized in our log descriptions, e.g., SAND, GRAVEL, SILT or CLAY. Lesser percentages of other constituents in the soil mixture are indicated by use of modifier words in general accordance with the Visual-Manual Procedure (ASTM D2488-06). “General Accordance” means that certain local and common descriptive practices have been followed. In accordance with ASTM D2488-06, group symbols (such as GP or CH) are applied on that portion of the soil passing the 3-inch (75mm) sieve based upon visual examination. The following describes the use of soil names and modifying terms used to describe fine- and coarse-grained soils. Fine - Grained Soils (More than 50% fines passing 0.075 mm, #200 sieve) The primary soil type, i.e. SILT or CLAY is designated through visual – manual procedures to evaluate soil toughness, dilatency, dry strength, and plasticity. The following describes the terminology used to describe fine - grained soils, and varies from ASTM 2488 terminology in the use of some common terms.

Primary soil NAME, adjective and symbols Plasticity Description

Plasticity Index (PI)

SILT ML & MH

CLAY CL & CH

ORGANIC SILT & CLAY

OL & OH

SILT Organic SILT Non-plastic 0 - 3 SILT Organic SILT Low plasticity 4 - 10

SILT / Elastic SILT

Lean CLAY Organic clayey SILT Medium Plasticity 10 – 20

Elastic SILT Lean/Fat CLAY Organic silty CLAY High Plasticity 20 – 40 Elastic SILT Fat CLAY Organic CLAY Very Plastic >40

Modifying terms describing secondary constituents, estimated to 5 percent increments, are applied as follows:

Description % Composition With sand; with gravel

(combined total greater than 15% but less than 30%, modifier is whichever is greater)

15% to 25%

Sandy; or gravelly (combined total greater than 30% but less than

50%, modifier is whichever is greater) 30% to 50%

Borderline Symbols, for example CH/MH, are used where soils are not distinctly in one category or where variable soil units contain more than one soil type. Dual Symbols, for example CL-ML, are used where two symbols are required in accordance with ASTM D2488. Soil Consistency. Consistency terms are applied to fine-grained, plastic soils (i.e., PI > 7). Descriptive terms are based on direct measure or correlation to the Standard Penetration Test N-value as determined by ASTM D1586-84, as follows. Note, SILT soils with low to non-plastic behavior (i.e. PI < 7) are classified using relative density.

Consistency Term SPT N-value Unconfined Compressive Strength

tsf kPa Very soft Less than 2 Less than 0.25 Less than 24

Soft 2 – 4 0.25 - 0.5 24 - 48 Medium stiff 5 – 8 0.5 - 1.0 48 – 96

Stiff 9 – 15 1.0 - 2.0 96 – 192 Very stiff 16 – 30 2.0 - 4.0 192 – 383

Hard Over 30 Over 4.0 Over 383

Table A-1

Terminology Used to Describe Soil 2 of 2

Soil Descriptions Coarse - Grained Soils (less than 50% fines) Coarse-grained soil descriptions, i.e., SAND or GRAVEL, are based on that portion of materials passing a 3-inch (75mm) sieve. Coarse-grained soil group symbols are applied in accordance with ASTM D2488-06 based upon the degree of grading, or distribution of grain sizes of the soil. For example, well graded sand containing a wide range of grain sizes is designated SW; poorly graded gravel, GP, contains high percentages of only certain grain sizes. Terms applied to grain sizes follow.

Material Particle Diameter Inches Millimeters

Sand (S) 0.003 - 0.19 0.075 - 4.8 Gravel (G) 0.19 - 3.0 4.8 - 75

Additional Constituents Cobble 3.0 - 12 75 - 300 Boulder 12 - 120 300 - 3050

The primary soil type is capitalized, and the amount of fines in the soil are described as indicated by the following examples. Other soil mixtures will provide similar descriptive names.

Example: Coarse-Grained Soil Descriptions with Fines

5% to less than 15% fines (Dual Symbols)

15% to less than 50% fines

GRAVEL with silt, GW-GM Silty GRAVEL: GM SAND with clay, SP-SC Silty SAND: SM

Additional descriptive terminology applied to coarse-grained soils follow.

Example: Coarse-Grained Soil Descriptions with Other Coarse-Grained Constituents

Coarse-Grained Soil Containing Secondary Constituents

With sand or with gravel > 15% sand or gravel With cobbles; with boulders Any amount of cobbles or

boulders. Cobble and boulder deposits may include a description of the matrix soils, as defined above. Relative Density terms are applied to granular, non-plastic soils based on direct measure or correlation to the Standard Penetration Test N-value as determined by ASTM D1586-84.

Relative Density Term SPT N-value Very loose 0 - 4

Loose 5 - 10 Medium dense 11 - 30

Dense 31 - 50 Very dense > 50

Key To Test Pit and Boring Log Symbols

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LOG GRAPHICS

Geotechnical Testing/Acronym Explanations

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raehS tceriDSDP200 Percent Passing U.S. Standard No. 200 Sieve

htgnertS evisserpmoC denifnocnUCUtimiL yticitsalPLP ecafrus dnuorg woleBsgbxednI yticitsalPIP leveL aeS naeMLSM

timiL diuqiLLL

HYD Hydrometer Gradation

1Note: Details of soil and rock classification systems are available on request. Rev. 02/23/15

Lithology Boundary - separates distinct units(i.e. Fill, Alluvium, Bedrock Fm) (at approx.depth indicated)

Soil-Type or Material-TypeChange Boundary - separateschanges in soil-type and material-type within the samelitholgic unit (at approx.depth indicated)

SamplerType

SampleRecovery Sample

Interval

Instrumentation Detail Sampling SymbolsSoil and Rock

Well Pipe

Piezometer

Piezometer

Ground Surface

Well Cap

Bottom of Hole

Soi

l or

Roc

k T

ypes

Well Seal

Well Screen

0.0

1.5

8.0

23.0

28.0

Hand-augered to 5 ft bgs

SPT sampler shoe broke on15 ft sample (recovered);continue sampling withModified California Sampler(2.5" OD, 2.0" ID) below 15ft.

Interpreted depth ofgroundwater

Disturbed ground

Very stiff to hard light gray-brown SILT (ML);low plasticity; weakly cemented; dry

Stiff to very stiff light brown SILT (ML); lowplasticity; uncemented; moist

Very stiff tan with brown and black spots SILT(ML) with sand; low plasticity; moderatelycemented; wet

Very stiff tan SILT (ML) with sand; low plasticity;uncemented; wet

0 50 100

CORE REC%RQD% MOISTURE CONTENT %

DYNAMIC CONE PENETROMETER

BLOW COUNT

DE

PT

H INSTALLATION ANDCOMMENTS

1500 D StreetVancouver, WA 98660Phone: 360.334.4727

GR

AP

HIC

LOG

DRILLED BY: Woodward DrillingLOGGED BY: B. Portwood

DRILLING METHOD: Hollow-Stem Auger

MATERIAL DESCRIPTION

SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-1

TE

ST

ING

DEPTHFEET

French Camp RoadAPPROX. BORING B-1 LOCATION:

Page 1 of 2FIGURE A1

LOGGING COMPLETED: 3/09/15HAMMER EFFICIENCY PERCENT:BIT DIAMETER: 8 inches

HDR VA STOCKTONSTOCKTON, CALIFORNIA

NOTE: Lines representing the interface between soil/rock units ofdiffering description are approximate only, inferred wherebetween samples, and may indicate gradual transition.

Surface Conditions: Sand fill, weeds

ALLEGIANCE PROJECT NUMBER:201422.000

BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

23-50/5"

S-1

S-2

S-3

S-4

S-5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

20

20

24

28

33.0

41.5

P200 = 60%

P200 = 61%

Very stiff tan SILT (ML) with sand; low plasticity;uncemented; wet

Stiff to very stiff tan sandy SILT (ML); lowplasticity; wet

Boring complete at 41.5 feet bgs; backfilledwith cement groutGroundwater interpreted at approximately 23feet bgs.

P200

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-1(continued)

TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-6

S-7

S-8

30.0

32.0

34.0

36.0

38.0

40.0

42.0

44.0

46.0

48.0

50.0

52.0

54.0

56.0

58.0

60.0

0 50 100

28

42

18

0.0

1.5

10.5

28.0

Hand-augered to 5 feet bgs

All sampling completed withModified California Sampler(2.5" OD, 2.0" ID)P200 = 29%

Interpreted depth togroundwater

Disturbed ground

Loose light gray-brown silty SAND (SM); finesand; uncemented; dry

becomes moistVery stiff to hard light gray-brown SILT (ML)with sand; low plasticity; weakly cemented; dry

becomes light gray-brown with rust spots

few small (<0.5" diameter) concretions

no concretions, moist

Very stiff light gray-brown CLAY (CH); highplasticity; small pockets of dark brown fine tomedium sand; wet

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-2

TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-1

S-2

S-3

S-4

S-5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

14

37

49

44

30

35.5

40.5

41.5

LL = 54%PL = 25%PI = 29%

Very stiff light gray-brown CLAY (CH); highplasticity; small pockets of dark brown fine tomedium sand; wet

Medium dense to dense orange-brown SAND(SP); fine to medium sand; wet

Very stiff gray SILT (ML); low plasticity; wet

Boring complete at 41.5 feet bgs, backfilledwith cement groutGroundwater interpreted at approximately 28feet bgs.

ATT

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID


TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-6

S-7

S-8

30.0

32.0

34.0

36.0

38.0

40.0

42.0

44.0

46.0

48.0

50.0

52.0

54.0

56.0

58.0

60.0

0 50 100

42

39

31

0.0

0.7

2.0

13.0

19.0

24.0

25.5

27.5

Hand-augered to 5 feet

All sampling completed withModified California Sampler(2.5" OD, 2.0" ID)

P200 = 53%

LL = 45%PL = 19%PI = 26%

Interpreted depth ofgroundwater

Asphalt concrete (8 inches)

Crushed rock fill (16 inches)

Stiff light brown sandy SILT (ML); low plasticity;fine sand; dry

becomes hard

Hard brown-gray SILT (ML); low plasticity;moist

Very stiff light brown-gray CLAY (CL); lowplasticity; moist

Medium dense light brown SAND (SP-SM) withsilt; fine to medium sand; moist to wet

Very stiff to hard gray-brown SILT (ML); lowplasticity; moist

Very stiff to hard gray-brown sandy SILT (ML);low plasticity; fine to medium sand; rapiddilatancy; wet

P200

ATT

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-3

TE

ST

ING

DEPTHFEET

Manthey RoadAPPROX. BORING B-3 LOCATION:





Surface Conditions: Roadway


BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-1

S-2

S-3

S-4

S-5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

16

48

82

41

41

41.5

P200 = 64%

Very stiff gray-brown sandy SILT (ML); lowplasticity; fine to medium sand; rapid dilatancy;wet

becomes dark grayBoring complete at 41.5 feet bgs; backfilledwith cement grout.Groundwater interpreted at approximately 28feet bgs.

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID


TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-6

S-7

S-8

30.0

32.0

34.0

36.0

38.0

40.0

42.0

44.0

46.0

48.0

50.0

52.0

54.0

56.0

58.0

60.0

0 50 100

32

27

32

0.0

0.5

1.5

3.0

9.0

13.0

19.0

20.3

27.5



P200 = 83%

Interpreted depth ofgroundwater (perched)

Asphalt concrete (6 inches)Crushed rock fill (12 inches)

Medium dense brown SAND (SP); fine tomedium sand; dry

Loose to medium dense tan SAND (SP); finesand; dry

Stiff tan SILT (ML) with sand; low plasticity; finesand; dry

Medium dense tan SAND (SP-SM) with silt;fine sand; dry

Stiff to very stiff tan with rust-colored spots SILT(ML); low plasticity; dry

Very stiff light gray-brown SILT (ML) with sand;low plasticity; fine sand; moist

Becomes stiff

Stiff to very stiff light gray-brown CLAY (CL);low plasticity; moist

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-4

TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-1

S-2

S-3

S-4

S-5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

30

15

20

43

27

17

41.5

Stiff to very stiff light gray-brown CLAY (CL);low plasticity; moist

Boring complete at 41.5 feet bgs; backfilledwith cement grout.Perched groundwater interpreted atapproximately 26 feet bgs.

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID


TE

ST

ING

DEPTHFEET








BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-6

S-7

S-8

30.0

32.0

34.0

36.0

38.0

40.0

42.0

44.0

46.0

48.0

50.0

52.0

54.0

56.0

58.0

60.0

0 50 100

22

25

24

0.00.4

0.8

3.5

5.3

10.0

19.0

21.5


All sampling completed withModified California Sampler(2.5" OD, 2.0" ID)P200 = 41%

Asphalt concrete (5 inches)Crushed rock fill (5 inches)Brown fine SAND

FILL

Very loose to loose dark brown SAND (SP-SM)with silt; fine sand; dry, occasional fine organics

Very loose to loose light gray-brown SAND(SP); fine sand; dry

Medium dense light gray-brown SAND(SP-SM) with silt; fine sand; dry

becomes moist

becomes dry

Medium stiff light gray-brown with rust- andwhite-colored spots SILT (ML); low plasticity;moist

Boring complete at 21.5 feet bgs; backfilledwith cement grout.Indications of presence of groundwater notobserved at time of exploration.

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-5

TE

ST

ING

DEPTHFEET

Yettner RoadAPPROX. BORING B-5 LOCATION:







BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-1

S-2

S-3

S-4

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

6

22

21

11

0.0

0.50.8

10.5

13.0

21.5



P200 = 23%

Asphalt concrete (6 inches)Crushed rock fill (4 inches)Loose brown SAND (SP); fine sand; dry

Very stiff light gray-brown with rust-coloredspots SILT (ML); low plasticity; dry

Medium dense light gray-brown silty SAND(SM); fine sand; dry

becomes loose, moist

Boring complete at 21.5 feet bgs; backfilledwith cement grout.Indications of presence of groundwater notobserved at time of exploration.

P200

0 50 100



BLOW COUNT

DE

PT



GR

AP

HIC

LOG




SA

MP

LE T

YP

E

SA

MP

LE ID

BORING B-6

TE

ST

ING

DEPTHFEET

Yettner RoadAPPROX. BORING B-6 LOCATION:







BO

RIN

G L

OG

20

1422

_BO

RIN

GS

_B1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/24

/15:

RW

S-1

S-2

S-3

S-4

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

0 50 100

7

44

31

12

APPENDIX B Laboratory Tests




B-1

APPENDIX B – LABORATORY TESTS B1.0 GENERAL

Samples obtained during the field explorations were examined in the laboratory. The physical characteristics of the samples were noted and the field classifications were modified where necessary. During the course of examination, representative samples were selected for further testing. The laboratory testing program on the soil samples included standard classification tests, which consisted of visual examination, moisture contents, and grain-size analyses. The classification tests yield certain index properties of the soils important to an evaluation of soil behavior. The testing procedures are presented in the following paragraphs. Unless noted otherwise, all test procedures followed applicable ASTM standards. “General accordance” means that certain local and common drilling and descriptive practices and methodologies have been followed. B2.0 CLASSIFICATION TESTS

B2.1 Visual Classification

The soils were classified in accordance with the Unified Soil Classification System with certain other terminology, such as the relative density or consistency of the soil deposits, in general accordance with engineering practice. In determining the soil type (that is, gravel, sand, silt, or clay), the term which best described the major portion of the sample was used. Modifying terminology to further describe the samples is defined in Table A-1 - Terminology Used to Describe Soil in Appendix A.

B2.2 Moisture (Water) Contents

Natural moisture content determinations were made on many samples of the fine-grained soils (that is, silts, clays, and silty sands). The natural moisture content is defined as the ratio of the weight of water to dry weight of soil, expressed as a percentage. The results of the moisture content determinations are presented on boring logs in Appendix A. B2.3 Atterberg Limits

Atterberg limits of select samples were determined for the purpose of classifying soils into various groups for correlation. The results of the Atterberg limits tests, which included liquid and plastic limits, are plotted on the Atterberg Limits Test Results, Figure B1, and included on the boring logs in Appendix A.

B2.4 Particle-Size Analyses

Grain-size analyses (sieves, gradations) and No. 200 washes (P200s) were completed on selected soil samples to determine their grain-size distribution or the portion of soil samples passing the No. 200 Sieve (i.e., silt and clay), respectively. The results of P200 testing are presented on the boring logs in Appendix A. The plots of grain-size distribution are included on Figure B2.

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70 80 90 100 110

CL or OL

ATTERBERG LIMITS TEST RESULTS

CH or OH

CL-ML

MH or OH

LIQUID LIMIT (PERCENT)

PL

AS

TIC

ITY

IN

DE

X (

PE

RC

EN

T)

TEST METHOD: ASTM D4318

"A" LINE

FIGURE B1Page 1 of 1

ML or OL

KEYSAMPLEDEPTH(FEET)

EXPLORATIONNUMBER

NATURAL MOISTURECONTENT(PERCENT)

PERCENT PASSINGNO. 40 SIEVE(PERCENT)

PLASTICLIMIT

(PERCENT)

PLASTICITYINDEX

(PERCENT)

SAMPLENUMBER

LIQUIDLIMIT

(PERCENT)

S-6

S-4

54

45

25

19

29

26

B-2

B-3

30.0

20.0

NA

NA

20

20




AT

TE

RB

ER

G L

IMIT

S

2014

22_B

OR

ING

S_A

LG1-

6.G

PJ

PB

S_D

AT

AT

MP

L_G

EO

.GD

T

P

RIN

T D

AT

E:

9/15

/15:

RW

0

10

20

30

40

50

60

70

80

90

100

0.0010.010.11101001,000

CLAYBOULDERS

MOISTURE CONTENT(PERCENT)

B-1

B-2

B-3

B-5

KEYSAMPLENUMBER

SAMPLE DEPTH(FEET)

40.0

5.0

10.0

5.0

SAND(PERCENT)

4

U.S. STANDARD SIEVE NUMBERS (ASTM E11)3/4" 10 2003" 1 1/2" 100

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

COARSE

PARTICLE-SIZE ANALYSIS TEST RESULTS

MEDIUM SILTCOBBLES

FINECOARSE

0.2

0.10

0.1

39

71

43

59

D50(MM)

D30(MM)

D10(MM)

D5(MM)

GRAVEL(PERCENT)

FINES(PERCENT)

61

29

53

41

0.1

0.09

0.08

PARTICLE-SIZE (MM)

TEST METHOD: ASTM C136

FINE

GRAVEL SAND FINES

EXPLORATIONNUMBER

D60(MM)

3/8" 404 16 30 50

S-8

S-1

S-2

S-1

Page 1 of 1

HDR VA STOCKTONSTOCKTON, CALIFORNIA ALLEGIANCE PROJECT NUMBER:

201422.000


PARTICLE-SIZE ANALYSIS 201422_BORINGS_ALG1-6.GPJ PBS_DATATMPL_GEO.GDT PRINT DATE: 9/15/15:RW

geotechnical engineering report - stocktongov.com

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