Amendment 0002 Attachment - 19-565.1 Sac VA Water System_Final.pdf

Sacramento VA Medical Center – Correct Campus Water System

Mather, California

Prepared By:

Crawford & Associates, Inc.

1100 Corporate Way, Suite 230

Sacramento, CA 95831

Prepared for:

Coleman Engineering, Inc.

1358 Blue Oaks Blvd, Suite 200 Roseville, CA 95678

GEOTECHNICAL REPORT

Corporate Office: 1100 Corporate Drive, Suite 230 | Sacramento, CA 95831 | (916) 455-4225 Modesto: 1165 Scenic Drive, Suite A | Modesto, CA 95350 | (209) 312-7668 Pleasanton: 6200 Stoneridge Mall Road, Suite 330 | Pleasanton, CA 94588 | (925) 401-3515 Rocklin: 4220 Rocklin Road, Suite 1 | Rocklin, CA 95677 | (916) 455-4225 Ukiah: 100 North Pine Street | Ukiah, CA 95482| (707) 240-4400

19-565.1 July 10, 2020

Simon Gray, PE Vice President Coleman Engineering, Inc.

1358 Blue Oaks Blvd, Suite 200 Roseville, CA 95678

Subject: GEOTECHNICAL REPORT

Sacramento VA Medical Center – Correct Campus Water System

Dear Mr. Gray, Crawford & Associates, Inc. (CAInc) prepared this Geotechnical Report for the Sacramento VA Medical Center – Correct Campus Water System project in Mather, California. We prepared this Report in accordance with our October 30, 2019 agreement. This Report is intended to support the design team during design and construction of the proposed water system project.

Thank you for selecting CAInc to be on your design team. Please call with questions.

Sincerely, CRAWFORD & ASSOCIATES, INC., Reviewed by, David P. Castro, PE Benjamin D. Crawford, GE Project Manager Principal Geotechnical Engineer

Hailey Wagenman Project Engineer

GEOTECHNICAL REPORT CAInc Sacramento VA Medical Center – Correct Campus Water System File: 19-565.1 Mather, California July 10, 2020

TABLE OF CONTENTS

1 INTRODUCTION

1.1 PURPOSE

1.2 SCOPE OF GEOTECHNICAL SERVICES

2 PROJECT LOCATION

2.1 SITE DESCRIPTION

2.1.1 TANK AND BOOSTER PUMP SITE

2.1.2 WATERMAIN PIPELINE

2.2 PROPOSED PROJECT

3 SITE GEOLOGY

3.1 GEOLOGIC SETTING

3.2 SITE GEOLOGY

4 SUBSURFACE CONDITIONS

4.1 TEST BORING EXPLORATIONS-TANK AND BOOSTER PUMP SITE

4.2 POTHOLE EXPLORATIONS-WATERMAIN PIPE ALIGNMENT

4.3 SOIL DESCRIPTIONS

4.4 PREVIOUS EXPLORATIONS

4.5 EXISTING FILL

4.6 GROUNDWATER

5 LABORATORY TESTING

6 CORROSION TEST RESULTS

7 SEISMICITY

7.1 2019 CBC SEISMIC DESIGN PARAMETERS

7.2 LIQUEFACTION POTENTIAL AND SEISMICALLY INDUCED SETTLEMENT

8 CONCLUSIONS

9 RECOMMENDATIONS

9.1 GRADING

9.1.1 SOIL EXCAVATABILITY

9.1.2 OVEREXCAVATION

9.1.3 SUBGRADE PREPARATION

9.1.4 FILL AND COMPACTION

9.1.5 OVER-OPTIMUM SOIL MOISTURE

9.2 UTILITY TRENCHES

9.2.1 TRENCH EXCAVATABILITY AND STABILITY

9.2.2 TRENCH BACKFILL

9.2.3 PIPE BEDDING (INITIAL BACKFILL)

9.2.4 HORIZONTAL THRUST BLOCKS

9.3 STEEL GROUND LEVEL WATER TANK FOUNDATION

9.3.1 PERIPHERAL CONCRETE RING FOOTING

9.3.2 SLIDING RESISTANCE

9.3.3 RESISTANCE TO UPLIFT

9.3.4 SETTLEMENT

9.4 BOOSTER PUMP STATION FOUNDATION

9.5 DIESEL FUEL STORAGE AND EQUIPMENT PADS

9.6 ELEVATED STEEL WATER STORAGE TANK FOUNDATION

9.6.1 SPREAD FOOTING

9.6.2 SLIDING RESISTANCE

9.6.3 RESISTANCE TO UPLIFT

9.6.4 SETTLEMENT

9.7 STRUCTURAL PAVEMENT SECTIONS

10 RISK MANAGEMENT

11 LIMITATIONS

LIST OF TABLES

Table 1: Test Boring Summary Table 2: General Soil Conditions Table 3: Pothole Sample Summary Table 4: Soil Corrosivity Test Results Table 5: Seismic Design Parameters Table 6: Tank Site New Pavement Sections (R-Value = 15) Table 7: Watermain Alignment New Pavement Sections (R-Value = 5)

LIST OF ATTACHMENTS

Figure 1: Vicinity Map Figure 2: Test Boring Location Map Figure 3: Pothole Sample Location Map Figure 4: Geologic Map Figure 5: Fault Map

APPENDIX

Boring Log Legend Boring Logs Laboratory Test Results Settle 3D Output Historical Aerial Photographs

1 INTRODUCTION

1.1 PURPOSE

Crawford & Associates, Inc. (CAInc) prepared this Geotechnical Report for the Sacramento VA Medical Center – Correct Campus Water System project. The purpose of this Report is to support Coleman Engineering and the design team during project design and construction of the water tanks, pumping facility and watermain pipe line. Do not use this report for different locations or improvements without the written consent of CAInc.

1.2 SCOPE OF GEOTECHNICAL SERVICES

To prepare this Geotechnical Report, CAInc:

• Discussed the proposed improvements with Simon Gray with Coleman Engineering;

• Reviewed “Sacramento Veterans Administration medical center – Correct Campus

Water Supply System Project – 95% Design Submittal,” prepared by Coleman Engineering, Inc. dated June 29, 2020;

• Reviewed geotechnical reports from previous projects at VA facilities in the vicinity;

• Reviewed historical aerial photographs at the project site;

• Completed three test borings within the proposed tank locations and booster pump station to a maximum depth of about 51.5 ft on March 12 and 13, 2020;

• Completed eight samples during potholing activities along the watermain pipe alignment between March 30 and April 7, 2020;

• Performed laboratory tests on representative soil samples from the test borings and pothole samples; and

• Performed geotechnical engineering calculations and analysis to develop our recommendations.

2 PROJECT LOCATION

The Sacramento VA Medical Center – Correct Campus Water System project is located in Mathers, California. The tanks and booster pump site are located about 500 ft south from the intersection of International Drive and Femoyer Street. We show the vicinity map on Figure 1 and the tank site on Figure 2. We use coordinates of about 38.574007° latitude and - 121.291683° longitude for the water tank facilities location.

Elevations referenced within this report are based on the North American Vertical Datum of 1988 (NAVD 88), unless otherwise noted.

2.1 SITE DESCRIPTION

2.1.1 TANK AND BOOSTER PUMP SITE

The existing tank and booster pump site ground surface is uneven with elevations ranging from about 98 ft to 102 ft above Mean Sea Level (MSL). The drainage is poorly defined. General land use in the area consists of commercial property and vacant parcels. The existing lot consists of exposed soil with no improvements and sparse seasonal grasses/weeds as observed during our 2020 field work.

No evidence of pre-existing structures was observed during our site visit or by review of historical aerial photographs, although their presence cannot be precluded. Review of historical aerials photos and discussion with the VA representatives show that fill and multiple grading operations have been conducted at the site and within the planned tank and booster pump locations.

In general, the site was vacant and untouched prior to 1998, by 2002 the middle of site had been graded and soil stockpiled along the north half of the site. The site remained unchanged until about mid 2011 when a temporary facility with storage containers and gravel parking was set up near the middle of the site. In mid 2012 (Photo 1) additional fill stockpiles (about 25,000

sq. ft,) are observed east of the temporary facility in the approximate location of the planned tank and booster pump improvements. In late 2015, additional fill stockpiles are observed east of the temporary facility. Between 2016 (Photo 2) and early 2018 (Photo 3) the site was graded and generally appears unchanged since that time.

Based on the above we expect undocumented fill is present at the proposed tank and booster pump site. We provide available aerial photos from google earth showing the various stockpiles in the Appendix.

2.1.2 WATERMAIN PIPELINE

The watermain pipeline area along Hospital Way west of the tank and booster pump station site consists of existing Sacramento VA Hospital and facilities. The area is completely improved with defined drainage and parking facilities for the VA buildings. In general, the pipeline vicinity consists of Mather Sports Complex to the west, commercial properties to the south and east, and mixed residential buildings to the north.

2.2 PROPOSED PROJECT

The proposed water tank facility is planned to include:

• A 565,000-gallon, 63 ft diameter steel ground level tank supported on shallow perimeter ring foundations and tank belly support type per AWWA D100-11, Section 12.6;

• 1,000 sq-ft booster pump station supported on shallow concrete perimeter footing;

• A 40,000-gallon, 23 ft diameter, 215 ft tall elevated steel water storage tank, supported by four 10.7 ft by 10.7 ft column spread foundations and one 10.3 ft by 10.3 ft center spread foundation achieving support at about elev. 91 ft;

• Approximately 3,150 linear ft of 6-inch to 8-inch diameter watermain pipe at depths of about 5 to 8 ft below existing grades. The pipeline will likely be installed using standard open cut methods and trenchless horizontal drilling methods within the roadways around the VA hospital to the west mostly along Hospital Way;

• 180 sq-ft diesel fuel storage pad supported on shallow concrete mat foundation;

• Anticipated cuts and fills less than 5 ft outside of water tower foundation area;

• Pavement improvements; and

• Associated utility improvements.

We show proposed tank site plan on Figure 2 and watermain pipe alignment with pothole sample locations on Figure 3.

3 SITE GEOLOGY

3.1 GEOLOGIC SETTING

The project site is located in the Great Valley Geomorphic Province that includes the Sacramento and San Joaquin Valleys and is bounded by the Sierra Nevada on the east and the Coast Ranges on the west. The site is located in the Sacramento Valley which is a structural trough comprising the northern portion of the Great Valley.

The relatively flat surface of the Sacramento Valley is underlain by alluvial, lacustrine, and marine sedimentary deposits that have accumulated as the structural trough formed and the adjacent mountain ranges were elevated. The thickness of the sediments varies from a thin veneer along the valley margins to thousands of feet at the axis of the trough. The main axis of the trough is oriented north-south along the valley’s main drainage.

3.2 SITE GEOLOGY

Published geologic mapping (Wagner, D.L., Jennings, C.W., Bedrossian, T.L., and Bortugno, E.J. Geologic map of the Sacramento quadrangle. Scale: 1:250,000. California Division of Mines and Geology, 1981.) shows surface materials at the site as Riverbank Formation that generally consists of semi-consolidated sands, silts/clays and gravels.

The site is not located within an Alquist-Priolo Seismic Hazard Zone. No evidence of significant hazards (such as faulting, settlement, very soft soils, severe erosion, subsidence) was observed in the project vicinity. We include a geologic map in Figure 4.

4 SUBSURFACE CONDITIONS

4.1 TEST BORING EXPLORATIONS-TANK AND BOOSTER PUMP SITE

To help characterize the subsurface conditions at the tank site and obtain samples for laboratory testing, CAInc retained Taber Drilling to drill and sample three test borings on March 12 and 13, 2020 at the proposed improvement locations. Taber Drilling used a CME 55 truck-mounted drill rig to complete the borings to a maximum depth of 51.5 ft below ground surface (bgs) using 4-inch solid-stem auger and 4-inch mud rotary drilling techniques.

Soil samples were recovered by means of a 2.0-inch O.D. “Standard Penetration” (per ASTM D1586) split-spoon and 3.0-inch O.D. “Standard California” spilt-spoon sampler with liners advanced with standard 350 foot-lb striking force using an auto hammer. An energy hammer analysis was not performed specific to this project/site, however Taber Drilling reports an auto-hammer efficiency of 78%. The field recorded (uncorrected) blow counts are shown on the boring logs, provided in the Appendix. We show the test boring summary in Table 1.

Table 1: Test Boring Summary

Boring Number

Completion Date

Drill Rig

Type

Hammer Type

Hammer Efficiency

Approx. Ground Surface

Elevation (ft) Boring

Depth (ft)

A-20-001 3/13/2020 CME

55 Automatic 78 101.1 21.5

R-20-002 3/13/2020 CME

55 Automatic 78 101.5 34.7

R-20-003 3/12/2020 CME

55 Automatic 78 100.8 51.5

CAInc’s Project Engineer, Barrett Updegraph, logged the test borings consistent with the Unified Soil Classification System (USCS) and the Caltrans 2010 Logging Manual. The test borings were logged and earth materials field-classified as to apparent density, color, texture and gradation on the bases of penetration resistance, examination of samples, and observation of drill cuttings. Consistency of cohesive soils was obtained in the field by means of a pocket penetrometer. Selected portions of recovered soil drive samples were retained in sealed containers for laboratory testing and reference. Bulk soil samples were retained in sealed bags for laboratory testing and reference. At completion, test borings were backfilled with lean cement grout per the county boring permit requirements.

We planned the general location and depth of the test borings based on the 35% plan set. We show the test boring locations on Figure 2. The boring locations were measured in the field to existing site features. The boring elevations were estimated based on topographic information provided by Coleman Engineering. We include a soil legend with descriptions and an explanation of the descriptive terms used to log the soil samples. The boring log legend and boring logs are included in the Appendix.

4.2 POTHOLE EXPLORATIONS-WATERMAIN PIPE ALIGNMENT

To help characterize the subsurface conditions along the watermain pipe alignment and obtain samples for R-value testing, CAInc collected eight samples during potholing activities by the contractor between March 30 and April 7, 2020. We summarize our pothole subsurface observations in Table 3. Our pothole location numbers match the pothole numbering sequence provided by Coleman Engineering.

4.3 SOIL DESCRIPTIONS

The soils encountered in the test borings at the tank and booster pump site and limited observations/sampling during utility potholing activities by the contractor along the watermain pipe alignment completed for this study are considered consistent with the published mapping.

We provide a summary below of the subsurface soil conditions encountered.

Refer to the Boring Logs in the Appendix for detailed soil descriptions, sampling methods, and blow count data for the test borings at the tank site.

Table 2: General Soil Conditions

Soil Type Density and/or

Consistency Depth / Elevation

(ft)

A-20-001 –Steel Ground Level Water Tank clayey gravel with sand; clayey sand with gravel;

clayey sand; dense 0 to 8.5 /101.1 to 92.6 poorly graded gravel with clay and sand very dense 8.5 to 21.5 / 92.6 to 79.6

R-20-002 – Booster Pump Station clayey sand with gravel very dense 0 to 4.5 / 101.5 to 97.0 clayey gravel Very dense 4.5 to 9.5 / 97.0 to 92.0 clayey gravel with sand dense 9.5 to 13.0 / 92.0 to 88.5 clayey sand with gravel; poorly-graded gravel very dense 13.0 to 34.7 / 88.5 to 66.8

R-20-003 – Elevated Steel Water Storage Tank gravelly lean clay with sand; lean clay with gravel stiff 0 to 9.5 / 100.8 to 91.3 clayey gravel with sand; poorly-graded gravel;

poorly-graded gravel with clay and sand dense to very dense 9.5 to 33.0 / 91.3 to 67.8 lean clay; lean clay with sand; sandy lean clay stiff to hard 33.0 to 51.5 / 67.8 to 49.3

Table 3: Pothole Sample Summary

Location Sample Description Sample Depth (ft)

Measured AC Depth

(in) P2 lean clay with sand 0 to 3 3.5 P5 clayey sand with gravel 0 to 3 -

P15 lean clay with sand 0 to 4.3 5.5 P22 aggregate base 0 to 2.5 5.5 P29 gravelly lean clay with sand 0 to 4 6.5 P31 gravelly lean clay with sand 0 to 5.5 4.0 P45 sandy lean clay 0 to 3 4.5 P46 lean clay with sand 0 to 2.5 4.0

4.4 PREVIOUS EXPLORATIONS

On July 25, 2019, Wallace and Kuhl (WK) performed two test pits in the vicinity of the planned tank and booster pump locations. Test Pit 5 (near our boring R-20-001) encountered 5 ft of brown, fine to coarse gravel. Test Pit 4 (about 200 ft north of our boring A-20-001) encountered

8.5 ft of light brown, fine to coarse gravels, underlain by gravelly sand down to about 10 ft. The test pit logs and report do not mention of encountering historical fill material. An R-value report completed by WK, about 400 ft west of the tank and booster pump site, show an R-value of 16.

On April 16, 2019, Engeo performed one test boring (1-B1) approximately 80 ft southwest of the planned elevated tank location on the adjacent property. At boring (1-B1) Engeo encountered about 2 ft of fill material logged as sandy lean clay with gravel, with a piece of asphalt in the sampler. The fill was underlain by native sandy lean clay with gravel to the depths explored (11.5 ft). R-values completed by Engeo resulting in an R-value of 16, which they corrected to 11 based on the presence of clay soils.

4.5 EXISTING FILL

Based on our review of historical aerial photos, discussions with the design team, review of our boring logs and nearby subsurface explorations, we expect up to 3 ft of undocumented fill is likely present at the tank and booster pump station site. The fill material was likely placed during previous VA Hospital improvements in the vicinity of the project site and is expected to consist of a mix of sands, lean clay, and gravels. Based on our review of the 35% Plan Set provided by Coleman Engineering finished grades are planned to be within the undocumented fill zone. We provide recommendations in Section 8 to mitigate potential adverse impacts due to the undocumented fill within planned tank and booster pump improvements.

4.6 GROUNDWATER

We did not encounter free groundwater at the tank and booster pump station site during our explorations. Based on review of nearby soil reports and the California Department of Water Resources Water Data Library website, the groundwater depth in the Mather Airport vicinity is generally 70 to 80 ft below ground surface. Groundwater is not expected to impact the design or construction of the project.

5 LABORATORY TESTING

The following laboratory tests were completed on representative soil samples obtained from the test borings. We present the laboratory results in the Appendix.

• Moisture Content-Dry Density (ASTM D2216/D2937)

• Atterberg Limits (ASTM D4318)

• Unconfined Compressive Strength (ASTM D2166)

• 200 Wash (ASTM D1140)

• Gradation (ASTM 6913)

• Corrosivity: pH and Minimum Resistivity (CTM 643); Chloride (CTM 422); Sulfate (CTM

417)

• Expansion Index (ASTM D4829)

• R-value (CTM 301)

6 CORROSION TEST RESULTS

Table 5 summarizes the results of soil corrosivity tests on samples obtained from the test borings completed for this project. We use Caltrans Corrosion Guidelines Version 3.0 as a reference regarding corrosivity potential for structural concrete/steel foundation elements.

Table 4: Soil Corrosivity Test Results

Sample Number

Depth

(ft) pH

Minimum Resistivity (ohm-cm)

Chloride (ppm)

Sulfate (ppm)

1-1A 3.5 to 4 6.71 3,220 2.1 19.7

2-1A 3.5 to 4 6.62 4,290 4.8 14.2

R-20-003 / 4A 8.5 to 9 5.86 2,630 2.7 9.8

For structural elements, Caltrans defines a corrosive environment as an area where the soil has either a chloride concentration of 500 ppm or greater, a sulfate concentration of 1500 ppm or greater, or has a pH of 5.5 or less. Soil and water are not required to be tested for chlorides and sulfates if the minimum resistivity is greater than 1,100 ohm-cm.

Based on the test results summarized above and current Caltrans guidelines, the site is not corrosive to structural concrete/steel foundation elements. The test results are only an indicator of soil corrosivity. The designer should consult with a corrosion engineer if these values are considered significant.

7 SEISMICITY

7.1 2019 CBC SEISMIC DESIGN PARAMETERS

Based on our test borings, we provide the ASCE 7-16 standards - California Building Code (CBC) design parameters below. We determined the values using an approximate latitude of 38.574007°N and longitude of 121.291683°W with the Seismic Design Map tool1 developed by the Structural Engineers Association of California/OSHPD. We show a fault map on Figure 5.

Based on ASCE 7-16 Chapter 11, Section 11.4.8 and ASCE 7-16 Supplement 1, the site (site class D with S1 ≥ 0.2) meets “Exception 2” provided the value of the seismic response coefficient Cs is determined by Eq. (12.8-2) for values of T ≤ 1.5Ts and taken as equal to 1.5 times the value computed in accordance with either Eq. (12.8-3) for TL ≥ T > 1.5Ts or Eq. (12.8-

4) for T > TL.

1 https://seismicmaps.org/, accessed April 10, 2020.

Table 5: Seismic Design Parameters Site Class D

Ss – Acceleration Parameter 0.458 g S1 – Acceleration Parameter 0.224 g

Fa – Site Coefficient 1.434 Fv – Site Coefficient 2.152

SMS – Adjusted MCE1 Spectral Response Acceleration Parameter 0.656 g SM1 – Adjusted MCE1 Spectral Response Acceleration Parameter 0.482 g

SDS – Design Spectral Acceleration Parameter 0.438 g SD1 – Design Spectral Acceleration Parameter 0.321 g

TL – Long-Period Transition Period2 12 sec Site Modified Peak Ground Acceleration (PGAm)2 0.273 g

1Risk Targeted Maximum Considered Earthquake

7.2 LIQUEFACTION POTENTIAL AND SEISMICALLY INDUCED SETTLEMENT

Liquefaction can occur when saturated, loose to medium dense, granular soils (generally within 50 ft of the surface), or specifically defined cohesive soils, are subjected to ground shaking.

Based on the dense to very dense granular layers encountered in the upper 50 ft, groundwater depths and current industry accepted liquefaction and seismic settlement evaluation methods, the potential for liquefaction and seismic settlement at the site are considered low.

8 CONCLUSIONS

Based on the data generated for this study, the site is considered stable with support available for the proposed project elements provided our recommendations are incorporated into the project improvement plans and specifications. Key geotechnical considerations include the presence of undocumented fill likely on the order of 2 to 3 ft and changes in support soil types and strengths within 10 ft of the surface (stiff, lower blow count, gravelly lean clay in Boring R- 20-003 vs dense to very dense, high blow count, coarse grained materials in borings A-20-001 and R-20-002).

Considering the fill and changes in subsurface conditions, we provide overexcavation and recompaction recommendations for shallow foundations at the steel ground level water tank, diesel fuel storage and other minor structures, and booster pump station building. We provide minimum installation depths to achieve uniform support in the deeper isolated spread footing foundations for the elevated steel water storage tank below.

Expansion potential of the onsite soils and groundwater are not expected to be a significantly impact to design and construction.

9 RECOMMENDATIONS

9.1 GRADING

Where referenced in this report, use the most current ASTM D 1557 test methods to determine relative compaction and optimum moisture. Compacted soil should not be considered suitable (even if it meets relative compaction requirements) if it is unstable and pumps or flexes excessively under construction equipment loads, as determined by CAInc.

9.1.1 SOIL EXCAVATABILITY

Based on the conditions encountered in our subsurface explorations and our experience, the on-site soil should be excavatable with typical grading equipment such as scrapers, dozers, backhoes and excavators. Previous test pits performed at the site in 2019 by WK encountered excavation refusal at about 5 to 6.5 ft below exiting grade with a Case 580M backhoe and 18-inch bucket.

9.1.2 OVEREXCAVATION

Remove existing fill at shallow supported structure locations (steel ground level water tank and booster pump station building, diesel fuel storage pad) to a depth of about 3 to 4 ft below existing grade. Based on our discussions with the design team, we understand that the steel ground level water tank and booster pump station building will have a finished floor of about elevation 101.25 ft and 101.50 ft respectively. Based on the results of our fieldwork and the provided grading plan we recommend the following overexcavation limits:

• Steel ground level water tank, overexcavate the onsite soils to an elevation of 97 ft and process the exposed subgrade per Section 9.1.3.

• Booster pump station building, overexcavate the onsite soils to an elevation of 98 ft and process the exposed subgrade per Section 9.1.3.

• Diesel Fuel Storage and other equipment pad overexcavate the onsite soils to an elevation of 97 ft and process the exposed subgrade per Section 9.1.3.

Extend the horizontal limits of the excavation at least 5 ft laterally in all directions outside the structure footprint limits.

A CAInc representative must review the exposed excavation prior to placement of engineered fill. Additional lateral or vertical overexcavation may be required based on soil exposure observations during earthwork activities.

Place and compact fill meeting the requirements of Section 9.1.4.

9.1.3 SUBGRADE PREPARATION

Clear the site to remove vegetation, concrete, debris, abandoned utilities, undocumented fill, soft or unstable areas, and other deleterious materials.

Process and compact the exposed subgrade, cut, and fill areas as follows:

Scarify the exposed soil to a depth of 10 inches. Moisture condition subgrade soil to within 2% of optimum moisture content and compact it to at least 90% relative compaction. Increase minimum soil compaction in portions of fills deeper than 10 ft and in the upper 6 inches of pavement subgrade to at least 95% relative compaction.

9.1.4 FILL AND COMPACTION

On-site soil may be used for fill provided it contains no rock fragments larger than 6” in maximum dimension and is free of concentrations of debris and vegetation. The onsite soils should be uniformly mixed to avoid nesting of larger cobbles and provide uniform support. We expect cobbles larger than 6” in diameter will be encountered at the site and should be removed/screened or broken down into smaller pieces.

If import material is required, it should meet the following criteria:

• Contain no concentration of organics, debris or deleterious materials,

• Maximum particle size of 3” with at least 50% passing the No. 4 Sieve,

• Expansion Index £ 25, per ASTM D4829.

• R-value > 20.

Import fill must be observed and tested by CAInc prior to its approval. Recycled aggregate base is a suitable import material provided it meets the above requirements.

Place fill in maximum 10 inch lifts, moisture condition to within 2% of optimum and compact to a minimum 90% relative compaction. Increase minimum soil compaction in portions of fills deeper than 10 ft and in the upper 6 inches of pavement subgrade to at least 95% relative compaction.

Compaction may be reduced to a minimum of 85% relative compaction in landscape areas.

If native soil meets the above requirements to be used as fill and is untestable per ASTM D 1557 using nuclear density gauge equipment due to cobbles, then CAInc recommends the following:

• Place fill in maximum 10 inch lifts;

• One pass is considered when the equipment moves away and returns to the start point;

• Roll each lift a minimum of 10 passes with sheepsfoot compaction equipment appropriate for the area. This is considered to be meet 90% relative compaction requirement.

• Roll each lift a minimum of 14 passes with sheepsfoot compaction equipment appropriate for the area. This is considered to be meet 95% relative compaction requirement.

• Roll each lift a minimum of 7 passes with sheepsfoot compaction equipment appropriate for the area. This is considered to be meet 85% relative compaction requirement.

CAInc must observe and document the minimum passes and equipment type observed during compaction efforts for each lift.

9.1.5 OVER-OPTIMUM SOIL MOISTURE

Excessively over-optimum (wet) soil conditions can make proper compaction difficult or impossible. Wet soil is commonly encountered during the winter and spring months. Excessively over-optimum soil conditions are not expected but in general, wet soil can be mitigated by:

• Discing the soil during prolonged periods of dry weather,

• Over-excavating and replacing with drier material,

• Stabilizing using aggregate and/or stabilization fabric or grid.

If wet, unstable soil is encountered, CAInc should observe the conditions and provide more specific mitigation recommendations.

9.2 UTILITY TRENCHES

In general, the onsite soils are likely suitable for use above the pipe zone as trench backfill as defined in the Sacramento County Standard Construction Specifications Section 19-2.03.

9.2.1 TRENCH EXCAVATABILITY AND STABILITY

Based on our subsurface exploration and experience, the near surface silts should be excavatable using conventional trenching equipment such as backhoes and excavators.

For planning and preliminary design, anticipate OSHA sloping requirements for Type B materials. The contractor is responsible for the safety of all temporary excavations and should provide excavation sloping and shoring in accordance with current Cal OSHA requirements.

9.2.2 TRENCH BACKFILL

Based on Sacramento County Standard Construction Specifications (SCSCS) on-site soil may be used for trench backfill above the pipe zone for trench depths of 4 ft or greater. Trench depths of 4 ft or less will require aggregate base backfill conforming to requirements described in Section 19-2.03 of the SCSCS. Controlled Density Backfill (CDF) or Controlled Low Strength Material (CLSM) can be used as backfill and should conform to Section 50-15 of the SCSCS.

9.2.3 PIPE BEDDING (INITIAL BACKFILL)

Support the pipe on granular bedding, consistent with the provisions of the pipe manufacturer.

Native soils contain a significant number of fines (passing #200 sieve) in the upper 10 ft, and will not meet the Sacramento County Standard Construction Specification 19-2.02.C for use as bedding material (initial backfill).

9.2.4 HORIZONTAL THRUST BLOCKS

Thrust blocks can be used to support and redirect piping as needed. Passive pressure values can vary throughout the alignment due to changes in subsurface soil conditions. To resist lateral movement, use a coefficient of friction of 0.62 and an allowable passive earth pressure of 250 psf per foot of embedment depth. For seismic design, reduce the allowable passive pressure to 240 pcf.

9.3 STEEL GROUND LEVEL WATER TANK FOUNDATION

The following footing dimensions are considered minimum recommendations based on the soil conditions at the site. The structural engineer should design the foundation dimensions based on the anticipated loads and anticipated settlements. Based on our conversations with Coleman Engineering and Pittsburg Tank and Tower Group we understand the following;

• Tank Diameter = 63 ft;

• Finished floor grade for the tank area is elev. 101.25 ft;

• Bottom of perimeter tank footing elev. At 98.75 ft;

• Perimeter ring footing width of 1.5 ft and 2.5 ft deep;

9.3.1 PERIPHERAL CONCRETE RING FOOTING

Provided the overexcavation requirements in Section 9.1.2 are followed the perimeter ring footing should be a minimum of 1.5 ft wide and extend a minimum of 2 ft below lowest adjacent grade. Use an allowable bearing capacity of 3,000 psf to design the perimeter ring foundation.

This value may be increased by one-third if wind and/or seismic loads are included.

Utility excavations should be outside a 1.5:1 (horizontal:vertical distance) plane extended downward from the perimeter toe of footing. Where utility lines cross footings, they should be sleeved and footings deepened as appropriate.

9.3.2 SLIDING RESISTANCE

Resistance to lateral loads (including those due to wind or seismic forces) may be determined using a coefficient of friction of 0.67 between the bottom of cast-in-place concrete perimeter ring foundation and the underlying soil and between the tank bottom and the underlying crushed rock support. Lateral resistance for foundations is also available from passive soil pressure acting against the vertical face of the footing. The passive pressure available in the engineered fill may be taken as equivalent to pressures exerted by fluids weighing 295 psf per foot of embedment depth. These two modes of resistance can be combined; however, since horizontal movement is required to mobilize passive resistance, decrease the passive pressure by on-half if both friction and passive pressures are used. For seismic design, reduce the allowable passive pressure to 280 pcf.

9.3.3 RESISTANCE TO UPLIFT

Resistance to uplift of shallow footing foundations may be calculated as the weight of soil (bulk density of 115 pcf) and concrete directly above the footing.

9.3.4 SETTLEMENT

We used SETTLE 3D Version 3.0 software to evaluate immediate and consolidation settlement for the proposed steel ground level tank based on the foundation loads and foundation dimensions provided by the design team. We used correlations, laboratory testing, and subsurface exploration data (blow count) to establish values used in the Settle 3D software analysis.

For the above bearing capacity of 3,000 psf at footing elevation 98.75 ft established within engineered fill as discussed in Section 9.1.2, we estimate the total settlement to be about 2-inches at the tank center. We expect differential settlement to be about 1-inch from the center of the tank to the outer perimeter ring edge.

9.4 BOOSTER PUMP STATION FOUNDATION

We understand the booster pump station slab will be supported on continuous perimeter spread footings. We recommend the spread foundations be constructed a minimum 12 inches wide and embedded a minimum of 12 inches below the lowest adjacent finished grade for an allowable bearing capacity of 2,500 psf. The total expected settlement will be on the order of ½ inch. We expect differential settlement will be on the order of half the total settlement.

The differential settlement between the at grade and below grade structures should be considered. The design engineer should allow for movement at the connection (ie. flexible connection) between the below ground pump structures and equipment building contents (piping, etc).

The above bearing capacity values may be increased by one-third if wind and/or seismic loads are included.

To resist lateral movement, use a coefficient of friction of 0.67 and a static passive earth pressure equal to 295 pcf. For seismic design, reduce the allowable passive pressure to 280 pcf.

9.5 DIESEL FUEL STORAGE AND EQUIPMENT PADS

Provided that the mat foundations are designed to evenly distribute the load, a modulus of subgrade reaction of 49 k/ft3 may be used for design (corresponds to 3,000 psf for 1 inch of settlement). We estimate that differential settlement across the mat foundations will be less than half of the total settlement.

The subgrade modulus may be increased by one-third if wind and/or seismic loads are included.

The above subgrade modulus must include the weight of the contents, equipment, structure and foundation. To resist lateral movement, use a coefficient of friction of 0.62 and an allowable passive earth pressure of 250 psf per foot of embedment depth. For seismic design, reduce the allowable passive pressure to 240 pcf.

9.6 ELEVATED STEEL WATER STORAGE TANK FOUNDATION

The following footing dimensions are considered minimum recommendations based on the soil conditions at the site. The structural engineer should design the foundation dimensions based on the anticipated loads and anticipated settlements. Compaction recommendations discussed below should follow ASTM procedures. Based on our conversations with Coleman Engineering and Pittsburg Tank and Tower Group we understand the following for design;

• Four isolated column spread footing dimensions, 10.7 ft by 10.7 ft;

• One isolated center spread footing dimension, 10.3 ft by 10.3 ft;

• Finished grade around tank area is elev. 99 ft;

• Bottom of isolated spread footings elev. at 91 ft;

• Anticipated load at each column spread footing = 238 kips;

• Anticipated load at the center spread footing = 213 kips;

• 1.5 inches of total settlement and 0.75 inches of differential settlement across entire water tower foundations.

9.6.1 SPREAD FOOTING

Based on our review of the 95% plans we understand the elevated steel water storage tank tower will be supported on four isolated 10.7x10.7 ft column spread footings and one 10.3x10.3 ft center spread footing about 8.0 ft below finished grade (approximate elevation of 91 ft) within dense, clayey gravel with sand (below the lower blow count, stiff lean clay).

Based on the above use an allowable bearing capacity of 2,000 psf to design the isolated spread footings.

This value may be increased by one-third if wind and/or seismic loads are included. Utility excavations are not anticipated to cross below the footings.

9.6.2 SLIDING RESISTANCE

Resistance to lateral loads (including those due to wind or seismic forces) may be determined using a coefficient of friction of 0.70 between the bottom of cast-in-place concrete foundations and the underlying soils. Lateral resistance for foundations is also available from passive soil pressure acting against the vertical face of the footing. The passive pressure available in the underlying soils may be taken as equivalent to pressures exerted by fluids weighing 315 psf per foot of embedment depth. These two modes of resistance can be combined; however, since horizontal movement is required to mobilize passive resistance, decrease the passive pressure by one-half if both friction and passive pressures are used. For seismic design, reduce the allowable passive pressure to 300 pcf.

9.6.3 RESISTANCE TO UPLIFT

Resistance to uplift of shallow footing foundations may be calculated as the weight of soil (bulk density of 120 pcf) and concrete directly above the footing. From top of spread footing corner, projecting a soil wedge limited to 25 degrees from vertical to finished grade is considered appropriate. Based on 95% plan set, the soil depth above the spread footing is 7 ft corresponding to a projected soil wedge offset of about 3 ft beyond the foundation footprint at finished grade surface. Use a minimum factor of safety of 1.5 (total weight of footing plus soil wedge divided by uplift force) to resist uplift loads.

9.6.4 SETTLEMENT

We used SETTLE 3D Version 3.0 software to evaluate immediate settlement for the proposed spread footing based on the foundation loads and foundation dimensions provided by Coleman Engineering. We used correlations, laboratory testing, and subsurface exploration data (blow count) to establish values used in the Settle 3D software analysis.

For the anticipated tank loading of 2,000 psf at footing elevation 91 ft, we estimate the total settlement is expected to be less than 1 inch at the isolated footing center. We expect differential settlement to be about ¼ inches from the water tower center to the center of an isolated footing.

9.7 STRUCTURAL PAVEMENT SECTIONS

CAInc completed two R-value tests (CTM 301) on bulk samples from R-20-003 at the tank and booster pump site and pothole P15 along the pipeline along Hospital Way of anticipated subgrade soils. The test results indicate R-values of 5 and 26. Based on the clay content observed in the samples and R-value results from other projects in the vicinity, we recommend using an R-value of 15 for the tank and booster pump station site and an R-value of 5 along the watermain pipe alignment.

Using an R-value of 5 and 15 and Chapter 600 of the CHDM, 5th Edition, we recommend the pavement sections in Table 8 and 9 for design of new pavement sections.

Table 6: Tank Site New Pavement Sections (R-Value = 15)

Layer Thickness (ft)

TI = 6.0 TI = 6.5

HMA1 0.25 0.30

AB 0.95 1.00

Total Thickness 1.20 1.30

Notes: HMA = New Hot Mix Asphalt; AB = Caltrans Class II Aggregate Base; TI = Traffic Index

Table 7: Watermain Alignment New Pavement Sections (R-Value = 5)

Layer Thickness (ft)

TI = 6.0 TI = 6.5

HMA1 0.25 0.30

AB 1.15 1.20

Total Thickness 1.40 1.50

A maximum of 0.20 ft of HMA may be replaced with gap graded rubberized hot mix asphalt.

Appropriate Traffic Index (TI) values should be determined by the Design Engineer. Additional pavement recommendations, if TI’s other than those listed above are needed, can be provided if requested by the design team.

10 RISK MANAGEMENT

Our experience and that of our profession clearly indicates that the risks of costly design, construction, and maintenance problems can be significantly lowered by retaining the geotechnical engineer of record to provide additional services. For this project, CAInc should be retained to:

• Review and provide written comments on the (civil, structural) plans and specifications prior to construction.

• Monitor construction to check and document our report assumptions. At a minimum, CAInc should review/observe pavement subgrade compaction and footing foundation excavations to confirm bearing materials in order to provide additional or alternate recommendations if necessary.

• Update this report if design changes occur, 2 years lapse between this report and construction, or site conditions change.

If CAInc is not retained to perform the above applicable services, we are not responsible for any other parties’ interpretation of our report, and subsequent addendums, letters, and discussions.

11 LIMITATIONS

CAInc performed these services in accordance with generally accepted geotechnical engineering principles and practices currently used in this area. This report is based on the current site and project conditions and should be used only for the design and construction of the proposed project described above. We assume the soil and groundwater conditions interpreted/encountered in our test borings are representative of the subsurface conditions on the site. Actual conditions between explorations can be different.

Modern design and construction are complex and it is common to experience changes and delays. The owner should set aside a reasonable contingency fund based on complexities and cost estimates to cover changes and delays. The interface shown between soil materials on the interpreted boring logs is approximate. The transition between materials may be abrupt or gradual. We base our recommendations on the final logs, which represent our interpretation of the field logs and general knowledge of the site and geological conditions.

FIGURES

Figure 1: Vicinity Map Figure 2: Test Boring Location Map

Figure 3: Pothole Sample Location Map Figure 4: Geologic Map

Figure 5: Fault Map

Project Location

Figure 1 Vicinity Map

1"=3,000'North Proj. No: 19-565.1 Scale:

Date:

Sacramento VA Medical Center - Correct Campus

Water System

Mather, California

Source:

USGS 7.5' Topographic Maps, Carmichael, Sacramento County, California, 2018, Scale: 1:24,000

4/14/20

Proj. No: 19-565.1 Scale:

Date:

Sacramento VA Medical Center - Correct Campus

Water System

Mather, CaliforniaNorth

LEGEND

APPROX. BORING LOCATION

A-20-001

R-20-002

R-20-003

Figure 2 Test Boring Location Map

1"=40'

Source:

-Plan provided by Coleman Engineering via Electronic Transfer on 3/26/2020

4/14/20

Fe m oy er

S t.

Prj. No:

Date:

19-565.1

Sacramento VA Medical Center - Correct Campus

Water System

Mather, California

LEGEND

POTHOLE LOCATION

P2 P5

P45

P46

P31

P29

P22

P15

North

Figure 3 Pothole Sample Location Map

1"=80'

Source:

Basemap: AutoCAD Civil3D Geolocation Tool using Bing Maps

4/28/20

8" WATER MAIN PIPE

Date:

Sacramento VA Medical Center - Correct Campus Water System

Mather, California t Mine and dredge tailings

Qa Levee and channel deposits

Qb Basin deposits (Alluvium)

Qr Riverbank Formation (Alluvium)

Qmr Modesto-Riverbank Formations (Arkosic alluvium)

Qm2 Modesto Formation lower member (Alluvium)

Qtl Turlock Lake Formation (Sand, silt, and gravel)

Tl Laguna Formation (Consolidated alluviul deposits)

Tm Mehrten Formation (Andesitic conglomerate, sandstone, and breccia)

Project Location

Figure 4 Geologic Map

1"=6,000'

Source: Wagner, D.L., Jennings, C.W., Bedrossian, T.L., and Bortugno, E.J.. Geologic map of the Sacramento quadrangle . Scale: 1:250,000. California Division of Mines and Geology, 1981.

North 4/14/20 t t t t t

Tl

Tl

Tl

Tl

Tl

Tl

Qa

Qa Qa

Qa

Qa

Qb

Qb

Qb

Qr

Qr

Qr

Qmr

Qmr

Qmr

Qtl

Qtl

Tm

Tm

Tm

Qm2

Tm

Tl

Tl

Tl t t

Date:

Sacramento VA Medical Center - Correct Campus Water System

Mather, California

LEGEND

Quaternary Fault (Age)

<15,000 years <130,000 years <1.6 million years

Location Well Constrained Moderately Constrained Inferred

Figure 5 Fault Map

Source:

Basemap: AutoCAD Civil3D Geolocation Tool, using Bing Maps

Fault Data: USGS GIS Data

Project Location

1"=25,000'North 4/14/20

Foothills fault system

Foothills fault system

Dunnigan Hills fault

Great Valley thrust fault system

M idland fault zone

APPENDIX

Boring Log Legend Boring Logs

Laboratory Test Results Settle 3D Output

Historical Aerial Photographs

BORING LOG / TEST PIT

LEGEND AND SOIL DESCRIPTIONS

MATERIAL

TYPES

GROUP

SYMBOLCRITERIA FOR ASSIGNING SOIL GROUP NAMES SOIL GROUP

NAMES

COARSE-

GRAINED

SOILS

FINE-

GRAINED

SOILS

GRAVELS

SANDS

SILTS AND CLAYS

SILTS AND CLAYS

HIGHLY ORGANIC SOILS

GW

GP

GM

GC

SW

SP

SM

SC

CL

ML

OL

CH

MH

OH

PT

SAMPLE TYPES

ADDITIONAL TESTS

CL-ML

PLASTICITY CHART

ML or OL

MH or OH

"A " L

INE

PL

AS

TI

CI

TY

I

N D

EX

PI

LIQUID LIMIT (LL)

BLOW COUNT

GROUND WATER LEVELS

"U " L

INE

CL or O L

CH or O H

Equation of "A"-line Horizontal at PI=4 to LL=25.5, then PI=0.73 (LL - 20)

Equation of "U"-line Vertical at LL=16 to PI=7, then PI=0.9 (LL - 8)

GRAPHIC

SYMBOL

7.3

7.5

CLAYEY GRAVEL with SAND (GC); dense; brown;

dry; about 38% some coarse to fine GRAVEL; about 28% little coarse to fine SAND; about 34% some fines.

CLAYEY SAND with GRAVEL (SC); dense; brown;

dry; about 28% little coarse to fine GRAVEL; about 29% little coarse to fine SAND; about 43% some fines.

Poorly graded GRAVEL with CLAY and SAND (GP-GC); very dense; brown and gray; dry; about 57% mostly coarse to fine GRAVEL; about 34% some coarse to fine SAND; about 9% few fines.

CLAYEY GRAVEL (GC); very dense; brown; moist;

mostly coarse to fine GRAVEL; little coarse to fine SAND; some fines.

Dense.

Medium dense.

Bottom of borehole at 21.5 ft bgs

Groundwater not encountered

Moderate drill chatter.

Chemical Analysis pH = 6.71 Min. Res. = 3220 ohm-cm Chloride = 2.1 ppm Sulfate = 19.7 ppm34

99.5

94.4

127.2

111.9

Bulk

DRILLING CONTRACTOR: Taber Drilling

DRILL RIG: CME 55

HAMMER TYPE: Automatic, 140 lbs, 30" drop

SAMPLER TYPE & SIZE: BULK, CAL (ID 2.5")

BOREHOLE DIAMETER: 4"

BACKFILL METHOD: Neat Cement

LOG OF BORING A-20-001

HAMMER EFFICIENCY: 78( %)

COMPLETION DATE: 3/13/20

LABORATORY

DRILLING METHOD: Solid-Stem Auger

PROJECT NO: 19-565.1

LOCATION: Mather, CA

DEPTH OF BORING: 21.5( ft)

READING TAKEN:

WATER DEPTH: ( ft)

BEGIN DATE: 3/13/20

CLIENT: Coleman Engineering SURFACE CONDITION: Soil

PROJECT: Sacramento VA

COUNTY: Sacramento

LOGGED BY: BJU

FIELD

SURFACE ELEVATION: 101.1( ft)

D E

P T

H f t)

M O

IS

T

U R

E

L

IQ

U

ID

L

IM

IT

P L

A S

T

IC

L

IM

IT

DESCRIPTION

R E

C O

V E

R Y

B L

O W

S P

E R

F O

O T

B L

O W

S P

E R

IN

D R

IL

L

M E

T H

O D

C A

S

IN

G D

E P

T H

REMARKS

P

A S

S

IN

G

S

IE

V

E

D . D

E N

S

IT

Y (P

C F

P O

C K

E T

P E

N

T S

F

G R

A P

H

IC

L O

G

S A

M P

L E

S A

M P

L E

N O

E L

E V

A T

IO

N

(f t)

R Q

D

PROJECT: Sacramento VA

PROJECT NUMBER: 19-565.1

ENTRY BY: BJU

SHEET 1 of 1CHECKED BY:

Crawford & Associates, Inc.

1100 Corporate Way, Suite 230 Sacramento, CA 95831

(916) 455-4225

TEST PIT: A-20-001

5.9

9.2

19.1

5.7

CLAYEY SAND with GRAVEL (SC); very dense;

brown to light brown; dry; about 23% little coarse to fine GRAVEL; about 31% some coarse to fine SAND;

about 46% some low plasticity, low toughness fines.

CLAYEY GRAVEL (GC); very dense; reddish brown;

dry; some coarse to fine GRAVEL; little coarse to fine SAND; some medium plasticity, high toughness fines.

Dense.

CLAYEY GRAVEL with SAND (GC); dense; brown;

dry; about 33% some coarse to fine GRAVEL; about 27% little coarse to fine SAND; about 40% some fines.

CLAYEY GRAVEL with SAND (GC); very dense;

multicolored, reddish brown, light olive brown, grayish green; dry; mostly coarse to fine GRAVEL;

some coarse to fine SAND; about 15% little fines.

Poorly graded GRAVEL (GP); very dense; coarse to fine GRAVEL.

50/5"

50/4"

Moderate drill chatter.

Chemical Analysis pH = 6.62 Min. Res. = 4290 ohm-cm Chloride = 4.8 ppm Sulfate = 14.2 ppm

Intense drill chatter.

Cobble in A tube.

Switch to Mud Rotary at 16 ft bgs.

104.5

109.1

129.2

2.75

Bulk

DRILLING CONTRACTOR: Taber Drilling

DRILL RIG: CME 55

HAMMER TYPE: Automatic, 140 lbs, 30" drop

SAMPLER TYPE & SIZE: BULK, CAL (ID 2.5")

BOREHOLE DIAMETER: 4"

BACKFILL METHOD: Neat Cement

LOG OF BORING R-20-002

HAMMER EFFICIENCY: 78( %)

COMPLETION DATE: 3/13/20

LABORATORY

DRILLING METHOD: Solid-Stem Auger, Mud Rotary

PROJECT NO: 19-565.1

LOCATION: Mather, CA

DEPTH OF BORING: 34.7( ft)

READING TAKEN:

WATER DEPTH: ( ft)

BEGIN DATE: 3/13/20

CLIENT: Coleman Engineering SURFACE CONDITION: Soil

PROJECT: Sacramento VA

COUNTY: Sacramento

LOGGED BY: BJU

FIELD

SURFACE ELEVATION: 101.5( ft)

D E

P T

H f t)

M O

IS

T

U R

E

L

IQ

U

ID

L

IM

IT

P L

A S

T

IC

L

IM

IT

DESCRIPTION

R E

C O

V E

R Y

B L

O W

S P

E R

F O

O T

B L

O W

S P

E R

IN

D R

IL

L

M E

T H

O D

C A

S

IN

G D

E P

T H

REMARKS

P

A S

S

IN

G

S

IE

V

E

D . D

E N

S

IT

Y (P

C F

P O

C K

E T

P E

N

T S

F

G R

A P

H

IC

L O

G

S A

M P

L E

S A

M P

L E

N O

E L

E V

A T

IO

N

(f t)

R Q

D

PROJECT: Sacramento VA

PROJECT NUMBER: 19-565.1

ENTRY BY: BJU

SHEET 1 of 2CHECKED BY:

Crawford & Associates, Inc.

1100 Corporate Way, Suite 230 Sacramento, CA 95831

(916) 455-4225

TEST PIT: R-20-002

93/11

50/4

Poorly graded GRAVEL (GP) (continued).

CLAYEY SAND with GRAVEL (SC); very dense;

brown; moist; some coarse to fine GRAVEL; mostly coarse to fine SAND; little fines.

Bottom of borehole at 34.7 ft bgs

Groundwater not observed due to drilling fluid

50/2"

50/5"

50/2"

Slight drill chatter.

Intense drill chatter.

Auger refusal.

FIELD LABORATORY

D E

P T

H f t)

M O

IS

T

U R

E

L

IQ

U

ID

L

IM

IT

P L

A S

T

IC

L

IM

IT

DESCRIPTION

R E

C O

V E

R Y

B L

O W

S P

E R

F O

O T

B L

O W

S P

E R

IN

D R

IL

L

M E

T H

O D

C A

S

IN

G D

E P

T H

REMARKS

P

A S

S

IN

G

S

IE

V

E

D . D

E N

S

IT

Y (P

C F

P O

C K

E T

P E

N

T S

F

G R

A P

H

IC

L O

G

S A

M P

L E

S A

M P

L E

N O

E L

E V

A T

IO

N

(f t)

R Q

D

PROJECT: Sacramento VA

PROJECT NUMBER: 19-565.1

ENTRY BY: BJU

SHEET 2 of 2CHECKED BY:

Crawford & Associates, Inc.

1100 Corporate Way, Suite 230 Sacramento, CA 95831

(916) 455-4225

TEST PIT: R-20-002

84/8

REF

50/2

9.5

5.6

GRAVELLY lean CLAY with SAND (CL); stiff; brown;

moist; little coarse to fine GRAVEL; little coarse to fine SAND; mostly medium plasticity, very high dry strength, low toughness fines.

Lean CLAY with GRAVEL (CL); stiff; brown; moist;

little coarse to fine GRAVEL; few coarse to fine SAND; mostly fines.

CLAYEY GRAVEL with SAND (GC); dense; brown;

moist; about 58% mostly coarse to fine GRAVEL;

about 19% little coarse to fine SAND; about 23% little fines.

Poorly graded GRAVEL (GP); coarse to fine

GRAVEL.

Poorly graded GRAVEL with CLAY and SAND (GP-GC); very dense; brown; moist; mostly coarse to fine GRAVEL; some coarse to fine SAND; few fines.

Moderate drill chatter.

Hard drilling.

R-Value = 26

EI = 29

No recovery in MCAL, chase with SPT at 3 ft bgs.

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