Attachment 7 Geotechnical Report.pdf

GEOTECHNICAL ENGINEERING INVESTIGATION

FOR

PROPOSED VA MARTINEZ CLINICAL BUILDING

AND REMOTE PARKING LOT

150 MUIR ROAD

MARTINEZ, CALIFORNIA

PROJECT NO. 612-162

PREPARED FOR

Ms. Charmian Maybury Architectural Design

Advance Design Consultants, Inc.

998 Park Avenue

San Jose, CA 95126

By

Mr. Ying-Chi Liao, C.E., G.E.

Senior Engineering Manager

MatriScope Engineering Laboratories, Inc.

601 Bercut Drive

Sacramento, California 95811

Project No. 2717 April 18, 2017

April 18, 2017

Ms. Charmian Maybury

Architectural Design

Advance Design Consultants, Inc.

998 Park Avenue

San Jose, CA 95126

., MatriScope ,.;i Engineering Laboratories, Inc .

Subject: Geotechnical Engineering Investigation Proposed VA Martinez Clinical Building and Remote Parking Lot 150 Muir Road Martinez, CA Project No. 612-162

Dear Ms. Maybury:

MEL File No. 2717

In accordance with your authorization, MatriScope Engineering Laboratories, Inc. (MatriScope) has performed a geotechnical engineering investigation for the proposed VA Martinez Clinical Building and Remote Parking Lot located at 150 Muir Road in Martinez, California. The purpose of our investigation was to explore and evaluate the subsurface conditions at various locations at the site in order to develop geotechnical engineering recommendations for use in the project design and construction.

It is imperative that MatriScope be provided the opportunity to review, in advance of construction, the civil and foundation plans related to grading and building construction to assure the recommendations contained herein are appropriate for the proposed development.

The attached report presents the results of our data review, field exploration, laboratory testing, and engineering analysis. Based on our investigation, it is our professional opinion the proposed project may be constructed at the subject site provided the recommendations contained in the attached report are implemented into project design and construction.

Recommendations provided herein are contingent on the provisions outlined in the ADDITIONAL SERVICES and LIMITATIONS sections of this report. The project Client and Owner should become familiar with these provisions in order to assess further involvement by MatriScope and other potential impacts to the proposed project.

Thank you for the opportunity of providing our services for this project. If you have questions regarding this report or if we may be of further assistance, please contact our office.

Respectfully Submitted, MatriScope Engineering Laboratories, Inc.

Liao, C.E., G.E.

ngineering Manager

601 Bercut Drive • Sacramento, CA 95811 • 916.375.6700 6244 Preston Avenue • Live rmore, CA 94 551 • 925.606.7700 www. m at ri scope. com

Geotechnical Engineering Investigation MEL File No.: 2717 Proposed VA Martinez Clinical Building and Remote Parking Lot April 18, 2017 150 Muir Road Martinez, CA

TABLE OF CONTENTS

1. INTRODUCTION

1.1 GENERAL

1.2 PROPOSED CONSTRUCTION

1.3 PURPOSE AND SCOPE OF SERVICES

2. SITE REVIEW

2.1 RECONNAISSANCE

2.2 SUBSURFACE EXPLORATION

2.3 LABORATORY TESTING

3. SITE CONDITIONS

3.1 SURFACE AND SUBSURFACE CONDITIONS

3.2 GROUNDWATER

4. CONCLUSIONS AND RECOMMENDATIONS

4.1 GENERAL

4.2 EXPANSIVE SOILS

4.3 SOIL CORROSIVITY

4.4 SITE PREPARATION

4.4.1 Stripping and Grubbing

4.4.2 Existing Utilities, Foundations, and/or Trees

4.4.3 Removal, Scarification and Compaction

4.5 TEMPORARY EXCAVATION

4.6 ENGINEERED FILL

4.6.1 Materials

4.6.2 Compaction Criteria

4.7 TRENCH PREPARATION AND BACKFILL

4.7.1 Subgrade Preparation

4.7.2 Backfill Materials

4.7.3 Compaction Criteria

4.8 SPREAD FOOTINGS

4.8.1 Allowable Bearing Pressures

4.8.2 Estimated Settlements

4.8.3 Lateral Resistance

4.8.4 Construction Considerations

4.8.5 International Building Code Seismic Design Parameters

4.9 CONCRETE SLABS-ON-GRADE

4.9.1 Subgrade Preparation

4.9.2 Rock Capillary Break

4.9.3 Construction Considerations

4.10 CONCRETE SIDEWALKS AND FLATWORK

4.11 PAVEMENTS

4.11.1 General

4.11.2 Asphalt Concrete Pavement Recommended Sections

4.11.3 Portland Cement Concrete Pavement Sections

4.11.4 Construction Consideration

150 Muir Road Martinez, CA

4.12 SITE DRAINAGE AND MOISTURE PROTECTION

5. ADDITIONAL SERVICES

5.1 PLANS AND SPECIFICATIONS REVIEW

5.2 CONSTRUCTION OBSERVATION AND TESTING

6. LIMITATIONS

PLATES

APPENDIX A FIELD INVESTIGATION AND LABORATORY TESTING

150 Muir Road Martinez, CA Page 1 of 18

GEOTECHNICAL ENGINEERING INVESTIGATION

PROPOSED VA MARTINEZ CLINICAL BUILDING

AND REMOTE PARKING LOT

150 MUIR ROAD

MARTINEZ, CA

1. INTRODUCTION

1.1 GENERAL

The proposed VA Martinez Clinical Building and Remote Parking Lot sites are located at 150 Muir Road in Martinez, California. This report contains the results of our geotechnical engineering investigation for the proposed development. The site locations relative to the vicinity of the site are shown on Plate 1.

This report includes recommendations related to the geotechnical aspects of project design and construction. Conclusions and recommendations presented in this report are based on the subsurface conditions encountered at the locations of our field exploration and the provisions and requirements outlined in the ADDITIONAL SERVICES and LIMITATIONS sections of this report.

Recommendations presented herein should not be extrapolated to other areas or used for other projects without prior review by MatriScope Engineering Laboratories, Inc. (MatriScope).

1.2 PROPOSED CONSTRUCTION

The proposed site development includes a new Clinical Building and a remote parking lot at the VA Martinez campus. The new VA Martinez Clinical Building will be two-story in height and approximately 116 feet by 62 feet in size with slab-on-grade. The proposed Remote Parking Lot (asphalt concrete pavement) will be approximately 4,600 square feet in size.

150 Muir Road Martinez, CA Page 2 of 18

1.3 PURPOSE AND SCOPE OF SERVICES

Our field investigation was performed to explore and evaluate subsurface conditions at various locations at the site in order to develop recommendations related to the geotechnical aspects of project design and construction. This report summarizes the results of our services including:

• A description of the proposed project

• A description of the site surface, subsurface and groundwater conditions observed during our field investigation

• Recommendations related to the geotechnical aspects of:

− Site preparation and earthwork construction − Utility trench excavations and backfill − Shallow foundation recommendations including allowable bearing capacity and anticipated total and differential settlements − 2015 IBC seismic design coefficients for use in structural analysis − Concrete slab-on-grade and sidewalk/flatwork − Asphalt concrete pavements − Surface drainage and moisture protection

• An appendix which includes a summary of our field investigation and laboratory programs

2. SITE REVIEW

2.1 RECONNAISSANCE

An initial site reconnaissance was performed on March 22, 2017 to observe surface conditions that may affect the geotechnical aspects of the project and to note areas of obvious geotechnical concerns. Four (4) boring locations were marked at the project site.

2.2 SUBSURFACE EXPLORATION

A subsurface exploration at the site was performed to investigate and sample soils beneath the site. One exploratory boring (B1) was advanced to an approximate depth of 10 feet near the

150 Muir Road Martinez, CA Page 3 of 18

Clinical Building site. Three exploratory borings (B2 through B4) were advanced to approximate depths of 6.5 feet in the Remote Parking Lot site. “Refusal” (an indication of very firm soils) was encountered at the bottom of boring B1. The borings were drilled with a truck-mounted drill rig equipped with flight augers. Approximate locations of exploratory borings are shown on Plates 2 and 3. After completion of drilling, the bore holes were backfilled with cuttings generated during the drilling. Obtained soil samples were sealed and transported to our Sacramento laboratory for visual examination and testing.

2.3 LABORATORY TESTING

Laboratory tests were performed on selected samples to evaluate physical properties of the soils which may affect the geotechnical aspects of project design and construction. Moisture content, dry density, Atterberg limits, compaction, R-Value and soil corrosivity parameters tests were performed in general accordance with ASTM and Caltrans test methods. Results of the moisture content and dry density are presented in the Log of Boring. Laboratory test reports (compaction, R-Value and soil corrosivity) are attached to this report in Appendix A.

3. SITE CONDITIONS

3.1 SURFACE AND SUBSURFACE CONDITIONS

The Clinical Building project site is currently occupied by a portable building as shown on Plate 2.

The portable building will be removed to allow for construction of the Clinical Building with some modification to the parking area immediately east of the existing portable building. The Remote Parking Lot site is currently used for construction staging and occupied by trailers, storage units and construction materials as shown on Plate 3.

The site soils in the Clinical Building areas are mainly weathered sandstone to the maximum explored depth of 10 feet below the existing ground surface. The top 24 inches of surficial soils are medium dense sand.

150 Muir Road Martinez, CA Page 4 of 18

The site soils in the remote parking areas consist of undocumented fill to the maximum explored depth of 6.5 feet below the existing ground surface. The fill are mainly loose to dense sand, clay and silty sand materials.

3.2 GROUNDWATER

At the time of our field investigation, no groundwater was encountered in any of our borings. It should be noted that soil moisture conditions within the site will vary depending on rainfall, and/or runoff conditions not apparent at the time of our field investigation. It is common that the soil moisture conditions will change seasonally.

Detailed descriptions of the subsurface conditions encountered during our field investigation are presented on the Log of Boring Plates A2 to A5.

4. CONCLUSIONS AND RECOMMENDATIONS

4.1 GENERAL

It is our professional opinion the proposed building pad and pavement may be supported on compacted engineered fill or undisturbed bedrock (sandstone) provided the recommendations contained in the attached report are implemented into project design and construction.

4.2 EXPANSIVE SOILS

Based on the visual examination of the soil samples obtained at the subject site, the site soils are mainly sandy materials which are considered as having very low expansion potential.

4.3 SOIL CORROSIVITY

Laboratory tests were performed for soil corrosivity parameters (minimum resistivity, pH, chloride and sulfate content) on one selected soil sample obtained from the site. Based on the minimum resistivity test result (2,630 ohm-cm), soils are not considered to be corrosive to buried metallic

150 Muir Road Martinez, CA Page 5 of 18 improvements. Results of pH (8.83), chloride (6.4 ppm) and sulfate (169.9 ppm) content tests do not indicate a significant corrosive potential to buried concrete structures and, therefore, Type II cement may be used. All underground utility lines should be corrosion-protected per recommendations of a corrosion engineer, if required.

We have provided the above preliminary corrosion test results only as indicator parameters of potential soil corrosivity for the sample tested. Other soils found on the site may be more, less, or of a similar corrosive nature.

4.4 SITE PREPARATION

4.4.1 Stripping and Grubbing

Prior to general site grading, existing vegetation, organic topsoil, and any debris should be stripped and disposed of outside the construction limits. MatriScope recommends the topsoil (less any debris) to be stripped and be stockpiled and reused for landscape purposes; however, this material should not be incorporated into any engineered fill.

4.4.2 Existing Utilities, Foundations, and/or Trees

The existing concrete slab and foundation and possible abandoned utility lines within the area of construction should be removed and disposed of off-site. Existing utility pipelines that extend beyond the limits of the proposed construction and that are to be abandoned in-place should be plugged with cement grout to prevent migration of soil and/or water.

Tree removal should include the entire root system and all surface roots larger than ½-inch in diameter. All excavations resulting from removal of these items should be cleaned of loose or disturbed material (including all previously-placed backfill) and dish-shaped (with sides sloped 3 (h): 1(v) or flatter) to permit access for compaction equipment.

4.4.3 Removal, Scarification and Compaction

Preparation of the subgrade exposed by excavation and requirements for engineered fill should be in accordance with recommendations provided below (see section ENGINEERED FILL). The

150 Muir Road Martinez, CA Page 6 of 18 bottom of removal areas should be observed and approved by the geotechnical engineer or his representative prior to scarification and compaction.

Clinical Building Area Following site stripping and any required grubbing, removal and/or over-excavation, to the design subgrade elevation, the building should be founded on a uniform building pad support. If the design subgrade elevation is not entirely founded on exposed competent sandstone, the subgrade elevation should be over-excavated to a depth of at least 12 inches below the design subgrade elevation, then backfilled with engineered fill to the design subgrade elevation. The removal and re-compaction of the site soils should extend to a horizontal distance of at least 5 feet beyond the outer edge of foundations and 2 feet beyond the outer edge of concrete sidewalk/flatwork.

Spread footing is anticipated to be supported on competent sandstone. If soil or weak/disturbed sandstone is encountered at the exposed footing excavation bottom, it should be over-excavated to competent sandstone. Over-excavations should be backfilled with lean concrete to the design footing bottom elevation.

Remote Parking Lot Area The subgrade for the proposed parking area should be removed to a depth of at least 24 inches below the design subgrade elevation. The exposed excavation bottom should be scarified to a depth of at least 8 inches, uniformly moisture-conditioned and compacted as required in the ENGINEERED FILL section prior to subsequent placement of engineered backfill to the design subgrade elevation. The removal and re-compaction of the site soils should extend to a horizontal distance of at least 2 feet beyond the outer edges of pavement and flatwork.

4.5 TEMPORARY EXCAVATION

The site soils should be excavatable with conventional equipment. Foundation excavations and shallow trenches less than five feet in depth for utilities should stand vertically for the short period of time required for construction under favorable weather conditions. All excavations must comply with applicable local, state, and federal safety regulations including the current OSHA Excavation and Trench Safety Standards. Construction site safety generally is the sole responsibility of the Contractor, who shall also be solely responsible for the means, methods, and sequencing of construction operations. We are providing the information below solely as a service to our client. Under no circumstances should the information provided be interpreted to

150 Muir Road Martinez, CA Page 7 of 18 mean that MatriScope is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred.

During wet weather, earthen berms or other methods should be used to prevent runoff water from entering all excavations. All runoff water and/or groundwater encountered within the excavation(s) should be collected and disposed of outside the construction limits.

4.6 ENGINEERED FILL

4.6.1 Materials

All engineered fill soils (on-site and imported soils) should be nearly-free of organic, rubble, rubbish, deleterious debris, clay with high plasticity, or contaminated materials, and less than 3 inches in maximum dimension.

On-Site Soils In general, near-surface, on-site soils similar to those encountered in our borings may be used in engineered fills provided they are free of deleterious debris, clays with high plasticity, organics and adequately moisture-conditioned during placement as recommended in the COMPACTION CRITERIA section. The existing concrete and asphalt concrete debris may be removed offsite.

Imported Soils All imported fill materials to be used for engineered fill should be sampled and tested by the project Geotechnical Engineer prior to being transported to the site. As a minimum, all imported fill should be free of contamination and be granular with a 3-inch maximum particle size, a Plasticity Index less than 15 and less than 30 percent passing the number 200 sieve; essentially non-plastic. Imported gravel fill should be, as a minimum, washed gravel, free from vegetation and debris, with a 1-inch maximum particle size and less than 5 percent passing the number 200 sieve.

4.6.2 Compaction Criteria

Soils scarified and material to be used for engineered fill should be uniformly moisture-conditioned to near the optimum moisture content, placed in horizontal lifts less than 8 inches in

150 Muir Road Martinez, CA Page 8 of 18 loose thickness, and compacted to at least 90 percent relative compaction as determined by the current ASTM (American Society for Testing and Materials) Test Method D1557. The upper 12 inches of subgrade in the parking area and all aggregate base materials should be compacted to a minimum of 95 percent relative compaction.

Should site grading be performed during or subsequent to wet weather, near-surface site soils may be significantly above the optimum moisture content. Additionally, it is common to encounter wet, unstable soils upon removal of site pavements or flatwork as a result of subsurface moisture becoming trapped above relatively impervious hardpan or beneath asphalt concrete or Portland cement concrete surfaces. This condition could hamper equipment maneuverability and efforts to compact site soils to the recommended compaction criteria.

Disking to aerate, chemical treatment, replacement with drier material, stabilization with a geotextile fabric or grid, or other methods may be required to reduce excessive soil moisture and facilitate earthwork operations.

4.7 TRENCH PREPARATION AND BACKFILL

4.7.1 Subgrade Preparation

Prior to placement of utility bedding, the exposed subgrade at the bottom of trench excavations should be examined to detect soft, loose, or unstable areas. Loose materials at trench bottoms resulting from excavation disturbance should be removed to firm material. If soft or unstable areas are encountered, these areas should be over-excavated to a depth of at least 2 feet or to a firm base and be replaced with additional bedding material. Where excavations cross the existing trench backfill materials, the need for and extent of over-excavation or stabilization measures should be evaluated by the Geotechnical Engineer on a case-by-case basis.

4.7.2 Backfill Materials

Pipe zone backfill (i.e., material beneath and in the immediate vicinity of the pipe) should consist of clean washed sand and/or crushed rock. If crushed rock is used for pipe zone backfill, we recommend it should have a maximum particle size less 1 inch and have less than 5 percent passing No. 200 U.S. sieve. Where crushed rock is used, the material should be completely surrounded by a non-woven filter fabric such as Mirafi 140N or equivalent. Recommendations

150 Muir Road Martinez, CA Page 9 of 18 provided above for pipe zone backfill are minimum requirements only. More stringent material specifications may be required to fulfill local codes and/or bedding requirements for specific types of pipes. We recommend the project Civil Engineer develop these material specifications based on planned pipe types, bedding conditions, and other factors beyond the scope of this study.

Trench zone backfill (i.e., material placed between the pipe zone backfill and finished subgrade) may consist of native soil and approved imported fill material that meets the requirements provided above for engineered fill.

4.7.3 Compaction Criteria

All trench backfill should be placed and compacted in accordance with recommendations provided above for engineered fill. Mechanical compaction is recommended; ponding or jetting should not be allowed, especially in areas supporting structural loads or beneath concrete slabs supported-on-grade, pavements, or other improvements.

4.8 SPREAD FOOTINGS

4.8.1 Allowable Bearing Pressures

We recommend spread footings constructed of reinforced concrete and founded on undisturbed competent sandstone as recommended in the SITE PREPARATION section of this report be used for support of the proposed building. Footings should be a minimum of 18 inches wide and embedded a minimum of 18 inches below the lowest final adjacent subgrade. If soil or weak/disturbed sandstone is encountered at the exposed footing excavation bottom, it should be over-excavated to competent sandstone and replaced with lean concrete or Controlled Low Strength Materials (CLSM) with a 28-day compressive strength of at least 100 pounds per square inch (psi).

The structural engineer should evaluate the need for reinforcement of foundation based on the anticipated loads. As a minimum, continuous foundations should be reinforced with a minimum of four No. 4 reinforcing bars, placed two each near the top and bottom, to provide structural continuity and allow the foundations to span isolated soil irregularities.

150 Muir Road Martinez, CA Page 10 of 18

An allowable bearing pressure of 6,000 pounds per square foot (psf) may be used for spread foundations with the above minimum dimensions. The allowable bearing pressure provided above is a net value; therefore, the weight of the foundation (which extends below grade) may be neglected when computing dead loads. The allowable bearing pressure applies to dead plus live loads may be increased by 1/3 for short-term loading due to wind or seismic forces.

4.8.2 Estimated Settlements

Total settlement of an individual foundation will vary depending on the plan dimensions of the foundation and the actual load supported. Based on anticipated foundation dimensions and loads, we estimate maximum settlement of foundations designed and constructed in accordance with the preceding recommendations to be less than one inch. Differential settlement between similarly loaded, adjacent footings is expected to be less than 1/2 inch. Settlement of all foundations is expected to occur rapidly and should be essentially complete shortly after initial application of the loads.

4.8.3 Lateral Resistance

Resistance to lateral loads (including those due to wind or seismic forces) may be provided by frictional resistance between the bottom of concrete foundations and the underlying soils, and by passive soil pressure against the sides of the foundations. A coefficient of friction of 0.35 may be used between cast-in-place concrete foundations and the underlying sandstone. Additional allowable passive pressure available may be taken as equivalent to the pressure exerted by a fluid weighing 350 pounds per cubic foot (pcf). These two modes of resistance should not be added unless the frictional component is reduced by 50 percent, since full mobilization of the passive resistance requires some horizontal movement, which significantly diminishes the frictional resistance.

4.8.4 Construction Considerations

Prior to placing steel or concrete, footing excavations should be cleaned of all debris, loose or soft soil, and water. All footing excavations should be observed by the project Geotechnical Engineer or his representatives just prior to placing steel or concrete to verify the recommendations contained herein are implemented during construction.

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4.8.5 International Building Code Seismic Design Parameters

Structures should be designed for lateral force requirements as set forth in Chapter 16 of the 2015 International Building Code (IBC). We recommend the following parameters:

Table 1 2015 IBC Seismic Design Parameters

Seismic Design Parameter Symbol

Recommended Value

Mapped Spectral Acceleration at Short Period

Ss 1.576g

Mapped Spectral Acceleration at 1-Second Period

S1 0.600g

Site Class A-F C Site Coefficient at Short Period Fa 1.000 Site Coefficient at 1-Second Period Fv 1.300

Spectral Response Accelerations SMS 1.576g SM1 0.780g

Design Spectral Response Accelerations SDS 1.051g SD1 0.520g

Site coordinates: Latitude 37.993819 degrees North Longitude 122.117391 degrees West

4.9 CONCRETE SLABS-ON-GRADE

Conventional concrete slab-on-grade floors are suitable for building pads provided excavations and subgrades are prepared as recommended in section titled SITE PREPARATION. Slab thickness and reinforcement should be determined by the structural engineer based on the anticipated loading. However, slabs should be at least 4 inches thick and reinforced with No. 3 reinforcing bars on 18 inches or No. 4 bars on 24 inches center-to-center spacing each way, placed at mid-slab depth. Proper and consistent location of the reinforcement at mid-slab is essential to its

150 Muir Road Martinez, CA Page 12 of 18 performance. The risk of uncontrolled shrinkage cracking is increased if the reinforcement is not properly located within the slab.

4.9.1 Subgrade Preparation

Prior to constructing interior concrete slabs supported-on-grade, surficial soils should be processed as recommended in the SITE PREPARATION and ENGINEERED FILL sections of this report.

4.9.2 Rock Capillary Break

In order to provide enhanced subgrade support, we recommend the compacted subgrade be overlain with a minimum 4-inch thickness of compacted crushed rock. If this layer is desired to also serve as a capillary break, there should be less than 5 percent by weight passing the No. 4 sieve size. A capillary break may reduce the potential for soil moisture migrating upwards toward the slab.

4.9.3 Construction Considerations

Subsurface moisture and moisture vapor naturally migrate upward through the soil and, where the soil is covered by a building or pavement, this subsurface moisture will collect. To reduce the impact of this subsurface moisture and the potential impact of introduced moisture (such as landscape irrigation or plumbing leaks) a vapor retarder may be placed on the compacted crushed rock layer (described above). This membrane typically consists of visquene or polyvinyl plastic sheeting at least ten (10) mil in thickness. The plastic sheet membrane should meet or exceed the minimum specifications for plastic water vapor retarders as outlined in ASTM E1745.

It should be noted that although capillary break and vapor barrier systems are commonly applied, this system may not be completely effective in preventing floor slab moisture problems. These systems will not "moisture proof" the floor slab nor will it assure floor slab moisture transmission rates will meet floor-covering manufacturer standards. The design and construction of such systems are dependent on the proposed use and design of the proposed building and all elements of building design and function should be considered in the slab-on-grade floor design. Building design and construction may have a greater role in perceived moisture problems since sealed buildings/rooms or inadequate ventilation may result in excessive moisture in a building and affect indoor air quality.

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Special precautions must be taken during the placement and curing of all concrete slabs.

Excessive slump (high water-cement ratio) of the concrete and/or improper curing procedures used during either hot or cold weather conditions could lead to excessive shrinkage, cracking, or curling in the slabs. High water-cement ratio and/or improper curing also greatly increase the water vapor permeability of concrete. We recommend that all concrete placement and curing operations be performed in accordance with the current edition of American Concrete Institute (ACI) Manual.

4.10 CONCRETE SIDEWALKS AND FLATWORK

Concrete sidewalks and flatwork should be a minimum of 4 inches thick and may be underlain by compacted engineered fills as recommended in the SITE PREPARATION and ENGINEERED FILL sections of this report.

4.11 PAVEMENTS

4.11.1 General

One Resistance Value (R-value) test was performed on one sample in accordance with ASTM Test Method D 2488. Result of the test indicates the site soil in the parking area has an R-value of 50. A design R-value of 35 was used in the design to account for the variance of subgrade materials which may be encountered during construction. All pavement subgrades should be prepared as recommended in the SITE PREPARATION and ENGINEERED FILL sections of this report.

4.11.2 Asphalt Concrete Pavement Recommended Sections

Pavement sections presented in the Table 3 below are based on the current Caltrans design procedures. Traffic indexes of 4.5, 5.5, and 6.5 were assumed for the design of automobile parking areas, automobile driveways/access ways, and fire truck access ways, respectively. Traffic indexes assumed above should be reviewed by the project Owner, Architect, and/or Civil Engineer to evaluate their suitability for this project. Changes in the traffic indexes will affect the corresponding pavement section.

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Table 2 Recommended Asphalt Concrete Pavement Sections

Pavement Description

Assumed Traffic Index

Asphalt Concrete

(inch)

Caltrans Class 2 Aggregate Base

(inch) Automobile Parking Areas 4.5 3 4 Automobile Driveways/Access Ways

5.5 3 7

Heavy Truck Access Ways 6.5 4 7

Asphalt paving materials and placement methods should meet current Caltrans specifications for asphalt concrete.

4.11.3 Portland Cement Concrete Pavement Sections

Portland cement concrete pavements are typically better able to resist the intense stresses induced in pavements by the turning motions of vehicles - particularly delivery and garbage trucks. Concrete pavements should be used in areas frequented by such vehicles as well as in driveway and entry aprons. Concrete pavement sections presented in the table below are based on current Portland Cement Association (PCA) design procedures and the assumptions listed below. These assumptions should be reviewed by the project Owner, Architect, and/or Civil Engineer to evaluate their suitability for this project. Changes in the assumptions will affect the corresponding pavement section.

Table 3 Recommended Concrete Pavement Sections

Pavement Description

Assumed Traffic Index

Portland Cement

Concrete (inch)

Caltrans Class 2 Aggregate Base

(inch)

Automobile Driveways/Access Ways

5.5 5 6

Heavy Truck Access Ways 6.5 7 6

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The concrete should be properly cured in accordance with PCA recommended procedures and vehicular traffic should not be allowed for 3 days (automobile traffic) or 7 days (truck traffic). To help offset plastic shrinkage, concrete pavement may be reinforced, as a minimum, with at least No. 3 bars, 24 inches on-center, each way. Construction and/or control joint spacing should not exceed 12 feet. Thickened edges should be used along outside edges of concrete pavements. Edge thickness should be at least 2 inches greater than the concrete pavement thickness and taper to the actual concrete pavement thickness 36 inches inward from the edge. Integral curbs may be used in lieu of thickened edges.

4.11.4 Construction Consideration

The above pavement recommendations should be incorporated into project plans and specifications by the project architect and/or engineer. These recommendations are not intended to be used as a specification for construction. Adequate drainage (both surface and subsurface) should be provided such that the subgrade soils and aggregate base materials are not allowed to become wet.

Unstable Subgrade In the event unstable (pumping) subgrade is encountered within planned pavement areas, we recommend a heavy, rubber-tired vehicle (typically a loaded water truck) be used to test the load/deflection characteristics of the finished subgrade materials. We recommend this vehicle have a minimum rear axle load (at the time of testing) of 16,000 pounds with tires inflated to at least 65 pounds per square inch pressure.

If the tested surface shows a visible deflection extending more than 6 inches from the wheel track at the time of loading, or a visible crack remains after loading, corrective measures should be implemented. Such measures could include disking to aerate, chemical treatment, replacement with drier material, or other methods. We recommend MatriScope be retained to assist in developing which method (or methods) would be applicable for this project.

4.12 SITE DRAINAGE AND MOISTURE PROTECTION

Foundation and slab performance depends greatly on how well runoff waters drain from the site.

This drainage should be maintained both during construction and over the entire life of the project. The ground surface around structures should be graded so that water flows rapidly away

150 Muir Road Martinez, CA Page 16 of 18 from structures and slopes without ponding. The surface gradient needed to do this depends on the landscaping type. In general, pavement and lawns within five feet of buildings should slope away at gradients of at least two percent. Densely vegetated areas should have minimum gradients of 5 percent away from buildings in the first five feet if it is practical to do so.

Planters should be built so that water exiting from them will not seep into the foundation areas or beneath slabs and pavement. In general, the elevation of exterior grades should not be higher than the elevation of the subgrade beneath the slab to help prevent water intrusion beneath slabs. In any event, maintenance personnel should be instructed to limit irrigation to the minimum actually necessary to properly sustain landscaping plants. Should excessive irrigation, waterline breaks, or unusually high rainfall occur, saturated zones and "perched" groundwater may develop. Consequently, the site should be graded so that water drains away readily without saturating the foundation or landscaped areas. Potential sources of water, such as water pipes, drains, garden sprinklers, and the like, should be frequently examined for signs of leakage or damage. Any such leakage or damage should be promptly repaired.

All utility trenches should be backfilled with compacted non-pervious fill material. Special care should be taken during installation of sub-floor water and sewer lines to reduce the possibility of leaks.

5. ADDITIONAL SERVICES

5.1 PLANS AND SPECIFICATIONS REVIEW

We recommend that grading plans and specifications should be reviewed by MatriScope in order to assure that our earthwork and foundation recommendations have been properly interpreted and implemented during design. In addition, prior to construction, the building structural design plans and specifications should be reviewed by MatriScope to verify the recommendations provided in this report are in compliance with the proposed design.

In the event MatriScope is not retained to perform this recommended review, we will assume no responsibility for misinterpretation of our recommendations.

150 Muir Road Martinez, CA Page 17 of 18

5.2 CONSTRUCTION OBSERVATION AND TESTING

We recommend that all earthworks during construction be monitored by a representative from MatriScope, including site preparation, placement of all engineered fill, trench backfill and wall backfill, construction of slab and roadway subgrade, and all foundation excavations. It is essential that the finished subgrade and footing excavation in all areas to receive engineered fill or to be used for the future support of structures, concrete slabs-on-grade or pavement sections be observed and approved by the Project Geotechnical Engineer or a representative from MatriScope PRIOR TO PLACEMENT OF ENGINEERED FILL OR CONCRETE POURING FOR BUILDING

PAD AND SLAB-ON-GRADE.

The purpose of these services would be to provide MatriScope the opportunity to observe the soil conditions encountered during construction, evaluate the applicability of the recommendations presented in this report to the soil conditions encountered, and recommend appropriate changes in design or construction procedures if conditions differ from those described herein.

6. LIMITATIONS

Recommendations contained in this report are based on our field observations and subsurface explorations, limited laboratory tests, and our present knowledge of the proposed construction.

It is possible that soil conditions could vary between or beyond the points explored. If soil conditions are encountered during construction which differ from those described herein, we should be notified immediately in order that a review may be made and any supplemental recommendations provided. If the scope of the proposed site development changes from that described in this report, our recommendations should also be reviewed.

We have prepared this report in substantial accordance with the generally accepted geotechnical engineering practice as it exists in the site area at the time of our study. No warranty is expressed or implied. The recommendations provided in this report are based on the assumption that an adequate program of tests and observations will be conducted by MatriScope or other qualified geotechnical professionals during the construction phase in order to evaluate compliance with our recommendations. Other standards or documents referenced in any given standard cited in this

150 Muir Road Martinez, CA Page 18 of 18 report, or otherwise relied upon by the author of this report, are only mentioned in the given standard; they are not incorporated into it or “included by reference”, as that latter term is used relative to contracts or other matters of law.

This report may be used only by the client and only for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both on site and off site) or other factors may change over time, and additional work may be required with the passage of time. Any party other than the client who wishes to use this report shall notify MatriScope of such intended use. Based on the intended use of the report, MatriScope may require that additional work be performed and that an updated report be issued. Non-compliance with any of these requirements by the client or anyone else will release MatriScope from any liability resulting from the use of this report by any unauthorized party.

601 Bercut Drive Sacramento, CA 95811 Phone: (916) 375-6700 Fax: (916) 447-6702 www.matriscope.com

Project No.: 2717 Plate

Project Name: VA Martinez Clinical Building and Remote Parking Lot Location: 150 Muir Road, Martinez, California Date: April 18, 2017

Site Vicinity Map

Clinical Building

Site

Remote Parking Lot Site http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fgalleryhip.com%2Fsimple-north-compass.html&ei=ftEVVeXBG5S2oQTgroHoCA&bvm=bv.89381419,d.cGU&psig=AFQjCNHB35LIGC6cWieZ5C52vw7MiYAw6Q&ust=1427579642539710�

Phone: (916) 375-6700 Fax: (916) 447-6702 www.matriscope.com

Project No.: 2717 Plate

Project Name: VA Martinez Clinical Building and Remote Parking Lot Location: 150 Muir Road, Martinez, CA Date: April 18, 2017

Clinical Building Boring Location Map

Legend:

Approximate Boring Location

B1 B1 http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fgalleryhip.com%2Fsimple-north-compass.html&ei=ftEVVeXBG5S2oQTgroHoCA&bvm=bv.89381419,d.cGU&psig=AFQjCNHB35LIGC6cWieZ5C52vw7MiYAw6Q&ust=1427579642539710�

Phone: (916) 375-6700 Fax: (916) 447-6702 www.matriscope.com

Project No.: 2717 Plate

Project Name: VA Martinez Clinical Building and Remote Parking Lot Location: 150 Muir Road, Martinez, CA Date: April 18, 2017

Remote Parking Lot Boring Location Map

Legend:

Approximate Boring Location

B1B2

B3

B4

Base Map:

New Parking Lot Coordination provided by Advance Design Consultants, Inc.

dated 2/24/17 http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fgalleryhip.com%2Fsimple-north-compass.html&ei=ftEVVeXBG5S2oQTgroHoCA&bvm=bv.89381419,d.cGU&psig=AFQjCNHB35LIGC6cWieZ5C52vw7MiYAw6Q&ust=1427579642539710�

150 Muir Road Martinez, CA Page 1 of 4

APPENDIX A

FIELD INVESTIGATION AND LABORATORY TESTING

FIELD INVESTIGATION

General

The subsurface conditions at the site were explored on April 1, 2017 by drilling 4 borings (B1- B4) to a maximum depth of 10 feet below existing ground surface. Borings were drilled using truck-mounted drill rig CME 75 equipped with 4-inch-diameter flight augers. The locations of borings performed for this investigation are shown on Plates 2 and 3 of the report.

Borings were located in the field by visual sighting and/or pacing from existing site features.

Therefore, the location of borings shown on Plates 2 and 3 should be considered approximate and may vary from that indicated on the plate. After completion of drilling, the boreholes were backfilled with cuttings generated during the drilling and patched with cement in asphalt paved areas.

Our representative maintained logs of the borings, visually classified soils encountered according to the Unified Soil Classification System (see Plate A1), and obtained relatively undisturbed and bulk samples of the subsurface materials. Logs of Borings are presented on Plates A-2 to A-5.

Sampling Procedures

Soil samples were obtained from the borings using either a Modified California Sampler driven 18 inches (unless otherwise noted) into undisturbed soil using a 30-inch drop of a 140-pound hammer. Blow counts were recorded at 6-inch intervals for each sample attempt and are reported on the logs in terms of blows-per-foot for the last foot of penetration. Soil samples obtained from the borings were packaged and sealed in the field to reduce moisture loss and disturbance, and returned to our laboratory for further testing.

150 Muir Road Martinez, CA Page 2 of 4

LABORATORY TESTING

General

Laboratory tests were performed on selected samples to aid in soil classification and to evaluate physical properties of the soils which may affect the geotechnical aspects of project design and construction. A description of the laboratory testing program is presented below.

Moisture Content and Dry Unit Weight

Moisture content and dry unit weight tests were performed to evaluate moisture-conditioning requirements during site preparation and earthwork grading; soil overburden, and active and passive earth pressures; and relative soil strength and compressibility. Moisture content was evaluated in general accordance with ASTM Test Method D2216; dry unit weight was evaluated using procedures similar to ASTM Test Method D2937. Results of these tests are presented on the logs of Borings.

Atterberg Limits

An Atterberg Limits (Liquid Limit and Plasticity Limit) test was performed to aid in soil classification and to evaluate the plasticity characteristics of the material. The test was performed in general accordance with ASTM Test Method D4318. Test results are presented on the log of Borings and summarized in Table A1 below. The laboratory test reports are attached.

Table A1 Summary of Atterberg Limits Test Results

Boring No.

Sample Depth (feet)

Liquid Limit

Plastic Limit

Plasticity Index

B2 5 50 19 31

150 Muir Road Martinez, CA Page 3 of 4

Compaction

Compaction test was performed on one near-surface bulk soil sample to evaluate maximum dry density and optimum moisture content. Test procedures were in general accordance with ASTM Test Method D1557. Results of this test are presented in Table A2. Laboratory test report is included in this appendix.

Table A2 Summary of Compaction Test Results

R-Value

Resistance value (R-value) test was performed on one bulk soil sample obtained from the site to evaluate pavement support characteristics of the near-surface site soils. Test procedures were in general accordance with ASTM Test Method D2488. Test result of R-value is shown in Table A3. The laboratory test report is attached.

Table A3 R-Value Test Result Summary

Soil Corrosivity

One sample of the near-surface soils encountered at the site was subjected to chemical analysis for the purpose of corrosion assessment. The sample was tested for pH, minimum resistivity, soluble sulfates, and soluble chlorides. The sample was tested in general accordance with California Test Methods 643, 422, and 417 for pH and minimum resistivity, soluble

Boring No.

Sample Depth (feet)

Maximum Dry Density (pcf)

Optimum Moisture Content

B1 0-5 119.4 10.2

Boring No. Sample Depth (feet)

R-Value

B3 0-5 50

150 Muir Road Martinez, CA Page 4 of 4 chlorides, and soluble sulfates, respectively. The test results are presented in Table A4 and attached in this appendix.

Table A4 Summary of Corrosivity Test Results

Boring No.

Sample Depth (feet)

Minimum Resistivity (Ohm-Cm) pH Water Soluble

Sulfates (ppm)

Water Soluble Chlorides

(ppm) B1 2 2,630 8.83 169.6 6.4

The 2003 California Department of Transportation (Caltrans) Corrosion Guidelines considers a site to be corrosive if water-soluble chloride content is 500 ppm or greater, sulfate concentration is 2,000 ppm or greater, or pH is 5.5 or less.

The Corrosion Guidelines indicates resistivity serves only as an indicator parameter for the possible presence of soluble salts and is not used by Caltrans to define a corrosive area. With the exception of Mechanically Stabilized Embankment (MSE) walls, soil and water are not tested by Caltrans for chlorides and sulfates if the minimum resistivity is greater than 1,000 ohm-cm because a minimum resistivity greater than 1,000 ohm-cm indicates that the chloride and sulfate contents are low (i.e. low corrosion potential).

We have provided the above preliminary corrosion test results. These test results are only indicator parameters of potential soil corrosivity for the sample tested. Other soils found on the site may be more, less, or of a similar corrosive nature.

LIST OF ATTACHMENTS

The following plates are attached and complete this appendix.

Plate A-1 to A-5 Unified Soil Classification System and Boring Logs Atterberg Limits Test Report (1 page) Compaction Test Report (1 page) R-Value Test Report (1 page) Soil Corrosivity Test Summary Report (1 page)

SYMBOLS

GW

GP

GM

GC

SW

SP

SM

SC

ML

CL

OL

MH

CH

OH

PT

SANDS AND

SANDY SOILS

50% OR MORE OF

COARSE

FRACTION PASSES

NO. 4 SIEVE

HIGHLY ORGANIC SOILS

SOIL CLASSIFICATION CHART

NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATION

601 Bercut Drive Sacramento, CA 95811 Phone: (916) 375-6700 Fax: (916) 447-6702

PLATE

A-1

FINE

GRAINED

SOILS

50% OR

MORE OF

MATERIAL

PASSES THE

NO. 200

SIEVE

SILTS AND CLAYS

SILTS AND CLAYS

LIQUID LIMIT LESS

THAN 50

LIQUID LIMIT 50 OR

MORE

INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR,

SILTY OR CLAYEY FINES SANDS OR CLAYEY SILTS WITH

SLIGHT PLASTICITY

INORGANIC CLAY OF LOW TO MEDIUM PLASTICITY,

GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN

CLAYS

ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW

PLASTICITY

INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS

FINE SAND OR SILTY SOILS

INORGANIC CLAYS OF HIGH PLASTICITY

ORGANIC CLAYS OR MEDIUM TO HIGH PLASTICITY,

ORGANIC SILTS

PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC

CONTENTS

MAJOR DIVISIONS TYPICAL DESCRIPTIONS

WELL-GRADED GRAVELS, GRAVEL-SAND MIXTURES,

LITTLE OR NO FINES

COARSE

GRAINED

SOILS

MORE THAN

50%

RETAINED

ON NO. 200

SIEVE

CLEAN GRAVELS

(LITTLE OR NO FINES)

GRAVEL AND

GRAVELLY SOILS

MORE THAN 50%

OF COARSE

FRACTION

RETAINED ON

NO. 4 SIEVE

POORLY-GRADED GRAVELS, GRAVEL-SAND MIXTURES,

LITTLE OR NO FINES

SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES

CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES

WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR

NO FINES

POORLY-GRADED SANDS, GRAVELLY SAND, LITTLE OR

NO FINES

SILTY SANDS, SAND-SILT MIXTURES

CLAYEY SANDS, SAND-CLAY MIXTURES

GRAVELS WITH FINES

(APPRECIABLE

AMOUNT OF FINES)

CLEAN SANDS

(LITTLE OR NO FINES)

SANDS WITH FINES

(APPRECIABLE

AMOUNT OF FINES)

Sheet no.

Logged By Tim P.

Boring Dia.

4"

Latitude N/A

MC 1-1 50 / 2" 7.4 108.2

MC 1-2 50 / 2"

MC 1-3 50 / 0.5"

601 Bercut Drive PLATE Sacramento, CA 95811 Phone: (916) 375-6700 Fax: (916)447-6702

A2

Sample Type Modified California Sampler

SA

M

PL

E

N U

M

BE

R

BL

O

W S/

FT

M O

IS

TU

RE

DR

Y

DE

N

SI

TY

(p cf

PE

N

ET

RO

M

ET

ER

(t sf

N/A

U

SC

S

SY

M

BO

LS

SA

M

PL

E

TY

PE

DESCRIPTION AND CLASSIFICATION

DE

PT

H (fe et

150 Muir Road, Martinez 2717 Ying-Chi Liao

Proposed VA Martinez Clinical Building and Remote Parking Lot B1

Hole Number

LOG OF BORING

Site Location Project Number Checked By

Project

Total Depth 4/1/2017 4/1/2017 Exploration Geoservices, Inc. 10' Started Completed Driller

2"AC/4" AB

WEATHERED SANDSTONE, yellowish brown, very dense, slightly moist

Boring was ended at 10'. No groundwater was encountered.

Drill Method Drill Equipment Flight Augers CME 75

Depth to Groundwater N/A

Longitude N/A

SP

SAND, yellowish brown, fine-grained, medium dense sand

Approx. Elevation

Logged By Tim P.

Boring Dia.

4"

Latitude N/A

MC 2-1 56 7.3 116.7

MC 2-2 18

601 Bercut Drive PLATE Sacramento, CA 95811 Phone: (916) 375-6700 Fax: (916)447-6702

SAND, yellowish brown, medium dense, slightly moist

FILL

dense

FILL

A3

Boring was ended at 6.5'. No groundwater was encountered.

FAT CLAY, dark yellowish brown, with gravel, medium stiff

PI = 50

SP

CH

Modified California Sampler

SA

M

M

BE

R

BL

O

W S/

FT

M O

IS

DR

Y

DE

N

PE

N

ET

RO

M

150 Muir Road, Martinez 2717 Ying-Chi Liao

Proposed VA Martinez Clinical Building and Remote Parking Lot B2

Hole Number

LOG OF BORING

Site Location Project Number Checked By

Project

Total Depth 4/1/2017 4/1/2017 Exploration Geoservices, Inc. 6.5' Started Completed Driller

Drill Method Drill Equipment Flight Augers CME 75

Depth to Groundwater N/A

Longitude N/A

Approx. Elevation N/A

U

SC

S

SY

M

BO

LS

SA

M

PL

E

TY

PE

DESCRIPTION AND CLASSIFICATION

DE

PT

H (fe et

Sample Type

Logged By Tim P.

Boring Dia.

4"

Latitude N/A

MC 3-1 46 5.9 104.2

601 Bercut Drive PLATE Sacramento, CA 95811 Phone: (916) 375-6700 Fax: (916)447-6702

SILTY SAND, yellowish brown, loose to medium dense, slightly moist

Drill Method Drill Equipment Flight Augers CME 75

Depth to Groundwater N/A

Longitud…