Attachment 5 - Geotechnical Report - 04-21-17.pdf

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Geotechnical Engineering Report VA Southern Oregon Rehabilitation Center and Clinics 8495 Crater Lake Highway White City, Oregon

Prepared for:

Mr. Bill Wilson VA Southern Oregon Rehabilitation Center and Clinics Buildings 225 and 226

White City, Oregon 97503

April 21, 2017 Project No. 70995.000

©2017 PBS Engineering and Environmental Inc

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Geotechnical Engineering Report VA Southern Oregon Rehabilitation Center and Clinics Buildings 225 and 226 8495 Crater Lake Highway White City, Oregon

Project No. 70995.000

Prepared for:

Mr. Bill Wilson VA Southern Oregon Rehabilitation Center and Clinics

White City, Oregon 97503

Prepared by:

Reviewed by:

Ryan White, PE, GE Geotechnical Discipline Lead

Arlan H. Rippe, PE, GE, D.GE Senior Geotechnical Consultant

6/30/2018

Geotechnical Engineering Report VA Southern Oregon Rehabilitation Center and Clinics i

TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 General

1.2 Purpose and Scope

1.2.1 Literature and Records Review

1.2.2 Subsurface Explorations

1.2.3 Soils Testing

1.2.4 Geotechnical Engineering Analysis

1.2.5 Report Preparation

1.3 Project Understanding

2.0 SITE CONDITIONS

2.1 Surface Description

2.2 Geologic Setting

2.2.1 Local Geology

2.3 Subsurface Conditions

2.3.1 Soil

2.3.2 Groundwater

3.0 CONCLUSIONS AND RECOMMENDATIONS

3.1 Geotechnical Design Considerations

3.2 Seismic Design Criteria

3.2.1 Liquefaction Potential

3.2.2 Other Seismic Considerations

3.3 Shallow Foundations

3.3.1 Footing Preparation

3.3.2 Footing Embedment Depths

3.3.3 Minimum Footing Widths / Design

3.3.4 Foundation Static Settlement

3.3.5 Lateral Resistance

3.3.6 Below Grade Construction

3.4 Floor Slabs

3.5 Recommended Pavement Sections

4.0 CONSTRUCTION RECOMMENDATIONS

4.1 Site Preparation

4.1.1 Proofrolling/Subgrade Verification

4.2 Subgrade Protection

4.2.1 Wet Weather and Wet Soil Conditions

4.3 Excavation

4.4 Structural Fill

4.4.1 On-Site Soil

4.4.2 Borrow Material

4.4.3 Select Granular Fill

4.4.4 Crushed Aggregate Base

4.4.5 Utility Trench Backfill

4.4.6 Stabilization Material

5.0 ADDITIONAL SERVICES AND CONSTRUCTION OBSERVATIONS

6.0 LIMITATIONS

7.0 REFERENCES

ii

SUPPORTING DATA

Figures

Figure 1 Vicinity Map Figure 2 Site Plan

Appendix A – Field Explorations

Table A-1 Terminology Used to Describe Soil Table A-2 Key to Boring Log Symbols Figures A1–A3 Logs for Borings B-1 through B-3

1.0 INTRODUCTION

1.1 General

This report presents the results of the PBS Engineering and Environmental Inc. (PBS) geotechnical engineering services for the proposed new Logistics Warehouse and Administrative Office building at the Veterans Affairs (VA) Southern Oregon Rehabilitation Center and Clinics (SORCC) facility in White City, Oregon. The site location is shown on the Vicinity Map, Figure 1. The exploration locations in relation to existing and proposed site features are shown on the Site Plan, Figure 2.

1.2 Purpose and Scope

The purpose of PBS’ services was to develop geotechnical design and construction recommendations in support of the proposed new building. This was accomplished by performing the following scope of services:

1.2.1 Literature and Records Review

PBS reviewed various relevant published geologic maps of the area for information regarding geologic conditions. We also reviewed previously completed reports for the project vicinity provided by you and the design team, or that were available in our files.

1.2.2 Subsurface Explorations

PBS completed three borings in the area of the demolition and new construction. The borings were advanced to depths between 26.5 and 31.5 feet below the existing ground surface (bgs); borings were logged and representative soil samples collected by a member of the PBS engineering staff.

1.2.3 Soils Testing

Collected soil samples were transported to our laboratory and classified in general accordance with the Unified Soil Classification System, Visual-Manual Procedure. Laboratory tests included natural moisture contents and grain-size analyses (refer, Appendix B, Laboratory Testing).

1.2.4 Geotechnical Engineering Analysis

Data collected during the subsurface explorations, literature research, and laboratory testing were used to develop specific geotechnical design and construction recommendations.

1.2.5 Report Preparation

This Geotechnical Engineering Report summarizes the results of our explorations, testing, and analyses, including information relating to the following:

• Exploration logs and site plan showing approximate locations

• Laboratory test results

• Groundwater conditions

• Earthwork, grading, and cut and fill recommendations:

− evaluation of the site soils for use as fill

− temporary and permanent slope inclinations

− structural fill materials and preparation

− wet weather/conditions considerations

− utility trench backfill

• Results of liquefaction and lateral spreading analysis

• Shallow foundation support recommendations

− minimum embedment

− allowable bearing pressure

− estimated settlement

− sliding coefficient

• Seismic Design Criteria in accordance with the 2014 Oregon Structural Specialty Code (OSSC), 2015 International Building Code (IBC) and VA Handbook H-18-8.

• Slab and pavement subgrade preparation recommendations

• Recommended pavement section thickness

• Geotechnical construction considerations

1.3 Project Understanding

PBS understands the Veterans Affairs (VA) plans to demolish two buildings (Buildings 225 and 226) and construct a new 22,600 square foot (sf) building. The new Logistics Warehouse and Administrative Office building will be a one- to two-story, brick-faced concrete CMU and steel building

The purpose of PBS’ services was to evaluate the subsurface conditions within the proposed building footprint and provide geotechnical information needed to develop recommendations for use in design and construction. The proposed project will include parking and utilities that will be retrofitted to fit the new building construction. Primary geotechnical considerations for development at the site are the presence of dense to very dense gravelly soils near the ground surface.

2.0 SITE CONDITIONS

2.1 Surface Description

The new building will be located adjacent to the southeast side of Mess Hall Road E, northwest of Hospital Road, and southwest of Avenue L in White City, Oregon (refer Figure 2). The area is currently occupied by two buildings, Buildings 225 and 226, which are separated by a gravel-surfaced area used for equipment storage. Based on our review of available topography, the area is generally flat.

2.2 Geologic Setting

2.2.1 Local Geology

Locally, the area is mapped (Wells, 1956) as Quaternary bench gravel (Qbg). These soils typically consist of poorly sorted gravel, sand, and silt, merging into alluvium in places. This is consistent with soils encountered during our explorations, which consisted primarily of gravel with silt and sand.

2.3 Subsurface Conditions

2.3.1 Soil

Subsurface conditions at the site were explored by drilling three borings designated as B-1 through B-

3. The borings were advanced to depths of 26.5 to 31.5 feet bgs and completed on March 13, 2017, by Western States Soil Conservation, Inc., of Hubbard, Oregon, using mud rotary drilling techniques.

The explorations were logged and representative samples collected by a geologist from PBS. Boring logs summarizing the subsurface conditions encountered in the explorations are presented in Appendix A. The soils encountered in all borings consisted of gravelly soils, with uncorrected SPT N-values ranging from 31 to over 50, corresponding to dense to very dense relative density.

2.3.2 Groundwater

Groundwater was encountered while drilling borings B-1 through B-3 on March 13, 2017, at a depth of approximately 5 feet below the ground surface (bgs). Additional information regarding the groundwater depths in the project area was obtained from local well logs and previous explorations performed by Marquess and Associates in November 4, 2010. These data were recorded on different dates and indicate groundwater was present at depths of 5 to 10 feet bgs.

Perched groundwater may be encountered at the project site due to variations in fill and alluvial deposits and will fluctuate due to variations in rainfall, agricultural irrigation, and the season.

3.0 CONCLUSIONS AND RECOMMENDATIONS

3.1 Geotechnical Design Considerations

The subsurface conditions at the site consisted mainly of gravelly soils including variable percentages of silt and sand. Based on our observations and analyses, conventional foundation support on shallow spread footings is feasible for the proposed replacement structures. Excavation with conventional equipment is feasible, in our current opinion.

Plans for the project had not been completed when this report was prepared. Design recommendations presented in this report are based on our engineering judgment and experience with projects within similar geologic areas. PBS should be engaged to review the project plans once they have been further developed so we can update our recommendations as necessary.

3.2 Seismic Design Criteria

Based on our review of VA Handbook H-18-8, dated October 1, 2016, and our understanding that the proposed new building will be considered ancillary facilities, the following seismic design criteria were developed considering the requirements of the 2014 Oregon Structural Specialty Code (OSSC) and the 2015 IBC, and are summarized in Table 1 as follows:

Table 1: 2014 OSSC (2015 IBC) Seismic Design Parameters

Parameter Short Period 1 Second Maximum Credible Earthquake Spectral Acceleration

Ss = 0.60 g S1 = 0.32 g

Site Class C

Site Coefficient Fa = 1.16 Fv = 1.48

Adjusted Spectral Acceleration SMS = 0.70 g SM1 = 0.0.48 g

Design Spectral Response Acceleration Parameters SDS = 0.46 g SD1 = 0.32 g

Design Spectral Peak Ground Acceleration 0.18 g g – Acceleration due to gravity

3.2.1 Liquefaction Potential

Liquefaction is defined as a decrease in the shear resistance of loose, saturated, cohesionless soil (e.g., sand) or low plasticity silt soils, due to the buildup of excess pore pressures generated during an earthquake. This results in a temporary transformation of the soil deposit into a viscous fluid.

Liquefaction can result in ground settlement, foundation bearing capacity failure, and lateral spreading of ground.

Based on a review of the Oregon Statewide Geohazard Viewer (HazVu), the existing VA buildings are not located in an area of liquefaction hazard. We did not encounter potentially liquefiable soils in any of our explorations. As a result, our current opinion is that the risk of structurally damaging liquefaction settlement at the site is very low.

3.2.2 Other Seismic Considerations

Other site-specific seismic hazards considered include earthquake-induced landslides, fault rupture, seiche and tsunami inundation, lateral spreading, and earthquake shaking. Based on the topography and geology at the site, we consider the risk from earthquake-induced landslides and seiche and tsunami inundation to be very low. Because the risk of liquefaction at the proposed building addition locations is also very low, our opinion is that lateral spreading during a design-level earthquake does not represent a significant hazard. Strong earthquake ground shaking likely will occur during a design-level seismic event on the Cascadia Subduction Zone (CSZ). The nearest faults are located 30 miles east of the site in the US Geological Survey (USGS) Quaternary Faults and Folds database. Based on our current understanding of the project, our opinion is that effects of earthquake ground motions can be accounted for by using code-based design procedures.

3.3 Shallow Foundations

Shallow spread footings bearing on native dense to very dense gravelly soils may be used to support loads associated with the new additions provided the recommendations in this report are followed.

Footings should not be supported on undocumented fill.

3.3.1 Footing Preparation

Excavations for footings should be carefully prepared to a neat and undisturbed state. A representative from PBS should confirm suitable bearing conditions and evaluate all exposed footing subgrades. Observations should also confirm that loose or soft materials have been removed from new footing excavations and concrete slab-on-grade areas. Localized deepening of footing excavations may be required to penetrate loose, wet, or deleterious materials.

We recommend a layer of compacted, crushed rock be placed over the footing subgrades to help protect them from disturbance due to foot traffic and the elements. Placement of this rock is the prerogative of the contractor; regardless, the footing subgrade should be in a dense or stiff condition prior to pouring concrete. Based on our experience, approximately 4 inches of compacted crushed rock will be suitable beneath the footings.

3.3.2 Footing Embedment Depths

We recommend that all footings be founded a minimum of 18 inches below the lowest adjacent grade. The footings should be founded below an imaginary line projecting upward at a 1H:1V (horizontal to vertical) slope from the base of any adjacent, parallel utility trenches or deeper excavations.

3.3.3 Minimum Footing Widths / Design

Continuous wall and isolated spread footings should be at least 18 and 24 inches wide, respectively.

Footings should be sized using a maximum allowable bearing pressure of 3,500 pounds per square foot (psf). This is a net bearing pressure and the weight of the footing and overlying backfill can be disregarded in calculating footing sizes. The recommended allowable bearing pressure applies to the total of dead plus long-term-live loads. Allowable bearing pressures may be increased by one-third for seismic and wind loads.

3.3.4 Foundation Static Settlement

Footings will settle in response to column and wall loads. Based on our evaluation of the subsurface conditions and our analysis, we estimate post-construction settlement will be less than 1 inch for the column and perimeter foundation loads. Differential settlement will be on the order of one-half of the total settlement.

3.3.5 Lateral Resistance

Lateral loads can be resisted by passive earth pressure on the sides of footings and grade beams, and by friction at the base of the footings. A passive earth pressure of 300 pounds per cubic foot (pcf) may be used for footings confined by native soils and new structural fills. The allowable passive pressure has been reduced by one-half to account for the large amount of deformation required to mobilize full passive resistance. Adjacent floor slabs, pavements, or the upper 12-inch depth of adjacent unpaved areas should not be considered when calculating passive resistance. For footings supported on native soils or new structural fills, use a coefficient of friction equal to 0.45 when calculating resistance to sliding. These values do not include a factor of safety (FS).

3.3.6 Below Grade Construction

Although unanticipated, below-grade excavation areas, such basements and utility vaults, likely would encounter shallow groundwater. Consequently, proposed permanent below-grade areas should include subdrainage or waterproofing, as well as provisions to resist buoyant uplift. If any such areas are planned, PBS can assist in providing appropriate design details.

3.4 Floor Slabs

Satisfactory subgrade support for building floor slabs can be obtained from the native gravel subgrade prepared in accordance with our recommendations presented in the Site Preparation, Wet Weather and Wet Soil Conditions, and Select Granular Fill sections of this report. A minimum 6-inch-thick layer of imported granular material should be placed and compacted over the prepared subgrade. Imported granular material should be composed of crushed rock or crushed gravel that is relatively well graded between coarse and fine, contains no deleterious materials, has a maximum particle size of 1 inch, and has less than 5 percent by dry weight passing the US Standard No. 200 Sieve.

Floor slabs supported on a subgrade and base course prepared in accordance with the preceding recommendations may be designed using a modulus of subgrade reaction (k) of 250 pounds per cubic inch (pci).

3.5 Recommended Pavement Sections

PBS understands that the parking areas at the site will consist of AC pavement limited to car and occasional truck traffic. The AC pavement was evaluated using a pavement design life of 20 years and an assumed truck factor of 1.0 equivalent single-axle loads (ESAL) per truck with up to 10 trucks per day. The subgrade under AC pavement areas should be prepared by scarifying, moisture conditioning, and recompacting a minimum of 12 inches below the bottom of the base course. The following table includes our recommended minimum pavement section thicknesses.

Table 2. Minimum AC Pavement Sections

Traffic Loading

AC

(inches)

Base Course (inches)

Subgrade

Pull-in Car Parking Only

2.5 8 Dense/Stiff subgrade as verified by PBS personnel Drive Lanes and Access Roads

3.5 8

The asphalt cement binder should be selected according to ODOT SS 00744.11 – Asphalt Cement and Additives. The AC should consist of ½-inch hot mix asphalt concrete (HMAC) with a maximum lift thickness of 3 inches. The AC should conform to ODOT SS 00744.13 and 00744.14 and be compacted to 91 percent of maximum theoretical density (Rice value) of the mix, as determined in accordance with

ASTM D2041.

Heavy construction traffic on new pavements or partial pavement sections (such as base course over the prepared subgrade) will likely exceed the design loads and could potentially damage or shorten the pavement life. Therefore, we recommend construction traffic not be allowed on new pavements, or that the contractor take appropriate precautions to protect the subgrade and pavement during construction.

If construction traffic is to be allowed on newly constructed road sections, an allowance for this additional traffic will need to be made in the design pavement section.

4.0 CONSTRUCTION RECOMMENDATIONS

4.1 Site Preparation

Construction of the proposed additions will involve clearing and grubbing of the existing vegetation or demolition of existing structures. Demolition should include removal of existing foundations, utilities, etc., throughout the proposed new building footprint. Underground utility lines, or other abandoned structural elements should also be removed. The voids resulting from removal of foundations or loose soil in utility lines should be backfilled with compacted structural fill. The base of these excavations should be excavated to firm native subgrade before filling, with sides sloped not steeper than 1H:1V, to allow for uniform compaction.

Materials generated during demolition should be transported off site or stockpiled in areas designated by the owner’s representative, away from any below-grade excavations.

4.1.1 Proofrolling/Subgrade Verification

Following site preparation and prior to placing aggregate base for the shallow foundations, building pad, or pavement sections, the exposed subgrade should be evaluated either by proofrolling or another approved method of subgrade verification. The subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify unsuitable areas. If evaluation of the subgrades occur during wet conditions, or if proofrolling the subgrades will result in disturbance, they should be evaluated by PBS using a steel foundation probe. We recommend that PBS be retained to observe the proofrolling and perform the subgrade verifications. Unsuitable areas identified during the field evaluation should be compacted to a firm condition or be excavated and replaced with structural fill.

4.2 Subgrade Protection

4.2.1 Wet Weather and Wet Soil Conditions

Protection of the subgrade is the responsibility of the contractor. Although unlikely, track-mounted excavating equipment may be required during wet weather. The thickness of the haul roads to access the site for below-grade excavation and staging areas will depend on the amount and type of construction traffic.

4.3 Excavation

The near-surface soils at the site can likely be excavated with conventional earthwork equipment.

Sloughing and caving should be anticipated. Depending on the depth of site utilities and foundation footings, additional equipment may be required to advance excavations through the very dense soils, if encountered.

All excavations should be made in accordance with applicable Occupational Safety and Health Administration (OSHA) and State regulations. The contractor is solely responsible for adherence to the OSHA requirements. Trench cuts should stand relatively vertical to a depth of approximately 4 feet bgs, provided no groundwater seepage is present in the trench walls. Open excavation techniques may be used in clayey silt, silty sand, and sandy silt, provided excavations are configured in accordance with the OSHA requirements, groundwater seepage is not present, and with the understanding that some sloughing may occur. The trenches should be flattened if sloughing occurs or seepage is present. If shallow groundwater is observed during construction, use of a trench shield or other approved temporary shoring is recommended for cuts that extend below groundwater seepage, or if vertical walls are desired for cuts deeper than 4 feet bgs. If dewatering is used, we recommend that the type and design of the dewatering system be the responsibility of the contractor, who is in the best position to choose systems that fit the overall plan of operation

4.4 Structural Fill

The property is relatively flat; however, the extent of site grading is currently unknown. Structural fill, including aggregate base course, should be placed over subgrades that have been prepared in conformance with the Site Preparation and Wet Weather and Wet Soil Conditions sections of this report.

Structural fill material should consist of relatively well-graded soil, or an approved rock product that is free of organic material and debris, and contains particles not greater than 4 inches nominal dimension.

4.4.1 On-Site Soil

On-site soils encountered in our explorations are generally suitable for placement as structural fill during moderate, dry weather when moisture content can be maintained by air drying and/or addition of water. The fine-grained fraction of the site soils are moisture sensitive, and during wet weather, may become unworkable because of excess moisture content. In order to reduce moisture content, some aerating and drying of fine-grained soils may be required. The material should be placed in lifts with a maximum uncompacted thickness of approximately 9 inches and compacted to at least 92 percent of the maximum dry density, as determined by ASTM D1557.

4.4.2 Borrow Material

Borrow material for general structural fill construction should meet the requirements set forth in ODOT SS 00330.12 – Borrow Material. When used as structural fill, borrow material should be placed in lifts with a maximum uncompacted thickness of approximately 8 inches and compacted to not less than 92 percent of the maximum dry density, as determined by ASTM D1557.

4.4.3 Select Granular Fill

Selected granular backfill used during periods of wet weather for structural fill construction should meet the specifications provided in ODOT SS 00330.14 – Selected Granular Backfill. The imported granular material should be uniformly moisture conditioned to within about 2 percent of the optimum moisture content and compacted in relatively thin lifts using suitable mechanical compaction equipment. Selected granular backfill should be placed in lifts with a maximum uncompacted thickness of 8 to 12 inches and be compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D1557.

4.4.4 Crushed Aggregate Base

Crushed aggregate base course below floor slabs, spread footings, and asphalt concrete pavements should be clean, crushed rock or crushed gravel that contains no deleterious materials and meets the specifications provided in ODOT SS 02630.10 – Dense-Graded Aggregate, and have less than 10 percent by dry weight passing the US Standard No. 200 Sieve. The crushed aggregate base course should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM D1557.

4.4.5 Utility Trench Backfill

Pipe bedding placed to uniformly support the barrel of pipe should meet specifications provided in ODOT SS 00405.12 – Pipe Zone Bedding. The pipe zone that extends from the top of the bedding to at least 8 inches above utility lines should consist of material prescribed by ODOT SS 00405.13 – Pipe Zone Material. The pipe zone material should be compacted to at least 90 percent of the maximum dry density, as determined by ASTM D1557, or as required by the pipe manufacturer.

Under pavements, paths, slabs, or beneath building pads, the remainder of the trench backfill should consist of well-graded granular material with less than 10 percent by dry weight passing the US Standard No. 200 Sieve, and should meet standards prescribed by ODOT SS 00405.14 – Trench Backfill, Class B or D. This material should be compacted to at least 92 percent of the maximum dry density, as determined by ASTM D1557 or as required by the pipe manufacturer. The upper 3 feet of the trench backfill should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM D1557. Controlled low-strength material (CLSM), ODOT SS 00405.14 – Trench Backfill, Class E, can be used as an alternative.

Outside of structural improvement areas (e.g., pavements, sidewalks, or building pads), trench material placed above the pipe zone may consist of general structural fill materials that are free of organics and meet ODOT SS 00405.14 – Trench Backfill, Class A. This general trench backfill should be compacted to at least 90 percent of the maximum dry density, as determined by ASTM D1557, or as required by the pipe manufacturer or local jurisdictions.

4.4.6 Stabilization Material

Stabilization rock should consist of pit or quarry run rock that is well-graded, angular, crushed rock consisting of 4- or 6-inch-minus material with less than 5 percent passing the US Standard No. 4 Sieve. The material should be free of organic matter and other deleterious material. ODOT SS

00330.16 – Stone Embankment Material can be used as a general specification for this material with the stipulation of limiting the maximum size to 6 inches.

5.0 ADDITIONAL SERVICES AND CONSTRUCTION OBSERVATIONS

In most cases, other services beyond completion of a geotechnical engineering report are necessary or desirable to complete the project. Occasionally, conditions or circumstances arise that require the performance of additional work that was not anticipated when the geotechnical report was written. PBS offers a range of environmental, geological, geotechnical, and construction services to suit the varying needs of our clients.

PBS should be retained to review the plans and specifications for this project before they are finalized. Such a review allows us to verify that our recommendations and concerns have been adequately addressed in the design.

Satisfactory earthwork performance depends on the quality of construction. Sufficient observation of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. We recommend that PBS be retained to observe general excavation, stripping, fill placement, and footing and pavement subgrades. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. Recognition of changed conditions requires experience; therefore, qualified personnel should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipated.

6.0 LIMITATIONS

This report has been prepared for the exclusive use of the addressee, and their architects and engineers, for aiding in the design and construction of the proposed development and is not to be relied upon by other parties. It is not to be photographed, photocopied, or similarly reproduced, in total or in part, without express written consent of the client and PBS. It is the addressee's responsibility to provide this report to the appropriate design professionals, building officials, and contractors to ensure correct implementation of the recommendations.

The opinions, comments, and conclusions presented in this report are based upon information derived from our literature review, field explorations, laboratory testing, and engineering analyses. It is possible that soil, rock, or groundwater conditions could vary between or beyond the points explored. If soil, rock, or groundwater conditions are encountered during construction that differ from those described herein, the client is responsible for ensuring that PBS is notified immediately so that we may reevaluate the recommendations of this report.

Unanticipated fill, soil and rock conditions, and seasonal soil moisture and groundwater variations are commonly encountered and cannot be fully determined by merely taking soil samples or soil borings and test pits. Such variations may result in changes to our recommendations and may require additional funds for expenses to attain a properly constructed project. Therefore, we recommend a contingency fund to accommodate such potential extra costs.

The scope of services for this subsurface exploration and geotechnical report did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site.

If there is a substantial lapse of time between the submission of this report and the start of work at the site, if conditions have changed due to natural causes or construction operations at or adjacent to the site, or if the basic project scheme is significantly modified from that assumed, this report should be reviewed to determine the applicability of the conclusions and recommendations presented herein. Land use, site conditions (both on and off site), or other factors may change over time and could materially affect our findings. Therefore, this report should not be relied upon after three years from its issue, or in the event that the site conditions change.

7.0 REFERENCES

OSSC (2014) Oregon Structural Specialty Code (OSSC). Based on IBC. (2012). International Building Code.

Country Club Hills, IL: International Code Council, Inc.

ODOT SS. (2015). Oregon Standard Specifications for Construction. Salem, Oregon. Oregon Department of Transportation.

OregonHazvu. Oregon Department of Geology and Mineral Industries. Portland, Oregon.

VA H-18-8. (October 1, 2016). VA Handbook H-18-8 Seismic Design Requirements. US Department of Veterans Affairs.

Wells, F.G., (1956). Geology of the Medford quadrangle, Oregon-California: U.S. Geological Survey, Geologic

Quadrangle Map GQ-89, scale 1:96,000

FIGURES

0' 1,000' 2,000' 4,000'

PROJECT LOCATION

FIGURE

F i l e n a m e

L

P r o j e c t s

W h i t e

C i t y V

A

B l d g a n d

D

W G f g d w

L y o u t

T a b

F

I G

U s e r

J m a n c o

C

A D

P o t

D a t e

T i m e

P

M

VICINITY MAP

BUILDING 225/226 REPLACEMENT

WHITE CITY, OREGON

MARCH 2017

70995.000

SCALE: 1" = 2,000'

SOURCE: USGS EAGLE POINT OR QUADRANGLE 1983,

PHOTO REVISED 1977.

PORTLAND

SALEM

EUGENE

OREGON

SITE

B-3

B-2

B-1

PROPOSED NEW BUILDING

SOURCE: © 2017 GOOGLE EARTH PRO

0' 40' 80' 160'

FIGURE

F l e n a m e

L

P r o j e c t s

W h i t e

C i t y V

A d g d

D

W G f d w

L y o u t

T a b

F

I

U s e r

J m a n c

C o t

D a t e

T i m e

P

M

SITE PLAN

BUILDING 225/226 REPLACEMENT

WHITE CITY, OREGON

MARCH 2017

70995.000

SCALE: 1" = 80'

B-1 BORING NUMBER AND APPROXIMATE LOCATION

LEGEND

APPENDIX A

Field Explorations

April 21, 2015

A-1

APPENDIX A – FIELD EXPLORATIONS

A1.0 GENERAL

PBS explored the subsurface conditions at the project site by advancing three borings to depths of up to 31.5 feet bgs. The approximate locations of the explorations are shown on Figure 2, Site Plan. The procedures and techniques used to advance the borings, collect samples, and other field techniques, are described in detail in the following paragraphs. Unless otherwise noted, all soil sampling and classification procedures followed local engineering practices that are in general accordance with relevant ASTM procedures. “General accordance” means that certain local and common drilling and descriptive practices and methodologies have been followed.

A2.0 BORINGS

A2.1 Drilling Borings were advanced with a truck-mounted drill rig provided and operated by Western States Soil Conservation, Inc., of Hubbard, Oregon, using mud rotary drilling techniques. The borings were observed by a geologist from PBS, who maintained a log of the subsurface conditions and materials encountered during the course of the work.

A2.2 Sampling Disturbed soil samples were taken in the borings at selected depth intervals. The samples were obtained using a standard 2-inch outside diameter (OD), split-spoon sampler following procedures prescribed for the standard penetration test (SPT). Using the SPT, the sampler is driven 18 inches into the soil using a 140-pound hammer dropped 30 inches. The number of blows required to drive the sampler the last 12 inches is defined as the standard penetration resistance (N-value). The N-value provides a measure of the relative density of granular soils such as sands and gravels, and the consistency of cohesive soils such as clays and plastic silts. The disturbed soil samples were examined by a member of the PBS geotechnical staff, and then sealed in plastic bags for further examination and physical testing in our laboratory.

A2.3 Boring Logs The boring logs show the various types of materials that were encountered in the boring and the depths where the materials and/or characteristics of these materials changed, although the changes may be gradual. Where material types and descriptions changed between samples, the contacts were interpreted.

The types of samples taken during drilling, along with their sample identification number, are shown to the right of the classification of materials. The N-values and natural moisture contents are shown further to the right.

A4.0 MATERIAL DESCRIPTION

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

Table A-1

Terminology Used to Describe Soil

Soil Descriptions

Soils exist in mixtures with varying proportions of components. The predominant soil, i.e., greater than 50 percent based on total dry weight, is the primary soil type and is capitalized in our log descriptions (SAND, GRAVEL, SILT, or CLAY). Smaller percentages of other constituents in the soil mixture are indicated by use of modifier words in general accordance with the

ASTM D2488-06 Visual-Manual Procedure. “General Accordance” means that certain local and common descriptive practices may have been followed. In accordance with ASTM D2488-06, group symbols (such as GP or CH) are applied on the portion of soil passing the 3-inch (75mm) sieve based on visual examination. The following describes the use of soil names and modifying terms used to describe fine- and coarse-grained soils.

Fine-Grained Soils (50% or greater fines passing 0.075 mm, No. 200 sieve)

The primary soil type, i.e., SILT or CLAY is designated through visual-manual procedures to evaluate soil toughness, dilatency, dry strength, and plasticity. The following outlines the terminology used to describe fine-grained soils, and varies from ASTM

D2488 terminology in the use of some common terms.

Primary soil NAME, Symbols, and Adjectives Plasticity

Description

Plasticity

Index (PI)

SILT (ML & MH) CLAY (CL & CH) ORGANIC SOIL (OL & OH)

SILT Organic SILT Non-plastic 0 – 3

SILT Organic SILT Low plasticity 4 – 10

SILT/Elastic SILT Lean CLAY Organic SILT/ Organic CLAY Medium Plasticity 10 – 20

Elastic SILT Lean/Fat CLAY Organic CLAY High Plasticity 20 – 40

Elastic SILT Fat CLAY Organic CLAY Very Plastic >40

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

Description % Composition

With Sand % Sand ≥ % Gravel 15% to 25% plus No. 200

With Gravel % Sand < % Gravel

Sandy % Sand ≥ % Gravel ≤30% to 50% plus No. 200

Gravelly

% Sand < % Gravel

Borderline Symbols, for example CH/MH, are used when soils are not distinctly in one category or when variable soil units contain more than one soil type. Dual Symbols, for example CL-ML, are used when two symbols are required in accordance with ASTM D2488.

Soil Consistency terms are applied to fine-grained, plastic soils (i.e., PI > 7). Descriptive terms are based on direct measure or correlation to the Standard Penetration Test N-value as determined by ASTM D1586-84, as follows. SILT soils with low to non-plastic behavior (i.e., PI < 7) may be classified using relative density.

Consistency

Term SPT N-value

Unconfined Compressive Strength tsf kPa

Very soft Less than 2 Less than 0.25 Less than 24

Soft 2 – 4 0.25 – 0.5 24 – 48

Medium stiff 5 – 8 0.5 – 1.0 48 – 96

Stiff 9 – 15 1.0 – 2.0 96 – 192

Very stiff 16 – 30 2.0 – 4.0 192 – 383

Hard Over 30 Over 4.0 Over 383

Table A-1

Terminology Used to Describe Soil

Soil Descriptions

Coarse - Grained Soils (less than 50% fines)

Coarse-grained soil descriptions, i.e., SAND or GRAVEL, are based on the portion of materials passing a 3-inch (75mm) sieve.

Coarse-grained soil group symbols are applied in accordance with ASTM D2488-06 based on the degree of grading, or distribution of grain sizes of the soil. For example, well-graded sand containing a wide range of grain sizes is designated SW;

poorly graded gravel, GP, contains high percentages of only certain grain sizes. Terms applied to grain sizes follow.

Material NAME Particle Diameter

Inches Millimeters

SAND (SW or SP) 0.003 – 0.19 0.075 – 4.8

GRAVEL (GW or GP) 0.19 – 3 4.8 – 75

Additional Constituents:

Cobble 3 – 12 75 – 300

Boulder 12 – 120 300 – 3050

The primary soil type is capitalized, and the fines content in the soil are described as indicated by the following examples.

Percentages are based on estimating amounts of fines, sand, and gravel to the nearest 5 percent. Other soil mixtures will have similar descriptive names.

Example: Coarse-Grained Soil Descriptions with Fines

>5% to < 15% fines (Dual Symbols) ≥15% to < 50% fines

Well graded GRAVEL with silt: GW-GM Silty GRAVEL: GM

Poorly graded SAND with clay: SP-SC Silty SAND: SM

Additional descriptive terminology applied to coarse-grained soils follow.

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

Coarse-Grained Soil Containing Secondary Constituents

With sand or with gravel ≥ 15% sand or gravel

With cobbles; with boulders Any amount of cobbles or boulders.

Cobble and boulder deposits may include a description of the matrix soils, as defined above.

Relative Density terms are applied to granular, non-plastic soils based on direct measure or correlation to the Standard

Penetration Test N-value as determined by ASTM D1586-84.

Relative Density Term SPT N-value

Very loose 0 – 4

Loose 5 – 10

Medium dense 11 – 30

Dense 31 – 50

Very dense > 50

SAMPLING DESCRIPTIONS

Table A-2

Key To Test Pit and Boring Log Symbols S P T D ri ve

S am p le r

S ta n d ar d P e n e tr at io n T e st

T M

D

S h e lb y T u b e P u sh

S am p le

T M

D

S p e ci al iz e d D ri ve

S am p le rs

(D e ta ils N o te d o n L o g s)

S p e ci al iz e d D ri ll o r

P u sh am p le r (D e ta ils N o te d

Lo s)

G ra b S am p le

R o ck

C o ri n g I n te rv al

S cr e

(W at e r o r

A ir S a m p lin

W at e r

Le ve l D u ri ri lli n g /E xc av at io n W at e r

Le ve l A ft ri lli n g /E xc av at io

LOG GRAPHICS

PP Pocket Penetrometer HYD Hydrometer Gradation

TOR Torvane SIEV Sieve Gradation

DCP DS Direct Shear

ATT Atterberg Limits DD Dry Density

PL Plasticity Limit CBR California Bearing Ratio

LL Liquid Limit RES Resilient Modulus

PI Plasticity Index VS Vane Shear

P200 Percent Passing US Standard No. 200 Sieve bgs Below ground surface

OC Organic Content MSL Mean Sea Level

CON Consolidation HCL Hydrochloric Acid

UC Unconfined Compressive Strength

Details of soil and rock classification systems are available on request. Rev. 02/2017

Dynamic Cone Penetrometer

Geotechnical Testing Acronym Explanations

Lithology Boundary:

separates distinct units

(i.e., Fill, Alluvium, Bedrock) at approximate depths inciated

Sampler

Type

Sample

Recovery Sample

Interval

Instrumentation Detail Sampling Symbols Soil and Rock

Well Pipe

Piezometer

Piezometer

Ground Surface

Well Cap

Bottom of Hole

S o il o r R o ck

T y p e s

Well Seal

Well Screen

Soil-type or Material-type

Change Boundary: separates soil and material changes within the same lithographic unit at approximate depth indicated

0.0

5.0

31.5

03/13/17

Iron staining on gravel from 5 to 15 feet bgs P200 = 16%

Driller notes harder driling from 19 to 20 feet bgs

Driller notes harder drilling from 24.5 to 25 feet bgs Switched to 3 7/8 drill bit

Very dense olive brown silty GRAVEL (GM);

medium plasticity; fine, subangular gravel; wet

Very dense brown GRAVEL (GP-GM) with silt and sand; medium plasticity; fine sand; fine to coarse, subrounded to subangular gravel; wet becomes dense becomes very dense becomes dense becomes very dense

Final depth 31.5 feet bgs; boring backfilled with bentonite.

P200

SIEV

D E

P T

H INSTALLATION AND

COMMENTS

0 50 100

CORE REC%RQD%

MOISTURE CONTENT %

DYNAMIC CONE

PENETROMETER

UNCORRECTED N-VALUE

B

O R

IN

G

L O

5.

0_ B

1- 3_

.G P

J P

B S

_D A

T A

T M

P L_

G E

O .G

T

R

IN

T

D A

T E

4/

/1

7:

R

W

G R

A P

H

IC

LO

G

DRILLED BY: Western States Soil Conservation, Inc.

LOGGED BY: T. Laird

DRILLING METHOD: Mud Rotary - Tricone

MATERIAL DESCRIPTION

S A

M P

LE

T

Y

E

M P

LE

ID

BORING B-1

T E

S T

IN

G

DEPTH

FEET

Lat. 42.44278, Long. -122.83667

APPROX. BORING B-1 LOCATION:

FIGURE A1

LOGGING COMPLETED: 3/13/17

HAMMER EFFICIENCY PERCENT: 85

BIT DIAMETER: 4 7/8 inches

WHITE CITY VA

WHITE CITY, OREGON

PBS PROJECT NUMBER:

70995.000

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

Surface Conditions: Sand

19-33-50/4

S -1

S -2

S -3

S -4

S -5

S -6

S -7

S -8

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0 50 100

5.0

7.5

15.0

20.0

26.5

P200 = 19%

Red coloring and iron staining from 5 to 15 feet bgs

Driller noted harder drilling at

12.5 feet bgs

P200 = 18%

Driller noted softer drilling at

17.5 feet bgs

Very dense brown poorly graded GRAVEL (GP) with sand; fine sand; fine to coarse, subangular gravel; wet

Dense brown poorly graded SAND (SP-SM) with silt; low plasticity; fine to coarse sand; wet

Dense brown poorly graded GRAVEL (GP) with sand; fine sand; fine to coarse, subrounded to subangular gravel; wet becomes very dense

Dense brown poorly graded GRAVEL (GP-GM) with silt and sand; medium plasticity;

fine sand; fine to coarse, subrounded to subangular gravel; wet

Very dense blue-gray silty GRAVEL (GM) with sand; medium plasticity; fine sand; fine to coarse, subrounded to subangular gravel; wet

Final depth 26.5 feet bgs; boring backfilled with bentonite.

P200

P200

D E

P T

H INSTALLATION AND

COMMENTS

0 50 100

CORE REC%RQD%

MOISTURE CONTENT %

DYNAMIC CONE

PENETROMETER

UNCORRECTED N-VALUE

B

O R

IN

G

L

5.

0_ B

1- 3_

.G P

J P

B S

_D A

T A

T M

P L_

G E

O .G

IN

T

D A

T E

4/

/1

7:

R

W

G R

A P

H

IC

LO

G

DRILLED BY: Western States Soil Conservation, Inc.

LOGGED BY: T. Laird

DRILLING METHOD: Mud Rotary - Tricone

MATERIAL DESCRIPTION

S A

M P

LE

T

Y

M P

LE

ID

BORING B-2

T E

S T

IN

G

DEPTH

FEET

Lat. 42.44222, Long. -122.83694

APPROX. BORING B-2 LOCATION:

FIGURE A2

LOGGING COMPLETED: 3/13/17

HAMMER EFFICIENCY PERCENT: 85

BIT DIAMETER: 4 7/8 inches

WHITE CITY VA

WHITE CITY, OREGON

PBS PROJECT NUMBER:

70995.000

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

Surface Conditions: Gravel and Grass

25-50/4

13-18-50/3

S -1

S -2

S -3

S -4

S -5

S -6

S -7

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0 50 100

20.0

26.5

Iron staining on gravel from 5 to 15 feet bgs P200 = 10%

Dense brown-gray poorly graded GRAVEL (GP) with sand; fine sand; fine, subrounded to subangular gravel; wet becomes very dense, brown; with fine to coarse gravel becomes dense, yellow-brown; with fine to medium sand; subrounded to angular gravel

Very dense blue-gray poorly graded GRAVEL (GP-GM) with silt and sand; medium plasticity;

fine to medium sand; fine to coarse, subrounded to angular gravel; wet

Final depth 26.5 feet bgs; boring backfilled with bentonite.

P200

SIEV

D E

P T

H INSTALLATION AND

COMMENTS

0 50 100

CORE REC%RQD%

MOISTURE CONTENT %

DYNAMIC CONE

PENETROMETER

UNCORRECTED N-VALUE

B

O R

IN

G

L

5.

0_ B

1- 3_

.G P

J P

B S

_D A

T A

T M

P L_

G E

O .G

IN

T

D A

T E

4/

/1

7:

R

W

G R

A P

H

IC

LO

G

DRILLED BY: Western States Soil Conservation, Inc.

LOGGED BY: T. Laird

DRILLING METHOD: Mud Rotary - Tricone

MATERIAL DESCRIPTION

S A

M P

LE

T

Y

M P

LE

ID

BORING B-3

T E

S T

IN

G

DEPTH

FEET

Lat. 42.44222, Long. -122.83722

APPROX. BORING B-3 LOCATION:

FIGURE A3

LOGGING COMPLETED: 3/13/17

HAMMER EFFICIENCY PERCENT: 85

BIT DIAMETER: 4 7/8 inches

WHITE CITY VA

WHITE CITY, OREGON

PBS PROJECT NUMBER:

70995.000

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

Surface Conditions: Grass

26-50/4

S -1

S -2

S -3

S -4

S -5

S -6

S -7

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0 50 100

APPENDIX B

Laboratory Testing

B-1

APPENDIX B – LABORATORY TESTING

B1.0 GENERAL

Samples obtained during the field explorations were examined in the PBS laboratory. The physical characteristics of the samples were noted and the field classifications were modified where necessary. The testing procedures are presented in the following paragraphs. Unless noted otherwise, all test procedures are in general accordance with applicable ASTM standards. “General accordance” means that certain local and common descriptive practices and methodologies have been followed.

B2.0 CLASSIFICATION TESTS

B2.1 Visual Classification The soils were classified in accordance with the Unified Soil Classification System with certain other terminology, such as the relative density or consistency of the soil deposits, in general accordance with engineering practice. In determining the soil type (that is, gravel, sand, silt, or clay) the term that best described the major portion of the sample is used. Modifying terminology to further describe the samples is defined in Terminology Used to Describe Soil in Appendix A.

B2.2 Grain-Size Analyses (P200 Wash) Mechanical grain-size (sieve) analyses were completed on two samples to determine the particle size distribution of the material. The results of the sieve analyses are repented on figure B1 in Appendix B. No.

200 wash (P200) analyses were performed on select samples to determine the portion of soil passing the No. 200 Sieve (i.e., silt and clay). The results of the P200 test results are presented on the logs of the borings in Appendix A and on figure B2 in Appendix B.

0.0010.010.11101001,000

CLAY

BOULDERS

MOISTURE CONTENT

(PERCENT)

B-1

B-3

KEY

SAMPLE

NUMBER

SAMPLE DEPTH

(FEET)

7.5

7.5

SAND

(PERCENT)

U.S. STANDARD SIEVE NUMBERS (ASTM E11)

3/4" 10 2003" 1 1/2" 100

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

COARSE

PARTICLE-SIZE ANALYSIS TEST RESULTS

MEDIUM SILT

COBBLES

FINECOARSE

1.6

5.7

D50

(MM)

D30

(MM)

D10

(MM)

D5

(MM)

GRAVEL

(PERCENT)

FINES

(PERCENT)

1.0

3.8

0.4

1.3

PARTICLE-SIZE (MM)

TEST METHOD: ASTM C136

FINE

GRAVEL SAND FINES

EXPLORATION

NUMBER

D60

(MM)

3/8" 404 16 30 50

S-3

S-3

PBS PROJECT NUMBER:

70995.000WHITE CITY, OREGON

WHITE CITY VA

__PARTICLE-SIZE ANALYSIS 70995.000_B1-3_20170321.GPJ PBS_DATATMPL_GEO.GDT PRINT DATE: 4/3/17:RPG

FIGURE B1

B-1 S-3 7.5 20.8 25 59 16

B-2 S-2 5 29.0 19

B-2 S-5 15 23.4 18

B-3 S-3 7.5 15.0 46 44 10

SUMMARY OF LABORATORY DATA

FIGURE B2

LIQUID

LIMIT

(PERCENT)

GRAVEL

(PERCENT)

DRY

DENSITY

(PCF)

PLASTIC

LIMIT

(PERCENT)

PLASTICITY

INDEX

(PERCENT)

SAND

(PERCENT)

P200

(PERCENT)

SIEVE ATTERBERG LIMITSSAMPLE INFORMATION

SAMPLE

DEPTH

(FEET)

SAMPLE

NUMBER

EXPLORATION

NUMBER

ELEVATION

(FEET)

MOISTURE

CONTENT

(PERCENT)

PBS PROJECT NUMBER:

70995.000

WHITE CITY VA

WHITE CITY, OREGON

LA

B S

U M

M A

Y

5.

0_

B 1-

3_

.G

P J

P B

S _D

A T

A T

M P

L_ G

E O

.G

IN

T D

A T

E

4/ 3/

:R

1.3 Project Understanding