Amendment 0003 - ATT 4 Ft. Meade VA Addition Geotech Report.pdf

Geotechnical Engineering Report Proposed VA Surgery Tower/Wing Addition

Ft. Meade VA Hospital

Ft. Meade, South Dakota

April 30, 2012

Terracon Project No. B4125017

Prepared for:

FourFront Design, Inc.

Rapid City, South Dakota

Prepared by:

Terracon Consultants, Inc.

Rapid City, South Dakota

Terracon Consultants, Inc. 2026 Samco Road, Suite 101 Rapid City, South Dakota 57702

P [605] 716.2924 F [605] 716.2924 terracon.com

April 30, 2012

Mr. David Jolly FourFront Design, Inc.

517 Seventh Street Rapid City, South Dakota 57701

Subject: Geotechnical Engineering Report

Proposed VA Surgery Tower/Wing Addition Ft. Meade VA Hospital Ft. Meade, South Dakota

Terracon Project No. B4125017

Dear Mr. Jolly, Terracon has completed the geotechnical engineering services for the proposed VA Surgery Tower/Wing to be constructed on the north side of the existing hospital building. This study was performed in general accordance with Terracon’s proposal No. GB412049, dated March 21, 2012, and the written authorization to proceed provided by Mr. Curt Huus, FourFront Design, Inc.

The results of our engineering study, including the boring location diagram, laboratory test results, boring logs, and the geotechnical recommendations needed to aid in the design of foundations and other earth connected phases of this project, are attached.

We appreciate being of service to you in the geotechnical engineering phase of this project and are prepared to assist you during the construction phases as well. If you have any questions concerning this report, please contact us at your convenience.

Sincerely, Terracon Consultants, Inc.

Teresa Serie, E.I. Walt Feeger, P.E.

Staff Professional Office Manager

Copies: Client (3 bound, 1 via e-mail) File (1)

Proposed VA Surgery Tower/Wing Addition ■ Ft. Meade, South Dakota April 30, 2012 ■ Terracon Project No. B4125017

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TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY ............................................................................................................... ii

1.0 INTRODUCTION

2.0 PROJECT INFORMATION

2.1 Project Description

2.2 Site Location and Description

3.0 SUBSURFACE CONDITIONS

3.1 Typical Profile

3.2 Groundwater

4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION

4.1 Earthwork

4.1.1 Site Preparation

4.1.2 Engineered Fill Material Requirements

4.1.3 Engineered Fill Compaction Requirements

4.1.4 Utility Trench Excavations and Backfill

4.1.5 Grading and Drainage

4.1.6 Construction Considerations

4.2 Foundations

4.2.1 Design Recommendations

4.2.2 Construction Considerations

4.3 Seismic Considerations

4.4 Concrete Slab-on-Grade

4.4.1 Interior Slab-On-Grade

4.4.2 Exterior Slab Construction Considerations

4.5 Basement Construction Considerations

5.0 GENERAL COMMENTS

APPENDIX A – FIELD EXPLORATION

Boring Location Diagram Boring Logs Field Exploration Description

APPENDIX B – LABORATORY TESTING

Laboratory Testing

APPENDIX C – SUPPORTING DOCUMENTS

General Notes Unified Soil Classification Laboratory Test Significance Report Terminology

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EXECUTIVE SUMMARY

A geotechnical engineering report has been completed for the proposed VA Surgery Tower/Wing addition to be constructed on the north side of the existing Ft. Meade Hospital building in Ft.

Meade, South Dakota. Three (3) soil borings, designated B-1 through B-3, were performed to depths of approximately 20½ feet below existing grades within the proposed building addition footprint. This report addresses the recommendations for the proposed project.

Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. The following geotechnical considerations were identified:

In general, within Borings B-1 and B-2, the subsurface soils consisted of approximately

1½ to 3 feet of medium stiff to very stiff lean clay soils overlying about 11 to 11½ feet of dense to very dense sand and gravel soils. Within Boring B-3, approximately 3 feet of stiff to medium stiff lean clay soils were encountered overlying about 15 feet of dense to very dense silty gravels. The soils are underlain by weathered shale bedrock which extended to the total depths explored within each of the borings. Groundwater was encountered within the borings at depths of approximately 14 to 15½ feet below existing grade.

Based on the soils encountered within the borings, the proposed structure can be supported on a conventional spread footing foundation system bearing on the site sand and gravel soils.

The lower level (basement) concrete-slab on grade floor system may be constructed on the reconditioned granular site soils. We recommend the main level floor slab be constructed on at least 12-inches of compacted granular engineered fill.

Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions involved with construction of the project.

This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations.

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GEOTECHNICAL ENGINEERING REPORT

PROPOSED VA SURGERY TOWER/WING ADDITION

FT. MEADE VA HOSPITAL

FT. MEADE, SOUTH DAKOTA

Terracon Project No. B4125017

April 30, 2012

1.0 INTRODUCTION

A geotechnical engineering report has been completed for the proposed VA Surgery Tower/Wing addition to be constructed on the north side of the existing hospital building located at the Ft.

Meade VA Hospital in Ft. Meade, South Dakota. Three (3) soil borings, designated B-1 through B-3, were advanced to depths of approximately 20½ feet below existing grades within the proposed building addition footprint. This report specifically addresses the recommendations for the proposed building addition. Logs of the borings along with a boring location diagram are included in Appendix A of this report.

The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

subsurface soil conditions site and subgrade preparation groundwater conditions foundation design and construction earthwork site drainage requirements seismic classification

2.0 PROJECT INFORMATION

2.1 Project Description

ITEM DESCRIPTION

Site layout See Appendix A, Figure 1, Boring Location Diagram

Building Construction Two-story building addition with a basement level within a portion of the structure.

Finished floor elevation, feet 96.0 feet (assumed as referenced to our project datum)

Maximum loads

Columns: 75 kips maximum (assumed)

Walls: 3 klf maximum (assumed)

Floor Slab: 150 psf (assumed)

Maximum allowable total settlement Columns: 1-inch (assumed)

Walls: 1-inch (assumed)

Grading within Building Footprint Cut and fill balances on the order of about 1 to 3 feet based on assumed finished floor elevation of 96.0 feet

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2.2 Site Location and Description

ITEM DESCRIPTION

Location The location of the proposed addition is on the north side of the existing hospital building at the Ft. Meade VA Hospital in Ft. Meade, South Dakota.

Current use The site is currently being utilized both as a landscaped area around the existing hospital building as well as an asphalt paved parking lot and associated access drives.

Existing topography Overall, the site slopes slightly downward to the north with and elevation differences of about 4 feet noted between the boring locations.

3.0 SUBSURFACE CONDITIONS

3.1 Typical Profile

In general, within Borings B-1 and B-2, the subsurface soils consisted of approximately 1½ to 3 feet of medium stiff to very stiff lean clay soils overlying about 11 to 11½ feet of dense to very dense sand and gravel soils. Within Boring B-3, approximately 3 feet of stiff to medium stiff lean clay soils were encountered overlying about 15 feet of dense to very dense silty gravels. The soils are underlain by weathered shale bedrock which extended to the total depths explored within each of the borings.

Conditions encountered at each boring location are indicated on the individual boring logs.

Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Details for each of the borings can be found on the boring logs in Appendix A of this report.

3.2 Groundwater

The boreholes were observed while drilling and after completion for the presence and level of groundwater. Measurable groundwater was encountered within Borings B-1 and B-3 at depths of approximately 14 to 15½ feet below existing grade, respectively . Borings were backfilled with auger cuttings once groundwater measurements were made.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff, local irrigation practices, and other factors not evident at the time the borings were performed.

The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. Evaluation of the factors that affect groundwater fluctuations is beyond the scope of this report.

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4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION

4.1 Earthwork

Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions involved with construction of the project.

4.1.1 Site Preparation

At this time it is anticipated that the main level floor of the proposed addition will match that of the existing building. Based on an assumed finished floor elevation of 96.0 feet as referenced to our project datum, cut and fill balances on the order of about 1 to 3 feet will be required within the proposed building addition footprint in order to reach the desired construction elevations.

Existing utilities (if encountered), topsoil, vegetation, man-made debris and other unsuitable materials should be removed in their entirety from within the proposed building footprint and areas to receive pavement. Once completed and where required, excavations should continue to the desired construction elevations and to allow for the placement of at least 12-inches of compacted imported granular material below the main level concrete-slab-on-grade floor. Care should be taken to not undermine the footings of the existing building.

Conventional earth moving equipment, such as large tracked excavators, should be able perform the required excavations within the site soils. Possible cobble to boulder sized material may be encountered within the site soils which may make excavation difficult where encountered.

The excavated granular soils, cleaned of all topsoil, organics, unsuitable materials, and gravel greater than 3 inches in nominal size, may be stockpiled on-site and reused as engineered fill, utility trench backfill, overlot fill, and wall backfill. Excavated clay soils should be used within landscape areas only and as a wall backfill cap in non-structural areas.

Although evidence of underground facilities, such as foundation elements, septic tanks, cesspools, basements were not observed during the field exploration, such features could be encountered during construction. If unexpected underground facilities and utilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction.

Prior to the placement of engineered fill (where required) and structural elements, we recommend that the subgrade soils be scarified to a depth of at least 8 inches, the moisture content adjusted to near optimum, and the soils re-compacted to at least 95 percent of the maximum dry density, as determined by ASTM D 698 (Standard Proctor). All exposed surfaces should be free of mounds and depressions which could prevent uniform compaction.

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This process will help to delineate soft or disturbed areas. Unstable areas identified during scarification and recompaction should either be stabilized or undercut to expose stable material.

If isolated soft or unstable areas are encountered, it may be necessary to place a layer of crushed stone to stabilize the subgrade and help expedite construction.

If extensive soft or unstable conditions are encountered during site preparation, additional mechanical or chemical stabilization of the soils may be required. Terracon can assist with developing appropriate stabilization procedures based on conditions encountered during construction if required.

Groundwater was encountered during our site explorations. Depending on the time of year construction takes place, groundwater may be encountered within the excavations performed at this site, especially within excavations performed for utilities and the basement level. We recommend that, if encountered during excavations, the groundwater be promptly removed using a de-watering technique that lowers and keeps the groundwater surface at least 2 feet below the bottom of excavations.

A potential side effect of any de-watering effort is settlement (consolidation) of the soils, resulting in surface settlements, which can adversely impact existing structures, pavements or underground facilities. The contractors working on the project should select de-watering systems that will limit the cone of groundwater depression to the immediate construction area.

Due to the potential of encountering groundwater, we recommend that contractors bidding and working on this project be made aware of the groundwater potential and include an itemization in their bid for dewatering. Additionally, the subgrade soils may require mitigation through the use of additional over-excavation and replacement with granular engineered fill and/or a geo-grid or stabilization fabric in order to build a solid platform for placing engineered fill material or foundations. Contractors should also provide an itemization in their bid for such remediation.

4.1.2 Engineered Fill Material Requirements

Engineered fill should meet the following material property requirements:

Fill Type1 USCS Classification Acceptable Location for Placement

Granular2 GM, GC, SM, SC Below foundations, concrete slabs-on-grade, interior/exterior wall backfill

On-Site Soils 3 SM, GM, CL

Cohesionless (Sand & Gravel) - Engineered fill, utility trench backfill, wall backfill, and overlot fill.

Cohesive (Lean Clay) - Utility trench backfill, and overlot fill.

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Engineered fill should consist of approved materials that are free of organic matter and debris.

Frozen material should not be used, and fill should not be placed on a frozen subgrade. Each proposed fill material type should be sampled and evaluated by the geotechnical engineer prior to its delivery and/or use.

Imported granular engineered fill required below foundations, columns, interior/exterior concrete slabs and for exterior wall backfill should consist of a granular pit run material, or conform to the following criteria.

Additionally, the material should be submitted to the project geotechnical engineer for review and approval.

Percent finer by weight Gradation (ASTM C136)

3" No. 4 Sieve ................................................................................................. 40-85 No. 200 Sieve ............................................................................................. 20-35

Liquid Limit ............................................................................................ 30 (max) Plasticity Index ...................................................................................... 10 (max)

Moisture conditioning and processing of the site soils will be required in order to maintain moisture control during placement

4.1.3 Engineered Fill Compaction Requirements

Item Description

Fill Lift Thickness

8 inches or less in loose thickness when heavy, self-propelled compaction equipment is used.

4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used.

Minimum Compaction Requirement (ASTM D698 Standard Proctor)

Engineered fill: 97% Scarified subgrade soils: 95% Aggregate base (beneath paving and slabs): 95% Wall/Trench backfill: 95% Miscellaneous backfill (non-structural areas): 90%

Moisture Content (ASTM D698)

Granular Engineered Fill: ±3% of optimum Site Sand/Gravel Soils: ±3% of optimum Site Clay Soils: -1 to +3 percent of optimum

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We recommend that each lift of engineered fill and backfill be tested by Terracon for moisture content and compaction prior to the placement of additional engineered fill or concrete. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved.

4.1.4 Utility Trench Excavations and Backfill

All trench excavations should be made with sufficient working space to permit construction including backfill placement and compaction. Utility trenches are a common source of water infiltration and migration. All utility trenches that penetrate beneath the building should be effectively sealed to restrict water intrusion and flow through the trenches that could migrate below the building. We recommend constructing an effective clay “trench plug” that extends at least 5 feet out from the face of the building exterior. The plug material should consist of clay compacted at a water content at or above the soil’s optimum water content. The clay fill should be placed to completely surround the utility line and compacted in accordance with recommendations in this report.

As previously noted, groundwater was encountered during our field work, and depending on the time of year construction takes place groundwater or surface runoff accumulation may be encountered within site excavations. Contractors working on the project should anticipate dewatering the excavations and have equipment on-site that will lower and maintain the groundwater level below the base of the excavations if encountered.

It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment such as large tracked excavators. The individual contractor’s competent person should be made responsible for designing and constructing stable, temporary excavations, as required, to maintain stability of both the excavation sides and bottom. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. In our opinion, the clay soils encountered at the site can be classified as Type B with maximum allowable slopes of 1H:1V for excavations less than 20 feet in depth. The site sand and gravel soils should be classified as Type C soils with a maximum allowable slope of 1½H:1V for excavations less than 20 feet in depth.

Depending on the depths of excavations and subsurface soil and groundwater conditions, the use of temporary shoring and/or trench boxes may be required. As a safety measure, vehicles and stockpiles should be kept away from the excavation crest a distance at least equal to the slope height. Where practical, the exposed slope face should be protected against the elements.

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4.1.5 Grading and Drainage

Positive drainage should be provided during construction and maintained throughout the life of the proposed project. Infiltration of water into utility or foundation excavations must be prevented during construction.

All grades must provide effective drainage away from the building during and after construction.

Water permitted to pond next to the building can result in greater soil movements than those discussed in this report. These greater movements can result in unacceptable differential floor slab movements, cracked slabs and walls, and roof leaks. Estimated movements described in this report are based on effective drainage for the life of the structure and cannot be relied upon if effective drainage is not maintained.

In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately 10 percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration.

Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. Sprinkler systems should not be installed within 10 feet of foundation walls. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated.

4.1.6 Construction Considerations

Although the exposed subgrade is anticipated to be relatively stable upon initial exposure, unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and/or subjected to repetitive construction traffic. The use of light construction equipment would aid in reducing subgrade disturbance. The use of remotely operated equipment, such as a backhoe, would be beneficial to perform cuts and reduce subgrade disturbance. Should unstable subgrade conditions develop, stabilization measures will need to be employed.

Upon completion of filling and grading, care should be taken to maintain the subgrade moisture content prior to construction of floor slabs and pavements. Construction traffic over the completed subgrade should be avoided to the extent practical. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. If the subgrade should become frozen, desiccated, saturated, or disturbed, the affected material should be removed or these materials should be scarified, moisture conditioned, and recompacted prior to floor slab and pavement construction.

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As a minimum, all temporary excavations should be sloped or braced as required by Occupational Health and Safety Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during grading operations.

The grading contractor, by his contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope or bench the sides of the excavations, as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state, and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards.

The geotechnical engineer and/or their representative should be retained during the construction phase of the project to observe/test earthwork and to perform necessary tests and observations during subgrade preparation; proof-rolling; placement and compaction of controlled compacted fills; backfilling of excavations into the completed subgrade, and just prior to construction of building floor slabs.

4.2 Foundations

In our opinion, the proposed building addition can be supported on a shallow spread footing foundation system bearing on the re-compacted and approved granular site soils and/or on newly placed and compacted granular engineered fill as required by site grading. Design recommendations for shallow foundations for the proposed structure are presented in the following paragraphs.

4.2.1 Design Recommendations

DESCRIPTION Column Wall

Allowable bearing pressure 1 3,500 psf 3,500 psf

Minimum dimensions 30 inches 18 inches

Minimum embedment below finished grade for frost protection 2

48 inches 48 inches

Approximate total movement 3 1 inch 1 inch

1. The recommended allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. Assumes any unsuitable material or soft/loose soils, if encountered, will be undercut and replaced with suitable engineered fill.

2. For exterior foundations beneath continuously heated structures, depth below the lowest adjacent exterior grade. The minimum depth for interior footings of continuously heated structures is 12 inches.

3. The foundation movement will depend upon the variations within the subsurface soil profile, the structural loading conditions, the embedment depth of the footings, the thickness of compacted fill, drainage, and the quality of the earthwork operations. If positive drainage around the structure cannot be maintained, the movement estimates provided cannot be relied upon.

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The design bearing pressures apply to dead loads plus the design live load conditions. The design bearing pressures may be increased by one-third when considering total loads that include wind or seismic conditions.

4.2.2 Construction Considerations

The base of all foundation excavations should be free of water and loose or soft soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. If the soils at bearing level become excessively dry, disturbed or saturated, or frozen, the affected soil should be removed prior to placing concrete.

It is recommended that the geotechnical engineer be retained to observe the soil foundation bearing materials. If unsuitable bearing soils are encountered in footing excavations, the excavation should be extended deeper to suitable soils and the footing bear directly on these soils at the lower elevation or on properly compacted structural backfill extending down to the suitable soils.

4.3 Seismic Considerations

Code Used Site Classification

2009 International Building Code (IBC) 1 C2

1. In general accordance with the 2009 International Building Code, Table 1613.5.2.

2. The 2009 International Building Code (IBC) requires a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include the required 100 foot soil profile determination.

Borings for the project extended to maximum depths of approximately 20½ feet below grade, and this seismic site class definition considers that shale bedrock continues below the maximum depth of the subsurface exploration. Additional exploration to deeper depths could be performed to confirm the conditions below the current depth of exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a higher seismic site class if required.

4.4 Concrete Slab-on-Grade

4.4.1 Interior Slab-On-Grade

Based on the soils encountered within the borings, lean clay soils will likely be present at the anticipated main level floor slab elevation. Because low plasticity clay soils shrink and swell to some extent with normal variations in moisture content, some movements normally occur and should be anticipated. However, to reduce the potential for movement related distress to the floor slab, we recommend the concrete floor slab bear on at least 12-inches of compacted granular engineered fill. The leveling course, typically 4 to 6 inches of base course material provided below the concrete, slab may be included in the 12-inch thickness of granular engineered fill placed below the slab. The basement level slab-on-grade floor may be placed on the reconditioned site granular soils.

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ITEM DESCRIPTION

Floor slab support

Main Level - 12-inches of compacted imported granular engineered fill.

Basement Level – Reconditioned granular site soils.

Modulus of subgrade reaction

Imported granular engineered fill – 250 pounds per square inch per inch (psi/in) for point loading conditions.

Site granular soils – 200 psi/in for point loading conditions

Aggregate base course/capillary break 2 4-6 inches of free draining granular material

1. Floor slabs should be structurally independent of any building footings or walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundation.

2. The floor slab design should include a capillary break, comprised of free-draining, compacted, granular material at least 4-6 inches thick.

Additional floor slab design and construction recommendations are as follows:

Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement.

Contraction joints should be provided in slabs to control the location and extent of cracking.

The use of a vapor retarder should be considered beneath concrete slabs-on-grade that will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 for procedures and cautions regarding the use and placement of a vapor retarder.

Floor slabs should not be constructed on frozen subgrade.

Other design and construction considerations, as outlined in Section 302.1R of the ACI

Design Manual, are recommended.

4.4.2 Exterior Slab Construction Considerations

Exterior slabs-on-grade founded on the site clay soils could experience movement exceeding one-inch due to the volume change of the clay material. This movement may lead to loss of positive drainage away from the building and could present a tripping hazard where slab sections move independently.

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Potential movement could be reduced by:

Placing slabs on a minimum of one (1) foot of imported granular engineered fill as specified in this report, Minimizing moisture increases in the subgrade, Controlling moisture-density during placement, Using designs which allow vertical movement between the exterior features and adjoining structural elements, and Placing effective control joints on relatively close centers.

4.5 Basement Construction Considerations

As indicated, groundwater was encountered in the borings at depths of approximately 14 to 15½ feet below existing grades. Based on this information, the lower (basement) level should be above the anticipated groundwater levels at this site. However, the following recommendations should be considered during the design and construction of the lower structural level in the event the groundwater levels rise due to seasonal variations.

To intercept the potential for water infiltration from impacting the foundation bearing stratum and entering the lower level, an exterior perimeter drain is recommended. The exterior drainage system should be constructed around the exterior perimeter of the basement foundation, and sloped at a minimum 1/8 inch per foot to a suitable outlet, such as the storm sewer or a sump and pump system. The new system could also be tied into the existing drain system, if present, around the existing building.

The exterior drainage system should consist of a properly sized perforated pipe, embedded in free-draining gravel, and placed along the exterior edge of the footing. Gravel should extend a minimum of 3 inches beneath the bottom of the pipe, and at least 1 foot above the bottom of the foundation wall. The gravel should be covered with drainage fabric prior to placement of foundation backfill.

Lateral Earth Pressures: For soils above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements are:

Active:

Site granular soils ........................................................... 50 psf Imported granular backfill ............................................... 35 psf

Passive:

Site granular soils ......................................................... 320 psf Imported granular backfill ............................................. 520 psf

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Where the design includes restrained elements, the following equivalent fluid pressures are recommended:

At rest:

Site granular soils ........................................................... 70 psf Imported granular backfill ............................................... 55 psf

The lateral earth pressures herein do not include any factor of safety and are not applicable for submerged soils/hydrostatic loading. Additional recommendations may be necessary if submerged conditions are to be included in the design.

Fill against basement walls should be compacted to densities specified in the “Earthwork” section of this report. Compaction within 5 feet of basement walls should be accomplished with hand-operated tampers or other lightweight compactors. Overcompaction may cause excessive lateral earth pressures which could result in cracking and/or wall movement.

5.0 GENERAL COMMENTS

Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, foundation construction, and other earth-related construction phases of the project.

The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided.

The scope of services for this project does not include, either specifically or by implication, any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken.

This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either expressed or implied, are intended or made.

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Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project, as outlined in this report, are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing.

APPENDIX A

FIELD EXPLORATION

0.5

2.5

19.5

20.5

94.4

92.4

80.9

75.4

74.4

TOPSOIL/VEGETATIVE LAYER

SANDY LEAN CLAY, brown, very stiff

(CL)

SILTY SAND with GRAVEL, brown, very dense possible cobbles present (SM)

SANDY CLAY with GRAVEL, brown, very stiff (CL)

WEATHERED SHALE, dark grey, stiff

End of Boring

CS

CS

SS

SS

SS

SS

SS

1.2

1.4

1.4

1.3

1.1

1.0

1.1

50/0.4

50/0.4

TESTS

DESCRIPTION

Approx. Surface Elev.: 94.9 ft U N

C O

N F

IN

E

D S

T R

E N

G T

H ps f between soil and rock types: in-situ, the transition may be gradual.

PROJECT

WD

WD

WD

WATER DEPTH OBSERVATIONS, ft

B4125017

BC

4-3-12

CME-55

GR

OWNER ARCHITECT

LOG OF BORING NO. B- 1

SITE

G R

A P

H

IC

L O

G

Boring Location: Proposed Building Addition

The stratification lines represent the approximate boundary lines

4/3/12

Ft. Meade VA Hospital Ft. Meade, South Dakota

FourFront Design, Inc.

Proposed VA Surgery Tower/Wing Addition

BORING STARTED

BORING COMPLETED

RIG

LOGGED

FOREMAN

JOB #

4-3-12

Ft. Meade VA Hospital

SAMPLES

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N .G

D T

4/

/1

0.3

20.5

95.9 95.7

94.2

82.2

78.2

75.7

CONCRETE

AGGREGATE BASE COURSE

SANDY LEAN CLAY, brown, very stiff

(CL)

SILTY SAND with GRAVEL, brown, very dense, possible cobbles present (SM)

SANDY CLAY with GRAVEL, brown, hard

(CL)

WEATHERED SHALE, dark grey, very stiff

End of Boring

CS

SS

SS

SS

SS

SS

SS

1.4

1.5

1.5

1.2

1.1

1.1

1.0

50/0.3

50/0.3

TESTS

DESCRIPTION

Approx. Surface Elev.: 96.2 ft U N

C O

N F

IN

E

D S

T R

E N

G T

H ps f between soil and rock types: in-situ, the transition may be gradual.

PROJECT

WD

WD

WD

WATER DEPTH OBSERVATIONS, ft

None

B4125017

BC

4-3-12

CME-55

GR

OWNER ARCHITECT

LOG OF BORING NO. B- 2

SITE

G R

A P

H

IC

L O

G

Boring Location: Proposed Building Addition

The stratification lines represent the approximate boundary lines

4/3/12

Ft. Meade VA Hospital Ft. Meade, South Dakota

FourFront Design, Inc.

Proposed VA Surgery Tower/Wing Addition

BORING STARTED

BORING COMPLETED

RIG

LOGGED

FOREMAN

JOB #

4-3-12

Ft. Meade VA Hospital

SAMPLES

D E

P T

H , f t.

U S

C S

S Y

M B

O L

N U

M B

E R

T Y

P E

R E

C O

V E

R Y

, f t.

S P

T

N B

LO

W

S ft.

W A

T E

R C

O N

T E

N T

D R

Y U

N

IT

W T pc f

B O

R E

H O

LE

_9

B

7.

G P

J T

E R

R A

C O

N .G

3.5

18.5

20.5

98.3

95.3

80.3

78.3

TOPSOIL/VEGETATIVE LAYER

SANDY LEAN CLAY, brown, stiff to medium stiff, gravel present (CL)

SILTY GRAVEL with SAND, brown, dense to very dense, possible cobbles present (GM)

WEATHERED SHALE, dark grey, very stiff

End of Boring

CS

SS

CS

SS

SS

SS

SS

1.4

1.4

1.3

1.2

1.4

1.1

1.3

50/0.4

TESTS

DESCRIPTION

Approx. Surface Elev.: 98.8 ft U N

C O

N F

IN

E

D S

T R

E N

G T

H ps f between soil and rock types: in-situ, the transition may be gradual.

PROJECT

WD

WD

WD

WATER DEPTH OBSERVATIONS, ft

15.5

B4125017

BC

4-3-12

DME-55

GR

OWNER ARCHITECT

LOG OF BORING NO. B- 3

SITE

G R

A P

H

IC

L O

G

Boring Location: Proposed Building Addition

The stratification lines represent the approximate boundary lines

4/3/12

Ft. Meade VA Hospital Ft. Meade, South Dakota

FourFront Design, Inc.

Proposed VA Surgery Tower/Wing Addition

BORING STARTED

BORING COMPLETED

RIG

LOGGED

FOREMAN

JOB #

4-3-12

Ft. Meade VA Hospital

SAMPLES

D E

P T

H , f t.

U S

C S

S Y

M B

O L

N U

M B

E R

T Y

P E

R E

C O

V E

R Y

, f t.

S P

T

N B

LO

W

S ft.

W A

T E

R C

O N

T E

N T

D R

Y U

N

IT

W T pc f

B O

R E

H O

LE

_9

B

7.

G P

J T

E R

R A

C O

N .G

Project: Proposed VA Surgery Tower/Wing Addition Site: Ft. Meade VA Hospital Ft. Meade, South Dakota Job #: B4125017 Date: 4-30-12

Topsoil

Concrete Section

Topsoil Sandy Lean Clay (CL)

Sandy Lean Clay (CL)

Sandy Clay w/ Gravel (CL)

Silty Sand w/ Gravel (SM)

Silty Sand w/ Gravel (SM)

Sandy Lean Clay (CL)

Sandy Clay w/ Gravel (CL)

E le va tio n, ft

T

C _L

IT

H

O

LO

G Y

_E

LE

V

.G P

J T

E R

R A

C O

N .G

9/

/0

SUBSURFACE DIAGRAM

Weathered Shale

T C

_L

IT

H O

LO

G

Y _E

LE

V

B

7.

G

P J

T E

R R

A C

O N

.G

/1

Weathered Shale

Weathered Shale

Silty Gravel w/ Sand (GM)

B- 1

B- 2

B- 3

Field Exploration Description The boring locations were selected and staked in the field by Terracon. The approximate boring locations are indicated on the attached Boring Location Diagram. The ground surface elevations indicated on the boring logs were referenced to a Temporary Benchmark (TBM). The TBM selected for this project was the finished main floor of the existing hospital building. The locations and elevations of the borings should be considered accurate only to the degree implied by the means and methods used to define them.

The borings were drilled with a CME-55 rotary drill rig using solid-stem augers to advance the boreholes. Samples of the soil encountered in the borings were obtained using split spoon and California Barrel samplers.

In the split-barrel sampling procedure, the number of blows required to advance a standard 2-inch O.D. split-barrel sampler the last 12 inches of the typical total 18-inch penetration by means of a 140-pound C.M.E. auto-hammer with a free fall of 30 inches, is the standard penetration resistance value (SPT-N). This value is used to estimate the in-situ relative density of cohesionless soils and consistency of cohesive soils.

Penetration resistance values for the California barrel sampler were recorded in a manner similar to the standard penetration test (SPT). This test consists of driving the sampler into the ground with a 140-pound hammer free-falling through a distance of 30 inches. The number of blows required to advance the California barrel sampler 18 inches, is recorded and can be correlated to the standard penetration resistance value (N-value). The blow count values are indicated on the boring log at the respective sample depths.

The samples were tagged for identification, sealed to reduce moisture loss, and taken to our laboratory for further examination, testing, and classification. Information provided on the boring logs attached to this report includes soil descriptions, consistency evaluations, boring depths, sampling intervals, and groundwater conditions. The borings were backfilled with auger cuttings in the follow days once follow-up groundwater measurements were recorded.

A field log of each boring was prepared by the field engineer. These logs included visual classifications of the materials encountered during drilling as well as the engineer’s interpretation of the subsurface conditions between samples. Final boring logs included with this report represent the engineer's interpretation of the field logs and include modifications based on laboratory observation and tests of the samples.

APPENDIX B

LABORATORY TESTING

Laboratory Testing As a part of the laboratory testing program, the soil samples were classified in the laboratory based on visual observation, texture, plasticity, and the laboratory testing performed as noted below. The soil descriptions presented on the boring logs for native soils are in accordance with our enclosed General Notes and Unified Soil Classification System (USCS). The estimated group symbol for the USCS is also shown on the boring logs, and a brief description of the Unified System is included in this report. Results of the laboratory tests are presented on the boring logs and/or included herein.

Selected soil samples were tested for the following properties:

Water Content Grain Size Distribution Atterberg Limits

0 20 40 60 80 100

PISpecimen Identification

ML

CL

MH

CH

CL-ML

P L A S T I C I T Y

I N D E X

SILTY SAND with GRAVEL(SM)

SILTY GRAVEL with SAND(GM)

LIQUID LIMIT

NP

NP

NP

LL PL %Fines Classification

4ft

7.5ft

B- 1

B- 3

LIQUID & PLASTIC LIMIT TEST RESULTS

Project: Proposed VA Surgery Tower/Wing Addition Site: Ft. Meade VA Hospital Ft. Meade, South Dakota Job #: B4125017 Date: 4-30-12T

C _A

T T

E R

B E

R G

_L

IM

IT

S

B

7.

G

P J

T E

R R

A C

O N

.G D

T

/3 0/

0.0010.010.1110100

16 20 30 40

GRAIN SIZE IN MILLIMETERS

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

SILT OR CLAY

5041 3/4 1/2

4.3

5.042

B- 1

B- 3

Specimen Identification

0.149

0.264

D10 fine coarse medium

6 810

D30

Cu

Specimen Identification

Classification coarse

D100 D60

63/8

LL PL

1.5 60 fine

HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS

SILTY SAND with GRAVEL(SM)

SILTY GRAVEL with SAND(GM)

NP

NP

NP

GRAIN SIZE DISTRIBUTION

4ft

7.5ft

4ft

7.5ft

%Clay

COBBLES

GRAVEL SAND

%Gravel %Sand %Silt

B- 1

B- 3

100 1403 2

PI Cc

Project: Proposed VA Surgery Tower/Wing Addition Site: Ft. Meade VA Hospital Ft. Meade, South Dakota Job #: B4125017 Date: 4-30-12T

C _G

R A

IN

_S

IZ

E

B

7.

G

P J

T E

R R

A C

O N

.G

APPENDIX C

SUPPORTING DOCUMENTS

Exhibit C-1

GENERAL NOTES

DRILLING & SAMPLING SYMBOLS:

SS: Split Spoon - 1-3/8" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger ST: Thin-Walled Tube - 2" O.D., unless otherwise noted PA: Power Auger CS: Ring Sampler - 2" I.D., 2½" O.D., unless otherwise noted HA: Hand Auger DB: Diamond Bit Coring - 4", N, B RB: Rock Bit BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary

The number of blows required to advance a split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”.

WATER LEVEL MEASUREMENT SYMBOLS:

WL: Water Level WS: While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB: After Boring ACR: After Casing Removal

Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations.

DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

FINE-GRAINED SOILS

COARSE-GRAINED SOILS

BEDROCK

(RS)

Blows/Ft.

(SS)

Blows/Ft.

Consistency

(RS)

Blows/Ft.

(SS)

Blows/Ft.

Relative Density

(RS)

Blows/Ft.

(SS)

Blows/Ft. Consistency

< 3 0-2 Very Soft 0-6 < 3 Very Loose < 30 < 20 Weathered 3-4 3-4 Soft 7-18 4-9 Loose 30-49 20-29 Firm 5-9 5-8 Medium Stiff 19-58 10-29 Medium Dense 50-89 30-49 Medium Hard

10-18 9-15 Stiff 59-98 30-50 Dense 90-119 50-79 Hard 19-42 16-30 Very Stiff > 98 > 50 Very Dense > 119 > 79 Very Hard > 42 > 30 Hard

RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY

Descriptive Terms of Other Constituents

Percent of Dry Weight

Major Component of Sample

Particle Size

Trace < 15 Boulders Over 12 in. (300mm) With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)

Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)

Sand

Silt or Clay #4 to #200 sieve (4.75mm to 0.075mm)

Passing #200 Sieve (0.075mm)

RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION

Descriptive Terms of Other Constituents

Percent of Dry Weight Term Plasticity Index

Trace With

Modifiers

< 5 5 – 12 > 12

Non-plastic

Low Medium

High

1-10 11-30 30+

UNIFIED SOIL CLASSIFICATION SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Soil Classification

Group Symbol

Group NameB

Coarse Grained Soils

More than 50% retained on No. 200 sieve

Gravels More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels Less than 5% finesC

Cu 4 and 1 Cc 3E GW Well graded gravelF

Cu 4 and/or 1 Cc 3E GP Poorly graded gravelF

Gravels with Fines More than 12% finesC

Fines classify as ML or MH GM Silty gravelF,G, H

Fines classify as CL or CH GC Clayey gravelF,G,H

Sands 50% or more of coarse fraction passes No. 4 sieve

Clean Sands Less than 5% finesD

Cu 6 and 1 Cc 3E SW Well graded sandI

Cu 6 and/or 1 Cc 3E SP Poorly graded sandI

Sands with Fines More than 12% finesD

Fines classify as ML or MH SM Silty sandG,H,I

Fines classify as CL or CH SC Clayey sandG,H,I

Fine-Grained Soils 50% or more passes the No. 200 sieve

Silts and Clays Liquid limit less than 50

Inorganic PI 7 and plots on or above “A” lineJ CL Lean clayK,L,M

PI 4 or plots below “A” lineJ ML SiltK,L,M

Organic Liquid limit - oven dried

0.75 OL

Organic clayK,L,M,N

Liquid limit - not dried Organic siltK,L,M,O

Silts and Clays Liquid limit 50 or more

Inorganic PI plots on or above “A” line CH Fat clayK,L,M

PI plots below “A” line MH Elastic siltK,L,M

Organic Liquid limit - oven dried

0.75 OH

Organic clayK,L,M,P

Liquid limit - not dried Organic siltK,L,M,Q

Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat

A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded gravel with silt, GW-GC well graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well graded sand with silt, SW-SC well graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay

E Cu = D60/D10 Cc =

DxD

)(D

F If soil contains 15% sand, add “with sand” to group name.

G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

HIf fines are organic, add “with organic fines” to group name.

I If soil contains 15% gravel, add “with gravel” to group name.

J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.

K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant.

L If soil contains 30% plus No. 200 predominantly sand, add

“sandy” to group name.

MIf soil contains 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.

N PI 4 and plots on or above “A” line.

O PI 4 or plots below “A” line.

P PI plots on or above “A” line.

Q PI plots below “A” line.

LABORATORY TEST

SIGNIFICANCE AND PURPOSE

TEST SIGNIFICANCE PURPOSE

California Bearing Ratio

Used to evaluate the potential strength of subgrade soil, subbase, and base course material, including recycled materials for use in road and airfield pavements.

Pavement Thickness Design

Consolidation Used to develop an estimate of both the rate and amount of both differential and total settlement of a structure.

Foundation Design

Direct Shear Used to determine the consolidated drained shear strength of soil or rock.

Bearing Capacity, Foundation Design, and Slope Stability

Dry Density Used to determine the in-place density of natural, inorganic, fine-grained soils.

Index Property Soil Behavior

Expansion Used to measure the expansive potential of fine-grained soil and to provide a basis for swell potential classification.

Foundation and Slab Design

Gradation Used for the quantitative…