57554 NYANG Beddown Stewart Subsurface Info.pdf

SUBSURFACE INFORMATION

for the

NYANG DEFENSE GROUP BEDDOWN PROJECT

STEWART AIR NATIONAL GUARD BASE

NEWBURGH, NEW YORK

for

US NATIONAL GUARD BUREAU

THERE IS NO EXPRESS OR IMPLIED GUARANTEE AS TO THE ACCURACY OR

COMPLETENESS OF THE INFORMATION AND DATA CONTAINED HEREIN, NOR

OF THE INTERPRETATION THEREOF BY THE OWNER, BURNS & McDONNELL

ENGINEERING COMPANY, OR ANY OF THEIR REPRESENTATIVES.

THE SUBSURFACE INFORMATION AND DATA CONTAINED HEREIN DO NOT

FORM A PART OF ANY CONTRACT DOCUMENT ISSUED BY THE OWNER

AND/OR BURNS & McDONNELL.

IF THIS SUBSURFACE INFORMATION IS BEING ISSUED IN ELECTRONIC (PDF) FORMAT IT SHALL ONLY BE ISSUED IN ITS ENTIRETY, CONSISTING OF THE 4-PAGE FRONT-END DOCUMENT WITH A 59-PAGE

APPENDIX (FLYSHEET AND REPORT BY KLEINFELDER).

BURNS & McDONNELL

PROJECT 57554

Burns & McDonnell

Engineers-Architects-Consultants Kansas City, Missouri

MARCH 2011

COPYRIGHT © 2011 BURNS & McDONNELL CONSULTANTS, PC

NYANG BEDDOWN MARCH 2011

PROJECT No. 57554

TABLE OF CONTENTS

Page No.

I. GENERAL

II. DESIGN NOTES

III. WATER LEVEL INFORMATION

IV. ADDITIONAL SUBSURFACE INFORMATION

V. LIMITATIONS

A. Document Use B. Variations

APPENDICES

APPENDIX A

Geotechnical Engineering Evaluation, Proposed NYANG Defense Group Beddown Project (Building 106 Addition), Stewart Air National Guard Base, Newburgh, New York; prepared by Kleinfelder Consultant, PC, dated February 21, 2011.

NYANG BEDDOWN 1 MARCH 2011

I. GENERAL

This subsurface information document consists of the data and results of a subsurface investigation described in a report titled Geotechnical Engineering Evaluation, Proposed NYANG Defense Group Beddown Project (Building 106 Addition), Stewart Air National Guard Base, Newburgh, New York, dated February 21, 2011. The investigation was performed by Kleinfelder Consultants, PC (Kleinfelder) of Exton, Pennsylvania. The report, as prepared by Kleinfelder, is included in Appendix A of this document.

Drilling and laboratory testing for this investigation was performed by Kleinfelder. The drilling phase was performed on December 8 through December 10, 2010. It included the completion of ten (10) borings, three of which were additional offsets borings due to preliminary auger refusal, drilled to depths ranging from 5 feet to 50 feet below grade.

Laboratory tests were conducted on select available samples following the completion of drilling operations. Boring logs and laboratory test results, as prepared by Kleinfelder, are included in the report in Appendix A of this document.

Samples recovered during the subsurface investigation were transported to the laboratory by Kleinfelder. Kleinfelder was not compensated to store the samples after testing and reporting beyond their customary retention period prior to disposal.

II. DESIGN NOTES

Geotechnical design notes have not been prepared for this project.

III. WATER LEVEL INFORMATION

Water levels were observed by Kleinfelder, see Appendix A. It should be noted by the reader that fluctuations in water levels may occur over more prolonged periods of readings and can be influenced by various outside factors. It may take groundwater several days to reach its hydrostatic levels in holes in cohesive soils.

Seasonal variations in rainfall, changes to on-site conditions, and changes to off-site conditions can affect groundwater levels. Fluctuations in groundwater levels from those noted in logs should be anticipated during construction. Water levels observed and recorded by others reflect only those conditions that existed at the time of investigation and may vary from true phreatic groundwater levels.

IV. ADDITIONAL SUBSURFACE INFORMATION

Burns & McDonnell requested from US National Guard Bureau (Owner) additional subsurface information in the vicinity of the Site. Burns & McDonnell was provided with the information as listed below. This information is available for review at Burns & McDonnell’s office upon prior written request.

1. Two boring logs conducted by Empire Subsurface (location unknown) and eight test pit logs conducted by John P. Stopen Consulting Engineer, of Syracuse, New York from previous projects in the near vicinity of building 106.

Burns & McDonnell is aware that construction activity has been undertaken in the near vicinity of the Site. Additional information in the form of geotechnical reports and/or

NYANG BEDDOWN 2 MARCH 2011

construction records may exist. Requests for additional information should be directed to the Owner.

Burns & McDonnell is not aware of any additional subsurface information in the vicinity of the Site. Requests for additional subsurface information should be directed to the Owner.

V. LIMITATIONS

A. DOCUMENT USE

The information provided in Appendix A has been prepared for the use of Burns & McDonnell for design purposes. No other warranty, express or implied, is made as to the information included in this document. In the event that conclusions and recommendations based on data contained in this document are made by others, such conclusions and recommendations are the responsibility of others.

The information gathered and presented in this document was not obtained for an environmental audit nor to evaluate the potential for hazardous materials at the Site. The equipment, techniques, and personnel used to perform geoenvironmental exploration differ substantially from those applied in soil and foundation engineering. The purpose of this document is not intended as preparation for a Geotechnical Baseline Report, nor to provide information for use in developing construction cost estimates.

B. VARIATIONS

The subsurface information submitted in this document is based upon data obtained from test borings completed at the approximate locations indicated on Plate 2 of the report in Appendix A of this document. This document does not reflect variations which may occur between test borings. The nature and extent of variations between the test borings may not become evident until excavation is performed. If during construction, soil, rock, and/or groundwater conditions appear to be different from those described herein, Burns & McDonnell should be advised at once so that recommendations made may be evaluated and modified, if necessary. Water levels, as described in this document, reflect only those conditions that existed at the time that this particular subsurface investigation was performed by Kleinfelder. Fluctuations or changes in water levels and groundwater conditions can be influenced by sources outside the site investigated, by seasonal rainfall, and by changes in drainage conditions in and around the Site. Fluctuations can occur and should be anticipated between the time of investigation and the time of construction.

Geotechnical Engineering Evaluation, Proposed NYANG Defense Group Beddown Project (Building 106 Addition), Stewart Air National Guard Base, Newburgh, New York;

prepared by Kleinfelder Consultant, PC, dated February 21, 2011.

114820EXPARptNYANGDefenseGroupBeddownProjFINAL022111

February 21, 2011 Project No. 114820

Mr. Joshua Bergsten, P.E.

Burns & McDonnell Consultants, P.C.

9400 Ward Parkway Kansas City, Missouri 64114

RE: Geotechnical Engineering Evaluation Proposed NYANG Defense Group Beddown Project (Building 106 Addition) Stewart Air National Guard Base Newburgh, New York

Dear Mr. Bergsten:

Kleinfelder has completed the authorized subsurface exploration and geotechnical engineering evaluation for the New York Air National Guard (NYANG) Defense Group Beddown project at the Stewart Air National Guard Base located in Newburgh, New York in general accordance with our revised proposal dated November 17, 2010. The purpose of our evaluation was to explore and evaluate the subsurface conditions at the project Site and develop geotechnical recommendations for the design and construction of the proposed facility.

The attached report contains a description of the findings of our field exploration and laboratory testing program, our engineering interpretation of the results with respect to the project characteristics, and our geotechnical site development recommendations as well as construction guidelines for the planned project.

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

Sincerely, Jonathan Morrison William C. Rinker, P.E.

Geotechnical Project Professional Geotechnical Group Manager Kleinfelder East, Inc. Kleinfelder Engineering, P.C.

Enclosures JKM/WCR:lmc

180 Sheree Blvd., Suite 3800 Exton, PA 19341 p| 610.594.1444 f| 610.594.2743 kleinfelder.com

Geotechnical Engineering Evaluation Report

NYANG DEFENSE GROUP BEDDOWN PROJECT

(BUILDING 106 ADDITION)

STEWART AIR NATIONAL GUARD BASE

NEWBURGH, NEW YORK

February 21, 2011

Project No. 114820

Prepared For:

Burns & McDonnell Consultants, P.C.

9400 Ward Parkway

Kansas City, MO 64114

This document was prepared for use only by the Client, only for the purposes stated, and within a reasonable time from issuance. Non-commercial, educational and scientific use of this report by regulatory agencies is regarded as a "fair use" and not a violation of copyright. Regulatory agencies may make additional copies of this document for internal use. Copies may also be made available to the public as required by law. The reprint must acknowledge the copyright and indicate that permission to reprint has been received.

180 Sheree Blvd., Suite 3800 Exton, PA 19341 p| 610.594.1444 f| 610.594.2743 kleinfelder.com

TABLE OF CONTENTS

SECTION PAGE

1.0 INTRODUCTION

1.1 GENERAL

1.2 PROPOSED SITE DEVELOPMENT

1.3 PURPOSE AND SCOPE OF SERVICES

1.4 SITE DESCRIPTION

1.5 PHYSICAL SETTING

1.6 PREVIOUS INVESTIGATION

2.0 SITE INVESTIGATION

2.1 SUBSURFACE CONDITIONS

2.1.1 Surface Materials

2.1.2 Existing Fill

2.1.3 Glacial Deposits

2.1.4 Weathered Rock

2.1.5 Groundwater

2.2 LABORATORY TESTING

3.0 SITE DEVELOPMENT RECOMMENDATIONS

3.1 SITE PREPARATION

3.2 SUBGRADE PREPARATION

3.3 EARTHWORK

3.4 UTILITIES

3.6 SEISMIC CONSIDERATIONS

4.0 DESIGN RECOMMENDATIONS

4.1 FOUNDATION RECOMMENDATIONS

4.2 LOAD BEARING FILL

4.3 SLAB-ON-GRADE

4.4 MOISTURE VAPOR TRANSMISSION

4.5 PAVEMENT DESIGN

4.6 GROUNDWATER MANAGEMENT

4.7 CORROSION AND SULFATE ATTACK

4.8 RETAINING WALLS

5.0 ADDITIONAL SERVICES

5.1 REVIEW OF PLANS AND SPECIFICATIONS

5.2 CONSTRUCTION OBSERVATION AND TESTING

6.0 LIMITATIONS

PLATES

PLATE 1 SITE LOCATION AND REGIONAL GEOLOGY MAP

PLATE 2 EXPLORATION LOCATION MAP

APPENDICES

APPENDIX A TEST BORING LOGS

APPENDIX B LABORATORY DATA

114820EXPARptNYANGDefenseGroupBeddownProjFINAL022111 February 21, 2011 Page 1 Copyright 2011 – Kleinfelder

1.0 INTRODUCTION

1.1 GENERAL

Kleinfelder has completed the authorized geotechnical engineering evaluation for the proposed Defense Group Beddown Project (Building 106 Addition) to be located at the Stewart Air National Guard Base (ANG) in Newburgh, NY. The project site location is shown on a USGS base map included as Plate 1, Site Location and Regional Geology Map.

This report includes our recommendations related to the geotechnical aspects of project design and construction. Conclusions and recommendations presented in this report are based on the subsurface conditions encountered at the locations of our explorations and the provisions and requirements outlined in the limitations section of this report. Recommendations presented herein should not be extrapolated to other areas or used for other projects.

1.2 PROPOSED SITE DEVELOPMENT

We understand that the proposed Defense Group Beddown project includes an addition to existing Building 106 at the Stewart Air National Guard Base. The proposed addition is approximately 34,000 square feet (s.f.) in size. Of the 34,000 s.f., approximately 28,000 s.f. will be a two-story structure with the remaining being one-story. The west wall of existing Building 106 will be demolished and a building expansion joint will connect the addition to the existing facility. The expansion joint will create a structural separation between the two structures. The new addition will be steel framed with CMU veneer to match existing base standards. The proposed improvements also include exterior pavements and two parking areas. The security forces vehicle parking area is planned to be constructed near the west side of the new addition. The proposed auxiliary parking area is planned east of Building 108 adjacent to an existing parking area and baseball field.

Preliminary columns loads will be less than 175 kips and the proposed addition finished floor elevation will match the existing Building 106 finished floor based on information provided by Burns and McDonnell. Grading information was not available for the proposed addition and parking areas at the time of this report. We have assumed cuts and fills of less than 5 feet.

1.3 PURPOSE AND SCOPE OF SERVICES

The purpose of this geotechnical evaluation was to explore and evaluate surface and subsurface conditions at the site and to develop recommendations for the geotechnical aspects of the design and construction of the project. The Scope of Services performed for this geotechnical evaluation consisted of a subsurface exploration program, laboratory testing of selected soil samples, engineering analysis of the field and laboratory data, and the preparation of a written report presenting the results of our field exploration, laboratory tests and engineering analyses.

The scope of the exploration and engineering evaluation for this study, as well as the conclusions and recommendations in this report, were based on our understanding of the project as described above.

If pertinent details of the project have changed or otherwise differ from our descriptions, we must be notified and engaged to review the changes and modify our recommendations, if needed.

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1.4 SITE DESCRIPTION

Stewart International Airport is located west of Newburgh in the southern Hudson Valley of New York. The airport is home to the 105th Airlift Wing of the New York Air National Guard (NYANG).

The NYANG base is situated in the southeastern portion of the airport.

The project site is located on the NYANG base roughly bounded by Tuskegee Road to the south, Freedom Road to the east, Militia Way to the north, and Building 105 to the west. The approximate 2.5-acre site includes a one-story building (Building 106), a relatively flat fenced-in asphalt paved area, and a grass-covered area. The Building 106 addition is planned to be constructed southwest of the existing building utilizing the asphalt paved and grass-covered areas.

According to the plan titled “Grading, Location, and Planting Plans” Quinlivan Pierik Krause (QPK), dated April 1990, the existing site grades along west wall of the existing building range in elevation from approximately El. 433 to El. 436.5 (datum not shown). The existing site grades within the asphalt paved area range in elevation from approximately El. 433 to El. 430. The grass covered area generally slopes up to the west from approximately El. 428 to El. 432.

Based on QPK structural drawings dated April 1990, Building 106 is supported on a shallow foundation system designed with allowable soil bearing pressures of 4,000 psf and 3,000 psf for interior and exterior footings respectively. The drawings show a finished floor elevation of 437 feet.

The exterior foundations in proximity to the proposed addition are reportedly approximately four to seven feet below exterior grade (varies with changing exterior grade).

The location of the proposed auxiliary parking area is a relatively flat area covered by grass adjacent to an existing parking area and baseball field.

1.5 PHYSICAL SETTING

The site is located within the Stewart International Airport property in Newburgh, New York. The project site is reportedly underlain by the Middle Ordovician-aged Austin Glen Formation.

The Austin Glen formation reportedly includes greywacke as a primary rock type and shale as a secondary rock type. Greywacke rock is a dark gray, firmly indurated, coarse-grained sandstone that consists of poorly sorted angular to subangular grains of quartz and feldspar, with a variety of dark rock and mineral fragments embedded in a compact clayey matrix having the general composition of slate and containing an abundance of very fine-grained illite, sericite, and chloritic minerals.

The surficial geology in the area of the site consists of glacial till material with variable texture such as clay, silty-clay, and boulder clay with variable amounts of sand.

1.6 PREVIOUS INVESTIGATION

During previous investigations performed in the vicinity of the project site, test borings B-104 and B-106 and test pits TP-1 through TP-8 were performed by Empire and John P. Stopen Consulting Engineer, respectively. A plan provided by Burns & McDonnell depicts the approximate locations of the previously-performed test borings and test pits.

Page 3 Copyright 2011 – Kleinfelder

According to the plan, Borings B-104 and B-106 were located north and south of existing Building 106, respectively. Boring B-104 was extended to a depth of approximately 22 feet below ground surface (bgs). Based on the log, subsurface conditions consisted of firm to compact re-worked material (gray coarse to fine sand and clayey silt with gravel, cobbles and boulders) to a depth of approximately 18 feet underlain by native very compact gray clayey silt and fine to coarse sand with gravel. Groundwater was not noted in boring B-104. Boring B-106 was extended to a depth of approximately 32 feet bgs. Subsurface conditions at the location of this boring reportedly consisted of loose, firm, or compact re-worked material (brown clayey silt with coarse to fine sand and gravel and cobbles or brown or gray clayey silt with coarse to fine sand and gravel) to a depth of about 30 feet. Concrete, brick and organic silt were noted deeper than 25 feet. Groundwater was noted to be first observed at 0.8 feet bgs in boring B-106. No free water was noted inside the augers at completion and after the augers were pulled water was observed at 1.2 feet.

The test pits were located around the perimeter of existing Building 106 and excavated to depths of approximately 5 to 10 feet bgs. Based on the test pits logs, subsurface soil consisted of clayey sand, clayey silt, sand, and silt with varying amount of gravel. Cobbles and boulders were observed during excavation of the test pits. Groundwater was not noted in the test pit logs.

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2.0 SITE INVESTIGATION

2.1 SUBSURFACE CONDITIONS

Subsurface conditions at the site were explored by seven test borings with three additional offset locations due to auger refusal in existing fills. Three borings (B-1, B-2, and B-5) were located within the proposed two-story addition area. Two borings (B-3 and B-4) were performed within the proposed one-story addition area. Subsurface conditions at the proposed security force vehicles parking and auxiliary parking areas were explored by borings B-6 and B-7, respectively. The approximate locations of the test borings are shown on Plate 2, Exploration Location Map.

The subsurface exploration program was performed from December 8 through December 10, 2010 under the technical supervision of Maryam Veisi, E.I.T. of Kleinfelder. The drilling was performed by CME using Diedrich D-120 and CME 45C truck-mounted drill rigs and hollow-stem auger drilling techniques. An automatic hammer was used with the Diedrich D-120 and a manual hammer was used with the CME 45C.

Standard Penetration Test (SPT) samples were taken at various depths in general accordance with ASTM D1586. The SPT uses a split-spoon sampler advanced with a 140-pound weight (known as the hammer) falling 30 inches. The number of hammer blows to advance the split-spoon sampler one foot is known as the N-value. Using a hammer efficiency of about 0.95 for the automatic hammer, correction factors of approximately 1.2 to 1.6 can be used to convert the measured N-value to N60 values. Bulk samples were obtained for CBR and compaction testing.

The test borings were extended to about 30 feet bgs in borings B-1 through B-4 and to about 50 feet bgs in boring B-5 within the footprint of the proposed building addition. The test borings were extended to depths ranging from about 5 to 10 feet bgs within the proposed parking areas. The borings were backfilled with cement-bentonite grout followed by asphalt cold-patch in existing paved areas. The thickness of the asphalt patch matched the existing pavement thickness.

The number, location, and depth of the borings were selected by Burns and McDonnell. The boring locations were located in the field by Kleinfelder personnel using the drawings provided and manual measurements from existing physical points of reference shown on the plans. Underground utility clearance was performed at proposed boring locations by Enviroprobe Service Inc. on December 7, 2010 using ground penetrating radar (GPR) and electromagnetic techniques and the utility plan provided by Burns & McDonnell, dated September 20, 2010.

Descriptions of the soil strata encountered are included in the test boring logs provided in Appendix A.

Descriptions for the test borings were based on the USCS classification system. The major soil groups encountered during the field evaluation are described below in the general order of their occurrence.

2.1.1 Surface Materials

The borings were drilled within existing grass-covered and asphalt paved areas and encountered either topsoil or asphalt at the ground surface. The asphalt pavement ranged in thickness from approximately seven to nine inches and was encountered in test borings B-1 and B-3 through B-5.

Approximately two inches of topsoil was encountered in Borings B-2, B-6, and B-7.

Page 5 Copyright 2011 – Kleinfelder

2.1.2 Existing Fill

Beneath the surface materials, the borings encountered existing fill materials that typically consisted of medium dense to very dense clayey or silty sand with variable amount of gravel.

Existing fill materials encountered in the borings also included firm to hard silt with variable amount of sand and gravel, soft to hard lean clay with variable amount of sand and gravel, and medium dense to very dense poorly graded sand with silt and variable amounts of gravel. Cobbles and boulders are likely present throughout the fills based on drilling observations and auger refusals within the existing fill materials (B-1, B-2 and B-2A). The existing fill materials extended to depths ranging from approximately 8 to 13 feet bgs in Borings B-1 through B-5. Fill material was encountered in boring B-6 to the termination depth and possible fill was encountered to the termination depth of boring B-7.

2.1.3 Glacial Deposits

Beneath the existing fill in borings B-1 through B-5, glacial deposits were encountered. The glacial deposits encountered primarily consisted of medium dense to very dense clayey sand with variable amounts of gravel or soft to hard lean clay with variable amount of gravel and sand. The glacial deposits were encountered at depths ranging from approximately 8 to 13 feet bgs and extended to the termination depth of borings B-1 through B-4 and to approximately 43 feet in boring B-5.

2.1.4 Weathered Rock

Gray, very weak, weathered shale was encountered at a depth of approximately 43 feet bgs in boring B-5 and extended to the termination depth of the boring. The drilling equipment was able to auger-through the weathered rock.

2.1.5 Groundwater

Groundwater was encountered at a depth of approximately 17 feet during drilling of boring B-2B and at a depth of approximately 8 feet 24 hours after drilling boring B-3. It should be noted that groundwater is known to fluctuate due to local and regional factors including, but not limited to, precipitation events, seasonal changes, and periods of wet or dry weather.

2.2 LABORATORY TESTING

Laboratory testing was performed on select soil samples obtained from the test borings to further evaluate physical and chemical soil properties. Laboratory testing included 7 sieve tests, 6 Atterberg Limits, 13 natural moisture content determinations, 2 modified proctors, 1 CBR test, and 2 corrosion series tests. The corrosion series included one soil pH determination, one redox potential (Eh) test, one soluble sulfate test, one chloride ion test, one sulfide test, and one soil box resistivity test each. Results of the laboratory tests can be found on the boring logs provided in Appendix A, and the Laboratory Data provided in Appendix B.

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3.0 SITE DEVELOPMENT RECOMMENDATIONS

3.1 SITE PREPARATION

The area of the proposed building addition currently consists of grass and asphalt pavement. The proposed parking areas are located in grassy areas. The locations of the proposed developments are shown on Plate 2, Exploration Location Map.

Site preparation should commence with removal of existing asphalt pavements, site features scheduled for demolition, topsoil, vegetation, trees, and tree roots greater than 1-inch in diameter within the area of the proposed addition and parking areas. Existing utilities within the proposed addition area should be re-routed or properly removed/abandoned. Site preparation work should be performed under the observation of a representative of the Geotechnical Engineer.

Care should be taken in performing any demolition work, as well as during site preparation work, so as not to disturb or cause damage to buildings and utilities scheduled to remain. Rubble from demolition may be crushed and re-used as load-bearing fill as defined in Section 4.2 of this report.

Based on subsurface conditions encountered in our field explorations, existing fill materials will be encountered during site development. If reuse of on-site excavated fill material is desired then it should be separated into suitable fill material and unsuitable material. Suitable fill material includes brick rubble, concrete rubble, masonry, gravel, sand, silt, clay, and rock fragments. Suitable fill material may be re-used as load-bearing fill as defined in Section 4.2 of this report. Unsuitable material includes any other material encountered during excavation such as wood, ash, glass, cloth, organic soils, timbers, pipes, mechanical equipment, or trash. Materials encountered that are unsuitable for use as backfill should be removed from the site and will likely require disposal at a landfill. Oversize materials should be crushed to suitable size or properly disposed of off-site.

3.2 SUBGRADE PREPARATION

Identification of unstable subgrade areas is critical to the successful redevelopment of the site. A representative of the Geotechnical Engineer should observe excavations and exposed subgrades to evaluate potential loose or soft zones within the existing fill and glacial soils. After site preparation procedures have been performed, subgrades scheduled to receive load-bearing fill to achieve proposed grades, or subgrades in cut areas should be proof-rolled under the observation of a representative of the Geotechnical Engineer to evaluate the load-carrying suitability of the subgrade.

Loose and/or soft zones identified by the representative of the Geotechnical Engineer should be stabilized at the recommendation of the representative of the Geotechnical Engineer. Excavated soils may be re-used provided any unsuitable materials have been removed and they meet the requirements of Section 4.2 of this report.

The proof-rolling should be performed with a loaded tri-axle dump truck or other means approved by the representative of the Geotechnical Engineer. The proof-rolling in areas adjacent to existing structures should be performed with “light” compaction equipment (such as a walk-behind vibratory trench-roller) and additionally evaluated with a hand probe by a representative of the geotechnical engineer. Proof-rolling should uniformly cover the subgrade in accordance with recommendations by the representative of the Geotechnical Engineer. Suspect areas should be further investigated by a representative of the Geotechnical Engineer, by methods that may include test pits (performed by the contractor) or laboratory testing, to identify causes and/or extents of instability. Soils which exhibit

Page 7 Copyright 2011 – Kleinfelder excessive rutting, pumping, movement, or other signs of instability as determined by a representative of the Geotechnical Engineer should be stabilized, or removed and replaced with compacted fill in accordance with Section 4.2 of this report, at the recommendation of a representative of the Geotechnical Engineer. Subgrade areas should be stable as determined by a representative of the Geotechnical Engineer prior to construction of structural elements.

3.3 EARTHWORK

We have assumed cuts and fills of less than 5 feet will be required to achieve proposed site grades.

Excavations will also be required for utility and foundation construction as well as existing fill removal and replacement operations.

The glacial materials encountered during our evaluation are generally considered suitable for reuse as load-bearing fill material as defined in Section 4.2 provided moisture contents are controlled and oversize materials are removed. Portions of the existing fill materials may be reused as load-bearing fill as defined in Section 4.2 provided moisture contents are controlled, oversize materials are removed, and unsuitable materials are removed as discussed in Section 3.1. Reworking of the on-site soils to be used as compacted fill should be anticipated considering the potential that they may not be within the range of optimum moisture content at the time earthwork proceeds. It should also be anticipated that crushing and/or sorting of proposed fill materials may be required to limit particle sizes and remove unsuitable materials from the existing fill deposits.

The drying of silty and clayey soils by aeration is not easily achieved and typically requires frequent working of the soil by methods such as discing and periods of warm dry weather. Load-bearing fills placed within the proposed addition area should generally have their moisture contents controlled to within 3 percent of optimum, and load-bearing fills placed outside the building area should generally have their moisture contents controlled to within 5 percent of optimum. The moisture content of proposed fill material can be greatly influenced by seasonal changes and precipitation events.

Depending on the moisture content of the proposed backfill material at the time of proposed reuse, wetting or drying of the proposed backfill material may be required. The greatest success in reusing on-site materials as compacted backfill and fill is generally achieved during periods of warm dry weather, however, fill material can be placed during any season provided the moisture content permits. If the moisture contents of the proposed on-site fill materials are too high and the schedule does not allow for drying, imported material as defined in Section 4.2 of this report may be used.

Quality assurance testing of in-place fill densities is critical throughout construction. During earthwork activities, a representative of the Geotechnical Engineer should be on-site to observe earthwork and evaluate the compaction of the fill placed.

Construction site safety is the sole responsibility of the contractor, who shall also be solely responsible for the means, methods and sequencing of construction operations. Excavations should be performed under the direction of the contractor’s “Competent Person” as defined by OSHA. The contractor should also be aware that slope height, slope inclination or excavation depths (including utility trench excavations) should in no case exceed those specified in local, state and/or federal safety regulations, such as OSHA Health and Safety Standard for Excavations, or more stringent applicable regulations. Stockpiles should be placed a minimum distance equal to that of the adjacent excavation height, from the edge of excavations and their heights should be controlled so they do not surcharge the sides of the excavation. Surface drainage should be carefully controlled to prevent flow of water into the excavations. The site should be graded to prevent surface water from ponding in construction areas and accumulating in excavations.

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If site grading and construction is to be performed during or shortly after seasons of wet weather, the owner and contractors should be fully aware of the potential impact of wet weather. Rainstorms can cause delay to construction and damage to previously completed work, such as saturating a compacted pad or subgrade, or flooding an excavation. Runoff can also cause erosion. Earthwork during rainy months will require extra effort and caution by the contractors. The soils may be too wet to compact, which will require processing to dry the soil. The grading contractor should be responsible to protect his work to avoid damage by rainstorms, including smooth rolling to seal off a pad or subgrade surface to facilitate drainage and to reduce rain damage and the covering of stockpiles with plastic sheeting. Ponded water should be pumped out of excavations and subgrade areas immediately. Construction in wet weather, if a possibility for project construction, should be addressed in the project construction bid documents and/or specifications. We recommend that the grading contractor submit a wet weather construction plan outlining procedures they will employ to protect their work and to minimize damage to their work by rainstorms.

3.4 UTILITIES

Utility excavations should comply with local codes, ordinances and OSHA requirements. Excavation side slopes are to be maintained in a safe condition until completion of backfilling. The backfilling of utility trenches in the building area must meet the same compaction criteria as the surrounding subgrade soil (i.e., 95 percent of the optimum dry density as determined by the Modified Proctor Test, ASTM D1557, most recent edition). Since a nuclear density gauge may read the conduit or pipe as a void, visual observations of backfill materials and manual techniques, performed by a representative of the Geotechnical Engineer should supplement nuclear density testing.

3.5 SEISMIC CONSIDERATIONS

Based on the properties of the soils encountered in our test borings and our knowledge of geologic conditions in the area of the site, a site class of ‘D’ (“stiff soil” profile) is considered appropriate as determined from Table 1613.5.2 of the 2006 International Building Code.

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4.0 DESIGN RECOMMENDATIONS

4.1 FOUNDATION RECOMMENDATIONS

Existing fill materials were encountered during our field exploration program up to a depth of about 13 feet bgs within the area of the proposed building addition. The existing fills encountered appear to be composed predominantly of natural soil materials that have been re-worked and compacted. Based on conditions encountered in the test borings, it is Kleinfelder’s opinion the fill materials are suitable for support of foundations. While not encountered in the borings performed for our evaluation, it is possible that pockets of loose or soft existing fill or existing fill material containing unsuitable materials may be encountered during construction. Areas of unsuitable existing fills as determined by a representative of the Geotechnical Engineer should be removed and replaced with properly compacted Select Load-Bearing Fill at the recommendation of the representative of the Geotechnical Engineer.

Based on our evaluation, Kleinfelder recommends that the proposed addition be supported on shallow continuous wall-footings and isolated spread-footings designed in accordance with the following criteria.

• The footings may be supported on either approved existing fills or properly compacted new

Select Load-Bearing fill.

• The footings may be designed for a maximum net allowable soil bearing pressure of 3,000 pounds per square foot (psf). Considering the allowable bearing pressure, the factor of safety with respect to shear failure is greater than 3. A one-third increase in allowable bearing pressure may be used for load combinations that include all transient loads including seismic and wind.

• Continuous footings should have a minimum width of two feet and isolated spread footings should have a minimum width of three feet.

• Post-construction total and differential settlements of the shallow foundation system are estimated to be less than 1 inch and ½-inch respectively.

During construction, footing excavations should be observed by a representative of the Geotechnical Engineer to evaluate the supporting capabilities of the bearing materials. The representative of the Geotechnical Engineer should “probe” the foundation subgrade with a manually operated soil-probe to identify potential loose or soft zones. If unsuitable bearing conditions or debris are encountered, the area should be over-excavated, and backfilled with compacted, select load-bearing fill at the recommendation of a representative of the Geotechnical Engineer.

The bottom of new addition foundations located adjacent to existing foundations should be situated at or below the bottom of existing foundation. If new construction adjacent to existing foundations extends below existing foundations, the existing foundation should be properly underpinned. Footings subject to frost are recommended to be located at least 42 inches below the lowest adjacent exterior grade or as required by more stringent codes. Interior footings not subject to frost should be based at least two feet below finished grades. Construction schedules which include a winter season may require temporary frost protection for interior footings and other building features which are not designed to be subject to frost upon building completion.

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For resistance to lateral loading, we anticipate the foundations will be constructed on either approved existing fills or properly compacted new Select Load-Bearing fill. An ultimate coefficient of friction of 0.35 may be assumed for calculation of frictional resistance along the bottom of the foundation. We recommend a minimum factor of safety of 1.5 when using sliding friction alone. A passive pressure coefficient of 2.77 may be used to calculate ultimate passive pressure resistance on the side of footings for resistance to sliding. The passive pressure can be assumed to act starting at the top of the lowest adjacent grade in paved areas and at a depth of 1-foot below grade in unpaved areas. A larger magnitude of movement is required to engage passive resistance than sliding friction. Therefore, a minimum factor of safety of 2.0 is recommended when using passive pressure in addition to friction to resist lateral loads. The passive resistance values discussed above are only applicable where the concrete for footings are either placed directly against undisturbed soils or that the voids created from the use of formwork are backfilled with properly compacted soil.

4.2 LOAD BEARING FILL

The backfill and fill used to support proposed structures and site features that will be adversely affected by settlement are considered load-bearing fills. Two classes of load-bearing fills are defined as follows:

General Load-Bearing Fill: Used for support of pavements, curbs, sidewalks, and finished site grades outside the building addition area. General Load-Bearing Fill should consist of or a combination of GW, GP, GM, GC, SW, SP, SM, SC, ML, and CL materials as classified by ASTM D2487. General load-bearing fill should consist of inorganic and readily compactable site soils, inert rubble or rock fragments. Inorganic soils may be defined as soils containing less than five percent of organic matter by weight and free of visible organic matter deemed excessive by the representative of the Geotechnical Engineer. Fragments larger than 8 inches (any dimension) should be excluded from general load-bearing fills. The glacial deposits and existing fill material encountered in the test borings are generally suitable for use as general load-bearing fill provided the moisture content and particle sizes are controlled. Prior to re-use of the existing fill materials any unsuitable materials should be removed as discussed in Section 3.1 of this report. General load-bearing fills should have a moisture content controlled to within 5 percent of optimum as determined by ASTM D1557, most recent edition.

Select Load-Bearing Fill: Recommended for fills exclusively in the building addition area and the area extending five feet beyond the building addition footprint Select load-bearing fill should consist of inorganic and readily compactable site soils, inert rubble or rock fragments. Inorganic soils may be defined as soils containing less than five percent of organic matter by weight and free of visible organic matter deemed excessive by the representative of the Geotechnical Engineer. Fragments larger than 4 inches (any dimension) should be excluded from select load-bearing Fills. Select Load-Bearing Fill should consist of or a combination of GW, GP, GM, GC, SW, SP, SM, and SC materials as classified by ASTM D2487. The granular on-site soils encountered in the test borings are generally considered suitable for use as Select Load-Bearing Fill provided the moisture content and particle sizes are controlled. Prior to re-use of the existing fill materials any unsuitable materials should be removed as discussed in Section 3.1 of this report. Select load-bearing fills should have a moisture content controlled to within 3 percent of optimum as determined by ASTM D1557, most recent edition.

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If imported fills are necessary, imported soils should meet the above requirements, and additionally, should have less than 35 percent by weight passing a No. 200 sieve, a liquid limit below 40, a plasticity index of 12 or less, and be within the proper range of optimum moisture content. Proposed import fill should be approved by the Geotechnical Engineer prior to delivery to the site.

Load-bearing fills should be placed on a stable, near level subgrade prepared by the removal of weak soil deposits. The load-bearing fills should be placed in lifts not exceeding a loose thickness of 12 inches, and 8 inches in confined trench and wall backfills.

It is recommended that general load-bearing fills have each lift compacted to at least 90 percent of the maximum Modified Proctor dry density as determined by ASTM D1557, most recent edition. It is recommended that select load-bearing fills have each lift compacted to at least 95 percent of the maximum Modified Proctor dry density as determined by ASTM D1557, most recent edition. In addition, fills should be stable without significant movement under construction equipment as judged by a representative of the Geotechnical Engineer. Quality control testing of in-place fill densities throughout construction should be performed by a representative of the Geotechnical Engineer. However, conformance with the specifications remains the contractor's responsibility.

The contractor should not place backfill or fill material on subgrade surfaces that are muddy, frozen, or contain frost/ice. Frozen soils are not suitable fill sources.

4.3 SLAB-ON-GRADE

It is Kleinfelder’s opinion that the proposed slab-on-grade may be supported on a subgrade consisting of suitable proof-rolled existing materials or new properly compacted select load-bearing fill used to construct the building pad.

The floor slab should be designed and constructed in accordance with the recommendations of ACI Committee Reports 360R-92 and 302.1 R-96. Concrete floor slabs are recommended to be simply supported at wall junctures to allow unrestricted rotation of the slab's edges. Alternatively, the slabs should be free to undergo vertical deflection at the joints. Saw joints or construction joints should be used to control shrinkage cracks. Based on the subgrade preparation procedures recommended herein and the existing soil conditions, a subgrade modulus (k) of 150 pounds per square inch per inch (psi per inch, or pci) is estimated for the slab design.

Conventional ground floor slab design should include a vapor retarder located immediately below the slab and at least six inches of free draining granular material below the vapor retarder as a capillary break. If the materials underlying the vapor retarder contain sharp or angular particles, a geotextile fabric should be provided to protect the vapor retarder from puncture.

Portions of the floor slabs may not be subjected to building heat during freezing weather and may be susceptible to frost heave. The soils beneath these slabs should consist of a non-frost susceptible, free-draining granular material for a minimum depth of two feet. The soil should contain drainage provisions to ensure that surface water is not trapped.

It is typical for construction activities to “damage” the building pad between the time the building pad is prepared and the new floor slab is constructed. Kleinfelder recommends that just prior to vapor retarder installation and slab construction, the building area subgrade be proof-rolled and any unstable zones be stabilized at the recommendation of the representative of the Geotechnical Engineer.

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4.4 MOISTURE VAPOR TRANSMISSION

Subsurface moisture and moisture vapor naturally migrate upward through the soil and, where the soil is covered by a building or pavement, this subsurface moisture will collect. To reduce the impact of the subsurface moisture and potential impact of future introduced moisture (such as landscaping irrigation or precipitation) the current industry standard is to place a vapor retarder on the compacted crushed rock layer. This membrane typically consists of visqueen or polyvinyl plastic sheeting of at least 10 mil in thickness. It should be noted that although vapor barrier systems are currently the industry standard, this system may not be completely effective in preventing floor slab moisture problems.

These systems will not necessarily assure that floor slab moisture transmission rates will meet floor-covering manufacturer standards and that indoor humidity levels be appropriate to inhibit mold growth.

The design and construction of such systems are totally dependent on the proposed use and design of the building and all elements of the building design and function should be considered in the slab-on-grade floor design. Building design and construction have a greater role in perceived moisture problems since sealed buildings/rooms or inadequate ventilation may produce excessive moisture in a building and affect indoor air quality.

Various factors such as surface grades, adjacent planters, the quality of slab concrete and the permeability of the on-site soils affect slab moisture and can control future performance. In many cases, floor moisture problems are the result of either improper curing of floor slabs or improper application of flooring adhesives. We recommend contacting a flooring consultant experienced in the area of concrete, slab-on-grade floors for specific recommendations regarding your proposed flooring applications.

Special precautions must be taken during the placement and curing of all concrete slabs. Excessive slump (high water-cement ratio) of the concrete and/or improper curing procedures used during either hot or cold weather conditions could lead to excessive shrinkage, cracking, or curling of the slabs.

High water-cement ratio and/or improper curing also greatly increase the water vapor permeability of concrete. We recommend that all concrete placement and curing operations be performed in accordance with the American Concrete Institute (ACI) manual.

It is emphasized that we are not floor moisture proofing experts. We make no guarantee nor provide any assurance that use of a capillary break/vapor retarded system will reduce concrete slab-on-grade floor moisture penetration to any specific rate or level, particularly those required by floor covering manufacturers. The builder and designers should consider all available measures for floor slab moisture protection.

4.5 PAVEMENT DESIGN

Grading information for the parking areas was not available at the time of this report. We have assumed cuts and fills of less than 5 feet to construct the parking areas.

The performance of pavements will be dependent upon a number of factors, including subgrade conditions at the time of paving, rainwater runoff, and loading. Rainwater runoff should not be allowed to seep below pavements from adjacent areas. Proper drainage below the pavement section helps prevent softening of the subgrade and has a significant impact on pavement performance and pavement life. Periodic maintenance should be performed throughout the life of the proposed pavements including periodic seal coats and crack maintenance/sealing.

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The pavement areas should be proof rolled and prepared in accordance with recommendations provided in Section 3.0 of this report. For design of each of the pavement areas, we recommend a subgrade modulus of 150 pci, a CBR value of 5, and a resilient modulus of 7,500 psi based on the properties of the soils encountered in our borings and subgrade preparation recommendations included herein.

4.6 GROUNDWATER MANAGEMENT

Groundwater was encountered at a depth of approximately 17 feet during drilling of boring B-2B and at a depth of approximately 8 feet about 24 hours after drilling boring B-3. The groundwater encountered at these locations appears to be associated with “pockets” of water or perched water as water was not encountered in the other borings at the time of drilling. It should be noted that groundwater is known to fluctuate due to local and regional factors including, but not limited to, precipitation events, periods of wet or dry weather, and seasonal changes.