Attch 7_FTIG_WestACP_Geotech.pdf

USACE Baltimore District | Final Design Fort Indiantown Gap West ACP Appendix G

G Geotechnical Investigation Reports

GEOTECHNICAL

INVESTIGATION REPORT

West Access Control Point

Fort Indiantown Gap, Lebanon County, Pennsylvania

August 2018

USACE NO. W912DR-16-D-0006, W912DR17F0298

Prepared for:

10 S Howard Street

Baltimore, MD 21201

Prepared by:

3025 Chemical Road, Suite 110

Plymouth Meeting, PA 19462-1736 hdrinc.com

3025 Chemical Road, Suite 110, Plymouth Meeting, PA 19462-1736

T 484.612.1100 F 484.612.1140

August 14, 2018

U.S. Army Corps of Engineers, Baltimore District 10 S. Howard Street Room 700 Baltimore, MD 21201

Attn: Ms. Vivian Wong, Design Manager

Re: USACE Purchase No. W912DR-16-D-0006, W912DR17F0298

West Access Control Point Fort Indiantown Gap Lebanon County, Pennsylvania Geotechnical Investigation Report

Dear Ms. Wong:

Enclosed is HDR’s Geotechnical Investigation Report for the referenced project.

We are available to review and discuss anything related to the enclosed submission.

Please do not hesitate to contact me at (484) 612-1121 or John Smith, HDR Project Manager, at (402) 399-1007.

Sincerely, HDR ENGINEERING, INC.

Vinay B. Singhal, P.E.

Sr. Geotechnical Engineer

VBS:JS/lja

Enclosures

GEOTECHNICAL INVESTIGATION REPORT

West Access Control Point

Fort Indiantown Gap

USACE NO. W912DR-16-D-0006, W912DR17F0298

Prepared for:

10 S Howard Street

Baltimore, MD 21201

Prepared by:

3025 Chemical Road, Suite 110

Plymouth Meeting, PA 19462-1736

August 2018

Page i

Table of Contents

1.0 INTRODUCTION

1.1 Purpose and Scope

1.2 Project Location

1.3 Project Description

2.0 GEOTECHNICAL RECOMMENDATIONS

2.1 Embankment Construction

2.2 Cut Slope Construction

2.3 Pavement Construction

2.4 Structure Foundation

3.0 GEOTECHNICAL ANALYSES

3.1 Embankment Design

3.2 Cut Slope Design

3.3 Pavement Design

3.4 Structure Foundation Design

4.0 CONSTRUCTION CONSIDERATIONS

4.1 Shallow Foundation Excavation

4.2 Foundation and Floor Slab

4.3 Concrete and Steel Corrosion

4.4 Seismic Site Class

4.5 Groundwater Control

4.6 Temporary Excavation Support

4.7 Earthwork

5.0 SOIL, ROCK AND GEOLOGIC SETTING

5.1 Physiographic Setting

5.2 Soils

5.3 Geology

6.0 SUBSURFACE INVESTIGATION

6.1 Test Boring Program

6.2 Laboratory Testing

6.2.1 Soil Classification

6.2.2 Soil CBR Strength

6.2.3 Soil Corrosion

6.2.4 Rock Strength

6.3 Subsurface Materials

7.0 LIMITATIONS

8.0 REFERENCES

Page ii

TABLES

Table 1 – Structure Foundation Design Features

Table 2 – Test Borings Summary

Table 3 – Soil Classification Summary

Table 4 – Soil CBR Strength Summary

Table 5 – Soil Corrosion Summary

Table 6 – Rock Strength Summary

FIGURES

Figure 1 – Project Location Map

Figure 2 – Project Aerial Map

Figure 3 – USGS Topographical Map

Figure 4 – Physiographic Provinces Map

Figure 5 – USDA Soils Map

Figure 6 – Bedrock Geologic Map

Figure 7 – West ACP Site Layout

APPENDICES

APPENDIX A – SUBSURFACE INVESTIGATION PLAN

APPENDIX B – SUBSURFACE INVESTIGATION REPORTS

APPENDIX C – SUBSURFACE SECTIONS

APPENDIX D – LABORATORY TEST REPORTS

APPENDIX E – GEOTECHNICAL ANALYSES

APPENDIX F – PRELIMINARY SITE PLANS

1.0 INTRODUCTION

This Geotechnical Investigation Report (GIR) summarizes pertinent information to aid in design and construction of the proposed improvements of West Access Control Point (ACP) located in

Fort Indiantown Gap, Lebanon County, Pennsylvania.

1.1 Purpose and Scope

The purpose of this report is to present the results of geotechnical exploration and laboratory testing programs, and to present geotechnical engineering conclusions and design recommendations for the facilities at the West ACP. The work completed has been performed under HDR’s Scope of Work (SOW) with the United States Army Corps of Engineers (USACE), Baltimore District (District) for the project under Agreement Nos. W912DR-16-D-0006 and

W912DR17F0298, dated Revised August 17, 2017. The project scope is to prepare and submit a GIR in general accordance with the requirements of USACE Engineering Manual

(USACE1, 2001). The GIR includes design considerations and recommendations for the construction of embankments, cut slopes, pavements, and structures located at the West ACP.

Work completed to date leading to preparation of this report includes the following:

• Preparation of the approved Boring Plan Report (BP, 2018);

• Preparation of the approved Health and Safety Plan Report (HASP, 2018);

• Preparation of 30% Concept Design Submission (CD, 2018);

• Completion of test borings at the site in April 2018;

• Completion of a laboratory testing program of soil and rock samples in May 2018 from the completed test borings;

• Completion of engineering analyses and development of geotechnical design and construction recommendations; and

• Preparation of this report.

This GIR summarizes the results of these initial studies, presents the results of engineering analyses completed, and provides foundation design and roadway construction recommendations necessary to allow final design progression for the improvements at the West

ACP. Note that the foundation design and recommendation for the Perimeter Fence is not part of this report per HDR’s SOW.

1.2 Project Location

The project site is located within the northeast quadrant from the intersection of State Route

0934 (Fisher Avenue), and Biddle Drive, approximately ¾-mile north of Interstate 80 (I-80), in

Fort Indiantown Gap, Lebanon County, Pennsylvania. The site is bound by Fisher Avenue to the west, Biddle Drive to the south, and Service Road to the north. A Project Location Map, Project Aerial Map and USGS Topographical Map are provided for reference as Figures 1 through 3.

The site terrain slopes upward from the three bounding roadways and crests near the center of the site. The site terrain currently contains grassland with a few trees located mainly along the

Fisher Avenue. The project site is located on the United States Geological Survey (USGS)

Indiantown Gap 7.5-minute topographic quadrangle. The approximate coordinates of the project site are 40°25'27" North latitude and 76°34'28" West longitude.

1.3 Project Description

The intent for this project is to design and construct the West Access Control Point (ACP) at the

Fort Indiantown Gap (FTIG) complex. FTIG is an 18,000 acre active National Guard Training

Center and headquarters for the Pennsylvania National Guard located in Lebanon County, Pennsylvania. The military installation is currently an open post that requires mandatory vehicle entry control per Department of Defense (DoD) requirement. The project includes a proposed

Perimeter Fence and Access Control Point at the intersections of Fisher Avenue and Biddle

Drive to satisfy the DoD requirement. This project will serve as the western and primary

Entrance Control Facility to the installation. It is designed to balance the security, safety, and traffic flow of FTIG by allowing FTIG security personnel to control traffic and individuals entering or exiting FTIG 24 hours a day throughout the year.

Referring to Figure 7, the Facility will include standard security components, canopies, a Visitor

Control Center (VCC), Privately Owned Vehicle (POV) and Commercially Owned Vehicle (COV)

Inspection areas, Gatehouse, and ID Check Stations. This project will provide guards with enhanced situational lines of sight, proper weather protection and an ability to control access entry to the base. Active and passive protection systems, combined with appropriate roadway layouts, will provide the base with threat control and necessary infrastructure to properly calm traffic and inspect incoming commercial and personal vehicles. Adequate space and design layout is required for the guardhouses and visitor centers to accommodate security personnel forces and supply 360 degree visibility. The Preliminary Site Plans are provided in

Appendix F.

2.0 GEOTECHNICAL RECOMMENDATIONS

This section summarizes the geotechnical design recommendations developed for the proposed improvements at the West ACP. Further discussion of individual recommendations is found in subsequent sections of this report, and discussions of analyses performed are included in

Section 3.0 and Section 4.0 of this report.

2.1 Embankment Construction

Use the following recommendations for the proposed embankment construction at the project site:

a) Construct all proposed embankment or fill slopes at 2H:1V or flatter slopes using random embankment fill materials derived from excavated soil and rock materials at the project site.

b) For embankments constructed with soil, place soil for the full width of the embankment in uniform horizontal lifts to achieve a compacted 6-inch lift thickness. Except for the top 3 feet, compact soil for the full width of embankments or fills to not less than 97% of the

Standard Effort (Standard Proctor) maximum dry density. Compact the top 3 feet of soil for the full width of embankments or fills to 100% of the Standard Effort (Standard

Proctor) maximum dry density. Compact soil to a stable condition (non-movement) so there is no rutting, displacement, or shear wave under compaction equipment.

c) For embankments constructed with rock, choke the surface of the rock with Select

Granular Material (2RC) of sufficient thickness to completely fill all voids in the rock and cover with a Class 4, Type A, Geotextile. Place an additional layer of Select Granular

Material (2RC) to reach the finished subgrade elevation. Place rock in uniform loose layers to a thickness not exceeding the approximate average size of the larger rock, but limited to a maximum size of 36 inches. Remove oversize rock or reduce in size until it can be readily incorporated in a maximum 36-inch layer. Compact rock to a condition of stable condition (non-movement) under the compaction equipment and the compaction acceptance shall be determined by the Representative. Do not place rock in embankments without acceptance of the planned excavation and embankment operations.

Select Granular Material (2RC) shall consists of durable bank or crushed gravel, stone, or slag mixed or blended with suitable filler materials to provide a uniform mixture.

Stockpile, sample, and test material before it is used to ensure reasonable uniformity and acceptability. Use material free from vegetable or organic matter, lumps, or an excessive quantity of clay or other objectionable or foreign substances, and not more than 10% deleterious shale by mass (weight). Select Granular Material (2RC) shall conform to the following gradation:

• Passing 50 mm (2-inch) sieve 100%

• Passing 4.75 mm (No. 4) sieve 15% to 60%

• Passing 150 µm (No. 100) sieve 0% to 30%

Over-excavate and replace any compressible soils encountered beneath the proposed embankment of the roadway alignment to provide suitable subgrade. Any soft or loose zones that are identified are to be over-excavated an additional 2 feet (for a maximum depth of 3 feet) and backfilled with compacted AASHTO No. 1 coarse aggregates.

AASHTO No. 1 coarse aggregates shall conform to the following gradation:

• Passing 100 mm (4-inch) sieve 100%

• Passing 90 mm (3½-inch) sieve 90% to 100%

• Passing 63 mm (2½-inch) sieve 25% to 60%

• Passing 37.5 mm (1½-inch) sieve 0% to 15%

• Passing 19 mm (¾-inch) sieve 0% to 5%

2.2 Cut Slope Construction

Use the following recommendations for the proposed cut slope construction at the project site.

a) Construct all proposed cut slopes at 2H:1V or flatter slopes.

b) Use controlled blasting techniques such as presplit or trim (cushion) for the construction of rock cut slopes. Do not blast within 300 feet of the existing structures, buildings or utilities. Drill and blast to complete the excavation to the required lines, with the least disturbance to remaining material. Do not blast within 5 feet of the proposed structures foundation bearing elevation. Remove remaining rock to bearing elevation using mechanical means such as excavator rippers, hydraulic hammer, hoe ram, etc.

c) Use a Shrink Factor of 8% for soil and a Swell Factor of 33% for excavated rock material for evaluating earthwork requirements for the on-site excavated materials.

2.3 Pavement Construction

Use the following recommendations for the proposed pavement construction at the project site.

a) Compact and proof roll the entire subgrade surface for the full width to 100% of the

Standard Effort (Standard Proctor) maximum dry density. Compact subgrade to a stable condition (non-movement) so there is no rutting, displacement, or shear wave under compaction equipment.

b) While no special subgrade treatments are anticipated to be required, if soft or loose areas are noted during subgrade preparation, undercut those areas to a minimum depth of 1-foot below subgrade elevation (for a maximum depth of 3 feet) and backfill with compacted AASHTO No. 1 coarse aggregate. If shallow bedrock, small pinnacles, or ledges of rock are encountered at subgrade elevation, undercut those areas to provide a suitable level surface for subbase placement.

c) Place Class 4, Type A, Geotextile separation material between the pavement structure

(i.e., PennDOT 2A, Modified subbase material) and foundation subgrade soil.

d) Construct the flexible pavement section as shown below for the main roadways (new

Fisher Avenue and Inspection Road):

• 2.0 inches of 9.5 mm Wearing Course

• 4.0 inches of 25 mm Base Course

• 10.0 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

e) Construct the flexible pavement section as shown below for the parking areas, entrances, exits, and travel lanes:

• 1.5 inches of 9.5 mm Wearing Course

• 3.5 inches of 25 mm Base Course

• 6.0 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

f) Construct the rigid pavement section as shown below for the ID Check Stations and

Inspection/Search Areas:

• 8 inches of Portland Cement Concrete

• 6 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

g) PennDOT 2A, Modified Subbase Material shall conform to the following gradation:

• Passing 50 mm (2-inch) sieve 100%

• Passing 19 mm (¾-inch) sieve 52 to 100%

• Passing 9.5 mm (⅜-inch) sieve 36% to 70%

• Passing 4.75 mm (No. 4) sieve 24% to 50%

• Passing 1.18 mm (No. 16) sieve 10% to 30%

• Passing 75 μm (No. 200) sieve 0% to 3%

2.4 Structure Foundation

Use the following recommendations for the proposed structure foundation construction at the project site.

a) Use spread footing foundations for the proposed structures at the West ACP.

b) Use the recommended foundation design parameters presented below in Table 1 for the proposed structures.

Table 1 – Structure Foundation Design Features

Structures

FFE

(feet)

Min.

BFE

(feet)

GWE

(feet)

Foundation Bearing Stratum

Bearing Capacity (ksf)

Allowable Settlement

(inches)

Footing Friction

Coefficient, tan δ

Ultimate Allowable

Visitor Control Center

509.2 505.7 500.9 Residuum/ Weathered

Soil

6.0 2.0 ≤1.0 0.45

Search Office 511.0 507.5 509.4

Search Area Canopy

-- NA 509.4

Silty Shale Bedrock

18.0 6.0 ≤1.0 0.70 Vehicle ID Check Area Canopy

-- NA 517.3

Gatehouse 517.0 513.5 520.5

FFE: Finished Floor Elevation (As-shown on the 30% Concept Design Plans) BFE: Bottom of Footing Elevation (Minimum elevations recommended based on design frost depth of 3.5 feet) GWE: Groundwater Elevation NA: Not Available

c) Place footings at minimum depth of 42 inches below the finished grade.

d) Use a Seismic Site Class “C” for structures with foundation bearing on soil or rock.

e) After the completion of foundation excavation, the foundation subgrade must be inspected and approved by the Professional Geotechnical Engineer (PGE)

Representative.

f) For spread footings bearing on soil, if foundation subgrade encountered any soft, loose, or deleterious bearing material that are unsuitable for foundation subgrades, over-excavate any unsuitable soils and backfill with compacted AASHTO No. 1 coarse aggregate.

g) For spread footings bearing on rock, if any unsuitable or deleterious bearing material is encountered at foundation subgrade, completely expose and over-excavate all soil material and areas of soft, weathered, or unsuitable bedrock at or below the bottom of footing, and replace with Class C Cement Concrete.

Class C Cement Concrete shall have a cement factor of 395 to 658 lbs/cyd, a maximum water cement ratio of 0.66, and a minimum 28-day compressive strength of 2,000 psi.

h) Blasting is not permitted for the excavation of footings in rock. Excavate rock using mechanical means such as excavator rippers, hydraulic hammer, hoe ram, etc.

i) Foundation excavations are expected to be situated below the ambient groundwater elevation at the site. Dewatering will be required at the project site and should be anticipated by the Contractor. Maintain all foundation soil/rock materials relative to exposure time and saturation by surface runoff to prevent degradation of the soil/rock and loss of strength. Divert all surface runoff away from project excavations using curbing or appropriate barriers. The Contractor must (as much as practical) maintain a dry subgrade at all times.

j) Building floor slabs on grade are recommended to be supported on a minimum 4-inch thick compacted layer of AASHTO No. 1 coarse aggregates. Place a minimum 6 mil thick vapor barrier beneath concrete slabs on grade. Use a modulus of subgrade reaction (K) of 125 pci or less for the in-situ saturated subgrade soils.

The in-situ subgrade soils should be within 2 percent of the optimum moisture content, and have an in-place dry density of at least 95 percent of the Standard Effort (Standard

Proctor) maximum dry density. If the moisture or density does not meet the above criteria, the subgrade soils should be scarified to a minimum depth of 8 inches, moisture adjusted to within 2 percent of the optimum moisture content, and compacted to at least

95 percent of the Standard Effort (Standard Proctor) maximum dry density.

Select Granular Material (2RC) as a fill in the building areas. Fill should be placed on prepared surfaces in lifts not to exceed 8 inches loose measure, with compacted thickness not to exceed 6 inches. Fill should be compacted to at least 95 percent of the

Standard Effort (Standard Proctor) maximum dry density at a moisture content within 2 percent of the optimum moisture content.

k) Design and construct all foundation excavations in accordance with OSHA requirements.

Use the following soil parameters for the computation of Lateral Earth Pressure:

• Soil Effective Unit Weight, γ’ = 65 pcf

• Soil Effective Friction Angle, Φ = 36°

• At-Rest Lateral Earth Pressure Coefficient, Ko = 0.41

• Active Lateral Earth Pressure Coefficient, Ka = 0.24

• Passive Lateral Earth Pressure Coefficient, Kp = 7.3

3.0 GEOTECHNICAL ANALYSES

This section summarizes the geotechnical analyses performed for the proposed improvements at the West ACP. The Subsurface Sections are presented in Appendix C. All applicable geotechnical calculations and design parameter justifications are provided in Appendix E.

The Concept Design Site Plans are provided in Appendix F.

3.1 Embankment Design

At the Inspection Road, approximately between Stations 202+00 and 207+00, Offset Right, the proposed embankment fill slopes will be constructed at 3H:1V or flatter, and embankment fill soil depths will vary from approximately 2 to 5 feet. Side hill benching will not be required for embankment construction since the existing grades are flatter than 4H:1V. All excavated soil and rock materials are considered to be a suitable source of fill material for roadway and embankment construction. Construct embankments using random embankment fill material derived from excavated soil and rock materials at the project site. No treatment or disposal of suspected hazardous materials is anticipated in the fill areas of the roadway.

Embankment Slope Stability

A slope stability analysis was performed at the proposed embankment fill slope at

Station 202+70, Offset Right, located at the Inspection Road. The soil design parameters were based on the average field Standard Penetration Testing (SPT) data (N60), in-situ soil density, soil type, and were developed from the empirical correlation charts as presented on Table 3-1 and Figure 3-1 (USACE2, 1994). Per Boring WACP-03, the foundation soil is underlain by the very dense residual soil derived from weathered Shale with average SPT (N60) of 76 blows per foot (bpf). The very dense residual soil was modeled with a design friction angle of 36°, and moist/saturated unit weights of 120/130 pcf were considered based on empirical correlation charts and the average laboratory tested soil moisture content of 15%. The groundwater was considered to be approximately 4 feet below the ground surface. An equivalent soil surcharge of 360 psf was applied to model vehicular traffic from Inspection Road. The required minimum

Factor of Safety (FS) of 1.5 for embankment stability was considered in accordance with

Table 3-1 (USACE3, 2003).

The global stability of proposed embankment slopes of 3H:1V and 2H:1V were checked using the equilibrium analysis program GSTABL7. The stability analyses resulted in a FS of 2.16 for a

3H:1V embankment slope and FS of 1.57 for a 2H:1V embankment slope, which were both greater than the minimum required safety factor. Based on the slope stability analysis, the proposed embankment fill slopes can be steepened to 2H:1V at the project site.

Embankment Settlement

The foundation soil of the proposed 3H:1V embankment consists of cohesionless soils. The elastic settlement analysis was performed in accordance with Section 10.6.2.4.2

(AASHTO2, 2014). Per Figure 10.6.2.4.2-1 (AASHTO2, 2014), the bearing capacity index of

177 was selected for the very dense foundation soil.

The magnitude of elastic settlement from the calculation is estimated to be 0.37 inches. The settlement will be elastic and will occur rapidly during the construction of the new embankment as new embankment load is added to the in-situ materials.

3.2 Cut Slope Design

At the newly aligned Fisher Avenue, approximately between Stations 1+00 and 26+50, Offset

Left, the proposed cut slopes will be constructed at a 3H:1V slope or flatter. The cut slope depths will vary from 2 to 10 feet in soil.

Similarly, at the Inspection Road, between approximate Stations 207+00 and 210+50, Offset

Right, the proposed cut slopes will be constructed at 3H:1V slopes or flatter. The cut slope depths will vary from 5 to 20 feet partially in soil and partially in rock.

All excavated soil and rock materials are considered to be suitable as fill material for roadway and embankment construction. No special treatments are necessary for the soil or rock cut slopes. No treatment or disposal of suspected hazardous materials is anticipated in the cut areas of the roadway.

Soil Cut Slope Stability

A slope stability analysis was performed for the proposed 3H:1V soil cut slope at

Station 209+15, Offset Right, of Inspection Road. The soil design parameters were based on the average field SPT data (N60), in-situ soil density, soil type, and were developed from the empirical correlation charts as presented on Table 3-1 and Figure 3-1 (USACE2, 1994). Per

Boring WACP-11, the overburden soil consists of dense well-graded Sand with average SPT

(N60) of 31 bpf to EL. 530, which was underlain by very dense residual soil derived from weathered Sandstone with average SPT (N60) of 122 bpf to EL. 527. The dense Sand (Soil

Layer 1) was modeled with a design friction angle of 33.0° and the very dense weathered

Sandstone (Soil Layer 2) was modeled with a design friction angle of 38.0°. The moist/saturated unit weights of 120/130 pcf were assumed for both layers based on empirical correlation charts and the average laboratory tested soil moisture content of 15%. The groundwater was modeled to be located at approximate EL. 525. An equivalent soil surcharge of 360 psf was applied to model vehicular traffic from the existing parking lot. The required minimum FS of 1.5 for embankment stability was considered in accordance with Table 3-1

(USACE3, 2003).

The global stability of proposed soil cut slopes of 3H:1V and 2H:1V were checked using the equilibrium analysis program GSTABL7. The stability analyses resulted in a FS of 2.2 for the

3H:1V cut slope and a FS of 1.6 for the 2H:1V cut slope, which were both greater than the minimum required safety factor. Based on the slope stability analysis, the proposed cut slopes can be steepened to 2H:1V at the project site.

Rock Cut Slopes

At the Inspection Road, approximately between Stations 207+00 and 210+50, Offset Right, Borings WACP-08 and WACP-11 indicated that proposed excavations in this area will encounter intact bedrock before reaching final grade, thus creating a rock cut in this area. At these locations, almost one-half of the cut slope will be in soil and remaining half will be in the

Sandstone bedrock underlying the site. The exposed surface of these cut slopes will be mostly in the fair to good quality Sandstone bedrock.

The rock excavation may involve enhanced mechanical means of excavation, such as excavation with rock buckets, ripping, pneumatic hammers, etc. Due to the amount of rock excavation required and the fair to good quality of the bedrock encountered, blasting is allowed to construct the rock cut slopes. Blasting should be controlled using presplit or trim (cushion) blasting techniques to produce a uniform surface in the rock. Blasting is not allowed if any structures, buildings or utilities are located within 300 feet of the blasting site.

3.3 Pavement Design

Frost Penetration Depth

A frost penetration depth was determined for the site in accordance with Section 9.3.1 of

Pavement Policy Manual (PennDOT2, 2015). A Design Freezing Index (DFI) of 839 was used for Lebanon in Lebanon County, which is located approximately 7 miles southeast of the project site. Based on a DFI of 839, a Frost Penetration Depth of 42 inches was estimated from

Figure 9.1 – Design Chart for Determination of Frost Penetration (PennDOT2, 2015).

The design Frost Penetration Depth at the project site is 42 inches (3.5 feet).

Pavement Analyses

The pavement recommendations were developed using Pavement Policy Manual

(PennDOT2, 2015), Design of Pavement Structures (AASHTO1, 1993), and Pavement-

Transportation Computer Assisted Structural Engineering (PCASE) software. The proposed pavements at West ACP include the following sections.

• Flexible Bituminous (Asphalt) Pavement – Located at main trafficked driveways (new

Fisher Avenue and Inspection Road), in and out of the West ACP and Parking Areas

• Rigid (Concrete) Pavement – Located in areas of ID Check Stations and

Inspection/Search Areas

In general, the roadway surface grade of the West ACP is proposed at a lower grade elevation than the existing area. Material will be excavated at a depth of approximately 2 to 15 feet below existing ground surface to construct the proposed pavements. Section 5.3 describes the subgrade material encountered in representative borings performed at the proposed pavement areas.

The laboratory testing program was structured to characterize these materials and provide relative strength condition (i.e., CBR - California Bearing Ratio) of subgrade soils. A summary of the laboratory strength testing on the subgrade is shown in Table 4. The laboratory CBR strength results were judged to be low when compared to the findings in the field including material types and SPT data. The subgrade material at the depth of the proposed grade elevation was described in Borings WACP-02 through WACP-05, and WACP-012 as very dense residual soil derived from weathered Shale. The subgrade material observed in Boring

WACP-13 consisted of very stiff lean Clay (cl) and medium dense Clayey Sand with Gravel

(SC). After a detailed review of the laboratory CBR strength results, this type of material

(i.e. residual soils) may result in low strength values due to the nature of the material when it is disturbed and soaked prior to the CBR test.

An evaluation of subgrade materials should be performed during preparation of subgrade and prior to pavement placement at all locations across the project site. Geotextile (Class 4, Type A) should be placed for separation after subgrade preparation, with the geotextile placed between the pavement structure (i.e. PennDOT 2A, Modified subbase material) and underlying foundation subgrade soil. A minimum CBR value of 5 was used in the design. Use of this value assumes that any wet, soft materials encountered below the subgrade, which would derive a lesser CBR value, would be excavated and replaced with suitable material. This CBR value corresponds to a Resilient Modulus (Mr) of 7,500 psi and Modulus of Subgrade Reaction

(k) of 150 pci subgrade strength values used in the design procedures.

Main Roadways (Fisher Avenue and Inspection Road):

Conventional flexible pavement using bituminous (asphalt) concrete will be placed in areas of the main roadways, including entrances and exits to the West ACP. An estimated traffic volume was derived from information provided in the Comprehensive Traffic Engineering Study

(Gannett, 2011). Traffic from adjacent roadways (Fisher Avenue and Biddle Drive) to the West

ACP was used in the calculation of the 20-year design, 18-kip Equivalent Single Axle Load

(ESAL) value. Although the total traffic counts were available in the study, a detailed breakdown of the various vehicle classes was not provided. Therefore, the type and amount of heavy truck traffic was unknown for the analysis. For design, a percentage of trucks of 3%, entering the WACP was assumed to determine the required pavement section. Truck traffic was also assumed to have a growth rate of 0%. The following flexible pavement section should be used for the main roadways (new Fisher Avenue and Inspection Road):

• 2.0 inches of 9.5 mm Wearing Course

• 4.0 inches of 25 mm Base Course

• 10.0 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

Parking Areas, Entrances, Exits, and Travel Lanes:

Conventional flexible pavement using bituminous (asphalt) concrete will be placed in all non-truck trafficked areas (entrances, exits, travel lanes, and stalls of parking lots). A pavement design was not performed for the proposed areas of bituminous flexible pavement in the lot.

Pavement design methodology as described in Design of Pavement Structures

(AASHTO1, 1993) was not intended to provide a design for parking lots. HDR utilized engineering standards and experience in parking lot designs and construction to provide a flexible pavement section. The following flexible pavement section should be used for the parking areas, entrances, exits, and travel lanes:

• 1.5 inches of 9.5 mm Wearing Course

• 3.5 inches of 25 mm Base Course

• 6.0 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

The traffic in the parking lot is expected to be a light-duty traffic mix consisting of predominately personal vehicles (passenger cars and light duty trucks/SUVs). HDR does not anticipate any heavy truck traffic within these travel areas.

ID Check Stations and Inspection/Search Areas:

A Portland Cement Concrete (PCC) pavement section is proposed for areas subject to heavy static loads from truck traffic. The pavement-design methodology described in Design of

Pavement Structures (AASHTO1, 1993), which solely looks at a pavement structural number based on traffic and support, may not be reliable. For this reason the pavement design software, PCASE was used determine a recommended PCC pavement section. A conservative design vehicle of a 5-axle truck with total passes of 2.5 million (approximately 3% of ADT over

20 years) was used as the design traffic. The reduced subgrade strength results were considered for the design to account for frost susceptible soils under the proposed pavement.

HDR recommends the following section for the rigid pavements for the ID Check Stations and

Inspection/Search Areas:

• 8 inches of Portland Cement Concrete

• 6 inches of PennDOT 2A, Modified Subbase Material

• Class 4, Type A – Non Woven Separation Geotextile

3.4 Structure Foundation Design

Based on conditions encountered during the subsurface investigation, spread footing foundations are considered to be most economical and feasible options for the proposed structures at the West ACP. The building walls will have a maximum linear dead load of

1.5 kips/LF and a maximum linear live load of 0.6 kips/LF. Foundation design analyses for the proposed structures were performed in accordance with the UFC (UFC, 2012) and AASHTO

(AASHTO2, 2014) Design Specifications. Note that a FS of 3.0 was used for calculation of the

Allowable Bearing Capacities referenced below.

Visitor Control Center (VCC): The VCC building is proposed to be supported on a conventional spread footing foundation system. The Bottom of Footing Elevation (BFE) is set at

EL. 505.7. Per Boring WACP-04, the subsurface soil consists of medium dense to very dense residuum/weathered soil derived from Shale. Therefore, the VCC building will be supported on spread footings bearing on very dense residuum/weathered soil. The Allowable Bearing

Capacity of the residuum/weathered soil for VCC building foundation design is 2.0 ksf.

Search Office: The Search Office building is proposed to be supported on conventional spread footing foundation system. The BFE is set at EL. 507.5. Per Boring WACP-05, the subsurface soil below the BFE consists of very dense residuum/weathered soil derived from Shale that is underlain by medium-hard Silty Shale bedrock. The Top of Rock Elevation (TOR) beneath the

Search Office is at approximate EL. 503. Therefore, the Search Office building will be supported on spread footings bearing on very dense residuum/weathered soil. The Allowable

Bearing Capacity of the residuum/weathered soil for Search Office building foundation design is

2.0 ksf.

Search Area Canopy: The Search Area Canopy is 42 feet in width and 60 feet in length. Per

Boring WACP-05, the subsurface soils consist of very dense residuum/weathered soil derived from Shale that is underlain by medium-hard Silty Shale bedrock. The TOR at Search Area

Canopy is at approximate EL. 503. The BFE for the Search Area Canopy has not been established. Based on the site grading, it is anticipated the Search Area Canopy will be supported on square spread footing foundations bearing on Silty Shale bedrock. The Allowable

Bearing Capacity of the Silty Shale bedrock for Search Area Canopy foundation design is 6.0 ksf.

Vehicle ID Check Area Canopy: The Vehicle ID Check Area Canopy is 72 feet in width and 64 feet in length. Per Boring WACP-09, the subsurface soil consists of dense to very dense residuum/weathered soil derived from Shale that is underlain by medium-hard Silty Shale bedrock. The TOR at Vehicle ID Check Area Canopy is at approximate EL. 515. The BFE for the Vehicle ID Check Area Canopy has not been established. Based on the site grading, it is anticipated the Vehicle ID Check Area Canopy will be supported on square spread footing foundation bearing on Silty Shale bedrock. The Allowable Bearing Capacity of the Silty Shale bedrock for Vehicle ID Check Area Canopy foundation design is 6.0 ksf.

Gatehouse: The Gatehouse building is proposed to be supported on conventional spread footing foundation system. The BFE is set at EL. 513.5. Per Boring WACP-08, the subsurface soil consists of dense to very dense residuum/weathered soil derived from Shale that is underlain by medium-hard Silty Shale bedrock. The TOR at Gatehouse building is at approximate EL. 515. Therefore, the Gatehouse building will be supported on spread footing foundation bearing on Silty Shale bedrock. The Allowable Bearing Capacity of the Silty Shale bedrock for Gatehouse building foundation design is 6.0 ksf.

4.0 CONSTRUCTION CONSIDERATIONS

4.1 Shallow Foundation Excavation

The excavations for the shallow footing foundation system should be performed with equipment capable of providing a relatively clean bearing area. The bottom 6 inches on the planned foundation excavations should be completed with a smooth-mouthed bucket or by hand labor.

The excavations should be neatly excavated and properly formed.

After the completion of foundation excavation and prior to steel placement, the foundation subgrade must be inspected and approved by the Professional Geotechnical Engineer (PGE)

Representative.

For spread footings bearing on soil, if foundation subgrade encountered any soft, loose, or deleterious bearing material that are unsuitable for foundation subgrades, over-excavate any unsuitable soils and backfill with compacted AASHTO No. 1 coarse aggregate. AASHTO No. 1 coarse aggregates shall conform to the following gradation:

• Passing 100 mm (4-inch) sieve 100%

• Passing 90 mm (3½-inch) sieve 90% to 100%

• Passing 63 mm (2½-inch) sieve 25% to 60%

• Passing 37.5 mm (1½-inch) sieve 0% to 15%

• Passing 19 mm (¾-inch) sieve 0% to 5%

For spread footings bearing on rock, if any unsuitable or deleterious bearing material is encountered at foundation subgrade, completely expose and over-excavate all soil material and areas of soft, weathered, or unsuitable bedrock at or below the bottom of footing, and replace with Class C Cement Concrete. Class C Cement Concrete shall have a cement factor of 395 to

658 lbs/cyd, a maximum water cement ratio of 0.66, and a minimum 28-day compressive strength of 2,000 psi.

Blasting is not permitted for the excavation of footings in rock. Excavate rock using mechanical means such as excavator rippers, hydraulic hammer, hoe ram, etc.

4.2 Foundation and Floor Slab

A ground supported, minimum 5-inch thick, interior concrete floor slabs are considered in the building areas. It is recommended the floor slabs be designed as slab-on-grade structures. For design purposes, a modulus of subgrade reaction (K) of 125 pounds per cubic inch (pci) or less should be used for the in-situ subgrade soils. The floor slabs should be supported on a minimum 4-inch thick compacted layer of AASHTO No. 1 coarse aggregates. The purpose of the coarse aggregate layer is to help distribute concentrated loads and act as a capillary break beneath the slab. The use of a vapor retarder, minimum 6-mil thick vapor barrier, should be considered beneath concrete slabs on grade.

Subsequent to proof rolling, and just prior to placement of fill, the exposed subgrade within the building floor areas should be evaluated for moisture and density. The subgrade should be within 2 percent of the optimum moisture content, and have an in-place dry density of at least 95 percent of the Standard Effort (Standard Proctor, ASTM D 698) maximum dry density of the in-situ soils. If the moisture or density does not meet the above criteria, the subgrade should be scarified to a minimum depth of 8 inches, moisture adjusted to within 2 percent of the optimum moisture content, and compacted to at least 95 percent of the Standard Effort (Standard

Proctor, ASTM D 698) maximum dry density.

Select Granular Material (2RC) may be considered for use as fill in the building areas, provided they are free of organics and debris. Fill soils should be compacted to at least 95 percent of the

Standard Effort (Standard Proctor, ASTM D 698) maximum dry density at a moisture content within 2 percent of the optimum moisture content. Fill soils should be placed on prepared surfaces in lifts not to exceed 8 inches loose measure, with compacted thickness not to exceed

6 inches. Fill soils should be compacted to at least 95 percent of the Standard Effort (Standard

Proctor, ASTM D 698) maximum dry density at a moisture content within 2 percent of the optimum moisture content.

Select Granular Material (2RC) shall consists of durable bank or crushed gravel, stone, or slag mixed or blended with suitable filler materials to provide a uniform mixture. Stockpile, sample, and test material before it is used to ensure reasonable uniformity and acceptability. Use material free from vegetable or organic matter, lumps, or an excessive quantity of clay or other objectionable or foreign substances, and not more than 10% deleterious shale by mass

(weight). Select Granular Material (2RC) shall conform to the following gradation:

• Passing 50 mm (2-inch) sieve 100%

• Passing 4.75 mm (No. 4) sieve 15% to 60%

• Passing 150 µm (No. 100) sieve 0% to 30%

4.3 Concrete and Steel Corrosion

The project site soils are non-corrosive to steel and concrete. Corrosion protection and mitigation methods are not required for the concrete elements and reinforcing steel of the structure foundations (see Section 6.2.3).

4.4 Seismic Site Class

An assessment was made of seismic response of project soils below the foundation footprints in accordance with Section A3.10.3.1 (AASHTO2, 2014). The proposed structures with foundation bearing on rock are classified as Site Class B and with foundation bearing on soil are classified as Site Class C. The Site Class definition is provided in Appendix E.

In accordance with Section D3.10.6 (PennDOT1, 2015), Pennsylvania is classified in Seismic

Zone 1. Per Section A10.5.4.2 (AASHTO2, 2014), a liquefaction assessment is required only for sites located in Seismic Zones 3 and 4, and the project site soils are predominantly dense to very dense residuum/weathered soils. The liquefaction analysis was not performed and is judged to not be a concern at the project site.

4.5 Groundwater Control

Based on groundwater levels measured in the borings, foundation excavations are situated below the ambient groundwater elevation at the site. Dewatering will likely be required at the project site and should be anticipated by the Contractor. Maintain all foundation soil/rock materials relative to exposure time and saturation by surface runoff to prevent degradation of the soil/rock and loss of strength. Divert all surface runoff away from project excavations using curbing or appropriate barriers. The Contractor must (as much as practical) maintain a dry subgrade at all times.

4.6 Temporary Excavation Support

The open-cut excavations will be required to allow construction of the structure foundations.

Shoring is not anticipated during the construction. Design and construct excavations in accordance with Occupational Safety and Health Administration (OSHA) requirements.

Use the following foundation soil parameters for the computation of lateral earth pressure:

• Soil Effective Unit Weight, γ’ = 65 pcf

• Soil Effective Friction Angle, Φ = 36°

• At-Rest Lateral Earth Pressure Coefficient, Ko = 0.41

• Active Lateral Earth Pressure Coefficient, Ka = 0.24

• Passive Lateral Earth Pressure Coefficient, Kp = 7.3

4.7 Earthwork

Clearing and Proof-rolling: Construction areas should be stripped of any vegetation, loose/soft topsoil, existing pavement and other unsuitable surface materials. If trees are present, the trees including their roots and root balls should be completely removed. Once final subgrade elevations have been achieved, the exposed soil subgrade areas should be carefully proofrolled to detect weak areas. Special care should be exercised when proofrolling the fill soils to detect soft/weak areas. Weak areas detected during proofrolling, as well as zones containing organics or debris, should be removed and replaced with Select Granular Material

(2RC) or soils of similar composition (i.e., similar classification), moisture content, and density as the adjacent in-situ soils. Proofrolling and removal of organics should be performed under the direct observation of the PGE Representative. Proper site drainage should be maintained during construction so that ponding of surface runoff does not occur and cause construction delays and/or inhibit site access.

Soil Compaction for Embankments: For embankments constructed with soil, place soil for the full width of the embankment or fill in uniform horizontal lifts to achieve a compacted 6-inch lift thickness. Except for the top 3 feet, compact soil for the full width of embankments or fills to not less than 97% of the Standard Effort (Standard Proctor, ASTM D 698) maximum dry density.

Compact the top 3 feet of soil for the full width of embankments or fills to 100% of the Standard

Effort (ASTM D 698) maximum dry density. Compact soil to a stable condition (non-movement) so there is no rutting, displacement, or shear wave (i.e., bulging of the soil surface in front of and behind the roller) under compaction equipment.

Rock Placement for Embankments: For embankments constructed with rock, choke the surface of the rock with Select Granular Material (2RC) of sufficient thickness to completely fill all voids in the rock and cover with a Class 4, Type A, Geotextile. Place an additional layer of

Select Granular Material (2RC) to reach the finished subgrade elevation. Place rock in uniform loose layers to a thickness not exceeding the approximate average size of the larger rock, but limited to a maximum size of 36 inches. Remove oversize rock or reduce in size until it can be readily incorporated in a maximum 36-inch layer. Compact rock to a condition of stable condition (non-movement) under the compaction equipment and the compaction acceptance shall be determined by the Representative. . Do not place rock in embankments or fills without acceptance of the planned excavation and embankment or fill operations.

Over-Excavation for Embankments: Over-excavate and replace any compressible soils encountered beneath the proposed embankment of the roadway alignment to provide suitable subgrade. Any soft or loose zones that are identified are to be over-excavated an additional

2 feet (for a maximum depth of 3 feet) and backfilled with compacted AASHTO No. 1 coarse aggregates.

Wet Weather Considerations: Construction following wet weather periods will likely encounter difficulties due to the wet or soft surface soils becoming a general hindrance to equipment due to rutting and pumping of the soil surface. If the subgrade cannot be adequately compacted to minimum densities, one of the following measures will be required:

1) Removal and replacement with Select Granular Material (2RC);

2) Chemical treatment of the soil to dry and increase the stability of the subgrade; or

3) Drying by natural means if the schedule allows.

5.0 SOIL, ROCK AND GEOLOGIC SETTING

The following sections discuss the site physiographic setting, soils, and geology developed from the geological literature and the subsurface investigation.

5.1 Physiographic Setting

As shown in Figure 4, the project site lies within the Great Valley Section of the Ridge and

Valley Province (PGS, 2000). The Great Valley Section topographically consists of very broad valley. The northwest half consists of dissected upland, and the southeast half consist of low karst terrain. Topographic relief is generally low to moderate with project elevations ranging approximately from Elevation 140 feet to 1100 feet. The area is underlain by shale and sandstone in the northwest and limestone and dolomite in the southeast. The bedrock was deformed by past thrusting episodes (forming nappes) and includes overturned folds and steep faults overprinted with many third- or fourth- order folds. Drainage type is typically dendritic and karst.

5.2 Soils

Based on the soil survey map of Lebanon County (USDA-NRCS, 2016), as shown in Figure 5, the typical soils found within the approximate project limits consists of Bedington channery silt loam (BegC), Calvin channery silt loam (CagD), Comly silt loam (CmB), and Urban land-Berks complex (UkgB).

The general characteristics of the Bedington channery silt loam (BegC) includes channery silt loam to 9 inches underlain by channery silty clay loam to 29 inches, very channery silt loam to

72 inches, and bedrock. The soil develops along hills with 8 to 15 percent slopes consists of residuum weathered derived from sedimentary rocks. The soils are generally well drained with a moderately high to high saturated hydraulic conductivity (0.6 to 2 in/hr). Depths to lithic bedrock are 60 to 80 inches, and depth to water table is estimated to be more than 80 inches.

The general characteristics of the Calvin channery silt loam (CagD) includes channery silt loam to 27 inches underlain by very channery silt loam to 31 inches, and bedrock. The soil develops along hills with 8 to 25 percent slopes, consists of red residuum weathered derived from shale and siltstone. The soils are generally well drained with a high saturated hydraulic conductivity

(2 to 6 in/hr). Depths to lithic bedrock are 20 to 40 inches, and depth to water table is estimated to be more than 80 inches.

The general characteristics of the Comly silt loam (CmB) includes silt loam to 9 inches underlain by channery silt loam to 32 inches, very channery silt loam to 61 inches, and bedrock. The soil develops along hills with 3 to 8 percent slopes consists of colluvium derived from shale and siltstone. The soils are moderately well drained with moderately high hydraulic conductivity

(0.2 to 0.6 in/hr). Depths to fragipan are 20 to 35 inches, depths to lithic bedrock are 60 to 96 inches, and depth to water table are estimated to be 6 to 36 inches.

The general characteristics of the Urban land-Berks complex (UkgB) includes channery loam to

10 inches underlain by very channery silt loam to 26 inches, extremely channery loam to 33 inches, and bedrock. The soil develops along hills, ridges, and valleys, with 0 to 8 percent slopes consists of brown residuum weathered derived from shale and siltstone. The soils are well drained with moderately high to high hydraulic conductivity (0.2 to 6 in/hr). Depths to lithic bedrock are typically 10 to 100 inches, and depth to water table is estimated to be more than 80 inches.

The project site soils are predominately Clayey Sand consists of brown-gray residual/weathered soils derived from Shale and Sandstone (see Section 6.3).

5.3 Geology

Based on the geological literature (PaGEODE, 2016), the project site is underlain by Hamburg

Sequence Rocks (Oh) of Ordovician age. The project site Bedrock Geologic Map is shown in

Figure 6. The Hamburg Sequence consists of transported rocks of the Hamburg overthrust and include gray, greenish gray, and maroon shale that is silty and siliceous in many places.