ENGINEERING ASSOCIATES, INC.

Scannell Properties

294 Grove Lane East

Wayzata, MN 55391

Attention: Mr. Tom McCary

Re:

Final Geotechnical Engineering Study

Project Oak Development – Proposed Industrial Facility

North Lebanon Township, Lebanon County, PA

HCEA Project No. R18085

Mr. McCary:

Hillis-Carnes Engineering Associates, Inc. (HCEA) is pleased to submit this final geotechnical report

concerning the subsurface exploration and subsequent geotechnical evaluation for the proposed

industrial facility at the Project Oak Development in North Lebanon Township, Lebanon County,

Pennsylvania. This report summarizes the subsurface soil conditions at the site and provides preliminary

recommendations for the design and construction of the foundations and associated earthwork for the

proposed construction. These services were provided in general accordance with our proposal dated

October 31, 2018.

We wish to advise you that the boring samples will be stored at our Harrisburg, Pennsylvania office for a

period of 30 days from the date of this letter. Should you wish the samples to be stored for a longer

period of time or to be delivered to you or another party, please advise us in writing prior to the end of the

30-day period. Otherwise, the samples will be discarded at the end of the 30-day storage period.

HCEA appreciates having had the opportunity to provide the geotechnical consultation for this project,

and we will remain available for further consultation during the various design stages. Should you have

any questions concerning the contents of this report, or require additional consultation, design,

inspection, or testing services, please contact our office.

Very truly yours,

HILLIS-CARNES ENGINEERING ASSOCIATES, INC.

Jerome Guy

Nathaniel J. Lauver, P.E.

Harrisburg Branch Manager

Project Engineer

[email protected]

[email protected]

3110 Pike Street

Harrisburg, PA 17111

Phone 717-561-1623

Fax 717-754-0084

www.hcea.com

Final Geotechnical Engineering Study

Project Oak Development – Proposed Industrial Facility

North Lebanon Township, Lebanon County, PA

HCEA Project No. R18085

Prepared For:

Scannell Properties

294 Grove Lane East

Wayzata, MN 55391

Prepared By:

Hillis-Carnes Engineering Associates, Inc.

3110 Pike Street

Harrisburg, PA 17111

Date:

February 28, 2019

1.0 PURPOSE AND SCOPE ... 1

2.0 PROJECT CHARACTERISTICS ... 1

3.0 FIELD EXPLORATION ... 2

3.1

Standard Penetration Test Borings ... 2

3.2

Cone Penetrometer Testing ... 3

3.3

Laboratory Testing ... 4

4.0 SUBSURFACE CONDITIONS ... 5

4.1

General Site Geology ... 5

4.2

Fill Material ... 7

4.3

Natural Soils ... 7

4.4

Bedrock ... 8

4.5

Groundwater ... 10

5.0 EVALUATIONS AND RECOMMENDATIONS ... 10

5.1

Karst Considerations ... 10

5.2

General Site Preparation ... 11

5.3

Fill Selection, Placement and Compaction ... 11

5.3.1 Fill Quarantine Period ... 13

5.4

Cold/Wet Weather Earthmoving Considerations... 13

5.5

Foundations ... 14

5.6

Settlement ... 15

5.7

Ground-Supported Slabs ... 16

5.8

Groundwater and Drainage ... 16

5.9

Lateral Earth Pressures ... 17

5.10 Seismic Design Parameters ... 17

5.11 Pavement Design ... 17

5.12 Construction Practices for Potential Reduction of Sinkhole Formation ... 19

6.0 RECOMMENDED ADDITIONAL SERVICES ... 21

7.0 REMARKS ... 21

1.0

PURPOSE AND SCOPE

The purpose of this study was to determine the general subsurface conditions at the boring

locations and to evaluate those conditions with respect to concept, design, and construction of a

foundation system for the proposed facility.

The evaluations and recommendations presented in this study were developed from a review of

the project information provided and an interpretation of the general subsurface conditions at the

site based on the results of the site exploration. An evaluation of the site with respect to potential

construction problems and recommendations dealing with the earthwork and inspection during

construction is also included. The inspection is considered necessary to confirm the subsurface

conditions are consistent with those identified during the geotechnical study and to document that

the soils-related construction activities are performed properly.

2.0

PROJECT CHARACTERISTICS

The proposed industrial facility is to be located within gently sloping agricultural fields within the

Lebanon Valley Business Park, along Hanford Drive just north of Cleona, Pennsylvania as shown

on Figure 1 - Project Location Map and Figure 2 – Aerial Location Map in the Appendix. The

proposed 277,200 square foot “Project Oak” facility will be located to the southwest of the

Hanford Drive/Winsdor Drive intersection and includes parking areas and stormwater

management facilities. Available plans also indicate a 59,400 square foot future expansion area

abutting to the south of the “main” facility.

Preliminary plans showing the building footprint were prepared and provided by Scannell

Properties during proposal development for the project. In order to assist in our evaluation,

HCEA was provided the following plans – “Proposed Project Site Plan – Warehouse Distribution

Facility” dated October 1, 2018 and received via e-mail from Scannell Properties during proposal

development.

At the time of this report, structural information was not available. It is our understanding the

structures will likely consist of steel framing with tilt-up precast concrete panels. No structural

loading information was provided, so maximum wall and column loads were estimated at 6 kips

per foot and 200 kips, respectively. We have assumed maximum tolerable total and differential

settlements of one inch and one-half inch, respectively.

Preliminary plans indicate a finished floor elevation (FFE) of 478 feet. Based on existing

topography of the site, up to approximately 16.5 feet of fill will be required near the proposed

southern portion of the facility to establish the FFE, while up to 12 feet of cut will be required near

the northern portion of the facility to establish the FFE.

Should any of the project characteristics, construction type, or structural loading conditions

differ from those outlined above, then this office should be contacted so revisions to these

recommendations can be made.

3.0

FIELD EXPLORATION AND LABORATORY TESTING

3.1

Standard Penetration Test Borings

Prior to the commencement of field operations, the project was registered with the

Pennsylvania One-Call System, Inc. HCEA drilled a total of twenty (20) structure

borings and four (6) pavement borings from mid-December 2018 to early-January 2019

with a track-mounted Diedrich D50 drill rig. The approximate boring locations are

shown on Figure 3 – Boring Location Sketch. A summary of the structure boring

results is presented in tabular form below.

Summary of Boring Data

Boring

No.

Drilled

Depth

(Feet)

Depth

to

Bedrock

(Feet)

Cut/Fill to

Establish FFE

Remarks

Proposed Finished Floor Elevation = 478 feet

B-1

32.0

Bedrock Encountered at 22.0

21.0’ Fill

Fat CLAY – Avg. N=8

B-2

30.0

Bedrock Encountered at 22.0

10.5’ Fill

Silty CLAY – Avg. N=11

B-3

18.0

Bedrock Encountered at 8.0

2.0’ Cut

Silty SAND with Gravel/Weathered Limestone

_{Avg. N>50}

B-4

30.5

Bedrock Encountered at 7.5

12.0’ Cut

FFE Approx. 4.5’ Below Top of Bedrock

B-5

24.0

Bedrock Encountered at 14.0

16.0’ Fill

Silty CLAY – Avg. N=7

B-6

21.0

Bedrock Encountered at 11.0

5.5’ Fill

Silty CLAY – Avg. N=6

B-7

16.0

Bedrock Encountered at 9.5

14.0’ Fill

Lean CLAY – Avg. N=8

B-8

39.0

Bedrock Encountered at 32.5

10.5’ Fill

_{Low Blow Counts (WOH) from 23.0-24.5}

Fat CLAY – Avg. N=8

B-9

16.0

Bedrock Encountered at 6.0

4.5’ Cut

Silty GRAVEL/Weathered Limestone

_{Avg. N>50}

B-10

30.5

Bedrock Encountered at 5.5

10.0’ Cut

FFE Approx. 4.5’ Below Top of Bedrock

B-11

26.0

Bedrock Encountered at 16.0

11.5’ Fill

Lean CLAY – Avg. N=10

B-12

33.5

Bedrock Encountered at 23.5

5.5’ Fill

Silty CLAY with Sand – Avg. N=9

_{Low SPT N-Value (N=4) at 20.0}

B-13

19.0

Bedrock Encountered at 9.0

13.5’ Fill

Silty CLAY – Avg. N=7

B-14

33.0

Auger Refusal Obtained at 33.0

10.0’ Fill

Silty CLAY – Avg. N=9

B-15

35.0

Bedrock Encountered at 24.0

5.0’ Fill

_{Low SPT N-Value (N=2) at 20.0}

Fat CLAY – Avg. N=9

B-16

21.0

Bedrock Encountered at 3.5

1.5’ Cut

Silty GRAVEL/Weathered Limestone

_{Avg. N>50}

B-17

24.5

Bedrock Encountered at 4.5

13.0’ Cut

FFE Approx. 8.5’ Below Top of Bedrock

B-18

16.0

Bedrock Encountered at 6.0

7.5’ Cut

FFE Approx. 1.5’ Below Top of Bedrock

B-19

16.0

Bedrock Encountered at 6.0

9.0’ Fill

Silty GRAVEL/Weathered Limestone

_{Avg. N>50}

B-20

18.5

Bedrock Encountered at 8.5

10.0’ Fill

Silty CLAY – Avg. N=6

Proposed Pavement/Parking Area Borings

P-1

3.0

Auger Refusal Obtained at 3.0 Grading Not Provided

Silty CLAY – Avg. N=4

P-2

10.0

Auger Refusal Not Obtained

Grading Not Provided

Fat CLAY – Avg. N=7

P-3

6.0

Auger Refusal Obtained at 6.0 Grading Not Provided

Silty CLAY – Avg. N=11

P-4

5.0

Auger Refusal Obtained at 5.0 Grading Not Provided

Silty GRAVEL/Weathered Limestone

_{Avg. N>50}

P-5

10.0

Auger Refusal Obtained at 10.0 Grading Not Provided

Silty CLAY – Avg. N=10

P-6

10.0

Auger Refusal Obtained at 10.0 Grading Not Provided

Silty CLAY – Avg. N=9

The borings were advanced through the soils using hollow-stem augers, spin casing,

and split-spoon samplers. Standard Penetration Testing (SPT) was performed at

regular intervals at each boring location to measure the resistance of the soil to the

penetration of the standard 2-inch O.D. split-spoon sampler driven by a 140-pound

hammer falling 30 inches. The sampler was first seated 6 inches to penetrate any

loose cuttings. The number of hammer blows required to drive the sampler the

following 12 inches after being seated is designated as the "Penetration Resistance" or

"N-value.” The penetration resistance can be used as an indication of soil strength and

compression characteristics.

Bedrock was obtained by diamond core drilling in general accordance with the

procedures in ASTM D2113 “Standard Method for Diamond Core Drilling for Site

Investigation. In-situ quality of bedrock was determined by physical observation of the

core retrieved (hardness, degree of weathering, fracture spacing, etc.) as well as

calculation of the Rock Quality Designation (RQD) of the recovered core. RQD is a

qualitative index used to identify the relative quality of the rock mass. It is a

percentage calculated by summing the lengths of intact pieces of rock core which

exceed 4 inches in length and dividing that length by the total length of the core run.

At completion of the drilling, the boreholes were backfilled with the auger cuttings for

safety reasons. Upon backfilling of the boreholes, no additional compaction effort or

site restoration was performed. Additional settlement and/or softening of the soil

replaced in the boreholes may occur, resulting in a depression or hole in the ground

surface. Consequently, future maintenance or restoration of the site may be required

by others.

During drilling operations, HCEA performed part-time boring inspection and prepared

field logs for each of the borings. Portions of each SPT soil sample were placed in

air-tight glass jars and rock cores were placed in wooden core storage boxes. After

completion of the drilling, the samples were transported to HCEA’s laboratory for future

examination. In the laboratory, the samples were visually reviewed by the

Geotechnical Engineer to review the inspector’s field classifications. The samples were

classified in accordance with the Unified Soil Classification System (USCS) and the

field classifications were revised where necessary. The USCS classifications appear

on the typed Records of Exploration.

The Records of Exploration, included in the Appendix, show subsurface sample depths

and recoveries, SPT results, RQD values, and water level measurement data. The

logs also show the approximate thickness, location, and visual classification of each

material encountered. The stratigraphic lines separating each material type represent

the approximate location of the boundary between them. The transition between

materials may be far more or less gradual than indicated on the logs.

3.2

Cone Penetrometer Testing

After the completion of the test boring program, HCEA personnel performed cone

penetrometer testing (CMT) adjacent to six (6) of the standard test boring locations to

better define and evaluate the settlement characteristics of the fine-grained on-site

soils. CMT soundings were performed adjacent to Borings B-1, B-2, B-8, B-12, B-13,

and B-14. All CPT soundings were extended to refusal (i.e. bedrock) of the cone.

Results of the testing indicate that the on-site soils are over-consolidated and the

majority of settlement will be induced by the placement of the fill material to establish

foundation grades. Time of consolidation data was obtained and indicates

approximately 6 weeks for the fill induced settlement to be complete. The results of the

CPT program are attached in the Appendix.

3.3

Laboratory Testing

Laboratory testing was performed in HCEA’s laboratory on representative samples

obtained during the standard test boring program for basic engineering properties.

Laboratory testing consisted of Particle Size Analysis (ASTM D442), Atterberg Limits

(ASTM D4318), Natural Moisture Content (ASTM D2216), Modified Proctor (ASTM

D1557), and California Bearing Ratio (ASTM D1883). The Unified Soil Classification

System (USCS) was used to assign group symbols and group names to the soils

tested. The results of the laboratory testing are summarized below. The Particle Size

Distribution Reports, Modified Compaction Test Report, and California Bearing Ratio

Test Report from the laboratory testing are also included in the Appendix of this report.

Summary of Soils Index Testing Results

Boring and

Sample

Numbers

Depth

(Feet)

USCS

Classification

USCS

Symbols

1

Natural

Water

Content

(%)

Atterberg Limits

Grain Size

Liquid

Limit

Plasticity

Index

%Gravel %Sand

%Fines

B-1

S-3

4.0 – 6.0

Fat CLAY

CH

1

30.4

82

56

0.0

4.6

95.4

B-2

S-3

4.0 – 6.0

Silty CLAY

cl

22.1

--

--

--

--

--

B-4

S-2

2.0 – 4.0

Silty CLAY

cl

22.5

--

--

--

--

--

B-5

S-3

4.0 – 6.0

Silty CLAY

cl-ml

32.6

--

--

--

--

--

B-6

S-3

4.0 – 6.0

Lean CLAY

CL

1

33.2

46

20

0.0

5.6

94.4

B-7

S-2

2.0 – 4.0

Lean CLAY

cl

31.6

--

--

--

--

--

B-8

S-4

6.0 – 8.0

Fat CLAY

CH

1

29.1

82

56

0.0

4.6

95.4

B-11

S-4

6.0 – 8.0

Lean CLAY

cl

33.0

--

--

--

--

--

B-12

S-4

6.0 – 8.0

Silty CLAY

cl-ml

29.5

--

--

--

--

--

B-13

S-3

4.0 – 6.0

Silty CLAY

cl-ml

23.6

--

--

--

--

--

B-14

S-3

4.0 – 6.0

Silty CLAY

cl-ml

30.4

--

--

--

--

--

B-14

S-5

8.0 – 10.0

Silty CLAY

cl-ml

32.6

--

--

--

--

--

NOTE

1

_{: Lower case classification symbol denotes that the sample was visually classified while an upper case classification}

denotes that the sample was laboratory classified.

4.0

SUBSURFACE CONDITIONS

Details of the subsurface conditions encountered at the site are shown on the Records of Soil

Exploration and included in the Appendix. A summary of the test boring results and brief

description of the subsurface conditions and pertinent engineering characteristics of the soils are

given below.

Strata divisions shown on the Records of Soil Exploration have been estimated based on visual

examinations of the recovered boring samples. In the field, strata changes could occur gradually

and/or at slightly different levels than indicated. Groundwater conditions indicated on the Records

of Soil Exploration are those observed during the period of the subsurface exploration.

Fluctuations in groundwater levels could occur seasonally and might also be influenced by

changes in grading, runoff and infiltration rates, and other influencing factors.

Generalized subsurface conditions based on the results of the test borings are discussed below:

4.1

General Site Geology

Available geologic maps and results from the subsurface exploration program indicate

that the project site spans three different geological formations. The northern portion of

the site is mapped within the Hershey and Myerstown Formations, undivided (Ohm).

The middle of the site is mapped within a thin band of the Annville Formation (Oan),

while the southern portion of the site is mapped within the Ontelaunee Formation (Oo).

A generalized description of each of the formations is given below.

The bedrock of the Hershey and Myerstown Formation, undivided (Ohm) is described

as gray to dark gray, medium crystalline limestone. The bedrock is described as well

bedded and most bedding is described as thin to flaggy. Joints have platy pattern and are

well developed. The rock is described as highly fractured with moderate distance

between fractures. Fractures are often steeply dipping and open. The rock is generally

moderately resistant to weathering and moderately to highly weathered to a moderate

depth. Pencil-like, jagged fragments to medium-sized, elongated plates and block often

result from the weathering process. Excavation is moderately easy in weathered rock but

B-15

S-7

18.5 – 20.0

Fat CLAY

CH

1

37.4

45

21

0.1

12.5

87.4

B-20

S-2

2.0 – 4.0

Silty CLAY

cl-ml

22.9

--

--

--

--

--

P-2

Bulk Sample

4.0 – 6.0

Fat CLAY

CH

1

31.0

69

41

0.3

8.7

91.0

Summary of Modified Proctor and California Bearing Ratio (CBR) Testing Results

Boring

No.

Depth

(Feet)

USCS

Classification

USCS

Symbol

Natural

Water

Content

(%)

Modified Proctor

Compaction Results

Results

CBR

Optimum

Moisture

(%)

Maximum

Dry Density

(pcf)

CBR at 95% of

Max. Dry Density

(%)

difficult at depth where rock is unweathered. Foundation stability is described as good but

foundations should be excavated to sound material and should be thoroughly investigated

for possible solution openings.

The bedrock of the Annville Formation (Oan) is described as light gray, high calcium

limestone. The bedrock is described as well bedded and most bedding is described as

massive to thick. Joints have blocky pattern and are moderately well developed,

moderately to highly abundant and regular. Most fractures are open, but some are filled

with calcite. Fractures are typically spaced at a moderate distance and often steeply

dipping to vertical. The rock is generally moderately resistant to weathering and slightly

weathered to a shallow depth. Medium-sized blocks often result from the weathering

process. The bedrock/mantle interface is pinnacled in most places. Excavation is difficult

with bedrock pinnacles being a special problem. Foundation stability is described as

good but foundations should be excavated to sound material and should be thoroughly

investigated for possible solution openings.

The bedrock of the Ontelaunee Formation (Oan) is described as light to dark gray, very

fine to medium crystalline dolomite. The bedrock is described as well bedded and most

bedding is described as thick. Joints have blocky pattern and are moderately to well

developed, moderately abundant and regularly spaced. Most fractures are open, but

some are filled with calcite. Fractures are typically spaced at a moderate distance. Both

a steeply dipping set and a gently dipping set of fractures occur. The rock is generally

moderately resistant to weathering and slightly weathered to a shallow depth. Small to

large blocky fragments often result from the weathering process. The bedrock/mantle

interface is characterized as pinnacled. Excavation is difficult with bedrock pinnacles

being a special problem. Foundation stability is described as good but foundations should

be excavated to sound material and should be thoroughly investigated for possible

solution openings.

Based on published information through the Pennsylvania Geological Survey’s “Karst

Features Mapping” and HCEA’s experience working on sites within the geological

formations present at the site, the project area in known to be prone to sinkhole

development. The dolomite and limestone formations mapped at the site are

characterized by a gently undulating ground surface and Karst geology. Karst geology

may contain numerous pinnacles, thin to thick clay seams, and an extremely erratic

depth to rock surface. Kart bedrock formations can also include deep bedrock fissures,

caves, sinkholes and closed depressions. While the presence of carbonate mineralogy

bedrock implies a potential for sinkhole occurrence, it does not mean that a sinkhole

will actually occur. In the opinion of HCEA, the probability or risk that a sinkhole will

occur at a specific location cannot be accurately quantified within practical budget

limitations. Some risk of sinkhole development can be reduced (but not eliminated)

based on construction methods and recommendations as discussed herein.

During the site investigation program, HCEA personnel spoke to personnel of the

Valspar/Sherman Williams warehouse located just to the east of the project site about

the conditions that were encountered on that site. The Valspar representative

indicated that three or four sinkholes expressed themselves during construction of the

warehouse facility requiring repair.

A review of DCNR’s web-mapping application “Pennsylvania Geologic Data

Exploration (PaGEODE)” shows ten (10) closed depressions (orange dots on below

Figure 2) mapped within the project area. No sinkholes are mapped within the project

site. It is suspected that additional areas of closed depressions and/or sinkholes may

have been filled during the historic farming at the site.

Figure 1 - “Pennsylvania Geologic Data Exploration (PaGEODE)” Web Mapping – Bedrock Geology

Figure 2 - “Pennsylvania Geologic Data Exploration (PaGEODE)” Web Mapping – Karst-Related Features

4.2

Fill Material

Apparent fill material was not encountered in any of the borings.

4.3

Natural Soils

As typical with overburden soils overlying limestone bedrock, the natural soils

encountered were generally fine-grained in nature with USCS classifications of fat

CLAY (ch), silty CLAY (cl-ml), and lean CLAY (cl). These soils were typically described

as organish-brown to brown in color and were generally in a moist condition. "N"

values from the Standard Penetration Test (SPT) borings typically indicated relative

densities ranging from medium stiff to stiff. Samples were generally cohesive in nature

with medium to high plasticity. Natural moisture content testing conducted indicated

that much of the on-site soils were substantially wet of optimum moisture at the time of

the test boring program.

The unconfined compressive strength of the cohesive soils samples was measured

where possible using a pocket penetrometer. The pocket penetrometer readings

varied from 0.75 tsf to 4.25 tsf and generally averaged 2.0 tsf which corresponds well

with medium stiff to stiff clay according to common design tables for the given soil type

and SPT N-values observed.

4.4

Bedrock

Limestone bedrock was encountered and cored in nineteen of the twenty building

borings at depths ranging from 4.5 feet to 32.5 feet. Auger refusal, indicating the

apparent top of bedrock, was encountered at a depth of 33.0 feet in boring B-14, but

rock was not cored. The limestone bedrock encountered toward the north side of the

site was generally described as dark gray to gray, medium hard, slightly to moderately

weathered, and very closely to closely fractured with fractures of shallow dip. The

limestone bedrock encountered near the middle and south side of the site was

generally described as light gray to gray, hard, slightly weathered to fresh, and closely

to medium spaced fractured with fractures of shallow to medium dip. The rock

conditions are summarized as follows:

Test Boring

No.

Depth to Drilling

Refusal/Bedrock

(feet)

Rock Quality Designation

(RQD)

Recovery

(%)

B-1

22.0

Rock Core 22.0 to 27.0 feet (RQD = 76%)

_{Rock Core 27.0 to 32.0 feet (RQD = 66%)}

_100%

84%

B-2

22.0

Rock Core 22.0 to 25.0 feet (RQD = 50%)

Rock Core 25.0 to 26.0 feet (RQD = 33%)

Rock Core 26.0 to 30.0 feet (RQD = 56%)

100%

100%

98%

B-3

8.0

Rock Core 8.0 to 11.0 feet (RQD = 11%)

Rock Core 11.0 to 16.0 feet (RQD = 22%)

Rock Core 16.0 to 18.0 feet (RQD = 50%)

83%

100%

100%

B-4

7.5

Rock Core 7.5 to 10.5 feet (RQD = 14%)

Rock Core 10.5 to 15.5 feet (RQD = 57%)

Rock Core 15.5 to 20.5 feet (RQD = 83%)

Rock Core 20.5 to 25.5 feet (RQD = 67%)

Rock Core 25.5 to 30.5 feet (RQD = 50%)

100%

100%

100%

100%

100%

B-5

14.0

Rock Core 14.0 to 19.0 feet (RQD = 42%)

_{Rock Core 19.0 to 24.0 feet (RQD = 80%)}

_100%

88%

B-6

11.0

_{Rock Core 16.0 to 21.0 feet (RQD = 58%)}

Rock Core 11.0 to 16.0 feet (RQD = 0%)

100%

_100%

B-7

6.0

_{Rock Core 11.0 to 16.0 feet (RQD = 80%)}

Rock Core 6.0 to 11.0 feet (RQD = 20%)

30%

_94%

B-8

32.5

_{Rock Core 34.0 to 39.0 feet (RQD = 45%)}

Rock Core 32.5 to 34.0 feet (RQD = 0%)

_100%

87%

Test Boring

No.

Depth to Drilling

Refusal/Bedrock

(feet)

Rock Quality Designation

(RQD)

Recovery

(%)

B-9

6.3

_{Rock Core 11.0 to 16.0 feet (RQD = 32%)}

Rock Core 6.0 to 11.0 feet (RQD = 38%)

_100%

92%

B-10

5.5

Rock Core 5.5 to 10.5 feet (RQD = 23%)

Rock Core 10.5 to 15.5 feet (RQD = 22%)

Rock Core 15.5 to 20.5 feet (RQD = 47%)

Rock Core 20.5 to 25.5 feet (RQD = 53%)

Rock Core 25.5 to 30.5 feet (RQD = 66%)

96%

100%

100%

100%

96%

B-11

16.0

Rock Core 16.0 to 21.0 feet (RQD = 80%)

_{Rock Core 21.0 to 26.0 feet (RQD = 70%)}

100%

_98%

B-12

23.5

Rock Core 25.5 to 30.5 feet (RQD = 60%)

Rock Core 23.5 to 25.5 feet (RQD = 0%)

Rock Core 30.5 to 33.5 feet (RQD = 47%)

98%

70%

100%

B-13

9.0

_{Rock Core 14.0 to 19.0 feet (RQD = 30%)}

Rock Core 9.0 to 14.0 feet (RQD = 24%)

84%

_80%

B-14

33.0

Auger Refusal Obtained at 33.0 – No Bedrock Cored

B-15

24.0

Rock Core 24.0 to 25.0 feet (RQD = 40%)

Rock Core 25.0 to 30.0 feet (RQD = 70%)

Rock Core 30.0 to 35.0 feet (RQD = 100%)

100%

96%

100%

B-16

3.5

Rock Core 3.5 to 8.5 feet (RQD = 16%)

Rock Core 8.5 to 13.5 feet (RQD = 50%)

Rock Core 13.5 to 18.5 feet (RQD = 54%)

Rock Core 18.5 to 21.0 feet (RQD = 40%)

100%

100%

100%

96%

B-17

4.5

Rock Core 4.5 to 9.5 feet (RQD = 0%)

Rock Core 9.5 to 14.5 feet (RQD = 20%)

Rock Core 14.5 to 19.5 feet (RQD = 22%)

Rock Core 19.5 to 24.5 feet (RQD = 60%)

48%

96%

98%

100%

B-18

6.0

_{Rock Core 11.0 to 16.0 feet (RQD = 70%)}

Rock Core 6.0 to 11.0 feet (RQD = 42%)

100%

_100%

B-19

6.0

_{Rock Core 11.0 to 16.0 feet (RQD = 52%)}

Rock Core 6.0 to 11.0 feet (RQD = 24%)

_100%

90%

B-20

8.5

_{Rock Core 13.5 to 18.5 feet (RQD = 40%)}

Rock Core 8.5 to 13.5 feet (RQD = 58%)

_100%

98%

The rock core samples obtained were observed to have RQD values ranging greatly

from 0% to 100%. Consequently, rock quality encountered at the site is highly variable

with rock quality characterized as ranging from very poor to excellent as shown on the

table below.

Based on the results of the boring program and review of published geological data,

the project site in underlain by Karst and the bedrock surface is likely pinnacled. The

irregularity of the rock surface means that the elevation of the rock surface can vary

greatly over even a short lateral distance. Therefore, the potential exists for bedrock to

be encountered at elevations that vary significantly from the elevation in which bedrock

was encountered in the boring program.

Rock Quality Designation (RQD)

Description

0 – 25%

Very Poor

26 – 50%

Poor

51 – 75%

Fair

76 – 90%

Good

4.5

Groundwater

Groundwater levels were measured immediately upon completion of the borings and

prior to backfilling the borings when applicable, i.e. greater than 24 hours upon

completion. In general, the borings were found to be “dry” upon completion and prior

to backfilling. Free water in the soils, indicative of soils below the water table, were not

observed in the borings. It is believed that the water table was at a depth below the top

of bedrock at the time of drilling.

A more accurate determination of the hydrostatic water table would require the installation

of perforated pipes or piezometers which could be monitored over an extended period of

time. The actual level of the hydrostatic water table and the amount and level of perched

water should be anticipated to fluctuate throughout the year, depending on variations in

precipitation, surface run-off, infiltration, site topography, and drainage. The Contractor

should determine the actual groundwater levels at the time of construction to evaluate

groundwater impact on the proposed construction procedures.

5.0

EVALUATIONS AND RECOMMENDATIONS

For projects underlain by Karst geology, the type of foundation system selected by the project

team is typically based on both cost considerations and the potential risk of structural damage

or disruptions to a facility operations should a sinkhole occur. Section 5.5 herein discusses

several options and HCEA’s understanding of the project team’s desired approach.

The following recommendations have been developed on the basis of the previously described

project characteristics and subsurface conditions. If there are any changes to the project

characteristics or if different subsurface conditions are encountered during construction, HCEA

should be consulted so that the recommendations of this report can be reviewed and revised,

if necessary.

5.1

Karst Considerations

Based on the available data at the time of this report, it would appear the site of the

proposed construction may one with a risk for future sinkhole occurrence. It should be

noted that the previous occurrence of a sinkhole or closed depression does not ensure

future occurrences of sinkhole activity; likewise, the absence of such features does not

ensure that sinkhole activity will not be encountered in the future. This does not imply that

a sinkhole will occur, nor in HCEA’s opinion, can the probability or risk of that a sinkhole

will actually occur at a specific location be accurately quantified within practical budget

restraints. However, special precautions should be taken during construction to further

assess the presence of sinkhole activity and to avoid construction conditions during

construction that could increase the potential for sinkholes to occur. In addition,

specialized foundation and slab design approaches should be considered based on the

project teams risk tolerance to reduce the potential of excessive settlement or sudden

collapse of a structure, should a sinkhole occur in the immediate vicinity of a proposed

structure. These approaches are discussed in greater detail in Section 5.5.

5.2

General Site Preparation

At the beginning of construction activities, all topsoil should be stripped from the proposed

structure areas. Removal of topsoil should extend a minimum of 5 feet beyond the

proposed structure areas. Topsoil will not be suitable for use as structural fill and

therefore may be stockpiled and used in landscaped areas and/or wasted.

After the initial stripping process is completed, areas of the site to receive fill, or areas of

the site at-grade where structures will be located, should be proofrolled. The proofrolling

operations should be performed using a 20-ton, fully-loaded dump truck or another

pneumatic-tire vehicle of similar size and weight. The purpose of the proofrolling is to

locate any near-surface pockets of soft or loose soils requiring undercutting or other form

of modification. A Geotechnical Engineer or experienced Soils Technician should

observe the proofrolling operations and should determine which areas need further

undercutting and/or stabilization.

Overall site grading should be designed to provide positive drainage away from the

proposed structure. Positive drainage should be maintained throughout construction

activities.

5.3

Fill Selection, Placement and Compaction

Materials to be used as fill or backfill should be observed, tested and approved by the

Geotechnical Engineer. In general, the on-site soils which have Unified Soil

Classifications of CL or better, have a Liquid Limit of less than 40 and a Plasticity Index of

less than 20, are free from organic matter, other deleterious components, and rock

fragments in excess of 4 inches in their largest dimension can be re-used as structural fill.

It should be noted that highly plastic CH soils were identified during the laboratory testing

program. HCEA recommends that these soils are not used as structural fill (i.e. within

building footprint and areas of future pavement) but can be used as fill for non-structural

areas such “green” areas or within SWM facilities. Soils of this type are very moisture

sensitive and difficult to stabilize throughout the grading process. Because these soils

hold a high amount of moisture, they also have a higher shrink-swell potential than soils of

lower plasticity which could be detrimental to building foundations and slab and areas of

pavement. Prior to mass grading operations, it is recommended that additional soil index

testing be conducted on on-site soils that are intended to be used as fill to determine if

they meet the requirements of structural fill as presented above.

Materials suitable for various construction purposes can be identified by an experienced

Soils Technician during grading operations. Crushed aggregate meeting the

requirements of PennDOT 2A or approved equivalent could also be utilized as structural

fill at locations recommended by the Geotechnical Engineer, and should be considered for

localized, relatively deep fills such as foundation undercuts or trenches where utilities are

removed.

Care should be exercised during the grading operations. Due to the fine-grained nature

of the soils encountered in the borings, heavy equipment could create pumping and a

general deterioration of these soils if conducted in the presence of water. Therefore,

earthwork should be carried out during a dry season and the subgrade stability should be

evaluated prior to fill placement. This should minimize these potential problems, although

they may not be eliminated. If such problems arise, the Geotechnical Engineer should be

consulted for an evaluation of the conditions. Methods of subgrade improvements could

include scarification, moisture conditioning and recompaction, removal of unstable

materials and replacement with granular fill (with or without geosynthetics), and chemical

stabilization. The appropriate method of improvement, if required, will be dependent on

factors such as project schedule, weather, the lateral and vertical extent of the area to be

stabilized, and the nature of the instability.

Due to the fine-grained nature of the on-site soils, the material will be moisture sensitive.

The in-situ water content of the residual soils at the time of drilling appear to be higher

than their optimum moisture content required for achieving the specified degree of

compaction. As a result, it should be anticipated that a significant amount of aeration

and drying will likely be necessary. Drying of the fine-grained surface soils will only be

feasible during the warm, dry season of the year and may require extended time and

aeration effort to achieve a moisture content that is acceptable for compaction.

Moisture conditioning, wetting or drying of the soils, should be anticipated to achieve

proper compaction. The moisture conditioning can include scarification, mixing, or other

processes of conditioning through chemical means such as lime stabilization, soil cement,

etc. The moisture contents of the soils should be controlled properly to avoid extensive

construction delays. Based on the soil types encountered, we recommend that the owner

budget for the possibility that overexcavation and/or subgrade stabilization may be

required and that the Contractor is prepared to handle potentially unstable and/or soft

conditions.

If necessary, imported structural fill may be used which consists of granular materials

meeting the USGS requirements of GW, GM, GW-GM, SW, SM or SW-SM materials

and be approved by the Geotechnical Engineer prior to use.

Imported structural or load bearing fill should meet the following criteria:

 free of organic matter, ash, cinders, trash, or other unsuitable materials;

 particle size distribution that is well-graded;

 plasticity index less than 10; liquid limit less than 30;

 less than 15 percent by weight rock fragments larger than 3 inches with no

particle size exceeding 6 inches, less than 30 percent by weight larger than the

¾ inches and less than 30 percent smaller than the no. 200 sieve.

It should be noted that the tolerances with respect to plasticity, gradation and fines

content for imported structural fills are more stringent than the existing on-site soils

being recommended for reuse. It is anticipated that importing of structural fill to the

project site may be necessary during winter or spring months. As such, the structural

fill brought to the site should be expected to possess properties that are conducive to

being workable and compactible during these time periods.

Imported materials meeting the classification of ML or CL are less desirable, as

fine-grained soils are more susceptible to instability. These fine-fine-grained soils should be

reviewed by the Geotechnical Engineer prior to use.

Structural fills should be placed in relatively horizontal 8-inch (maximum) loose lifts and

should be compacted to a minimum of 95 percent of the Modified Proctor (ASTM D1557)

maximum dry density. General fill materials in landscape and other non-structural areas

should be compacted to at least 90 percent of the Modified Proctor maximum dry density

if significant subsidence of the fill under its own weight is to be avoided.

Structural fill should extend a minimum of 10 feet beyond building lines where floor slabs

are to be constructed on the fill material. Fill slopes of 3-horizontal to 1-vertical (3H:1V) or

flatter should be used. Exposed subgrades should be sloped and sealed at all times to

facilitate rainfall runoff.

Grading operations within structural areas, including pavement, and utility trench and

wall backfill, should be observed and tested on a full-time basis by an experienced

Soils Technician under the supervision of a Geotechnical Engineer. All compactive

effort should be verified by in-place density testing. HCEA recommends that final

subgrades be proofrolled immediately prior to placement of subbase stone, concrete

slabs, or asphalt pavement to evaluate stability of the subgrade, which may have been

impacted by exposure to wet weather and disturbance by construction traffic

subsequent to mass grading. This procedure will allow for identification and

remediation of any soft or otherwise unstable areas prior to placement of base courses,

concrete, and/or asphalt pavement.

5.3.1 Fill Quarantine Period

Due to the significant amount of fill required to establish the proposed finished floor

elevation and time-dependent settlement characteristics of the on-site soils, settlement

monitoring within the fill areas is recommended, and foundation construction within

areas receiving more than three (3) feet of fill should not commence until settlement of

the soils underlying the fill areas is complete. Settlement monitoring should consist of

the installation of a minimum of three (3) settlement monitoring plates prior to fill

placement, with periodic surveying of the tops of the settlement monitors as fill is being

placed. HCEA recommends that the settlement plates be located near borings 8,

B-11, and B-13. Settlement monitoring should continue until the survey data indicates

steady state conditions have been achieved. Based on the results of the CPT testing,

we estimate at least 6 weeks from the end of fill placement until the start of foundation

installation in the fill areas to allow for settlement to occur. If the settlement monitoring

indicates that the fill induced settlement has stopped prior to the six weeks, foundation

construction can begin at the direction of the Geotechnical Engineer. The Geotechnical

Engineer should review the settlement data to determine when foundation construction

can commence.

5.4

Cold/Wet Weather Earthmoving Considerations

In order to facilitate construction during late fall, winter, and early spring, special

considerations should be recognized. Specifically, “cold weather” and “wet weather” can

significantly reduce the potential to practically lower natural soil moisture content to

optimum moisture content needed for acceptable compaction levels. “Cold weather” is

when temperatures drop below freezing at any time or when temperatures are

consistently sustained below 40°F. “Wet weather” is any period of time with increased

precipitation and can occur during any time of the year. The following considerations are

offered if fill operations are anticipated during the aforementioned difficult conditions:



The natural moisture contents of materials used as fill which are above optimum

percentages for compaction will require moisture conditioning. The moisture content

may need to be lowered by spreading out material wet of optimum moisture in thin

layers and disking in order to facilitate evaporation. This methodology becomes less

practical during “wet weather” and “cold weather” conditions.



Any compacted fill materials should be positively graded and sealed with a

smooth-drum roller as soon as practical after achieving finished grade or immediately prior to

any anticipated precipitation event. These measures will help to reduce the potential

for rutting and pumping of the subgrade and ponding of undrained water.



Imported granular and well-graded fill, along with a stabilizing geosynthetic grid, may

aid in facilitating construction during difficult weather conditions. The use of properly

graded crushed rock as a working surface will aid in creating a stable working pad.

The Geotechnical Engineer should review all design and construction operations that

specifically address earthwork in “cold weather” and “wet weather” conditions.

5.5

Foundations

It is understood that a conventional shallow foundation system is the preferred method by

the design team based on project economics and relatively minimal disturbance to the

facility’s operations if a sinkhole were to occur after construction. A conventional shallow

foundation system is typically considered to be more cost effective than deep foundations,

rigid mat foundations and/or ground improvement methods. Since it is not possible to

predict the location or extent of a future sinkhole developing in relationship to the

proposed building, conventional shallow foundation systems are often utilized on similar

structures within the project vicinity. The utilization of deep foundations, grade-beam type

foundation, rigid mat foundations and/or ground improvement methods can reduce, but

not eliminate, the severity of damage should a sinkhole affect the structure. However, the

use of either foundation system would not eliminate the need for remediation should a

sinkhole form either within the footprint of the building or within the general vicinity.

Therefore, it is HCEA’s opinion that the “natural” medium stiff to stiff clays and limestone

bedrock encountered are generally suitable for supporting the proposed building on a

shallow spread foundation system. Structural fill, placed over suitable natural soils,

compacted and reviewed as recommended in this report, is also considered suitable for

support shallow foundations.

It is recommended that the proposed foundations bearing on the in-situ soils and/or

structural fill be designed for a maximum net allowable bearing pressure of 3,000 psf.

Where bedrock is found to be at a shallow depth below the foundation elevations,

foundations bearing on intact limestone bedrock should be sized using an allowable

bearing pressure of 8,000 psf. The base of all exterior spread foundations in areas

exposed to frost should be located at least 36 inches below the final exterior grades or

deeper if required by local building codes as to provide adequate protection from frost

heave. Interior foundations located in insulated areas should be located at least 18 inches

below the proposed finished floor elevation. All isolated column footings should be at

least 4 feet wide, and all continuous wall footing should be at least 2 feet wide regardless

of bearing pressures.

Footing excavations should be observed by a Geotechnical Engineer or experienced

Soils Technician prior to the placement of reinforcement steel and concrete. All

foundations should be constructed on firm, dry, non-frozen subgrade free of loose soil

and/or debris. Prior to the placement of reinforcement steel or concrete, the foundation

subgrade should be densified and compacted using a walk-behind vibratory roller,

gas-powered automatic tamper, or similar equipment. Densification should be performed to

provide uniform density of the foundation subgrade and allow for proper distribution of

loads. If soft or loose pockets are encountered in the footing excavations, the unsuitable

materials should be removed and backfilled with structural fill as recommended herein, or

if acceptable to the project’s structural engineer, the base of foundation elevation could be

lowered to the bear on suitable subgrade soils. Proper compaction and densification of

the foundation subgrade should be verified by an experienced Soils Technician or

Geotechnical Engineer prior to placement of concrete.

Caution should be exercised to not disturb foundation subgrade soils. Should the

subgrade be disturbed, the soil should be compacted in place or removed until firm soil

is encountered and the resulting excavation backfilled with concrete or controlled

structural fill as described above. Every effort should be made to prevent water from

entering open foundation excavations. Water that may accumulate in foundation

excavations should be removed immediately. Footing excavation and placement of

concrete should be performed on the same day whenever practical.

If massive rock is encountered in localized areas of a foundation, the rock should be

over-excavated by at least 8 inches, and the resulting excavation should be backfilled with

structural fill as recommended herein. The purpose of this over-excavation is to reduce

the potential for abrupt changes in subgrade support and decrease the potential for abrupt

differential settlement and stress concentrations.

Exterior footings and footings in unheated areas should be located at depths of at least 3

feet below final exterior grades so as to provide adequate protection from frost heave. If

the structure is to be constructed during the winter months or if the building interior will

likely be subjected to freezing temperatures after footing construction, then all footings

should be provided with adequate frost cover protection. Otherwise, interior footings can

be located on suitable materials at nominal depths below finished floor grade.

Wall footings should be at least 24 inches wide regardless of the calculated bearing

pressure. To preclude punching shear failures, any isolated column foundation footings

should be at least 3 feet wide. Since a net soil pressure is specified, the weights of the

footing concrete and backfill need not be added to the structural loads when proportioning

the footings.

In areas where foundations will be supported on structural fill, the structural fill should

extend a sufficient distance laterally beyond the perimeter of the footings. For design

purposes, plans should reflect structural fill extending a minimum distance of 9 inches

laterally beyond a footing perimeter for each linear foot of structural fill below the bearing

level.

5.6

Settlement

Estimates of foundation settlement were performed to assist in evaluating the effects of

the structural loads on the subsurface conditions. Based on this analysis, it is

estimated that maximum total foundation settlement for the proposed foundation

should be on the order of 1 inches or less provided there is a lag time between fill

placement and foundation construction to allow for the settlement attributed to the fill

placement to occur. Refer to Section 5.3.1. Post-construction differential settlement is

estimated to be on the order of ½ inch or less. The settlement tolerances of the

proposed structure should be verified with the project’s structural engineer.

5.7

Ground-Supported Slabs

Floor slabs should be supported on approved, firm in-situ soils, or on newly compacted fill.

The slab subgrade should be prepared in accordance with the procedures outlined in

Section 5.2 and Section 5.3 of this report. In particular, the slab subgrade should be

heavily proofrolled to delineate any soft or loose areas requiring undercutting and/or

stabilization.

It is recommended that the slab be directly supported on a minimum 6-inch layer of clean

granular materials such as AASHTO No. 57 stone or approved equivalent. These

materials will require acquisition from an off-site source. A suitable moisture/vapor barrier

(that is, polyethylene sheeting) should also be provided. These procedures will provide a

moisture break that will help to prevent capillary rise and also help to cure the slab

concrete. It is also recommended that construction joints on the slab surface and isolation

joints between the slab and structural walls be provided (such that the slab would be

ground-supported) walls to allow differential settlement of the slab and foundations

without damage. Subgrade conditions should be modeled for design utilizing a subgrade

modulus, K

s

, of not more than 100 pci.

On most projects, there is a significant time lag between initial grading and a point when

the contractor is ready to pour the slabs-on-grade. Environmental conditions and

construction traffic often disturb the subgrade soils. Provisions should be made in the

construction specifications for the restoration of the subgrade soils to a stable condition

prior to the placement of the concrete for the floor slabs.

Prior to the placement of the slab subbase, the subgrade should be rough graded and

thoroughly proofrolled and evaluated for stability, uniformity, and moisture. Particular

attention should be paid to areas of high construction traffic that may have be rutted and

disturbed as well as areas of sub-slab utility trenches. Areas of unsuitable/unstable

materials should be repaired as discussed in Section 5.2 at the direction of the

Geotechnical Engineer or experienced Soils Technician.

5.8

Groundwater and Drainage

Groundwater levels taken immediately upon completion of the borings and the lack of

visible water in the test samples indicate that groundwater is likely below any

construction-related activities, and therefore, major construction-related groundwater

problems are not anticipated.

It is recommended that wherever significant quantities of water infiltration from

precipitation, surface run-off or perched conditions are encountered during foundation

construction, the resulting excavation be over-excavated by at least 6 inches and

backfilled with AASHTO No. 57 aggregate to facilitate sumping and protect the

exposed subgrade during construction. Any water infiltration should be able to be

controlled by means of sump pits and pumps, or by gravity ditching procedures. If

conditions are encountered that cannot be handled in such a manner, the Geotechnical

Engineer should be consulted.

Adequate drainage should be provided at the site to minimize any increases in the

moisture contents of the foundation soils. Pavement or parking areas should be sloped

away from the structure to prevent the ponding of water. The site drainage should also be

such that run-off onto adjacent properties is controlled properly.

5.9

Lateral Earth Pressures

Subsurface structural walls that are restrained from deflection should be designed for

the at-rest condition, K

o

, while subsurface structural walls that are free to deflect should

be designed for the active condition, K

a

. The lateral earth pressure coefficients

presented are based on vertical subsurface wall elements, horizontal backfill, and no

wall friction between the back of the wall and soil backfill. In addition, the values

presented do not carry a factor of safety, so it is recommended that a factor of safety

be utilized during the evaluation.

Wall Backfill Properties for Lateral Load Determination

Effective Angle of Internal Friction, Φ’

26 degrees

Moist Unit Weight, γ

moist

125 pounds per cubic foot

Rankine Active Earth Pressure Coefficient, K

a

0.39

Rankine At-Rest Earth Pressure Coefficient, K

o

0.56

Rankine Passive Earth Pressure Coefficient, K

p

2.56

5.10 Seismic Design Parameters

Based on the subsurface conditions encountered during the field exploration at the site, a

Site Class “D”, as defined by Table 1613.5.2 of the International Building Code (IBC), is

recommended for design purposes.

5.11 Pavement Design

Areas of paving should be proofrolled as specified in Section 5.2 of this report near the

time of pavement construction and any subgrade fill required should be compacted to a

minimum of 95% of the Modified Proctor (ASTM D1557) maximum dry density prior to

placement of the subbase material and pavement section. A Geotechnical Engineer or

experienced Soils Technician should witness the proofrolling operations and should

determine any areas need further undercutting and/or stabilization. Due to the

fine-grained nature of the subgrade soils, the subbase and pavement section should be

placed as soon as practical upon testing and approval to limit exposure to atmospheric

conditions, surface runoff, and/or construction traffic.

Based on the results of the boring program, it appears that pavement subgrade areas

will likely be comprised of materials having visual classifications of lean silty CLAY

(cl-ml) to Fat Clay (CH) in accordance with the Unified Soil Classification System. A

California Bearing Ratio (CBR) test was conducted on a representative sample and

resulted in a CBR value of 5.9%. Materials exhibited minor swell which indicates that

lower values may occur with longer soak times. Since clay soil have such a low

permeability, it is likely that water will eventually become trapped with the pavement

and the subgrade soils. Under such conditions, the subgrade soils could be expected

to deteriorate substantially. We therefore recommend a conservative CBR value of 3%

for pavement design.

5.11.1 Bituminous Concrete Pavement

Light-Duty Parking Areas:

No light-duty traffic volumes were provided at the time of this report. Therefore, based

on an assumed traffic loading consisting of primarily passenger vehicles (with limited

access for trash collection vehicles) and the subgrade conditions encountered during

this evaluation, the following pavement section is recommended for the light-duty

parking lot areas. A 20-year design life and an allowable traffic load ESAL’s of 5.0x10

4

has been assumed.

Compacted Thickness

Materials

1.5 inches

HMA Superpave 9.5 mm Wearing Course

4 inches

HMA Superpave 25.0 mm Base Course

6 inches

PennDOT 2A Stone Subbase

11.5 inches

Total Thickness

Heavy-Duty Truck/Construction Equipment Areas: This section can be utilized in areas

where the traffic will be comprised of heavy trucks and/or construction equipment

associated with facility’s operations. No heavy-duty traffic volumes were provided at

the time of this report. A 20-year design life and an allowable traffic load ESAL’s of

20.0x10

4

_{has been assumed.}

Compacted Thickness

Materials

2 inches

HMA Superpave 9.5 mm Wearing Course

4.5 inches

HMA Superpave 25.0 mm Base Course

6 inches

PennDOT 2A Stone Subbase

12.5 inches

Total Thickness

The shallow subgrade soils were observed to be medium to high plasticity, fine-grained

soils (lean clays and fat clays). Fine-grained subgrade soils are generally not

considered to be “well-draining.” These soils correspond to American Association of

State Highway and Transportation Officials (AASHTO) classifications A-4 or A-6 and

typically require a deeper paving section to provide drainage and reduce frost

susceptibility than more coarse-grained (sand and gravel) subgrade soils. All

pavement construction and materials should conform to the Commonwealth of

Pennsylvania Department of Transportation Publication 408, “Construction

Specifications”, 2016 Edition and as subsequently revised.

The on-site soils have a low degree of permeability, and therefore is a possibility that

water will eventually become trapped between the pavement and the subgrade soils.

Under such conditions, the subgrade soils could be expected to deteriorate

substantially. Proper drainage will be important to the overall performance of the

pavement section, and therefore, it is imperative that grading is provided to prevent

ponding and traverse surface water beyond the limits of pavement.