Geotech_Report.pdf

COVER PAGE

Joint Base Charleston Cryogenics Facility North Charleston, South Carolina

December 1, 2017 Terracon Project No. EN175203

Prepared for:

CEMS Engineering, Inc.

Summmerville, South Carolina

Prepared by:

Terracon Consultants, Inc.

North Charleston, South Carolina lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil lpvanbrunt Pencil

REPORT TOPICS

GEOTECHNICAL OVERVIEW

PROJECT DESCRIPTION

SITE CONDITIONS

EXPLORATION AND TESTING PROCEDURES

GEOTECHNICAL MODEL

SEISMIC CONSIDERATIONS

SITE PREPARATION

SHALLOW FOUNDATIONS

FLOOR SLABS

GENERAL COMMENTS

ATTACHMENTS

APPENDIX:

SITE LOCATION

EXPLORATION PLAN

EXPLORATION RESULTS

v In Situ Logs v Hand Auger Boring Logs

SUPPORTING DOCUMENTS

v CPT General Notes v Unified Soil Classification System

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GEOTECHNICAL ENGINEERING REPORT

JOINT BASE CHARLESTON CRYOGENICS FACILITY

NORTH CHARLESTON, SOUTH CAROLINA

Terracon Project No. EN175203

December 1, 2017

INTRODUCTION

This report presents the results of our geotechnical investigation performed for The Joint Base Charleston Cryogenics Facility located at air base building 679 on Joint Base Charleston in North Charleston, South Carolina. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

n subsurface soil conditions n floor slab design and construction n groundwater conditions n seismic evaluation per IBC n site preparation and earthwork n other geotechnical design parameters n foundation design and construction

The geotechnical engineering scope of work for this project included the advancement of a combination of in situ testing techniques including a Cone Penetration Test (CPT), a Seismic Cone Penetration Test (SCPT), and Hand Auger Borings (HABs) to depths of 4 to 76 feet below existing site grades.

The site and boring locations are shown in the Site Location and Exploration Plan sections, respectively, and logs of the borings are included in the appendix of this report.

Geotechnical Engineering Report Joint Base Charleston Cryogenics Facility ■ North Charleston, South Carolina December 1, 2017 ■ Terracon Project No. EN175203

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GEOTECHNICAL OVERVIEW

This report presents the results of our geotechnical investigation performed for the new Joint Base Charleston Cryogenics Facility located at air base building 679 on Joint Base Charleston in North Charleston, South Carolina. Our geotechnical scope of work for this project included conducting geotechnical fieldwork, associated engineering analysis, and this geotechnical engineering report.

This report provides recommendations for foundation options, seismic considerations, site preparation, and the other geotechnical related conditions that might affect the proposed construction. The following geotechnical considerations were identified during our investigation:

n Assuming proper site preparation, the structures may be supported on a traditional shallow foundation system bearing on in situ soils or properly compacted Controlled Fill. Total estimated static settlement for traditional shallow foundations is 1 inch or less, with differential settlement up to ½ inch.

n Based on the procedures outlined in IBC 2015 and the results of our field testing, a seismic Site Class D will be available for this project. However, the structural engineer should verify that the site class exemption provided by this code is available for the proposed structure.

n We estimate that liquefaction-induced settlements from the design seismic event may range from 2 to 3 ½ inches with differential settlement 50% of the total. While the project structural engineer should review our estimates, our experience indicates that the liquefaction settlement estimates will not require mitigation.

The recommendations presented herein have been developed on the basis of the subsurface conditions encountered during field investigation and our understanding of the proposed construction. Should changes in the project criteria occur, a review must be made by Terracon to determine if modifications to our recommendations will be required.

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PROJECT DESCRIPTION

During the period of collaboration that has transpired since the project was initiated, our understanding of the project conditions have been modified to reflect the following:

Item Description

Project location The project is located at Air Base Building 679 on Joint Base Charleston in North Charleston, South Carolina.

Proposed structure One-story metal building that has a footprint of 600 SF.

Maximum loads

Based on information provided by the client, the following loading conditions were provided for our analysis:

n Columns – 10 kips n Walls – 4 kips per linear foot n Slabs – 125 psf (live load) and 100 psf (dead load)

If final loads vary from these assumptions, further review will be necessary.

Grading Finished floor elevation is unknown at this time. We are assuming 1 foot or less of fill will be required to develop final grade.

SITE CONDITIONS

The following description of site conditions is based on our site visit in association with the field exploration.

Item Description

Site Location

The project is located at Air Base Building 679 at Joint Base Charleston in North Charleston, South Carolina.

Latitude: 32.9108º Longitude: -79. 0505º

Current ground cover Grass, brush and sporadic trees.

Existing Improvements Small structure with attached transformer Existing topography Existing grades are between elevations 43 to 45 feet.

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EXPLORATION AND TESTING PROCEDURES

Field Exploration

Our field exploration services were performed in general accordance with the information provided in our proposal number PEN175203 dated August 28, 2017.

Type of Test Test Location Number of Tests Test Depth

Cone Penetration Test (CPT) Adjacent to new structure 1 43 feet

Seismic Cone Penetration Test (SCPT) Adjacent to new structure 1 46 feet

Hand Auger Borings (HABs) Adjacent to each CPT/SCPT 2 4 feet

The approximate location of each test is indicated on the Exploration Plan. The test locations were determined by Terracon and located in the field by Terracon personnel utilizing a commercially available handheld Global Position System (GPS) unit which are typically considered accurate to within ±10 to 20 feet. The locations should be considered accurate only to the degree implied by the means and methods used to define them. The field exploration was performed on October 12, 2017. The in situ tests were advanced with a track mounted Pagani TG73-200 rig.

The field logs and recovered samples were compiled and reviewed by the geotechnical engineer.

Final in situ and Hand Auger Boring logs and details for each of the tests can be found in Exploration Results.

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GEOTECHNICAL MODEL

Subsurface Profile

Based on the results of the field exploration, subsurface conditions on the project site can be generalized as follows:

Description

Approximate Depth to

Bottom of Stratum

Material Encountered1

Surface 5 to 6 inches Topsoil

Stratum 1 4 feet Loose to medium dense silty sand

Stratum 2 18 feet Medium dense clean to silty sand

Stratum 3 31 feet Medium stiff silty clay to clay with interbedded medium dense silty sand

Stratum 4 44 feet Stiff to very stiff clayey/sandy silt

Stratum 5 46 feet2 Firm to stiff clayey silts to silty clay

1. Material descriptions are based on visual classification from HAB samples and correlations with in situ data.

2. Termination of deepest sounding.

Conditions encountered at each test location are indicated on the individual test records.

Stratification boundaries on the test records represent the approximate location of changes in soil types. The transition between materials may be gradual. Details for each of the tests can be found in Exploration Results.

Groundwater Conditions

Groundwater depths were determined from estimating from the hydrostatic line on the CPT pore water pressure (u) graph and from physical observations in in the Hand Auger Borings.

The water levels as observed during field exploration are summarized in the following table and noted on the attached in situ and boring logs, in Exploration Results.

Test Depth to Groundwater within Voids left from Testing (ft)

Estimated Depth to Groundwater based on CPT Pore Pressure Data (ft)

SCPT-1 NE2 3.5

CPT-3 NE2 3.5

HAB at SCPT-1 NE2 NA1

HAB at CPT-2 NE2 NA1

1. NA- Not Applicable

2. NE- Not Encountered

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Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. The groundwater surface should be checked prior to construction to assess its effect on site work and other construction activities.

Groundwater levels were measured using the following criteria:

n Physical observation within hand auger borings (HAB).

n Where not physically encountered in HABs, groundwater levels are measured using a groundwater probe within the voids left by cone penetration (CPT) or flat blade dilatometer (DMT) tests.

n Where not encountered within CPT or DMT voids, groundwater levels are estimated using the hydrostatic line (height of water below the ground surface) on the CPT Porewater pressure (U) graph shown on the CPT logs.

n Unless otherwise specified on the logs or in the report, all groundwater measurements are collected during or immediately after drilling.

SEISMIC CONSIDERATIONS

According to the International Building Code 2015 edition (IBC 2015), structures are required to avoid collapse during a design earthquake event. The design earthquake has a 50 year exposure period with a 2% probability of exceedance (i.e. a 2500 year design earthquake). The 2500 year design earthquake has a Moment Magnitude (Mw) of 7.3 and a design Peak Ground Acceleration (PGAM) of 1.04 g, as determined by data provided by the IBC 2015 Code and ASCE 7-10. The seismic evaluation of the site identified potentially liquefiable soils. According to the IBC (2015) and ASCE 7-10, this potential for liquefaction classifies the site as Site Class F.

ASCE 7-10 (Section 20.3.1) provides an exception to the Site Class recommendation for structure(s) with a fundamental period equal to or less than 0.5 seconds. This exception states that a site can be classified without considering liquefaction to determine spectral accelerations for structural design. The structural engineer should verify this exception. If the proposed structures meet the requirements of the exception, Seismic Site Class D would be applicable and the following seismic design parameters can be used for the site:

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Code Used Site Classification 2015 International Building Code (IBC)1 D2

Seismic Design Parameter Value Fa 1.00

Fv 1.50

FPGA 1.00

SDS 1.01 g

SD1 0.50 g

PGAM3 1.04 g

1. In general accordance with the 2015 International Building Code and ASCE 7-10 Table 20.3-1, and an average weighted shear wave velocity of 742 feet per second collected from in situ testing methods.

2. Based upon the fundamental period exception outlined in ASCE 7-10 Section 20.3.1

3. Based on procedures outlined in ASCE 7-10 for geotechnical hazards

Liquefaction Potential

Due to the high seismicity of the Coastal Plain of South Carolina, we performed a liquefaction potential analysis to evaluate the stability of the soils. Ground shaking at the foundation of structures and liquefaction of the soil under the foundation are the principal seismic hazards identified for the design of earthquake-resistant structures. Liquefaction occurs when a rapid buildup in water pressure, caused by the ground motion, pushes sand particles apart, resulting in a loss of strength and later densification as the water pressure dissipates. This loss of strength can cause bearing capacity failure while the densification can cause excessive settlement.

While the amount of settlement is dependent on the magnitude and distance from a seismic event, and geologic age of the soil deposit, we estimate that settlements from the design earthquake may range from 2 to 3 ½ inches. Differential settlement may be up to 50% of the total settlement depending on depth and amount of liquefaction, and location relative to a seismic event epicenter.

Design under the IBC allows for buildings to sustain damage during the design earthquake event, but they must remain standing. Therefore, our liquefaction settlement estimate should be reviewed from the standpoint of risk of total collapse of the structure. While the project structural engineer should review our estimates, our experience indicates that the liquefaction settlement estimates will not require mitigation.

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SITE PREPARATION

Site Preparation Considerations

The initial step in site preparation is to remove the existing structure, foundations, utilities, trees, organic material, topsoil, root balls, and other deleterious material from within the proposed structural areas. If site constraints allow, stripping should extend a minimum of 5 feet outside the construction area footprint. We anticipate stripping depths to average up to 6 inches across the moderately landscaped site. Voids remaining from existing foundations, existing utility lines, large roots, and the clearing/stripping operation should be backfilled with properly compacted Controlled Fill.

After stripping and subgrade repair is completed, the existing subgrade should be proofrolled with a loaded tandem axle dump truck or other similar approved construction equipment. A geotechnical engineer should monitor proofrolling operations. Areas that pump or rut excessively should be undercut and reworked or replaced with Controlled Fill. The project site should be graded to promote drainage and direct stormwater runoff away both during construction and the operational life of the structures. Fill placement may commence after the subgrade stability has been verified by the geotechnical engineer.

Material Types

Controlled fill should meet the following soil property requirements:

Fill Type1 USCS Classification Acceptable Location for Placement

Controlled/Imported Fill SP, SP-SM, SP-SW, SW, SM (Passing #200<12%)

All locations

Onsite Soil SM, SP-SM, SP (Passing #200<25%)

All locations

1. Controlled, compacted fill should consist of approved materials that are free of organic matter and other deleterious debris.

The near surface site soils within the proposed location consist of silty sands. These sandy soils can likely be used as Controlled Fill, however, the grading contractor should provide samples of proposed fill soils prior to placement.

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Compaction Requirements

ITEM DESCRIPTION

Fill Lift Thickness

When hand-guided equipment (i.e. jumping jack or plate compactor) is used, fill lifts shall have a maximum of 2 to 4 inches in loose thickness. We recommend the use of light to hand-operated vibratory equipment in order to mitigate compaction on existing structures.

Compaction Requirements1

The upper 12 inches of the floor slab subgrade should be compacted to 100% of the material’s maximum modified Proctor dry density (ASTM D1557).

Other structural areas should be compacted to 95% of the material’s maximum Modified Proctor dry density (ASTM D1557).

Moisture Content – Controlled Fill or Onsite Soils2

Within the range of ±2% of optimum moisture content value as determined by the Standard Proctor test.

1. Fill should be tested for moisture content and compaction during placement. If the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved.

2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the Controlled Fill material pumping when proofrolled.

Backfill Construction Observation and Testing

The exposed subgrade and each lift of compacted fill should be tested, evaluated, and reworked, as necessary, until approved by the geotechnical engineer’s representative prior to placement of additional lifts. We recommend that each lift of fill be tested for density and moisture content at a frequency of one test for every 600 square feet for building areas. We recommend one density and moisture content test for every 50 linear feet of compacted utility trench backfill.

Earthwork Construction Considerations

It is anticipated that shallow excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Upon completion of filling/cutting and grading, care should be taken to maintain the subgrade moisture content prior to construction of floor slabs.

Construction traffic over the completed subgrade should be avoided to the extent practical. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. If the subgrade should become desiccated, saturated, or disturbed, the affected material should be removed or these materials should be scarified, moisture conditioned, and recompacted prior to floor slab construction and observed by Terracon.

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Surface water should not be allowed to pond on the site and soak into the soil during construction.

Construction staging should provide drainage of surface water and precipitation away from the building areas. Any water that collects over or adjacent to construction areas should be promptly removed, along with any softened or disturbed soils. Surface water control in the form of sloping surfaces, drainage ditches and trenches, and sump pits and pumps will be important to avoid ponding and associated delays due to precipitation and seepage.

Terracon should be retained during the construction phase of the project to observe earthwork and to perform necessary tests and observations during subgrade preparation; proofrolling;

placement and compaction of controlled compacted fills; backfilling of excavations into the completed subgrade, and just prior to construction of building floor slabs.

SHALLOW FOUNDATIONS

Assuming that proper site preparation in completed, the proposed structure can be supported by a shallow spread footing foundation bearing on in situ or compacted Controlled Fill. Design recommendations for shallow foundations for the proposed structure are presented in the following paragraphs.

Design Recommendations

Description Columns Walls

Allowable bearing pressure1 2,000 psf 2,000 psf

Minimum dimensions 24 inches 12 inches

Minimum embedment below finished grade 12 inches 12 inches

Estimated total static settlement3 1 inch or less 1 inch or less

Estimated differential static settlement3 Less than ½ inch over 30 feet

Less than ½ inch over 30 feet

1. The recommended net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. This assumes that any unsuitable fill, debris or soft soils, if encountered, will be undercut and replaced with Controlled Fill.

2. The settlement estimates are based on maximum loads of 10 kip column footings and 4 kips per linear foot strip footings and the above allowable bearing pressure. The foundation settlement will depend upon the variations within the subsurface soil profile, the structural loading conditions, the embedment depth and dimensions of the footings, the thickness of compacted fill, and the quality of the earthwork operations. These settlement magnitudes assume the foundation subgrade will be repaired as recommended in this report. The settlement calculations were based on footing sizes of 2 ft x 2 ft for columns and 2 foot wide strip footings.

3. If final loads vary from those listed above, a review must be made by Terracon to determine if modifications to our recommendations will be required.

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Foundation Construction Considerations

The base of all foundation excavations should be free of water and loose soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance.

Care should be taken to prevent wetting or drying of the bearing materials during construction.

Excessively wet or dry material or any loose/disturbed material in the bottom of the footing excavations should be removed before foundation concrete is placed. If the soils at bearing level become excessively dry, disturbed, saturated, or frozen, the affected soil should be removed prior to placing concrete.

If debris or unsuitable bearing soils are encountered in footing excavations, the excavation could be extended deeper to suitable soils and the footing could bear directly on these soils at the lower level or on lean concrete backfill placed in the excavations. As an alternative, the footings could also bear on properly compacted Controlled Fill extending down to the suitable soils.

Overexcavation for compacted backfill placement below footings should extend laterally beyond all edges of the footings at least 8 inches per foot of overexcavation depth below the “Design Footing Level.” The overexcavation should then be backfilled up to the footing base elevation with well-graded granular material placed as recommended in the Site Preparation section. The overexcavation and backfill procedure is shown in the figure below.

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FLOOR SLABS

Floor slabs can be supported by the in-situ soils or properly compacted Control Fill if prepared as described in Site Preparation. Concrete floor slabs constructed on grade can be designed using the modulus of subgrade reaction presented in the following table.

Design Recommendations

ITEM DESCRIPTION

Modulus of subgrade reaction1 200 pounds per square inch per inch (psi/in) for properly compacted point loading conditions

1. Modulus of subgrade reaction value is for a 1 ft by 1 ft area and should be adjusted for appropriate size.

If a conventional slab and shallow foundation are used, the structural engineer should design the slab to limit differential movements between the slab and foundation to reduce the possibility of floor slab cracking. Where appropriate, saw-cut control joints and expansion joints should be placed in the slab to help control the location and extent of cracking. For additional recommendations refer to the ACI Design Manual. Floor slab subgrade should be compacted to 100% of its modified Proctor maximum dry density (ASTM D1557).

The use of a vapor retarder should be considered beneath concrete slabs on grade that will be covered with wood, tile, carpet or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier.

Floor Slab Construction Considerations

On most project sites, the site grading is generally accomplished early in the construction phase.

However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, rainfall, etc. As a result, the floor slab subgrade may not be suitable for placement of concrete, and corrective action would be required.

We recommend the area underlying the floor slab be rough graded and then proofrolled with a tandem axle dump truck while being observed by the geotechnical engineer so as to achieve final grade. Areas where unsuitable conditions are located should be repaired by removing and replacing the affected material with properly compacted fill. All floor slab subgrade areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to placement of the subbase and concrete. Any trenches should be backfilled with Controlled Fill as described in the Material Types section in this report.

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GENERAL COMMENTS

Our work is conducted with the understanding of the project as described in the proposal, and will incorporate collaboration with the design team prior to completing our services. Terracon has requested verification of all stated assumptions. Revision of our understanding to reflect actual conditions important to our work will be based on these verifications and will be reflected in the final report. The design team should collaborate with Terracon to confirm these assumptions.

The design team should also collaborate with Terracon to prepare the final design plans and specifications. This facilitates the incorporation of our opinions related to implementation of our geotechnical recommendations.

Our analysis and opinions are based upon our understanding of the geotechnical conditions in the area, the data obtained from the site exploration performed and from our understanding of the project. Variations will occur between exploration point locations, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. So, Terracon should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

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

Our services and any correspondence are intended for the exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made.

Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for that specific purposes to obtain the specific level of detail necessary for costing. Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. In the event that changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

ATTACHM ENTS

ATTACHMENTS

SITE LOC ATION AND EXPLOR ATION PLAN S

SITE LOCATION AND EXPLORATION PLANS

TOPOGRAPHIC MAP IMAGE COURTESY OF

THE U.S. GEOLOGICAL SURVEY

QUADRANGLES INCLUDE: LADSON, SC

(1/1/1979).

SITE LOCATION

Joint Base Charleston Cryogenics Facility North Charleston, SC

1450 Fifth St W

North Charleston, SC 29405-2326

EN175203

DIAGRAM IS FOR GENERAL LOCATION ONLY,

AND IS NOT INTENDED FOR CONSTRUCTION

PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

L. Van Brunt

W. Wright

W. Wright

L. Van Brunt Project No.

File Name:

Date:

SITE

1”=2,000’ Scale:

EXPLORATION PLAN

1450 Fifth St W

North Charleston, SC 29405-2326

EN175203AERIAL PHOTOGRAPHY PROVIDED BY

MICROSOFT BING MAPS

Joint Base Charleston Cryogenics Facility North Charleston, SCDIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION

PURPOSES

Project Manager:

Drawn by:

Checked by:

Approved by:

L. Van Brunt

W. Wright

W. Wright

L. Van Brunt Scale:

Project No.

File Name:

Date:

AS SHOWN

EXPLOR ATION RESULTS

IN SITU TEST RESULTS

SITE: Long St North Charleston, SC

4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt 6 Sands - clean sand to silty sand

1 Sensitive, fine grained 2 Organic soils - clay 3 Clay - silty clay to clay

CPT LOG NO. SCPT-1

CLIENT: CEMS Engineering, Inc.

Summerville, SC

Project No.: EN175203

PROJECT: See Exhibit A-2JBC Cryogenics Facility

Depth (ft)

7 Gravelly sand to dense sand 8 Very stiff sand to clayey sand 9 Very stiff fine grained

CPT Completed: 10/23/2017

Operator: R. Frazier

Auger anchors used as reaction force.

CPT sensor calibration reports available upon request.

TEST LOCATION:

Latitude:

Longitude:

32.9111° -80.0506°

Depth (ft)

1450 Fifth St W North Charleston, SC

CPT Started: 10/23/2017

Rig: Pagani TG73-200

Probe no. 4815 with net area ratio of 0.88 U2 pore pressure transducer location Manufactured by Geotech A.B.; calibrated 2/20/2017 Tip and sleeve areas of 10 cm2 and 150 cm2

Ring friction reducer with O.D. of 1.875 in

3.5 ft estimated water depth (used in normalizations and correlations;

see Appendix C)

WATER LEVEL OBSERVATION

3 6 9 12 Tip Resistance, qt

(tsf)

30 60 90 120

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

C

P T

R E

P O

R T

E N

J

B C

C R

Y O

G E

N

IC

S F

A .G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

0/

/1

Friction Ratio, Fr

2 4 6

Material Description

Normalized CPT Soil Behavior Type 1 2 3 4 5 6 7 8

Hydrostatic Pressure

Pore Pressure, u2

(tsf)

-1 0 1 2 3 4 5 6 7

0.12 0.24 0.36 0.48 Sleeve Friction, fs

(tsf)

1.2 2.4 3.6 4.8

Shear Wave Velocity, Vs

(ft/sec)

650 1300 1950 2600

CPT Terminated at 45.9 Feet

SITE: Long St North Charleston, SC

4 Silt mixtures - clayey silt to silty clay 5 Sand mixtures - silty sand to sandy silt 6 Sands - clean sand to silty sand

1 Sensitive, fine grained 2 Organic soils - clay 3 Clay - silty clay to clay

CPT LOG NO. CPT-2

CLIENT: CEMS Engineering, Inc.

Summerville, SC

Project No.: EN175203

PROJECT: See Exhibit A-2JBC Cryogenics Facility

Depth (ft)

7 Gravelly sand to dense sand 8 Very stiff sand to clayey sand 9 Very stiff fine grained

CPT Completed: 10/23/2017

Operator: R. Frazier

Auger anchors used as reaction force.

CPT sensor calibration reports available upon request.

TEST LOCATION:

Latitude:

Longitude:

32.9108° -80.0506°

Depth (ft)

1450 Fifth St W North Charleston, SC

CPT Started: 10/23/2017

Rig: Pagani TG73-200

Probe no. 4815 with net area ratio of 0.88 U2 pore pressure transducer location Manufactured by Geotech A.B.; calibrated 2/20/2017 Tip and sleeve areas of 10 cm2 and 150 cm2

Ring friction reducer with O.D. of 1.875 in

3.5 ft estimated water depth (used in normalizations and correlations;

see Appendix C)

WATER LEVEL OBSERVATION

3 6 9 12 Tip Resistance, qt

(tsf)

30 60 90 120

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

C

T

R E

P O

R T

E N

J

B C

C R

Y O

G E

N

IC

S F

A .G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

0/

/1

Friction Ratio, Fr

2 4 6

Material Description

Normalized CPT Soil Behavior Type 1 2 3 4 5 6 7 8

Hydrostatic Pressure

Pore Pressure, u2

(tsf)

-1 0 1 2 3 4 5 6 7

0.12 0.24 0.36 0.48 Sleeve Friction, fs

(tsf)

1.2 2.4 3.6 4.8

CPT Terminated at 42.9 Feet

0.5

4.0

TOPSOIL, black

SILTY SAND (SM), black to brown

Boring Terminated at 4 Feet

G R

A P

H

IC

L O

G

Hammer Type: N/AStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

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D F

R O

M O

R

IG

IN

A

L R

E P

O R

G

E O

S M

A R

T L

O G

-N O

W E

LL

E

N

J B

C C

R Y

O G

E N

IC

S

F A

.G P

J T

E R

R A

C O

N _D

A T

A T

E M

P

LA

T E

.G D

T

0/

/1

Long St North Charleston, SC

SITE:

Advancement Method:

Hand Auger

Abandonment Method:

Boring backfilled with auger cuttings upon completion.

Notes:

Project No.: EN175203

Drill Rig: Pagani TG73-200

Boring Started: 10/23/2017

BORING LOG NO. HAB AT SCPT-1

CEMS Engineering, Inc.CLIENT:

Summerville, SC

Driller: R. Frazier

Boring Completed: 10/23/2017

PROJECT: JBC Cryogenics Facility

1450 Fifth St W North Charleston, SC

Groundwater not encountered

WATER LEVEL OBSERVATIONS

DEPTH

LOCATION

Latitude: 32.9111° Longitude: -80.0506°

See Exhibit A-2

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

S A

M P

LE

T

Y

0.4

4.0

TOPSOIL, black

SILTY SAND (SM), black to tan

Boring Terminated at 4 Feet

G R

A P

H

IC

L O

G

Hammer Type: N/AStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

G

O

S M

A R

T L

O G

-N O

W E

LL

E

N

J B

C C

R Y

O G

E N

IC

S

F A

.G P

J T

E R

R A

C O

N _D

A T

A T

E M

P

LA

T E

.G D

T

0/

/1

Long St North Charleston, SC

SITE:

Advancement Method:

Hand Auger

Abandonment Method:

Boring backfilled with auger cuttings upon completion.

Notes:

Project No.: EN175203

Drill Rig: Pagani TG73-200

Boring Started: 10/23/2017

BORING LOG NO. HAB AT CPT-2

CEMS Engineering, Inc.CLIENT:

Summerville, SC

Driller: R. Frazier

Boring Completed: 10/23/2017

PROJECT: JBC Cryogenics Facility

1450 Fifth St W North Charleston, SC

Groundwater not encountered

WATER LEVEL OBSERVATIONS

DEPTH

LOCATION

Latitude: 32.9108° Longitude: -80.0506°

See Exhibit A-2

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

S A

M P

LE

T

Y

SUPPORTING INFORM ATION

SUPPORTING INFORMATION

Unit Weight, RELATIVE RELIABILITY OF CPT CORRELATIONS

WATER LEVEL

REPORTED PARAMETERS

7 Gravelly sand to dense sand

8 Very stiff sand to clayey sand

9 Very stiff fine grained

1 Sensitive, fine grained

2 Organic soils - clay

3 Clay - silty clay to clay

4 Silt mixtures - clayey silt to silty clay

5 Sand mixtures - silty sand to sandy silt

6 Sands - clean sand to silty sand

N O

R M

A

LI

Z E

D C

O N

E R

E S

IS

T

A N

C E q t a tm

10.1 10

Relative Density, Dr

NORMALIZED FRICTION RATIO, Fr atm = atmospheric pressure = 101 kPa = 1.05 tsf

REFERENCES

CONE PENETRATION SOIL BEHAVIOR TYPE

CPT GENERAL NOTES

Small Strain Modulus, G0* and Elastic Modulus, Es*

Sensitivity, St

Undrained Shear Strength, Su

* improves with seismic Vs measurements

Reliability of CPT-predicted N60 values as commonly measured by the Standard Penetration Test (SPT) is not provided due to the inherent inaccuracy associated with the SPT test procedure.

DESCRIPTION OF MEASUREMENTS

AND CALIBRATIONS

DESCRIPTION OF GEOTECHNICAL CORRELATIONS

Over Consolidation Ratio, OCR

Constrained Modulus, M

Permeability, k

Effective Friction Angle, '

Low Reliability High Reliability

Kulhawy, F.H., Mayne, P.W., (1997). "Manual on Estimating Soil Properties for Foundation Design," Electric Power Research Institute, Palo Alto, CA.

Mayne, P.W., (2013). "Geotechnical Site Exploration in the Year 2013," Georgia Institue of Technology, Atlanta, GA.

Robertson, P.K., Cabal, K.L. (2012). "Guide to Cone Penetration Testing for Geotechnical Engineering," Signal Hill, CA.

Schmertmann, J.H., (1970). "Static Cone to Compute Static Settlement over Sand," Journal of the Soil Mechanics and Foundations Division, 96(SM3), 1011-1043.

CPT logs as provided, at a minimum, report the data as required by ASTM D5778 and ASTM D7400 (if applicable). This minimum data include qt, fs, and u. Other correlated parameters may also be provided. These other correlated parameters are interpretations of the measured data based upon published and reliable references, but they do not necessarily represent the actual values that would be derived from direct testing to determine the various parameters.

To this end, more than one correlation to a given parameter may be provided. The following chart illustrates estimates of reliability associated with correlated parameters based upon the literature referenced below.

Small Strain Shear Modulus, G0

G0 (1) = Vs

G0 (2) = 0.015 x 10(0.55Ic + 1.68)(qt - V0)

Corrected Tip Resistance, qt

Cone resistance corrected for porewater and net area ratio effects qt = qc + u2(1 - a)

SPT N60

N60 = (qt/atm) / 10(1.1268 - 0.2817Ic)

Pore Pressure, u Pore pressure measured during penetration u1 - sensor on the face of the cone u2 - sensor on the shoulder (more common)

Typically, silts and clays have high Fr values and generate large excess penetration porewater pressures; sands have lower Fr's and do not generate excess penetration porewater pressures.

The adjacent graph (Robertson et al.) presents the soil behavior type correlation used for the logs. This normalized SBT chart, generally considered the most reliable, does not use pore pressure to determine SBT due to its lack of repeatability in onshore CPTs.

The estimated stratigraphic profiles included in the CPT logs are based on relationships between corrected tip resistance (qt), friction resistance (fs), and porewater pressure (u2). The normalized friction ratio (Fr) is used to classify the soil behavior type.

Hydraulic Conductivity, k For 1.0 < Ic < 3.27 k = 10(0.952 - 3.04Ic)

For 3.27 < Ic < 4.0 k = 10(-4.52 - 1.37Ic)

Relative Density, Dr

Dr = (Qtn / 350)0.5 x 100

Unit Weight, = (0.27[log(Fr)]+0.36[log(qt/atm)]+1.236) x water

V0 is taken as the incremental sum of the unit weights

Effective Friction Angle, ' ' (1) = tan-1(0.373[log(qt/ 'V0) + 0.29]) ' (2) = 17.6 + 11[log(Qtn)]

Undrained Shear Strength, Su

Su = Qtn x 'V0/Nkt

Nkt is a soil-specific factor (shown on Su plot)

Over Consolidation Ratio, OCR OCR (1) = 0.25(Qtn)

1.25

OCR (2) = 0.33(Qtn)

Soil Behavior Type Index, Ic Ic = [(3.47 - log(Qtn)

2 + (log(Fr) + 1.22)2]0.5

Clay and Silt

Sand

The groundwater level at the CPT location is used to normalize the measurements for vertical overburden pressures and as a result influences the normalized soil behavior type classification and correlated soil parameters. The water level may either be "measured" or "estimated:"

Measured - Depth to water directly measured in the field Estimated - Depth to water interpolated by the practitioner using pore pressure measurements in coarse grained soils and known site conditions While groundwater levels displayed as "measured" more accurately represent site conditions at the time of testing than those "estimated," in either case the groundwater should be further defined prior to construction as groundwater level variations will occur over time.

Sleeve Friction, fs Frictional force acting on the sleeve divided by its surface area

Sand Clay and Silt

Sand

To be reported per ASTM D7400, if collected:

Shear Wave Velocity, Vs

Measured in a Seismic CPT and provides direct measure of soil stiffness

Normalized Friction Ratio, Fr

The ratio as a percentage of fs to qt, accounting for overburden pressure

Uncorrected Tip Resistance, qc

Measured force acting on the cone divided by the cone's projected area

Where a is the net area ratio, a lab calibration of the cone typically between 0.70 and 0.85

To be reported per ASTM D5778:

Clay and Silt

Clay and Silt

Sand Clay and Silt

Sand

Sand Clay and Silt

Clay and Silt

Sensitivity, St

St = (qt - V0/Nkt) x (1/fs) Constrained Modulus, M M = M(qt - V0) For Ic > 2.2 (fine-grained soils)

M = Qtn with maximum of 14 For Ic < 2.2 (coarse-grained soils)

M = 0.0188 x 10(0.55Ic + 1.68)

Clay and Silt

Sand

Normalized Tip Resistance, Qtn

Qtn = ((qt - V0)/Pa)(Pa/ 'V0) n n = 0.381(Ic) + 0.05( 'V0/Pa) - 0.15

Elastic Modulus, Es (assumes q/qultimate ~ 0.3, i.e. FS = 3) Es (1) = 2.6 G0 where = 0.56 - 0.33logQtn,clean sand

Es (2) = G0

Es (3) = 0.015 x 10(0.55Ic + 1.68)(qt - V0) Es (4) = 2.5qt

UNIFIED SOIL CLASSIFICATION SYSTEM

Port Royal Hilton Head Timeshare ■ Hilton Head Island, South Carolina

October 13, 2017 ■ Terracon Project No. EN175218

UNIFIED SOIL C LASSIFIC AT ION SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A

Soil Classification

Group

Symbol Group Name B

Coarse-Grained Soils:

More than 50% retained on No. 200 sieve

Gravels:

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

Clean Gravels:

Less than 5% fines C

Cu 4 and 1 Cc 3 E GW Well-graded gravel F

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

Gravels with Fines:

More than 12% fines C

Fines classify as ML or MH GM Silty gravel F,G,H

Fines classify as CL or CH GC Clayey gravel F,G,H

Sands:

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

Clean Sands:

Less than 5% fines D

Cu 6 and 1 Cc 3 E SW Well-graded sand I

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

Sands with Fines:

More than 12% fines D

Fines classify as ML or MH SM Silty sand G,H,I

Fines classify as CL or CH SC Clayey sand G,H,I

Fine-Grained Soils:

50% or more passes the

No. 200 sieve

Silts and Clays:

Liquid limit less than 50

Inorganic:

PI 7 and plots on or above “A” line

J

CL Lean clay K,L,M

PI 4 or plots below “A” line J ML Silt K,L,M

Organic:

Liquid limit - oven dried

0.75 OL

Organic clay K,L,M,N

Liquid limit - not dried Organic silt K,L,M,O

Silts and Clays:

Liquid limit 50 or more

Inorganic:

PI plots on or above “A” line CH Fat clay K,L,M

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

Organic:

Liquid limit - oven dried

0.75 OH

Organic clay K,L,M,P

Liquid limit - not dried Organic silt K,L,M,Q

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

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

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

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

E Cu = D60/D10 Cc =

DxD

)(D

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

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

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

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

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

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

L If soil contains 30% plus No. 200 predominantly sand, add “sandy” to group name.

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

“gravelly” to group name.

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

O PI 4 or plots below “A” line.

P PI plots on or above “A” line.

Q PI plots below “A” line.