1614720_P1035 Geotechnical and Geophysical Reports.pdf

REPORT OF

SUBSURFACE

EXPLORATION

AND

GEOTECHNICAL

ENGINEERING

SERVICES

P-1035 Corrosion Control and Paint Facility

Norfolk, Virginia

G E T Project No: VB19-292G

June 25, 2020

PREPARED FOR:

5465 Greenwich Road • Virginia Beach, VA 23462

Phone: (757)-518-1703 www.getsolutionsinc.com

5465 Greenwich Road · Virginia Beach, VA 23462 · Phone: (757)-518-1703 · Fax: (757)-518-1704 info@getsolutionsinc.com

June 25, 2020

TO: Clark Nexsen 4525 Main Street Suite 1400 Virginia Beach, VA 23462

Attn: Ms. LouAnn Fornataro, PE

RE: Report of Subsurface Exploration and Geotechnical Engineering Services P-1035 Corrosion Control and Paint Facility Contract: N40085-19-D-9041 Naval Station Norfolk, Norfolk, Virginia G E T Project No: VB19-292G

Dear Ms. Fornataro:

In compliance with your instructions, we have completed our Subsurface Exploration and Geotechnical Engineering Services for the above referenced project. The results of this study, together with our recommendations, are presented in this report.

Often, because of design and construction details that occur on a project, questions arise concerning subsurface conditions. G E T Solutions, Inc. would be pleased to continue its role as Geotechnical Engineer during the project implementation.

We appreciate the opportunity to work with you on this project. We trust that the information contained herein meets your immediate need, and should you have any questions or if we could be of further assistance, please do not hesitate to contact us.

Respectfully Submitted, G E T Solutions, Inc.

Kenan J. Beninati Project Engineer

Bruce R. Spiro, P.E.

Principal Engineer VA Lic. No. 015791

Copies: (1) Client

TABLE OF CONTENTS

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020 P-1035 Corrosion Control and Paint Facility Contract: N40085-19-D-9041 Naval Station Norfolk, Norfolk, Virginia G E T Project No: VB19-292G

EXECUTIVE SUMMAY ............................................................................................................... i

1.0 PROJECT INFORMATION

1.1 Project Authorization

1.2 Project Location and Description

1.3 Project Construction Description

1.4 Purpose and Scope of Services

2.0 FIELD AND LABORATORY PROCEDURES

2.1 Field Exploration

2.2 Field and Laboratory Testing

2.2.1 Soil Classification and Index Testing

2.2.2 Bulk Soil Sample Testing

2.2.3 In-Situ Permeability Testing

2.2.4 Consolidation Testing

2.2.5 Chemical Analysis

3.0 SITE AND SUBSURFACE CONDITIONS

3.1 Site Geology

3.2 Recent Land Reclamation and Site Development

3.3 Existing Pavement Conditions

3.4 Subsurface Soil Conditions

3.5 Initial Test Pit Excavation Results

3.6 Geophysical Study and Test Pit Verification – Scope Mod001

3.7 Groundwater Discussion

4.0 EVALUATIONS AND RECOMMENDATIONS

4.1 Clearing and Grading

4.2 Subgrade Preparation

4.3 Structural Fill and Placement

4.4 Suitability of On-Site Soils

4.5 Settlement Discussion – Grade Supported Elements

4.6 Slab-on-Grade Design

4.7 Shallow Foundation Discussion

4.7.1 Ground Improvement/Replacement Techniques

4.8 Deep Foundation Design Recommendations

4.8.1 Pile Capacity Recommendations

4.8.2 Lateral Capacity Recommendations

4.8.3 Pile Group Settlement

4.8.4 Test Pile Program

4.8.5 Pile Installation Monitoring – Augercast Piles

4.8.6 Dynamic Testing – Driven Piles

4.8.7 Production Pile/Acceptance Criteria – Driven Piles

4.8.8 Allowable Driving Stresses – Driven Piles

4.8.9 Hammer Types and Energies – Driven Piles

4.8.10 Adjacent Structures – Driven Piles

4.9 Below Grade Soil Parameters

4.10 On-site Shrink/Swell Properties

4.11 Seismic Evaluation

4.12 Liquefaction Potential

4.13 Pavement Design

TABLE OF CONTENTS

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041 Naval Station Norfolk, Norfolk, Virginia

5.0 CONSTRUCTION CONSIDERATIONS

5.1 Anticipated Excavation Characteristics

5.2 Excavation Stability

5.3 Dewatering

5.4 Site Utility Installation

5.5 Structure Protection and Monitoring

5.6 Construction Monitoring and Inspections

6.0 REPORT LIMITATIONS

APPENDIX I SITE VICINITY MAP (USGS 7.5 MINUTE SERIES)

APPENDIX II SUBSURFACE INVESTIGATION LOCATION PLAN

APPENDIX III SOIL CLASSIFICATION SYSTEM

APPENDIX IV SOIL TEST BORING LOGS

APPENDIX V GENERALIZED SOIL PROFILE

APPENDIX VI S&ME CPTu AND DMT REPORT

APPENDIX VII SUMMARY OF LABORATORY RESULTS

APPENDIX VIII CBR TEST RESULTS

APPENDIX IX SHELBY TUBE CLASSIFICATION LOG SHEETS

APPENDIX X CONSOLIDATION TEST RESULTS

APPENDIX XI INFILTRATION TEST RESULTS

APPENDIX XII ENVIRONMENTAL ANALYTICAL RESULTS

APPENDIX XIII PAVEMENT SECTION COMPOSITION LOGS

APPENDIX XIV INITIAL TEST PIT PHOTOGRAPHIC DOCUMENTATION

APPENDIX XV SETTLEMENT CALCULATIONS

APPENDIX XVI PILE CAPACITY CALCULATIONS

APPENDIX XVII LPILE ANALYSES

APPENDIX XVIII SEISMIC ANALYSIS

APPENDIX XIX LIQUEFACTION POTENTIAL

APPENDIX XX PAVEMENT SECTION ANALYSIS (PCASE)

APPENDIX XXI HISTORICAL SITE INFORMATION

APPENDIX XXII GEOPHYSICAL STUDY REPORT

APPENDIX XXIII FOLLOW UP TEST PIT PHOTOGRAPHIC DOCUMENTATION

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041 i

EXECUTIVE SUMMAY

The project site is located within Naval Station Norfolk in the City of Norfolk, Virginia.

Specifically, the site is bounded by Bellinger Boulevard to the south, Third Avenue to the west and the concrete apron serving Building V-147 to the northeast. The site for the new facility is currently occupied by asphalt pavement parking lots and open space created by the demolition of former Building V-57. The site has reported elevations of roughly 5.5 to 9.5 feet (NAVD88). Based on a historical review, the site appears to be comprised of reclaimed land. In addition, the site formerly contained Building V-57 which has since been demolished. At the time of the demolition it was reported that the deep foundation system was removed, and the wooden piles left in place below grade. Our investigation revealed components of the deep foundation system and other infrastructures of Building V-57 that were reported to have been removed to still be in place. The proposed construction at this site will consist of building a facility composed of three separate high hanger bays along with administrative and support spaces. In addition to the main structure, five turf areas, a concrete pavement loading area, and other related infrastructure will be constructed. The facility will be roughly 53,500 square feet in gross area. The finished floor elevation (FFE) is expected to be raised to 10.00-ft (NAVD88). As indicated in the basis-of-design documents, portions of the site currently are within the 100-year flood zone based on current FEMA flood hazard data therefore an increase in site grades are necessary. This increase to site grades may cause settlement of the underlying Uncontrolled FILL materials and such cannot be accurately quantified due to the inconsistent nature of these materials but can be expected to range up to approximately 7 inches. This settlement may potentially cause connection issues to grade bearing members such as pavement, utilities, sidewalks, etc. Based on information provided by the structural engineer and review of the Statement of Architectural and Engineering Services (SAES), the maximum truss reaction is expected to be 110 kips and the maximum Concrete wall load is expected to be 10 klf. The first-floor slab will be supporting live loads of ranging between 100 and 300 psf.

Our field exploration program included:

• Four (4) 100-foot deep Standard Penetration Test (SPT) borings (designated as 19SPT-01 thru 19SPT-04) drilled within the proposed structure’s footprint.

• Three (3) 10-foot deep SPT borings (designated as 19CBR-01 thru 19-CBR-03) drilled within the proposed pavement areas. Also, one bulk soil sample was collected from each of the California Bearing Ratio (CBR) boring locations.

• Three (3) 15-foot deep SPT borings (designated as 19BMP-01 thru 19BMP-03) drilled within proposed BMP areas. Temporary groundwater monitoring wells were installed at each of these locations and two (2) were completed with manhole covers.

• Three (3) infiltration tests were performed at boring locations 19BMP-01 thru 19BMP-03 at a depth of 2 feet above the Estimated Seasonal High Water Table (ESHWT) as directed by the civil engineer.

• Three (3) 60- to 100-foot deep Cone Penetration Test (CPTu) probes (designated as 19CPT-01 thru 19CPT-03) advanced within the proposed structure’s footprint. Down-hole shear wave velocity measurements were performed at 1-meter intervals to the termination depth at location 19CPT-02. (All were attempted to 100-ft)

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041 ii

• One (1) 84-foot deep Dilatometer (DMT) probe (designated as 19DMT-01) advanced within the proposed structure’s footprint. (Attempted to 100-ft)

• Six (6) test pits excavated where former building foundations and utilities were expected.

Remains of the concrete components of the deep foundation and utilities were found in 4 out of 6 excavations.

• Review of historical site data.

Based on the full extent of the field investigations, it is concluded that the site contains large amounts of Uncontrolled FILL reaching depths up to approximately 30-feet, which are underlain by compressible Fat CLAY (CH) and organic deposits. The subsurface soil profile is detailed in Section 3.4 of this report.

The initial groundwater-level was measured to occur at depths ranging from 4.5 to 6 feet below existing site grades at all of the boring locations. The boreholes were backfilled upon completion for safety considerations. Seasonal groundwater fluctuations of ± 2 are common in the project’s area; however, greater fluctuations have been documented. Temporary groundwater monitoring wells were installed at boring locations 19BMP-01 thru 19BMP-03 to document stabilized groundwater levels. These stabilized groundwater levels were measured to occur at depths ranging from 4.5 to 5.3 feet below existing site grades (corresponding to elevations of 2.4 to 3.1 feet (NAVD 88)).

An ESHWT was established using current and historical groundwater monitoring data within the vicinity of the project site. The ESHWT at the site ranges from a depth of 3.1 to 3.9 feet (elevations of 3.8 to 4.5 feet (NAVD 88)), per the results of this investigation. Further information about the groundwater level is provided in Section 3.7.

The following evaluations and recommendations were developed based on our field exploration and laboratory-testing program:

� The proposed construction areas should be cleared by means of demolishing and removing any existing structures, associated buried foundations and utilities, as well as the topsoil, concrete, asphalt and any other unsuitable materials that would prevent the establishment of a stable working platform for construction equipment (particularly pile installation equipment). It is recommended that the clearing operations extend laterally at least 5 feet beyond the perimeter of the proposed construction area, where feasible.

� A field testing program is recommended during earthwork construction activities for building and pavement areas. This testing program should include at a minimum, proofrolling and subgrade load testing, test pits, compaction testing, foundation excavation inspection, and probing.

� It is recommended that the proposed Corrosion Control and Paint Facility structure be supported on a deep foundation system. Pile design characteristics and capacity analyses for 14-inch diameter Augercast piles, 12-inch Square Precast Prestressed Concrete (SPPC) piles or 12-inch Steel H piles are provided in Section 4.8 of the report.

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Contract: N40085-19-D-9041 iii

� It is recommended that the ground floor be structurally supported on the deep foundation system discussed in Section 4.8.

� Expected post construction settlements for the deep foundation system are evaluated to fall within acceptable limits after proper subgrade improvements and installation procedures.

� Any increases to site grades may cause settlement of the underlying

Uncontrolled FILL materials and soft cohesive soils. Any such settlements cannot be accurately quantified due to the inconsistent nature of these materials but can be expected to range up to approximately 7 inches. This settlement may potentially cause connection issues to grade bearing members such as pavement, utilities, sidewalks, etc.

� The shallow subsurface Uncontrolled FILL materials encountered at the boring locations do not appear to meet the criteria recommended in this report for reuse as structural fill; however, these soils may be used as fill in green areas. Granular soils (SP, SP-SM) recovered at the boring locations could potentially qualify as structural backfill material. However, because the soils are not consistent across the project site, care must be taken to segregate the SAND (SP, SP-SM) soils from the fill debris, clayey and silty SAND (SC, SM) soils.

� The pavement sections for the parking bay and storage area should be designed as recommended in Section 4.14 of this report. The project’s budget should include an allowance for subgrade improvements.

� Based on the information obtained from the Cone Penetration Test (CPTu) that was provided in the S&ME Inc. report, and our experience within the vicinity of the project site, it is recommended that this site be classified as a Site Class “E” in accordance with Table 20.3-1 of ASCE 7-10 as referenced by the 2015 International Building Code (IBC).

� Chemical Evaluation of the soil and liquid drilling spoils as well as the soil composite samples. Results are currently pending. Discussion provided in Section 2.2.5.

� Corrosivity Evaluation of the two (2) composite soil samples concluded to not be corrosive material. Discussion provided in Section 2.2.5.

This summary briefly discusses some of the major topics mentioned in the attached report.

Accordingly, this report should be read in its entirety to thoroughly evaluate the contents.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

1.0 PROJECT INFORMATION

1.1 Project Authorization

G E T Solutions, Inc. has completed our subsurface exploration and geotechnical engineering services for the proposed P-1035 Corrosion Control and Paint Facility project located at Naval Station Norfolk (NSN) in the City of Norfolk, Virginia. The geotechnical engineering services were conducted in general accordance with the scope presented in G E T Proposal No. PVB19- 428G dated June 24, 2019. Authorization to proceed with our services was received from the client on September 24, 2019 in the form of electronic mail.

1.2 Project Location and Description

The project site is located within Naval Station Norfolk in the City of Norfolk, Virginia.

Specifically, the site is bounded by Bellinger Boulevard to the south, Third Avenue to the west and the concrete apron serving Building V-147 to the northeast. The site for the new facility is currently occupied by asphalt pavement parking lots and open space created by the demolition of former Building V-57, a former Laundromat. Record drawings for the demolition indicate the slabs, pile caps and grade beams were to be removed and the timber piles were to be cut off below grade and abandoned in place. However during site investigations, concrete remains of the former foundation including pile caps and grade beams were discovered. The project site has reported elevations of roughly 5.5 to 9.5 feet (NAVD88). The project site is within a Land Use Control (LUC) boundary of Environmental Restoration (ER) Site 20. Review of historical aerial photographs and United States Geological Survey (USGS) topographic maps indicates site reclamation and development dating back to the 1920s. Prior to that timeframe, the site location appears to be situated within the bounds of former Bush Creek. Manmade land formed by filling former Bush Creek on Naval Station Norfolk property has a documented history of ground settlement problems. The project site is also located within the boundary of IRP Site 20. A site vicinity map is presented in Appendix I and in Figure 1.

Figure 1: Site Vicinity Map

Source: USGS, Norfolk North Quadrangle, VA, 7.5 Minute Series (2016)

Project Site

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

1.3 Project Construction Description

The proposed construction at this site will consist of building a facility composed of three separate high hanger bays along with administrative and support spaces. In addition to the main structure, five turf areas, a concrete pavement loading area, and other related infrastructure will be constructed. The facility will be roughly 53,500 square feet in gross area. Based on information provided by the Design Narrative/Site Engineering Investigation (SEI) the building structure and the ground floor slabs are expected to be supported by a deep foundation system.

The structure will be constructed of load-bearing precast concrete wall panels supporting a steel framed roof and load-bearing CMU walls for the attached support spaces. The structural loads were provided by the structural engineer. The wall loads are expected to range from 6 to 10 kips/ft.

Wall supported truss loads vary from 20 kips in the Paint Bay hanger to 110 kips in the Wash Bay hanger. The floor slab will be supporting live loads of 300 psf in the Wash Bay, 200 psf in the Paint Bay, 150 psf in the Equipment Rooms and 100 psf elsewhere.

As indicated in the basis-of-design documents, portions of the site currently are within the 100-year flood zone based on current FEMA flood hazard data. The site will be graded to support a finished floor elevation (FFE) of 10.00-ft (NAVD88). This increase to site grades is expected to cause settlement of the underlying Uncontrolled FILL materials. These settlements cannot be accurately quantified due to the inconsistent nature of these materials but can be expected to range up to approximately 7 inches. This settlement may potentially cause connection issues to grade bearing members such as pavement, utilities, sidewalks, etc.

If any of the noted information is incorrect or has changed, please inform G E T Solutions, Inc. so that we may amend the recommendations presented in this report, if appropriate.

1.4 Purpose and Scope of Services

The purpose of this study was to obtain information on the general subsurface conditions at the proposed project site. The subsurface conditions encountered were then evaluated with respect to the available project characteristics. In this regard, engineering assessments for the following items were formulated:

1. General assessment of the soils revealed by the borings, probes and test pits performed at the proposed development.

2. General location and description of potentially deleterious material encountered in the borings that may interfere with construction progress or structure performance, including existing fills or surficial/subsurface organics.

3. Soil subgrade preparation, including stripping, grading and compaction.

Engineering criteria for placement and compaction of approved structural fill material.

4. Construction considerations for subgrade preparation and pile installation.

5. Evaluation of the on-site soils for re-use as structural fill.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

6. Determine pertinent Best Management Practices (BMP) design criteria and information regarding the groundwater conditions within the project site limits based on the data collected from the temporary groundwater monitoring wells and infiltration testing.

7. Feasibility of utilizing shallow foundation systems to for support of the proposed structure and slab on grade design. Evaluate ground improvement/replacement measures to permit the use of shallow foundation systems.

8. Recommendations for a deep foundation system for support of the proposed structure and structural slab. Design parameters required for the foundation system, including pile type and length, design parameters, testing, and installation criteria.

9. Considerations for preloading or surcharging to mitigate excessive consolidation settlement.

10. Pavement design recommendations for light and/or heavy duty pavement based on the field exploration activities, laboratory testing and our experience with similar soil conditions.

11. Site seismic classification in accordance with Table 20.3-1 of ASCE 7-10 as referenced by the 2015 International Building Code (IBC).

12. Assessment of the soils’ resistance against liquefaction.

13. Assessment of the shallow subsurface soils’ expansive properties in accordance with the 2015 International Building Code.

14. Presentation of soil sample chemical analytical results and soil corrosivity characteristics and properties.

Other than the defined scope of work, the scope of services did not include any additional environmental assessment for determining the presence or absence of wetlands or hazardous or toxic material in the bedrock, surface water, groundwater or air, on or below or around this site.

2.0 FIELD AND LABORATORY PROCEDURES

2.1 Field Exploration

In order to explore the general subsurface soil types and to aid in developing associated foundation design parameters, the following exploration program was performed:

• Four (4) 100-foot deep Standard Penetration Test (SPT) borings (designated as 19SPT-01 thru 19SPT-04) drilled within the proposed structure’s footprint.

• Three (3) 10-foot deep SPT borings (designated as 19CBR-01 thru 19-CBR-03) drilled within the proposed pavement areas. Also, one bulk soil sample was collected from each of the California Bearing Ratio (CBR) boring locations.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

• Three (3) 15-foot deep SPT borings (designated as 19BMP-01 thru 19BMP-03) drilled within proposed BMP areas. Additionally, a temporary groundwater monitoring wells were installed at these locations two (2) are complete with manhole covers.

• Three (3) infiltration tests were performed at boring locations 19BMP-01 thru 19BMP-03 at a depth of 2 feet above the Estimated Seasonal High Water Table (ESHWT) determined by the civil engineer.

• Three (3) 60- to 100-foot deep Cone Penetration Test (CPTu) probes (designated as 19CPT-01 thru 19CPT-03) advanced within the proposed structure’s footprint. Down-hole shear wave velocity measurements were performed at 1-meter intervals to the termination depth at location 19CPT-02. (All were attempted to 100-ft)

• One (1) 84-foot deep Dilatometer (DMT) probe (designated as 19DMT-01) advanced within the proposed structure’s footprint. (Attempted to 100-ft)

• Six (6) test pits excavated where former building foundations and utilities were expected.

Remains of the concrete components of the deep foundation and utilities were found in 4 out of 6 excavations.

• Review of historical site data.

The SPT borings were performed with the use of rotary wash “mud” drilling procedures in general accordance with ASTM D 1586. The soil samples were obtained with a standard 1.4-inch I.D., 2-inch O.D., 30-inch long split-spoon sampler. The sampler was driven with blows of a 140 lb. hammer falling 30 inches, using an automatic hammer. The number of blows required to drive the sampler each 6-inch increment of penetration was recorded and is shown on the boring logs. The sum of the second and third penetration increments is termed the SPT N-value (uncorrected for automatic hammer). The tests were performed continuously from the existing ground surface to a depth of 12 feet, and at 5-foot intervals thereafter starting at a depth of 13 feet. A representative portion of each disturbed split-spoon sample was collected with each SPT, placed in a glass jar, sealed, labeled, and returned to our laboratory for review. All soil boring and sampling operations (excluding in-situ testing) were monitored and logged on-site on a full time basis by an appropriately trained geotechnical engineer. All soil cuttings (IDW solids) and decontamination fluids (IDW liquids) were containerized in separate sealable 55-gallon steel drums, properly labelled and temporarily stored on the project site in an area designated by the Activity POC. All boreholes were backfilled upon completion with the cement-bentonite grout mix. Borings that were performed in paved areas were patched with the same surface material that was present at the time.

The monitoring wells were installed using 5.25-inch I.D. hollow stem auger and constructed of 2-inch diameter, Schedule 40 PVC materials. A 10-foot section of 0.010-inch slotted screen was placed in each borehole with casing threaded to the top. An appropriately graded sand/gravel pack was placed around each screen and extended 1 to 2 feet above the top of the screen. A 1- to 2-foot bentonite seal was then placed above each sand/gravel pack and hydrated with potable water. The remainder of each borehole annular space was pumped full of a neat cement grout. The monitoring wells that were installed in paved areas were complete with manhole covers.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

Three (3) relatively undisturbed, 3-inch diameter, thin-walled Shelby tube samples were collected from the boring locations at depths identified in Table I. The Shelby tube samples were obtained by hydraulically pressing a 3-inch outside diameter Shelby tube into the targeted soils using the drill rig.

The tubes were sealed in general accordance with ASTM standards and returned to G E T Solutions, Inc.’s Virginia Beach laboratory for extraction, classification, and consolidation testing (ASTM D 2435) on two (2) of the tubes.

Table I – Schedule of Collected Shelby Tube Samples

Boring ID Depth of Shelby Tube Sample(1)

19SPT-01 25-37 feet

19SPT-03 30-32 feet

19SPT-03 45-47 feet

Note(s): (1) Depth below existing grade.

The CPTu and DMT soundings were advanced and performed by S&ME, Inc. personnel. The CPTu’s were conducted using an integrated electronic piezocone penetrometer and a data acquisition system. The piezocone penetrometers are compression type designs in which the tip and friction sleeve load cells are independent and have separate load capacities. The piezocones use strain gauge load cells for tip and sleeve friction and a strain gauge diaphragm type transducer for recording pore pressure.

The DMT was conducted using a flat dilatometer stainless steel blade with an expandable circular steel membrane mounted flush on one face. The control unit is connected to the blade by a pneumatic-electrical cable running through the rods to the pushing rig. The control unit is used to transmit gas pressure and electrical signals. A compressed gas tank supplies the required pressure to the blade.

The project’s SAES indicated that at a minimum of one (1) of the four (4) CPTu or DMT soundings was to be extended to a depth of 100 feet below existing grade. All soundings were attempted to a depth of 100 feet; however, due to refusal conditions (dense Sand) the CPTu and DMT soundings terminated at shallower depth. The nominal weight of the rig used for this project was 15 tons. The hydraulic thrust capacity of the push frame used for these soundings was in excess of 22 tons. All soundings were conducted by advancing the cone penetrometer/ dilatometer blade and tooling to depths where the CPT rig began to lift off of the ground surface, and physical and mechanical identifiers indicated rod bending/buckling, or deviation of the tooling resulting in excessive bending stress, as assessed by the rig operator.

Shear wave velocity testing (SCPTu) is performed in conjunction with the CPTu in order to collect interval velocities. Vertek's piezocone penetrometers are manufactured with two horizontally active geophones mounted in the body of the cone penetrometer above the cone friction sleeve. The geophones are firmly mounted in an orientation offset 90 degrees from the other. Shear waves are typically generated by using a steel impact hammer horizontally striking a steel beam that is held in place by a normal load. The hammer and beam act as a contact trigger that initiates the recording of the seismic wave traces. An accelerometer is used for measurement of these wave traces. The traces are recorded using an up-hole integrated digital oscilloscope which is part of the SCPTu data acquisition system.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

The subsurface investigation locations were established by the client and G E T Solutions Inc.

and were approved by NAVFAC on October 21, 2019. The boring locations were staked in the field by a representative of G E T Solutions, Inc. with a hand held GPS device and by corroborating the location with easily identifiable landmarks. The borings were denoted with their respective boring name using spray paint for the topographical survey personnel. The approximate boring locations are shown on the attached “Subsurface Investigation Location Plan” provided in Appendix II.

2.2 Field and Laboratory Testing

Soil testing provided by G E T Solutions, Inc. was performed in accordance with American Society for Testing and Materials (ASTM) standards. All soils and materials tests were performed in our AASHTO re:source (formally AMRL) and US Army Corps of Engineers certified Virginia Beach laboratory.

2.2.1 Soil Classification and Index Testing

Representative portions of all soil samples collected during drilling operations were labeled, preserved and transferred to our laboratory in accordance with ASTM D4220 for classification and analysis. Soil descriptions on the boring logs are provided using visual-manual methods in general accordance with ASTM D2488 using the Unified Soil Classification System (USCS).

Soil samples that were selected for index testing were classified in general accordance with ASTM D2487. It should be noted that some variation can be expected between samples classified using the visual-manual procedure (ASTM D2488) and the USCS (ASTM D2487). A summary of the soil classification system is provided in Appendix III.

Representative split-spoon soil samples were selected and subjected to natural moisture, #200 sieve wash, and Atterberg Limits testing in order to support the visual classification. A summary of these laboratory test results are presented in Appendix VII and on the soil test boring logs provided in Appendix IV. Generalized subsurface soil profiles are provided in Appendix V. The comprehensive results of the CPTu, SCPTu and DMT soundings are presented in Appendix VI.

2.2.2 Bulk Soil Sample Testing

The bulk soil sample were returned to our AASHTO re:source certified Virginia Beach laboratory and subjected to Standard Proctor and CBR testing in accordance with ASTM D698 and D1883, respectively. The CBR samples were adjusted to wet of optimum and compacted to approximately 95% maximum dry density at 0-3% above optimum moisture content and evaluated after a soaking period of four days utilizing a 15-pound surcharge weight. This method as specified by NAVFAC via SAES. The bulk samples were collected from a depth of 1 to 3 feet below the existing grade as specified by the project specific SAES and approved by the Civil Engineer.

The stress-strain curves were plotted for each specimen. If necessary, the stress-strain curves were corrected by adjusting the locations of the origin for concave shaped curves.

Subsequently, the CBR values were selected at 0.1-inch penetration using the corrected load values. A summary of the CBR test results is presented in Table II on the following page and the Proctor Curves, Particle Size Distribution Reports, and the CBR curves are provided in Appendix VIII.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

Table II – CBR Test Results

Boring

ID

Depth(1) (ft)

Soil Material

(2) wN (3)

Passing #200 Sieve

Atterberg Limits

(LL/PL/PI)

Max.

Dry

Densit y (pcf)

Optimum Moisture

CBR

Value

Swell

19CBR-01 1-3

Clayey

SAND

15 29.0 22/13/9 121.5 11.1 6.5 0.2

19CBR-02 1-3

Silty

SAND

19 19.9 NP 125.9 9.9 11.0 0.0

19CBR-03 1-3

Clayey

SAND

9 31.0 24/14/10 116.8 10.9 7.9 0.2

Note(s): (1) Depth below the existing grade.

(2) Underlying soil consists of Uncontrolled FILL

(3) wN – Natural Moisture Content

2.2.3 In-Situ Permeability Testing

Infiltration testing, using a constant-head borehole permeameter, was performed at boring locations 19BMP-01 thru 19BMP-03 at depths ranging from 1.1 to 1.9 feet below existing grades. The tests were performed approximately 2 feet above the ESHWT as identified in the SAES and recommended by the Civil Engineer. Further discussion on the ESHWT is provided in Section 3.7 of this report.

The boreholes were prepared utilizing a planar auger to remove soil clippings from the base.

Permeability testing was then conducted within the vadose zone utilizing an Aardvark PermeameterTM and the following testing procedures:

An adjustable-height table was assembled and placed adjacent to the boreholes. The table was leveled at a height to provide the proper amount of overhead pressure for shallow measurements. The table holds a digital scale accurate to 0.01g upon which rests a water reservoir. A supported flexible pipe of an appropriate length so as not to induce a weight upon the reservoir served as a conduit to the Aardvark Permeameter Module (APM). The APM establishes a constant water head within the borehole during testing by use of a precision valve and float assembly. The APM was supported by a calibrated tape measure and lowered into the borehole to the test depth elevation.

Testing began as the shut-off valve was opened allowing water to pass through the APM to fill the borehole to the constant water level elevation. The absorption rate slowed as the soil voids became filled and an equilibrium developed as a wetting bulb developed around the borehole.

Water was added to the reservoir as needed. As the water drained into the borehole and surrounding soils during testing, the water level within the reservoir was recorded by weight at a regular time interval. The test was continued until relatively consistent flow rates were documented. During testing the quick release connections and shutoff valve were monitored to ensure that no leakage occurred. The flow rate (Q), height of the constant water level (H), and borehole diameter (D) were used to calculate Ks utilizing the Glover Solution.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

Based on the field testing, the hydraulic conductivities of the soils are presented in Table III.

The comprehensive hydraulic conductivity worksheets are provided in Appendix XI.

Table III – Constant Head Borehole Permeameter Test Results

Test Depth(1)

(ft) Ksat Value

(in/hr) Ksat Value (cm/sec)

Ksat Class Soil Material

19BMP-01 1.6 0.12 8.37 x10-5 Moderately

Low Silty SAND -

Uncontrolled FILL

19BMP-02 1.1 0.02 1.13 x10-5 Moderately

Low Clayey SAND -

Uncontrolled FILL

19BMP-03 1.9 19.84 1.0 x10-2 Very High

SAND -

Uncontrolled FILL

Note(s): (1) Depth below the existing grade.

These infiltration tests were performed in uncontrolled fill which often results in great differences in permeability of soil in close proximity to each other. The permeability test results provided in this report are the result of testing at the locations and depths indicated. Varying site conditions, including soil composition, man-made debris, soil density, stratum depth, and stratum thickness should be expected throughout the site. As such, the permeability test results should not be assumed for all locations and depths across the project site.

2.2.4 Consolidation Testing

Two (2) one-dimensional consolidation tests were performed at our Virginia Beach laboratory in general accordance with ASTM D 2435 on the specimens extracted from the Shelby tube samples obtained at boring locations 19SPT-01 from 35 to 37 feet and 19SPT-03 from 45 to 47 feet below existing grades. More detailed information is provided in the Shelby Tube Classification Log Sheets presented in Appendix IX. A representative specimen from each of the Shelby tubes was also subjected to natural moisture content, Atterberg Limits, and -#200 sieve testing. The consolidation test results are presented in Table IV. The comprehensive test results are provided in Appendix X.

Table IV – Consolidation Test Results

Boring

ID

Depth(1)

(ft)

Overburden (tsf)

Pc (2)

(tsf) OCR(2) Cc

(2) Cr

(2) eo

19SPT-01 35-37 1.1 1.3 1.18 0.86 0.11 1.492

19SPT-03 45-47 1.0 1.3 1.08 0.74 0.10 1.345

(2) Value obtained from re-constructed consolidation curve (Schmertmann correction method).

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

2.2.5 Chemical Analysis

Two (2) composite soil samples were created from 1 to 4 feet below surface grades from boring and test pit locations in the immediate vicinity of Test Pits 19TP-01 and 19TP-03 as well as 19TP05 and SPT Boring 19SPT-04 for the purpose of construction and disposal related characterization of the site soils and for information on soil corrosiveness and aggressiveness potential.

The sampling equipment was cleaned and decontaminated using non-phosphate industrial grade detergent and a distilled water rinse prior to collecting and compositing each of the samples. The resultant composite soil samples were placed in appropriately preserved certified clean glass containers, labeled, packed on ice and delivered to the contract laboratory under chain-of-custody protocol for analysis for the presence and concentrations of the following analytes:

� pH � moisture content � soluble sulfates � chlorides � sulfates/sulfides � electrical resistivity � redox potential

A summary of the corrosivity and aggressiveness laboratory testing results is presented in Table V.

Table V - Summary of Corrosivity Test Results

Sample Location

Depth(1)

(ft) pH(2) (Std.

Units)

Percent Moisture

Redox Potential(3)

(mV)

Resistivity(4) (ohms-cm)

Chloride(5) (mg/Kg)

Sulfate(6) (mg/Kg)

Sulfide(7) (mg/Kg)

19TP-01 &

19TP-03

1-4 8.2 19.2 139.4 3360 ND 62.1 ND

19TP-05 &

19SPT-04

1-4 8.1 10.7 120.3 5100 ND 69.5 ND

Note(s): (1) Depth below the existing grade.

(2) – Method 9045D

(3) – Method 2580

(4) – Method 120.1

(5) – Method 9056

(6) – Method 9056

(7) – Method 4500-S2D-2011 ND – Not Detectable above the laboratory’s Method Detection Limit

An evaluation of the soil analytical data submitted from the two (2) composite soil samples at depths of 1 to 4 feet below existing grade shows that the submitted soil samples do not appear to be corrosive to steel, ferrous material or ductile iron pipe when compared to the AWWA- DIPRA 10 Point Evaluation Method. Based upon the higher resistivity values (>3000 ohms-cm), relative neutral pH (6.0-8.5), and the non-detectable concentrations of chlorides and sulfides in the composite soil samples, the soils represented do not appear to be considered aggressive from a corrosion potential to buried steel reinforced concrete structures.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

Likewise, the following chemical environmental analyses were performed on the two composite samples.

� TPH-DRO/GROMethod 8015C � TCLP-RCRA-8 Metals Method 1311-6000/7000 Series � VOCs Method 8260B

A summary of the construction and disposal related laboratory testing results is presented in Table VI.

Table VI - Summary of Soil Environmental Analytical Results

Sample Location

Depth(1)

(ft)

TPH-DRO/GRO

Method 8015C

(mg/Kg)

TCLP-RCRA-8 Metals Method 1311-

6000/7000 Series (mg/L)

VOCs Method 8260B

(µg/Kg)

19TP-01 &

19TP-03

1-4

ND/ND

Barium – 0.47 Lead – 0.055 sec-Butylbenzene – 9.9 1,2,4-Trimethylbenzene – 8.4 1,3,5-Trimethylbenzene – 14.3

19TP-05 &

19SPT-04

1-4

ND/ND ND ND

Note(s): (1) Depth below the existing grade.

ND – Analyte Not Detected Above Laboratory’s Method Detection Limits mg/Kg – Milligrams/Kilogram or parts per million mg/L – Milligrams/Liter or parts per million µg/Kg – micrograms/kilogram or parts per billion

An evaluation of the soil analytical data submitted from the composite samples at depths of 1 to 4 feet below existing surface grade shows that the submitted soil samples did not produce concentrations of the analytes that would be considered hazardous from a disposal or exposure to construction workers perspective. The composite sample 19TP01&19TP-03 produced detectable concentrations of the VOCs sec-Butylbenzene, 1,2,4-Trimethylbenzene and 1,3,5- Trimethylbenzene at concentrations that are orders of magnitude below the established Virginia DEQ’s risk based soil screening concentrations for residential and industrial sites.

The comprehensive laboratory analytical results are provided in Appendix XII.

All soil cuttings (IDW solids) and decontamination fluids (IDW liquids) were containerized in separate sealable 55-gallon steel drums, properly labelled and temporarily stored on the project site in an area designated by the Activity POC. IDW liquids and solids were stored in separate containers. One representative composite sample of the IDW liquids and one representative composite sample of the IDW solids was collected and sent in for laboratory analytical testing.

Each sample was analyzed for full TCLP (8 RCRA metals, volatiles, semi-volatiles, PCBs, pesticides, herbicides), TPH (DRO and GRO), plus ignitability, corrosivity, reactivity, and paint filter using the appropriate EPA SW 846 method. The analytical test results prove the IDW liquid and solid samples to be non-hazardous and are presented in Appendix XII. The results were provided to the Activity POC prior to arranging disposal. Appropriate protocols were followed regarding the disposal of the non-hazardous waste drums.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

3.0 SITE AND SUBSURFACE CONDITIONS

3.1 Site Geology

The project site lies within a major physiographic province called the Atlantic Coastal Plain.

Numerous transgressions and regressions of the Atlantic Ocean have deposited marine, lagoonal, and fluvial (stream lain) sediments. The regional geology is very complex and generally consists of interbedded layers of varying mixtures of sands, silts and clays. Based on our review of existing geologic and soil boring data, the geologic stratigraphy encountered in our subsurface explorations generally consisted of formations from the Pliocene Epoch, Pleistocene Epoch and the Holocene Epoch.

The formation of the Pliocene Epoch encountered within the project limits consists of the Yorktown Formation (Ty). The Yorktown Formation is typically characterized by its blue-gray and green-gray color, distinct compact nature and the abundance of marine shell fragments.

The Yorktown Formation stratum, once encountered, generally extends to depths of several hundred feet below sea level.

Formations of the Pleistocene Epoch encountered within the project limits consist of the Norfolk Formation (Qn) and the Sand Bridge Formation (Qsb). More recent publications indicate varying correlations between geological formations of the Upper Pleistocene Epoch.

Specifically, the upper and lower members of the Norfolk Formation and the Sand Bridge Formation have been categorized as facies within the Lynnhaven Member (Qtl) and Sedgefield Member (Qts) of the Tabb Formation (Qt).

The most recent geological depositions at the project site are of the Holocene Epoch and consist of soils referred to as Alluvium (Qal or al). Alluvium is typically comprised of Sand, Silt and Clay with deposits of organic laden soils of varying thicknesses. The Alluvium sediments typically overlay the above mentioned Tabb Formation increasing in thickness in the vicinity of pre-existing water features (deep waterways, tributaries, etc.). It is common to encounter organic laden soils (organic Silt and Clay soils and Peat) at lower elevations.

3.2 Recent Land Reclamation and Site Development

Based on a review of historical USGS topographic maps of Norfolk, Virginia produced between the years of 1907 and 2016, it is believed that the majority of the project site appears to be located within previously reclaimed areas. Specifically, the site appears to be within the footprint of the former Bush Creek noted in the 1907 and 1921 maps. Based on a review of the available USGS maps, this area, and much of what was known as the U.S. Naval Reservation, was filled between the years of 1921 and 1948. The soils recovered from boring locations could be interpreted to support this supposition. In order to obtain information regarding historical land use of the project site and its vicinity, we reviewed the 1907, 1921, 1948, 1955, 1965 and 1980 USGS historic maps for Norfolk, Virginia. Appropriate portions of those USGS geological maps referenced above are provided in Appendix XXI.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

3.3 Existing Pavement Conditions

A summary of the results from our pavement coring exploration program are presented in Table VII on the following page. Individual logs of the pavement cores extracted from each of the test locations are presented in Appendix XIII (Pavement Section Composition Logs).

Table VII – Summary of Pavement Section Composition

Boring Location Asphalt

Thickness (in) Concrete

Thickness (in) Aggregate Base Thickness (in)

Subgrade Soil Material

19SPT-01 5.0 5.0 3.0 Clayey SAND-Uncontrolled FILL

19SPT-04 4.0 0 4.0 Clayey SAND-Uncontrolled FILL

19BMP-01 3.0 0 4.0 Silty SAND-Uncontrolled FILL

19BMP-03 2.0 4.5 0 SAND-Uncontrolled FILL

19CBR-01 5.5 0 3.0 Clayey SAND-Uncontrolled FILL

19CBR-02 4.75 0 4 Silty SAND-Uncontrolled FILL

19CBR-03 2.75 0 6 Clayey SAND-Uncontrolled FILL

19CPT-01 3.75 0 - -

19CPT-02 3 0 - -

19CPT-03 1 8 - -

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

3.4 Subsurface Soil Conditions

A summary of our SPT soil test borings is presented below in Table VIII on the following page.

Table VIII - Subsurface Soil Conditions

AVERAGE

DEPTH (ft)

STRATUM DESCRIPTION

RANGES OF

SPT(1)

N-VALUES

to

0.54 - 0.71 Pavement � See Table VII – to

0.33 - 0.42 Surficial � 4 to 5 inches of Topsoil –

0.33 - 0.71 to

12.5 - 16.5

Uncontrolled FILL/Possible

FILL

� SAND with varying amounts of Silt, Clay, Gravel, fibrous organic matter, brick, concrete, wood and marine shell fragments

� CLAY with varying amounts of Sand, Silt, marine shell fragments and fibrous organic matter

Non-cohesive 0 – 26

Cohesive 0 – 2

12.5 - 16.5 to

41.5 - 61.5 I

� CLAY (CH & CL) with varying amounts of Silt, Sand, organic matter and marine shell fragments *Deposits of SM and SC are present in varying quantities.

0 – 7

41.5 - 61.5 to

51.5 - 66.5

II

� ORGANIC SOIL (OH/OL & PEAT) with varying amounts organic matter

*Deposits of Fat CLAY (CH) encountered underlying OH/OL stratum only at 19SPT-04

2 – 15

56.5 - 66.5 to

61.5 - 71.5

III

� SAND (SM) with varying amounts of Silt, Clay, organic matter and marine shell fragments

2 – 5

61.5 - 71.5 to

IV

� SAND (SM, SC) with varying amounts of Silt, Clay and marine shell fragments “Yorktown Formation”

5 – 33

Note(s): (1) SPT = Standard Penetration Test, N-Values in Blows-per-foot (uncorrected)

The subsurface descriptions are of a generalized nature provided to highlight the major soil strata encountered. The records of the subsurface exploration are included in Appendix IV (Soil Test Boring Logs) and in Appendix V (Generalized Soil Profile), which should be reviewed for specific information as to the individual borings. The stratifications shown on the records of the subsurface exploration represent the conditions only at the actual boring locations. Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the transition may be gradual.

It is noted that the topsoil designation references the presence of surficial organic laden soil, and does not represent any particular quality specification. It is recommended this material be tested for approval prior to use.

Report of Subsurface Exploration & Geotechnical Engineering Services June 25, 2020

Contract: N40085-19-D-9041

3.5 Initial Test Pit Excavation Results

Test pit/trench excavations were initially performed at six (6) locations where former building foundations and utility connections were suspected. Photographs were taken of the excavated test pits to clearly convey the character and composition of the encountered soils and stratigraphy.

These photographs are included in Appendix XIV. Remains of former structure such as underground utilities and concrete foundation components were observed in four (4) of the six

(6) initial test pit excavations. A summary of the of the findings from each the six (6) test pits is provided in Table IX. Upon completion of the test pits the excavations were backfilled with the spoils and compacted in layers, then were covered with seed and straw. These initial test pit findings were followed up with additional investigation of the site, including a geophysical study as well as additional test pits to verify those findings.

Table IX – Summary of Initial Test Pit Findings

Test Pit ID Below Grade Findings

19TP-01 Concrete Beam & Old Utilities

19TP-02 Pile Cap & Composite Piles(1)

19TP-03 Old Utilities

19TP-04 N/A

19TP-05 Pile Cap & Large Concrete Fragments

19TP-06 N/A

Note(s): (1) As identified in Historic Drawings provided by Client.

3.6 Geophysical Study and Test Pit Verification – Scope Mod001

A geophysical study was conducted on a selected portion of the project site in effort to locate buried foundation components. The objective of this study was to map the existing buried foundation system (i.e.