Geotech Report.pdf

Geotechnical Investigation and Design Report

TN ERFO FS CHRKE804 2020-2(2)

Rehabilitation of McFarland Road (FS 23)

Slope Failures at MP 9.245, MP 10.189, MP 10.378

Cherokee National Forest, Polk County, Tennessee

Contact No.: 693C7321D000005

Task Order: 693C7323F00085N

JMT No.: 19-01472-007

Johnson, Mirmiran & Thompson, Inc 40 Wight Avenue Hunt Valley, Maryland 21030

Prepared By:

Prepared For:

Eastern Federal Lands Highway Division, 22001 Loudoun County parkway Ashburn, Virginia 20147

July 08, 2024

July 08, 2024

Mr. Dan Weston

Project Manager

Federal Highway Administration

Eastern Federal Lands Highway Division

Building E2, Suite 200

Ashburn, Virginia 20147

Re: Geotechnical Investigation and Design Report

McFarland Road, Cherokee National Forest, Tennessee.

Design Services to Rehabilitate Sites at MP 9.245, 10.189, and 10.378, McFarland Road (FS 23)

Contact No.: 693C7321D000005

Task Order: 693C7323F00085N

JMT Job No.: 19-01472-007

Dear Mr. Weston:

Johnson, Mirmiran & Thompson, Inc. (JMT) is pleased to submit this Geotechnical Investigation and Design

Report for the above referenced project. This report contains a discussion of our understanding of the project, exploration procedures, the exploration results, and the recommendations for the design and construction of the proposed repairs at MP 9.245, 10.189, and 10.378 on McFarland Road (FS 23), Tennessee.

It has been our pleasure to be of service to the Eastern Federal Lands Highway Division (EFLHD). If you have any questions or require any additional information, please do not hesitate to contact this office.

Very truly yours, JOHNSON, MIRMIRAN & THOMPSON, INC.

Shuo Yang, Ph.D. Kumar Garimella, Ph.D, P.E., D.GE

Geotechnical Engineer Associate Vice President

Garimella Image

MCFARLAND ROAD

GEOTECHNICAL INVESTIGATION AND DESIGN REPORT

Table of Contents

1.0 INTRODUCTION 1

1.1 General 1

1.2 Background 1

1.3 Scope of Work 1

1.4 Purpose of Report 1

2.0 GEOLOGIC SETTING 2

3.0 SUBSURFACE EXPLORATION PROGRAM 3

3.1 Subsurface Exploration 3

3.2 Field Testing and Sampling 3

3.3 Laboratory Testing 4

4.0 SUBSURFACE CONDITIONS 6

4.1 General 6

4.1.1 MP 9.245 (Borings FS 23-B1 and FS 23-B2) 6

4.1.2 MP 10.189 (Borings FS 23-B3 to FS 23-B5) 7

4.1.3 MP 10.378 (Borings FS 23-B6 and FS 23-B7) 7

4.2 Groundwater Conditions 7

5.0 GEOTECHNICAL ANALYSIS AND RECOMMENDATIONS 9

5.1 Design Alternatives 9

5.2 Seismic Design Considerations 9

5.3 Proposed Retaining Walls at MP 9.245 (Pin 365), MP 10.189 (Pin 370) and MP 10.378 (Pin 371) 10

5.3 Soil/Rock Design Parameters 11

5.4 External Stability 12

5.4.1 MP 9.245 (Pin 365) 12

5.4.2 MP 10.189 (Pin 370) and MP 10.378 (Pin 371) 14

5.5 Construction Considerations 15

5.5.1 Excavation Considerations 15

5.5.2 Construction Groundwater 15

5.5.3 Temporary Excavation Support 15

5.5.4 Soil Erosion and Slope Protection 15

6.0 REPORT ASSUMPTIONS AND LIMITATIONS 16

7.0 REFERENCES 17

MCFARLAND ROAD

GEOTECHNICAL INVESTIGATION AND DESIGN REPORT

Appendix A – Site Location Map, Geologic Map and General Plans

Appendix B – Boring Logs and Laboratory Testing Report

Appendix C – Geotechnical Design Computations

Geotechnical Investigation and Design Report – July 08, 2024 1

1.0 INTRODUCTION

1.1 General

As authorized by our agreement with the Federal Highway Administration’s Eastern Federal Lands Highway

Division (FHWA-EFLHD), Johnson, Mirmiran & Thompson, Inc. (JMT) has completed this Geotechnical

Investigation and Design Report (GDR) for the design and construction of the proposed rehabilitation of three distressed slopes on McFarland Road (FS 23), at Milepost (MP) 9.245, 10.189, and 10.378, within the

Cherokee National Forest, Tennessee. The site location map is included in Appendix A.

1.2 Background

McFarland Road (FS 23) is within the limits of the Cherokee National Forest, Polk County, Tennessee. The road is a single lane12 to 14 feet wide, crushed stone surfaced roadway with no shoulders. There are a number of widened areas where vehicles can pass.

Heavy rain events caused roadway damage to a number of sites on McFarland Road. The three sites that are the subject of this report are located at MP 9.245 (Pin 365), MP 10.189 (Pin 370), and MP 10.378 (Pin

371). These sites are also identified by Pin numbers in the CherokeeMaster_Pin Final kml file supplied with the client data for this task. All three sites were originally constructed with one side of the road cut into the face of the mountain and the other roadside constructed on fill. The failures consist of the downslope fill side slipping away which results in a narrow treacherous roadway. The length of the failure at all slide locations is approximately 80 feet. The General Plans for proposed improvements are included in Appendix A of this report.

1.3 Scope of Work

The scope of JMT’s services on this project consists of exploring the subsurface conditions using soil borings, laboratory testing of soil and rock samples, evaluating the subsurface conditions development of geotechnical recommendations and submittal of our findings in this report.

The project is being designed using the Load and Resistance Factor Design (LRFD) methodology and the geotechnical analysis was performed in accordance with the AASHTO LRFD Bridge Design Specifications, 9th Edition, 2020.

1.4 Purpose of Report

The purpose of this report is to provide the results of the general subsurface exploration at the location of the sites and the evaluation of those conditions with respect to geotechnical engineering recommendations to aid in the design and construction of the proposed repairs. The geotechnical engineering recommendations presented in this report are based on JMT’s geotechnical engineering analysis of the subsurface conditions indicated by the test borings.

Geotechnical Investigation and Design Report – July 08, 2024 2

2.0 GEOLOGIC SETTING

The project locations are within the Blue Ridge Physiographic Province. The Blue Ridge is described as a

550-mile-long belt of Appalachian Mountains that extends from Pennsylvania to Georgia. In this area, the

Blue Ridge is represented by the Great Smokey Mountains. The topography is described as ridges and rolling hills. All three sites are at the base of Smith Mountain with MP 9.245 on the west and MP 10.189 and MP

10.378 on the east side.

The slope in the area of MP 9.245 faces northwest and surface drainage is to the Hiwassee River which is to the northwest of the slope. There is an active excursion railroad at the base of the slope. This line is believed to be operated by the Tennessee Valley Railroad.

The slopes at MP 10.189 and MP 10.378 face east, and surface drainage in those areas is towards Wolf

Creek. Wolf Creek flows north to the Hiwassee River. Some or all of the site at MP 10.378 may be within the

Right-of Way of the TVA Apalchia Tunnel. This tunnel, constructed during WWII to provide waterpower to a hydroelectric plant located about 3.5 miles west of MP 10.378, and named after the town of Apalachia, TN is listed on the National Register of Historic Places.

According to the Geologic Map of Tennessee (East-Central Sheet), Hardman, Miller, and Swingle, 1966, Tennessee Division of Geology, the three sites are underlain by members of the Precambrian Age Great

Smokey Group. The Great Smokey is described as massive layers of coarse graywacke and arkose. The sediments are folded and fractured. The site geologic map is provided in Appendix A.

According to the Geologic Map of southwestern North Carolina including adjoining southeastern Tennessee and northern Georga, Weiner, L.S., and Merschat, C.E., North Carolina Geological Survey, 1992. The closest published reading for the strike and dip of the formation layers is N 40° E and 82°SE, respectively This results in the rock dipping into the slope face for MP 9.245 and dipping out of the slope face for MP 10.189 and MP 10.378.

Geotechnical Investigation and Design Report – July 08, 2024 3

3.0 SUBSURFACE EXPLORATION PROGRAM

3.1 Subsurface Exploration

Seven soil test borings, designated FS 23-B1 through FS 23-B7, were drilled at three sites by S&ME, Inc. of

Louisville, Tennessee, between January 23, 2024, and January 25, 2024. The locations of the borings are indicated on the Roadway Plan sheet included in Appendix A of this report.

3.2 Field Testing and Sampling

The borehole was performed with a track-mounted drill rig, using a 4-inch ID casing-advancer to advance the borehole. S&ME provided full-time supervisors for the field investigation, including drilling inspectors and an on-site geologist knowledgeable of standard test boring procedures and the soil and rock sampling requirements of the AASHTO. The geologist and drilling team worked under the supervision of a Professional

Engineer. Representative soil samples were obtained by means of the split-barrel sampling procedure in general accordance with ASTM D 1586. In the split-barrel sampling procedure, a 2-inch O.D. split-barrel sampler is driven into the soil a distance of 18 or 24 inches by means of an automatic 140-pound hammer falling 30 inches. The number of hammer blows required to drive the sampler through a 12-inch interval is termed SPT value (blow count, or N-value) and is indicated for each sample on the Boring Log. The SPT was performed using an automatic hammer. A representative portion of each SPT sample was placed in a glass jar and appropriately marked.

Rock coring was accomplished in general accordance with ASTM D2113. Rock coring commences when the boring can no longer be advanced using the casing-advancer. A double tube NQ Series core barrel and bit were employed. As the core barrel is advanced through the rock, the bit is cooled with water which also removes the cuttings. The inner barrel protects the core sample from erosion. The resulting rock core is a nominal 2 inches in diameter. The core sample is boxed and measured. The length of the sample is measured and reported as a percentage of the run. Rock Quality Designation (RQD) is measured in accordance with

ASTM D6032, where the sum of the lengths of unweathered core pieces equal to or greater than 4 inches is reported as a percentage of the total run. After drilling and measuring the water level, each borehole was filled with grout.

Groundwater levels were measured in the borings before the coring commenced and after drilling. The results of the groundwater readings are shown on the test boring logs. Groundwater data is discussed further in

Section 4.2 of this report.

Table 1 summarizes the locations and depths of the completed borings. JMT precisely located all the borings and tied the geographic position to the project’s survey datum, State Plane Coordinate System

(NAD83/2011), and North American Vertical Datum of 1988 (NAVD88). The boring location plan and boring logs are included in Appendix A and B of this report, respectively.

Geotechnical Investigation and Design Report – July 08, 2024 4

Table 1: Soil Borings Along McFarland Road FS 23

Milepost

(Pin Number) No. of Borings Boring ID

Boring Depth

(feet)

Rock Coring

(feet)

9.245

(Pin 365)

FS 23 - B1 50.6 15.4

FS 23 - B2 20.5 14.5

10.189

(Pin 370)

FS 23 - B3 15 9.7

FS 23 - B4 10.5 9.6

FS 23 - B5 14 11

10.378

(Pin 371)

FS 23 - B6 16.6 14.9

FS 23 - B7 12.4 9.4

3.3 Laboratory Testing

The representative samples of soils encountered in the subsurface exploration were tested for natural moisture contents, Atterberg Limits, grain size (sieve), and soil classification to understand the engineering properties of the soils. Laboratory testing was performed in accordance with the appropriate AASHTO and

ASTM guidelines. Table 2 summarizes the soil test results.

Table 2: Soil Laboratory Tests

Boring Depth Moisture

Atterberg Limits %

Fines

USCS

Classification

AASHTO

Classification LL PL PI

FS 23-B1 2 20.4 30 26 4 58.0 ML A-4,1

FS 23-B1 8.5 8.3 30 28 2 56.9 ML A-4,0

FS 23-B1 18.5 8.0 31 29 2 64.7 ML A-4,1

FS 23-B2 2 19.8 29 24 5 66.8 ML A-4,2

FS 23-B2 4 4.1 29 26 3 35.6 SM A-4,0

FS 23-B3 0 14.8 26 21 5 28.3 SC-SM A-2-4,0

FS 23-B3 2 20.8 26 19 7 26.9 SC-SM A-2-4,0

FS 23-B3 4 5.2 24 19 5 21.0 SC-SM A-1-b,0

FS 23-B6 0 3.5 34 23 11 24.7 SC A-2-6,0

Geotechnical Investigation and Design Report – July 08, 2024 5

Representative samples of rock core from the borings were subjected to testing for unconfined compressive strength. Table 3 below summarizes the test results.

Table 3: Rock Tests – Unconfined Compression

Boring Depth Unit Weight

(pcf) Unconfined Compression (psi) Classification

FS 23-B2 20.0-20.4 172.8 13,924 Slate

FS 23-B3 5.6-6.0 166.2 32,730 Graywacke

FS 23-B4 4.8-5.2 168.5 28,372 Graywacke

FS 23-B6 7.98.3 175.7 5,474 Slate

FS 23-B7 3.5-3.9 174.4 1,260 Slate

Conducted soil corrosion tests on representative soil samples, analyzing pH, resistivity, and chloride and sulfate content. The summarized test results are presented in Table 4 below.

Table 4: Chemical Tests Results

Boring Depth

(ft) pH

Sulfates (SO4) Chloride (CL) Resistivity

(ohm-cm) Classification

(mg/kg) (%) (mg/kg) (%) Received Minimum

FS 23-B1 13.5-15 8.9 2.3 0.0002 5.0 0.0005 36,180 27,470 SILT (ML)

FS 23-B5 1-3 7.2 33.2 0.0033 6.6 0.0007 63,000 13,050

Poorly Graded

GRAVEL (GP)

FS 23-B7 1-3 6.8 554.0 0.0554 34.4 0.0034 21,000 2,550

Poorly Graded

SAND (SP)

The potential acidity test was performed in accordance with U.S. Environmental Protection Agency (EPA) guidelines EPA-600/2-78-054, and the results are presented in Table 5. Other test results, such as sulfur content and neutralization potential, can be found in Appendix B.

Table 5: Potential Acidity Tests Results

Boring Sample ID Sample Depth Test Value Unit

FS-23-B5 Run-3 13.0 to 13.4 ft Potential Acidity 7.94 Ton CaCO3/T Ton

Any untested soil samples and rock cores will be sent to the FHWA EFLHD Laboratory in Sevierville, Tennessee

Geotechnical Investigation and Design Report – July 08, 2024 6

4.0 SUBSURFACE CONDITIONS

4.1 General

The subsurface conditions at the site were analyzed by utilizing data from the seven test borings performed for the three sites. Borings FS 23-B1, FS 23-B2, FS 23-B3 FS 23-B5 and FS 23-B6 were drilled in the crushed aggregate surfaced roadway which ranged from 1 to 11 inches thick. The boring FS 23-B4 was drilled by the side of the road and encountered residuum at the surface. Boring FS 23-B7 encountered one (1) inch of topsoil.

All seven borings were advanced into rock which was encountered directly below the residual soils. The rock is described as SLATE and GRAYWACKE. Slate may generally be considered as a low grade of metamorphosed shale. Graywacke may be considered as an impure sandstone. The impurities consist of silt and clay sized micaceous and chlorotic minerals. Boring plans and log are included in Appendix A and B, respectively. The generalized subsurface profiles are included in Appendix C. The stratification lines shown on the profiles represent approximate transitions between material types at the location of the borings. Note that in-situ strata changes could occur gradually or at slightly different levels between the borings. Also, the borings depict conditions at the boring location and particular times indicated. Some conditions, particularly groundwater conditions between borings could vary from the conditions encountered at the particular boring locations.

The borings indicated the subsurface conditions below the aggregate surface and topsoil consisted of the following materials:

4.1.1 MP 9.245 (Borings FS 23-B1 and FS 23-B2)

Residuum

Residual soils were encountered beneath the crushed aggregate road surface in both borings. The residual soils generally consisted of SILT (ML), little sand. Rock fragments were found in some samples. The relic structure of the parent slate was noted in most samples. The residual soils extended down to the depth of

35.2 at elevation EL 1014.85 in boring FS 23-B1 and to the depth of 6 feet at elevation EL 1040.765 in boring

FS 23-B2.

The N-values from SPTs for the fine-grained soils generally ranged from 7 to 31 blows per foot (bpf), which indicated medium stiff to hard consistencies.

Rock

Rock was encountered at the depth of 35.6 feet, EL 1014.45 in boring FS 23-B1 and at the depth of 6 feet, EL 1040.765 in boring FS 23-B2. The rock is described as blue slate in both borings. Run #1 in boring FS

23-B1 was only 4.8 inches and is described as an incompetent slate and therefore is not included in the core recovery and RQD averages. Core recoveries ranged from 32% to 80% and averaged 48%. RQD ranged from 0% to 16% and averaged 6%.

Geotechnical Investigation and Design Report – July 08, 2024 7

4.1.2 MP 10.189 (Borings FS 23-B3 to FS 23-B5)

Residuum

Residual soils were encountered beneath the crushed aggregate road surface in all three borings. The residual soils generally consisted of Silty, Clayey SAND (SC-SM) with gravel and Poorly Graded GRAVEL

(GP) with sand. The depths to the bottom of the residuum ranged from 0.9 feet to 5.6 feet. Elevations of the bottom of the residuum ranged from EL1136.95 to EL 1143.08.

The N-values from SPTs for the coarse-grained soils for the residuum generally ranged from 5 bpf to 50 blows for 3 inches of penetration indicating loose to very dense relative densities.

Rock

Rock was encountered at the depths of 0.9 feet to 6 feet. The elevations of the top of rock ranged from

EL1136.95 to EL 1143.08.

The rock is described as graywacke in borings FS 23-B3 and FS 23-B4. The 30-inch Run#1 of boring FS 23-

B5 was described as slate. Beneath the slate the rock was described as graywacke. Core recoveries ranged from 40% to 100% and averaged 81%. RQD ranged from 0% to 88% and averaged 48%.

A subsurface void was reported from 7.2 feet to 9.9 feet in boring FS 23-B3. The run that measured as 0%

RQD was the slate from Run#1 in boring FS 23-B5.

4.1.3 MP 10.378 (Borings FS 23-B6 and FS 23-B7)

Residuum

Residual soils were encountered beneath the crushed aggregate road surface in boring FS 23-B6 and the topsoil of boring FS 23-B7. The residual soils generally consisted of Clayey SAND (SC) with gravel and

Poorly Graded SAND (SP) with gravel. The depths to the bottom of the residuum ranged from 1.7 feet to 3 feet. Elevations of the bottom of the residuum ranged from EL1180.9 to 1185.46.

The N-values from SPTs for the coarse-grained soils for the residuum generally ranged from 23 bpf to 50 blows for 3 inches of penetration indicating medium dense to very dense relative densities.

Rock

Rock was encountered at the depth of 1.7 feet, EL 1180.9 in boring FS 23-B6 and at the depth of 3 feet, EL

1185.46 in boring FS 23-B7. The rock is described as blue slate in both borings. Core recoveries ranged from 83% to 100% and averaged 94%. RQD ranged from 26% to 100% and averaged 78%.

4.2 Groundwater Conditions

The groundwater levels recorded on the logs were measured after the drilling operations. The depths and elevations of the groundwater are shown in Table 6. Groundwater readings were not taken for Boring FS 23-

B3 due to surface water running into the borehole. It should be noted that groundwater levels could fluctuate with changes in seasonal conditions. The recorded water levels, or absence of water, reflect the conditions

Geotechnical Investigation and Design Report – July 08, 2024 8 at the time of this exploration only. Fluctuations in the location of hydrostatic groundwater level and perched water levels can occur as a result of seasonal variations in evaporation, precipitation, surface water run-off, and other factors. Some conditions, particularly groundwater conditions between borings, could vary from the conditions encountered at the particular boring locations.

Table 6: Groundwater Levels Along McFarland Road FS 23

Milepost

(Pin Number) Boring ID

Groundwater

Before Coring

Groundwater After Completion Groundwater

Elevation

(feet) Hours After Depth (feet)

9.245

(Pin 365)

FS 23 - B1

Not

Encountered 48 Not Encountered -

FS 23 - B2

Not

Encountered 48 Not Encountered -

10.189

(Pin 370)

FS 23 - B3

Not

Encountered

- Not Measured -

FS 23 - B4

Not

Encountered 48 1.3 1142.68

FS 23 - B5

Not

Encountered 24 6 1138.98

10.378

(Pin 371)

FS 23 - B6

Not

Encountered 24 4.5 1178.10

FS23 - B7

Not

Encountered 24 3 1185.46

Geotechnical Investigation and Design Report – July 08, 2024 9

5.0 GEOTECHNICAL ANALYSIS AND RECOMMENDATIONS

Recommendations regarding proposed rehabilitation of three distressed slopes on McFarland Road (FS 23) at MP 9.245, MP 10.189 and MP 10.378 are presented herein.

5.1 Design Alternatives

A riprap revetment was first considered for these sites based on its lowest cost and ease of construction.

However, based on subsurface conditions, field reconnaissance information, and the physical attributes of the sites, the use of the revetment alternative was found to be inadequate. Due to the presence of a stream or the railroad at the base of slope, there is not enough room for the footprint of the 1.5H:1V slope needed to insure long term stability.

Alternatives being considered for stabilization techniques to mitigate existing and future roadway embankment failures at the proposed site locations:

1. Cast-in-Place (CIP) Retaining Wall supported on rock.

2. Gabion Basket Wall.

3. Mechanically Stabilized Earth (MSE) Wall.

4. T-Wall.

5. Modular Block Wall.

Based on engineering judgment, CIP type walls were not considered due to anticipated construction time and costs. Generally, T-wall and MSE wall constructions are more expensive compared to gabion walls and modular block walls. Unlike modular block walls, gabion basket metal mesh has a history of rusting which results in failure and requires regular maintenance. Therefore, JMT recommends the use of a Modular Block

Wall for the proposed stabilization at all three sites.

5.2 Seismic Design Considerations

The subsurface exploration findings were utilized to determine the Seismic Site Class for the project sites according to Table 3.10.3.1-1 of AASHTO. The SPT N-values of soil samples were used in classifying the project site, which is classified as Seismic Site Class C. The current AASHTO Bridge Design Specifications

(2020) stipulate a design seismic event with a 7 percent probability of occurrence in 75 years, roughly equivalent to a 1000-year return period. The peak seismic ground acceleration (PGA) at the project sites for this specified return period was calculated to be 0.178g for Site Class C. The 0.2 Second Horizontal

Response Spectral Acceleration SDS is 0.324g, and the 1 Second Horizontal Response Spectral Acceleration

SD1 is 0.117g. Seismic Zone classification of the project sites based on Acceleration Coefficient SD1 is presented in Table 3.10.6-1 of the AASHTO. With an SD1 value of 0.117g, the project sites fall within Seismic

Zone 1. Detailed seismic results can be found in Appendix D.

Per ASHTO 11.5.4.2, seismic design is not mandatory for retaining walls in Seismic Zone 1 where the peak ground acceleration (PGA) is less than or equal to 0.4g. Consequently, neither external nor internal seismic

Geotechnical Investigation and Design Report – July 08, 2024 10 evaluations are needed for the proposed retaining walls. However, an Extreme Event I global stability analysis is required for all sites.

5.3 Proposed Retaining Walls at MP 9.245 (Pin 365), MP 10.189 (Pin 370) and MP 10.378 (Pin 371)

Based on field observations and the results of subsurface exploration programs, it is recommended to use retaining walls to stabilize the landslide at all three locations. Table 7 provides the location and maximum wall height.

Table 7: Proposed Retaining Wall Locations

(Pin Number)

Station Proposed

Roadway Grade

Elevation (feet)

Approx. Max. Wall

Height

(feet)

From To

9.245

(Pin 365) 2+00 2+80 1048 15

10.189

(Pin 370) 4+80 5+60 1144 10

10.378

(Pin 371) 9+00 9+80 1184 10

The proposed walls will be around 80 feet in length, with a maximum height of 15 feet at MP 9.245 and 10 feet at MP 10.189 and MP 10.378. The proposed walls are planned to be constructed using Redi-Rock prefabricated gravity concrete blocks or equivalent modular block wall. The proposed retaining walls will be constructed on the existing slopes and a minimum horizontal bench width of 4 feet shall be provided in front of the proposed walls.

The internal stability design of the proposed Redi-Rock or equivalent wall should be the responsibility of an approved specialty wall contractor who is a registered professional engineer licensed in the State of

Tennessee and reviewed by the Engineer. The Contractor should use the established soil profile and soil parameters included in the report. The specialty wall contractor should provide design computations and plans for the proposal walls. All design computations should be in accordance with AASHTO LRFD Bridge

Design Specifications 9th Edition, 2020. The wall should be designed for a minimum design life of 75 years.

The backfill behind the proposed wall should consist of free draining, granular backfill meeting requirements for AASHTO Porous Fill (No. 57 Stone). The No. 57 stone should meet the requirements stated in Section

704 of Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects, FP-14

(FP-14).

Geotechnical Investigation and Design Report – July 08, 2024 11

5.3 Soil/Rock Design Parameters

Tables 8 to 10 present the representative soil/rock properties for the generalized subsurface profiles at the sites of MP 9.245, MP 10.189 and MP 10.378, respectively. These properties were utilized in evaluating the foundations for the proposed structures.

Table 8: Summary of Recommended Soil Parameters for MP 9.245 (Pin 365)

Stratum Unit

Weight, γsat (pcf)

Cohesion, C’

(psf)

Friction Angle, ɸ’

Residuum 125 0 34

Rock - Slate 170 1000 30

AASHTO NO. 57 Stone 110 0 38

Riprap 110 0 45

Table 9: Summary of Recommended Soil Parameters for MP 10.189 (Pin 370)

Unit

Weight, γsat (pcf)

Cohesion, C’

(psf)

Friction Angle, ɸ’

Rock – Slate/Graywacke 170 1000 30

Table 10: Summary of Recommended Soil Parameters for MP 10.378 (Pin 371)

Unit

Weight, γsat (pcf)

Cohesion, C’

(psf)

Friction Angle, ɸ’

Rock - Slate 170 1000 30

Geotechnical Investigation and Design Report – July 08, 2024 12

5.4 External Stability

External stability for overturning, sliding and bearing capacity for the Redi-Rock Walls were analyzed using the Redi-Rock Walls Analysis Computer Program Version 2024.29 supplied by Redi-Rock International, USA. The proposed walls have a 5-degree batter at the front and a minimum base width of 5 feet. The minimum Capacity Demand Ratio (CDR) for overturning, sliding and bearing capacity should be greater than or equal to 1.0. A uniform distributed live load surcharge of 250 psf was applied along the road to account for traffic loading. The CDR is greater than or equal to 1 and is considered acceptable.

The global stability of the proposed structures were analyzed using the Modified Bishop’s Circular Method using Slide 2 program, Rocscience, Inc., Toronto, Canada. A live load surcharge of 250 psf was applied on the roadway. Per AASHTO, a minimum Factor of safety (FS) of 1.3 and 1.1 is required for static and seismic loading conditions, respectively.

5.4.1 MP 9.245 (Pin 365)

Based on field observations and subsurface exploration results, it is recommended to use a Redi-Rock wall to stabilize the landslide at MP 9.245. Weathered rock or bedrock was encountered at a depth of 35.6 feet

(EL 1014.45) in boring FS 23-B1 and at a depth of 6 feet (EL 1040.765) in boring FS 23-B2.

The proposed wall is expected to have a maximum height of approximately 15 feet and a base width of 5 feet. The proposed wall will be founded on the existing 1.3H:1V slope, with a minimum horizontal bench width of 4 feet in front of the wall.

The proposed wall can be situated on a residuum near the roadway with level backfill. Alternatively, it can be placed on weathered rock at EL 1015, with a 1.5H:1V rip-rap back slope above the wall.

There are two issues with placing the wall on residuum: reduced bearing capacity due to the existing slope and the risk of slope instability affecting the foundation. The nominal bearing resistance of the wall founded on residuum on the existing 1.3H:1V slope was evaluated in accordance with AASHTO Section 10.6.3.1.2c.

The nominal bearing resistance of the proposed wall founded on residuum is 1.5 ksf. The factored bearing resistance at the strength limit state is 0.675 ksf with a resistance factor of 0.45. The CDR for the wall founded on residuum is 0.2, which is less than 1.0 and therefore not acceptable. The global stability of the proposed wall founded on residuum is 1.17 for static loading, which is less than 1.3 and therefore not acceptable.

Bearing capacity and global stability computations are included in Appendix C of this report.

The existing slope is approximately 38 degrees, with weathered rock expected around elevation 1014. To address bearing and global stability concerns, it is recommended to base the proposed wall on this weathered rock. Table 11 outlines the location and maximum height of the wall.

Geotechnical Investigation and Design Report – July 08, 2024 13

Table 11: Proposed Retaining Wall Locations

Milepost

(Pin

Number)

Station

Proposed

Roadway

Grade

Elevation

(feet)

Top

Leveling

Pad

Elevation

(feet)

Approx.

Max. Wall

Height

(feet)

Finish Grade Conditions

From To Top of Wall Base of Wall

9.245

(Pin 365) 2+00 2+80 1048 1015 15

1.5H:1V

Riprap

Ascending slope

1.3H:1V

Descending

Slope

The proposed wall founded on weathered bedrock materials and should be designed for the strength limit state using a factored bearing resistance of 9 ksf. The factored bearing resistance at the strength limit state is calculated using a resistance factor of 0.45 and nominal bearing resistance of 20 ksf. The bearing resistance calculations are included in Appendix C. As the proposed walls are to be founded on rock, it is anticipated that the vertical settlements of the walls will be negligible. The bearing stratum should be visually inspected to verify the presence of weathered rock. If site conditions differ from the conditions described above, JMT should be notified to evaluate these conditions and provide revised recommendations. In addition, the footings should be founded at a minimum depth of 2.0 feet below exterior finish grade. A sliding resistance factor, Фt, of 0.9 was used to the nominal sliding resistance of Redi-rock block. The eccentricity of loading at the strength limit state, based on factored loads, shall not exceed one-third (1/3) of the footing dimension.

The global stability analysis estimated FS for the proposed wall to exceed 1.3 under static loading conditions.

The detailed results of the stability analyses can be found in Appendix C.

A pseudostatic global stability analysis was conducted under seismic loading conditions. The calculated global factor of safety for earthquake events is about 0.98 at MP 9.245, which is below the required FS of

1.1. Consequently, the lateral displacement was assessed using the Simplified Newmark Seismic

Displacement method. The analysis indicates that the resulting lateral displacement is approximately 1.14 inches, which falls within the allowable limits and is therefore deemed acceptable. The results of the stability analyses are included in Appendix C.

At MP 9.245, the proposed fill slope above the wall will be graded to 1.5:1V to reach roadway grade. It is recommended to use riprap fill slope to avoid surficial instability. Without cohesion, slope stability solutions approach an infinite slope solution with a factor of safety equal to tan(φ)/tan(β) with φ equal to the friction angle and β equal to the slope angle. The riprap filling materials with a friction angle of 45 degrees can graded at a slope of 1.5H:1V to obtain a required factor of safety of 1.3.

Geotechnical Investigation and Design Report – July 08, 2024 14

5.4.2 MP 10.189 (Pin 370) and MP 10.378 (Pin 371)

Based on field observations and the results of subsurface exploration programs, it is recommended to use retaining walls to stabilize the landslide at MP 10.189 and MP 10.378 locations. Table 12 provides the location and maximum wall height.

Table 12: Proposed Retaining Wall Locations

(Pin

Number)

Station

Proposed

Roadway

Grade

Elevation

(feet)

Top

Leveling

Pad

Elevation

(feet)

Approx.

Max. Wall

Height

(feet)

Finish Grade Conditions

From To Top of Wall Base of Wall

10.189

(Pin 370) 4+80 5+60 1144 1131 10 Level

0.5H:1V

Descending

Slope

10.378

(Pin 371) 9+00 9+80 1184 1176 10 Level

0.9H:1V

Descending

Slope

The proposed walls at MP 10.189 and MP 10.378 will be founded on bedrock materials and should be designed for the strength limit state using a factored bearing resistance of 9 ksf. The factored bearing resistance at the strength limit state is calculated using a resistance factor of 0.45 and nominal bearing resistance of 20 ksf. The bearing resistance calculations are included in Appendix C. As the proposed walls are to be founded on rock, it is anticipated that the vertical settlements of the walls will be negligible. The bearing stratum should be visually inspected to verify the presence of competent rock. If site conditions differ from the conditions described above, JMT should be notified to evaluate these conditions and provide revised recommendations. In addition, the footings should be founded at a minimum depth of 2.0 feet below exterior finish grade. A sliding resistance factor, Фt, of 0.9 was used to the nominal sliding resistance of Redi-rock block. The eccentricity of loading at the strength limit state, based on factored loads, shall not exceed one-third (1/3) of the footing dimension.

Based on the global stability analyses, the FS for the proposed walls at MP 10.189 and MP 10.378 were estimated to be in excess of 1.3 for static loading. The results of the stability analyses are included in

Appendix C.

The global stability analyses indicate that the FS for the proposed walls at MP 10.189 and MP 10.378 is in excess of 1.1 for seismic loading and therefore are considered to be acceptable. The results of the stability analyses are included in Appendix C.

Geotechnical Investigation and Design Report – July 08, 2024 15

5.5 Construction Considerations

5.5.1 Excavation Considerations

Excavation at this site is expected to consist of the removal of loose materials on the slopes, and excavations required to construct the proposed retaining walls. Bedrock should be anticipated at the depths as indicated by “casing refusal” in the boring logs. In certain borings, the rock cores revealed low RQD and recovery, thereby suggesting the possibility of layers or ledges of less weathered rock (i.e. intact rock) within the completely weathered rock matrix. During excavation, in some areas, these layers/ledges of intact rock may be seen as large boulders. In some areas, rock was encountered above the proposed depth of excavation.

The depth of the rock is anticipated to vary considerably, depending upon the degree of weathering. Hard digging of the residual soil and/or decomposed rock should also be anticipated above the rock surface. The rock/weathered rock could be excavated using special equipment, such as hoe-ram or heavy excavator; or soundless chemical demolition agents (SCDA), hydraulic splitting or by blasting. If blasting is employed, it should comply with Section 205 of the FP-14 guidelines.

5.5.2 Construction Groundwater

Groundwater was found in some borings, indicating its likely presence at depths in proposed excavations.

Perched water conditions might occur during wet seasons or after heavy rain or snow melt. The contractor should be ready to manage groundwater if encountered. Excavations for the retaining wall foundations must remain dry, with surface water prevented from entering. Site grading should prevent water ponding in excavations.

5.5.3 Temporary Excavation Support

All excavations must be performed in accordance with applicable Federal, local and OSHA standards, including any temporary support of excavation structures determined to be needed by the contractor for their means and methods of construction.

5.5.4 Soil Erosion and Slope Protection

The soils at and near the surface consisting of sands, silty sands, silts, and silty clay are considered susceptible to erosion. Therefore, all exposed surfaces should be seeded and vegetated to prevent erosion, as soon as possible. Exposed slopes should be protected from erosion in accordance with local sediment and erosion regulations and as described in Erosion and Sediment Control Plans.

Geotechnical Investigation and Design Report – July 08, 2024 16

6.0 REPORT ASSUMPTIONS AND LIMITATIONS

This report has been prepared to assist the Design Team with evaluating the sites and proposing repairs on

McFarland Road (FS 23) at MP 9.245, 10.189, and 10.378, Tennessee. The report scope is limited to recommendations specific to this project and the locations. The project description represents our current understanding of the significant aspects of the proposed improvements relevant to the geotechnical considerations.

The analysis and recommendations contained in this report are based on the data obtained from the test borings performed at the locations indicated on the boring location plans. The report does not account for subsurface variations that could occur at locations not investigated by the test boring. The nature and extent of such variations may only become evident during construction. If subsurface conditions differ from those described in this report, the recommendations must be re-evaluated.

Plans and specifications should be developed to accommodate possible additional costs that may be required for construction or foundations and/or excavation, as recommended in this report. Additional costs may arise due to various factors, such as project needs or resource requirements, extra foundation depth, potential footing redesign, unsuitable fill material, disturbance of subgrades, groundwater, subsurface obstructions, and others. Based on discussions with USFS Forest Managers and maintenance staff, similar repair projects within the forest have experienced challenges with backslope stability during slope repairs, necessitating increased quantities of fill stone material.

Geotechnical Investigation and Design Report – July 08, 2024 17

7.0 REFERENCES

AASHTO LRFD Bridge Design Specifications, 9th Edition, 2020.

Federal Land Highway Project Development and Design Manual (2018), Federal Highway Administration, Washington, DC.

Design Manual 7.01: Soil Mechanics (1986), Naval Facilities Engineering Command, Virginia.

Design Manual 7.02: Foundations and Earth Structures (1986), Naval Facilities Engineering Command, Virginia.

Geologic Map of Tennessee, (east central sheet), Hardeman, W.D., Miller, R.A., Swingle, G.D. Tennessee

Division of Geology, 1966.

Slide2 Modeler, Rocscience, Toronto, Ontario, Canada.

Soils and Foundation (2006), Volume I, Publication No. FHWA NHI-06-088, Washington, DC.

Soils and Foundation (2006), Volume II, Publication No. FHWA NHI-06-089, Washington, DC.

Geotechnical Investigation and Design Report – May 13, 2024

Appendix A

Site Location Map, Site Geologic Map and General Plans

Site Location Map

McFarland Road

FS 23

Polk County, Tennessee

Project Location

Project Area

N

Site Geologic Map

FS 23

Polk County, Tennessee

Project Location

McFarland Road

Source: Geologic Map of Tennessee, Miller, Swingle, 1966, Tennessee Division of Geology

CHEROKEE

0 5

0 45

0 5

0 6

5 9

0 115

5 240

5 310

320325

0 365

455460

5 4

0 3000 6000

SCALE IN FEET

R d

Lost C reek

FR

R d 80

M ountain

S m ith

M cFarland R d

McFarland Rd

M cF a rl a n d R d

N

:3

A

M

M a y

M c F a rl a n d L o c a ti o n

M a p c p w w o r k in g

\j m t\ d

\m

H D

M c F a r la n d

O v e r a ll

.d g n

MCFARLAND LOCATION MAP

STATE PROJECT

NUMBER

SHEET

NPS Drwg No. XXX/XXXX NPS PMIS No. 000000

McFARLAND RD (GRAVEL)

10" MAPLE

15" POP

18" POP

XCP 5/8 RBC

SEABOARD SYSTEMS RAILROAD

ROW

PPROXIMATE

CP

299A

15" OAK

24" POP

CP

XCP 5/8 RBC

14" POP

301A

H

D P E

INV = 1052.36

INV = 1044.91

N

0 20 40

SCALE IN FEET

RIPRAP SLOPE

LEGEND

BORING

RETAINING WALL

FS23-B1

FS23-B2

:5

M a y

P

P la n V ie w p w w o r k in g

\j m t\ d

\m

H D

M c F a r la n d

.d g n

P 365 PLAN VIEW

MILEPOST 9.245

STATE PROJECT

NUMBER

SHEET

P 365

W O

LF

C

R E E K

McFA

RLAND R

D (G

RAVEL)

X C

P R

B C

I

N H

IC

K O

R Y1 I

N P

IN

E

B H

C P

A

I

N H

IC

K O

R Y

I

N B

IR

C H

P O

P L

A R

I

N

P O

P L

A R I

N

N

0 20 40

SCALE IN FEET

FS23-B4

FS23-B5

FS23-B3

:3

M a y

P

B

L

P la n p w w o r k in g \j m t\ d \m

H D

M c F a r la n d

.d g n

P 370 BL - PLAN

MILEPOST 10.189

STATE PROJECT

NUMBER

SHEET

Plan 1

McFARLAND RD (GRAVEL)

WOLF CREEK

A

A

C P

X C P R

B C

P

O P

B

IR

C H

P

O P

C P

X C P R

B C

P

IN

E

P

O P

P

O P

N

0 20 40

SCALE IN FEET

0FS23-B6

FS23-B7

:4

M a y

P

B

L

P

P la n p w w o r k in g \j m t\ d \m

H D

M c F a r la n d

.d g n

P 371 BL - P 371 PLAN

MILEPOST 10.378

STATE PROJECT

NUMBER

SHEET

P 371 Plan

Appendix B

Boring Log and Laboratory Testing Report

S&ME, Inc. | 1413 Topside Road | Louisville, Tennessee 37777 | p 865.970.0003 | www.smeinc.com

April 22, 2024

Johnson, Mirmiran & Thompson, Inc.

40 Wright Avenue

Hunt Valley, Maryland 21030

Attention: Mr. Vijaya Garimella, P.E., Ph. D., D. GE.

Reference: Data from Geotechnical Exploration

Task 24: FS – 23 McFarland Road

McFarland Road, Turtletown, Tennessee

S&ME Project No. 23430366

Dear Mr. Garimella, The following presents the results of our geotechnical exploration and laboratory testing performed for the Task

24: FS-23 McFarland Road project in Turtletown, Tennessee. The work was performed in general accordance with

S&ME Proposal No. 23430366 dated September 7, 2023 and as authorized by Mr. William Schaub with Johnson

Mirmiran & Thompson, Inc. The purpose of the project was to characterize general subsurface conditions in the project area and provide laboratory test results for use in making geotechnical recommendations. The boring logs, laboratory tests results, and photographs are attached to this letter. Please let us know if you have any questions or if we may be of further assistance.

Sincerely, S&ME, Inc.

Joshua A. Baines, EI Daniel R. Boles, PE

Geotechnical Operations Manager Principal Geotechnical Engineer

Attachments: Boring Logs

Laboratory Test Results

Site Photographs

Appendix B

Boring Log and Laboratory Testing Report

DE

PT

H (fe et

NOTES

0.1

4.0

15.5

O rig in /I de nƟ

Įe r

Re sid uu m

G

RA

PH

IC

SAMPLE NO.

(RECOVERY)

SS-1

SS-2

SS-3

SS-4

SS-5

SS-6

SS-7

MATERIAL DESCRIPTION

AGGREGATE BASE, 1 inch SILT (ML), liƩle sand, Įrm to very sƟī, blue gray with brown, relict structure, moist

SILT (ML), liƩle sand, sƟī to hard, blue gray with brown, relict structure, moist

SILT (ML), liƩle sand, liƩle rock fragments, very sƟī, blue gray with brown, relict structure, moist

BLOW COUNT

DATA

(SPT N-value)

7-11-8-6 N = 19

4-4-3-2 N = 7

6-6-5-7 N = 11

17-15-10 N = 25

10-12-19 N = 31

14-11-17 N = 28

5-7-15 N = 22

STANDARD PENETRATION TEST DATA

EL

EV

AT

IO

N

% Fines

NMC

PL---LL

20 40 60 80 100

PROJECT: Task 24: FS - 23 McFarland Road Turtletown, Tennessee

S&ME Project No. 23430366

BORING LOG: FS-23-B1

Sheet 1 of 3

DATE DRILLED: 01/24/2024

DRILL RIG: D-50

DRILLER: Frank Crane

HAMMER TYPE: AutomaƟc hammer

DRILLING METHOD: HQ CA, NQ

ELEVATION: 1050 Ō

DATUM: NAVD88

BORING DEPTH: 50.6 Ō

CLOSURE: Cement Grout LOGGED BY: Pen Sibley

NOTES: Sample descripƟons based on visual observaƟons of obtained samples.

NORTHING: 308783.6 EASTING: 2449545.7

SAMPLING METHOD: SS, CORE PROJECT COORDINATE SYSTEM - NAD 1983 StatePlane Tennessee FIPS 4100 Feet

GROUNDWATER DATE DEPTH

(FT) REMARKS

ATD 01/23/2024 Not encountered prior to coring

END OF DRILLING

AFTER DRILLING 01/25/2024 Not encountered

AFTER DRILLING

GROUNDWATER DEPTHS ARE NOT EXACT AND MAY VARY SUBSTANTIALLY FROM THOSE INDICATED. ATD = AT TIME OF DRILLING LL=Liquid Limit, PL = PlasƟc Limit, NMC = Natural Moisture Content, PPV = Pocket Penetrometer (tsf), PTV = Pocket Torvane (tsf), AR = Auger Refusal, IGM = Intermediate Geomaterial

H (fe et

NOTES

Casing Advancer Refusal at 35.2 feet

22.0

O rig in /I de nƟ

Įe r

Re sid uu m

G

RA

PH

IC

SAMPLE NO.

(RECOVERY)

SS-8

SS-9

SS-10

MATERIAL DESCRIPTION

SILT (ML), liƩle sand, liƩle rock fragments, very sƟī, yellow brown with brown, relict structure, moist

BLOW COUNT

DATA

(SPT N-value)

7-9-11 N = 20

7-11-11 N = 22

9-11-13 N = 24

STANDARD PENETRATION TEST DATA

EL

EV

AT

IO

N

% Fines

NMC

PL---LL

20 40 60 80 100

35.2 35.6

Run-1

REC-8%

RQD-0%

Run-2

REC-34%

RQD-0%

Run-3

SLATE, gray, incompetent, very poor quality, highly weathered, moderately hard SLATE, gray with yellow brown, incompetent, very poor quality, slightly weathered to highly weathered, moderately hard to hard

PROJECT: Task 24: FS - 23 McFarland Road Turtletown, Tennessee

S&ME Project No. 23430366

BORING LOG: FS-23-B1

Sheet 2 of 3

DATE DRILLED: 01/24/2024

DRILL RIG: D-50

DRILLER: Frank Crane

HAMMER TYPE: AutomaƟc hammer

DRILLING METHOD: HQ CA, NQ

ELEVATION: 1050 Ō

DATUM: NAVD88

BORING DEPTH: 50.6 Ō

CLOSURE: Cement Grout LOGGED BY: Pen Sibley

NOTES: Sample descripƟons based on visual observaƟons of obtained samples.

NORTHING: 308783.6 EASTING: 2449545.7

SAMPLING METHOD: SS, CORE PROJECT COORDINATE SYSTEM - NAD 1983 StatePlane Tennessee FIPS 4100 Feet

GROUNDWATER DATE DEPTH

(FT) REMARKS

ATD 01/23/2024 Not encountered prior to coring

END OF DRILLING

AFTER DRILLING 01/25/2024 Not encountered

AFTER DRILLING

GROUNDWATER DEPTHS ARE NOT EXACT AND MAY VARY SUBSTANTIALLY FROM THOSE INDICATED. ATD = AT TIME OF DRILLING LL=Liquid Limit, PL = PlasƟc Limit, NMC = Natural Moisture Content, PPV = Pocket Penetrometer (tsf), PTV = Pocket Torvane (tsf), H (fe et

NOTES

Hole Cave at 46.6 feet

45.6

50.6

G

RA

PH

IC

SAMPLE NO.

(RECOVERY)

REC-32%

RQD-0%

Run-4

REC-80%

RQD-16%

MATERIAL DESCRIPTION

SLATE, gray with yellow brown, incompetent, very poor quality, slightly weathered to highly weathered, moderately hard to hard

SLATE, gray with yellow brown, fairly conƟnuous, very poor quality, slightly weathered to highly weathered, moderately hard to hard

Borehole terminated at 50.6 feet

EL

EV

AT

IO

N

PROJECT: Task 24: FS - 23 McFarland Road Turtletown, Tennessee

S&ME Project No. 23430366

BORING LOG: FS-23-B1

Sheet 3 of 3

DATE DRILLED: 01/24/2024

DRILL RIG: D-50

DRILLER: Frank Crane

HAMMER TYPE: AutomaƟc hammer

DRILLING METHOD: HQ CA, NQ

ELEVATION: 1050 Ō

DATUM: NAVD88

BORING DEPTH: 50.6 Ō

CLOSURE: Cement Grout LOGGED BY: Pen Sibley

NOTES: Sample descripƟons based on visual observaƟons of obtained samples.

NORTHING: 308783.6 EASTING: 2449545.7

SAMPLING METHOD: CORE, SS PROJECT COORDINATE SYSTEM - NAD 1983 StatePlane Tennessee FIPS 4100 Feet

GROUND WATER DATE/TIME DEPTH

(FT) REMARKS

ATD 01/23/2024 Not encountered prior to coring

END OF DRILLING

AFTER DRILLING 01/25/2024 Not encountered

AFTER DRILLING

GROUNDWATER DEPTHS ARE NOT EXACT AND MAY VARY SUBSTANTIALLY FROM THOSE INDICATED. ATD = AT TIME OF DRILLING

Project:

Task 24: FS - 23 McFarland Road

Turtletown, Tennessee 23430366

LocaƟon Photos: FS-23-B1 Sheet 1 of 1

Date: 01/24/2024 ElevaƟon: 1050 Ō Notes:

Photograhed by: Pen Sibley Northing: 308783.6 EasƟng: 2449545.7

Box 1 of 1: 35.2' to 50.2'

H (fe et

NOTES

Casing Advancer Refusal at 6.0 feet

0.1

4.0

O rig in /I de nƟ

Įe r

Re sid uu m

G

RA

PH

IC

SAMPLE NO.

(RECOVERY)

SS-1

SS-2

SS-3

MATERIAL DESCRIPTION

AGGREGATE BASE, 1 inch SILT (ML), liƩle sand, liƩle rock fragments, sƟī to very sƟī, blue gray with brown, relict structure, moist

SILTY SAND WITH GRAVEL (SM), liƩle sand, liƩle rock fragments, sƟī to very sƟī, blue gray with brown, relict structure, moist

BLOW COUNT

DATA

(SPT N-value)

8-10-12-14 N = 22

9-6-4-5 N = 10

9-16-14-19 N = 30

STANDARD PENETRATION TEST DATA

EL

EV

AT

IO

N

% Fines

NMC

PL---LL

20 40 60 80 100

Hole Cave at 17.4 feet

6.0

10.5

15.5

20.5

Run-1

REC-51%

RQD-9%

Run-2

REC-42%

RQD-0%

Run-3

REC-52%

RQD-12%

SLATE, gray with yellow brown, competent, very poor quality, slightly weathered to highly weathered, moderately hard

SLATE, gray with yellow brown, competent, very poor quality, highly weathered to completely weathered, soŌ

SLATE, gray with yellow brown, competent, very poor quality, slightly weathered to highly weathered, moderately hard

Borehole terminated at 20.5 feet

PROJECT: Task 24: FS - 23 McFarland Road Turtletown, Tennessee

S&ME Project No. 23430366

BORING LOG: FS-23-B2

Sheet 1 of 1

DATE DRILLED: 01/24/2024

DRILL RIG: D-50

DRILLER: Frank Crane

HAMMER TYPE: AutomaƟc hammer

DRILLING METHOD: HQ CA, NQ

ELEVATION: 1047 Ō

DATUM: NAVD88

BORING DEPTH: 20.5 Ō

CLOSURE: Cement Grout LOGGED BY: Pen Sibley

NOTES: Sample descripƟons based on visual observaƟons of obtained samples.

NORTHING: 308829.0 EASTING: 2449617.5

SAMPLING METHOD: SS, CORE PROJECT COORDINATE SYSTEM - NAD 1983 StatePlane Tennessee FIPS 4100 Feet

GROUNDWATER DATE DEPTH

(FT) REMARKS

ATD 01/23/2024 Not encountered prior to coring

END OF DRILLING

AFTER DRILLING 01/25/2024 Not encountered

AFTER DRILLING

GROUNDWATER DEPTHS ARE NOT EXACT AND MAY VARY SUBSTANTIALLY FROM THOSE INDICATED. ATD = AT TIME OF DRILLING LL=Liquid Limit, PL = PlasƟc Limit, NMC = Natural Moisture Content, PPV = Pocket Penetrometer (tsf), PTV = Pocket Torvane (tsf), Turtletown, Tennessee 23430366

LocaƟon Photos: FS-23-B2 Sheet 1 of 1

Date: 01/24/2024 ElevaƟon: 1047 Ō Notes:

Photograhed by: Pen Sibley Northing: 308829.0 EasƟng: 2449617.5

Box 1 of 1: 6.0' to 20.5'

H (fe et

NOTES

Hole Cave at

3.2 feet

Casing Advancer Refusal at 5.6 feet

0.1

2.0

O rig in /I de nƟ

Įe r

Re sid uu m

G

RA

PH

IC

SAMPLE NO.

(RECOVERY)

SS-1

SS-2

SS-3

MATERIAL DESCRIPTION

AGGREGATE BASE, 1 inch

SILTY, CLAYEY SAND WITH GRAVEL (SC-

SM), loose, gray, Įne to medium grained, wet

SILTY, CLAYEY SAND WITH GRAVEL (SC-

SM), loose to very dense, orange brown with gray, Įne to medium grained, moist

BLOW COUNT

DATA

(SPT N-value)

5-6-3-5 N = 9

3-3-2-3 N = 5

3-5-50/3" N = 50/3"

STANDARD PENETRATION TEST DATA

EL

EV

AT

IO

N

% Fines

NMC

PL---LL

20 40 60 80 100

5.6

7.2

9.9

15.3

Run-1

REC-43%

RQD-23%

Run-2

REC-90%

RQD-52%

GRAYWACKE, blue gray, competent to fairly conƟnuous, very poor quality to fair quality, medium grained to coarse grained, fresh to moderately weathered, very hard

Void

GRAYWACKE, blue gray, conƟnuous, good quality, medium grained to coarse, slightly weathered to fresh, very hard

Borehole terminated at 15.3 feet

PROJECT: Task 24: FS - 23 McFarland Road Turtletown, Tennessee

S&ME Project No. 23430366

BORING LOG: FS-23-B3

Sheet 1 of 1

DATE DRILLED: 01/24/2024

DRILL RIG: D-50

DRILLER: Frank Crane

HAMMER TYPE: AutomaƟc hammer

DRILLING METHOD: HQ CA, NQ

ELEVATION: 1143 Ō

DATUM: NAVD88

BORING DEPTH: 15.3 Ō

CLOSURE: Cement Grout LOGGED BY: Pen Sibley

NOTES: Sample descripƟons based on visual observaƟons of obtained samples.

NORTHING: 307897.5 EASTING: 2451910.2

SAMPLING METHOD: SS, CORE PROJECT COORDINATE SYSTEM - NAD 1983 StatePlane Tennessee FIPS 4100 Feet

GROUNDWATER DATE DEPTH

(FT) REMARKS

ATD 01/23/2024 Not encountered prior to coring

END OF DRILLING

AFTER DRILLING 01/25/2024 Rain water running into boring

AFTER DRILLING

GROUNDWATER DEPTHS ARE NOT EXACT AND MAY VARY SUBSTANTIALLY FROM THOSE INDICATED.