AK FWS 74525(1) Swan Lake - Final AOP Foundation and Geotechnical Recommendations Memo.pdf

158377846

M E M O R A N D U M Western Federal Lands Highway Division

610 E. Fifth Street Vancouver, WA 98661

DATE: October 14, 2022

TO: Reuben Johnson Project Manager

FROM: Hayden Gluck Geotechnical Engineer

SUBJECT: Geotechnical Memo 17-22 Final AOP Foundation and Geotechnical Recommendations Swan Lake Road

AK FWS KNA 74525(1)

Kenai National Wildlife Refuge, Alaska

INTRODUCTION

This memorandum summarizes subsurface investigation results and provides final aquatic organism passage (AOP) foundation recommendations and geotechnical recommendations for the Swan Lake Road project. The subsurface investigation was performed July 15, 2022 with WFLHD Geotechnical personnel present. The recommendations presented herein are based on the 30-percent plan set. A site photography log may be found in Attachment A, site maps may be found in Attachment B, and laboratory test results may be found in Attachment C.

PROJECT DESCRIPTION

This project includes three sites along portions of Swan Lake Road and Swanson River Road in the Kenai National Wildlife Refuge in Alaska. Both roads are two-lane, low-volume, gravel-surfaced access roads utilized primarily for nearby recreation. Swanson River Road project limits begin 14 ½ miles north of the Sterling Highway intersection at approximate milepost (MP)

14.5 and end at Swanson River Campground, approximately four miles north. Swan Lake Road project limits begin at the Swanson River Road intersection at approximate MP 18.0 and end at the Swanson River Canoe Route, approximately 12.7 miles east. Refer to Figure B-1 for a project location map and Figure B-2 for a vicinity map.

Project Scope

The project will improve passage of aquatic organisms at each of the three existing culvert locations. It will also include ditch reconditioning to alleviate existing drainage issues and preserve the pavement section integrity. Roadway repairs and improvements within the project scope are intended to address safety and functionality deficiencies Based on correspondence with the cross-functional design team, the roadway prism structural integrity was observed to be generally good. Subsurface investigation results presented herein support development of geotechnical strength parameters for soils in direct proximity to proposed AOP locations. Refer to Figure B-3 for the test pit exploration location.

GEOLOGY

The project area is located west of the Chugach mountain range in the lowlands portion of the Kenai Peninsula, slightly south of the Swanson River. As shown in below, Geologic Map of the Cook Inlet Region, Alaska, Including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale Quadrangles (Wilson, et. al., 2012), the project area is located within the vicinity of Holocene- to upper Pleistocene-aged glaciolacustrine deposits (Qgl). Glaciolacustrine deposits are described as well-stratified, laminated to massive silt and clay, with some sand and gravel. Unconsolidated glaciolacustrine deposits may include surface layers of muck and peat.

Figure 1. Excerpt of the Geologic Map of the Cook Inlet Region, Alaska, Including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale Quadrangles (Wilson, et. al., 2012)

Project Area

Qgl

SITE CONDITIONS

Initial site reconnaissance was conducted July 12, 2022 with a follow-up visit later in the week on July 15 to conduct a test pit excavation with the USFWS. Please refer to Appendix A for photographs of site conditions.

AOP Site 1 – Sucker Creek

Surface observations within the vicinity of the existing pair of 42-inch CMP culverts indicate aggregate surfacing on Swan Lake Road consists of poorly-graded SAND with silt and gravel.

Surface water in Sucker Creek was observed at inlet and outlet locations of the double-barrel CMP culverts at approximately 5 to 6 below existing grade. Boulders up to 4 ½ feet in diameter were observed upstream at the inlet location south of Swan Lake Road. Vegetation consists of horsetail, water lilies, and spruce, birch, and cottonwood trees. A test pit was advanced at this site southeast of the existing culverts. Excavation observations of this test pit are summarized below in Subsurface Conditions.

AOP Site 2 – Unnamed Creek

Surface observations within the vicinity of the existing pair of 36-inch corrugated metal pipe (CMP) culvert indicate aggregate surfacing on Swan Lake Road consists of poorly-graded SAND with silt and gravel. Gravels were observed to be approximately 4 inches or fewer in diameter and subrounded to rounded in shape. Surface water was identified in the existing culvert location. Hydrophytic vegetation was observed primarily in the vicinity of the culvert and its inlet and outlet. Mucky conditions at the culvert and the presence of hydrophytic vegetation indicate surface soils may contain organics and likely consist primarily of soft, fine-textured soils.

Test pits were not advanced at this proposed AOP location due to shallow surface water and possible wetland soil conditions making it difficult for the backhoe to safely backfill the excavation.

AOP Site 3 – Rainbow Lake

Surface observations within the vicinity of the site and review of 30 percent design plan sheets indicate the existing 48-inch diameter CMP culvert is approximately 15 feet below existing grade. The culvert inlet was observed to be angled up, indicating the culvert may be bent or broken beneath the roadway prism on Swanson River Road. A portion of the bottom of the culvert outlet has corroded away. This may be a result of loading excess loading on the culvert or from complications due frozen soil and water conditions. Minor sinkholes observed within the roadway telegraph possible scour of material beneath the middle of the roadway, indicating the pipe culvert may be leaking. Photos from a previous site visit conducted by WFL Hydraulics Group staff in 2019 show that visibility to between the culvert inlet and outlet is obstructed. Test pits were not advanced at this proposed AOP location because the available excavation equipment lacked the necessary reach.

SUBSURFACE CONDITIONS

The subsurface investigation for this project consisted of one test pit (TP22-01). The test pit was excavated to a maximum depth of 5 feet bgs, where exploration was terminated due to the presence of groundwater. Material sampling methods included bulk grab samples and one-gallon bag samples for moisture content testing. Table 1 summarizes subsurface investigation activity performed for this project and Figure B-3 of Attachment B – Site Maps shows the excavation location. A tabulated test pit log may be found in AOP Site 1 – Sucker Creek.

Table 1. Test Pit Excavation

Designation Location Groundwater

Depth (feet bgs)

Maximum Depth (feet bgs)

Coordinates 1 (Decimal Degrees)

Latitude Longitude

TP22-01

~20 feet SE of Existing

Culvert at Sucker Creek

5.0 5.0 60.724771° -150.678113°

1. Coordinates were obtained using a hand-held GPS device and locations are not surveyed.

AOP Site 1 – Sucker Creek

Test pit TP22-01 was advanced southeast of and adjacent to the existing culvert and proposed AOP location at Sucker Creek. Subsurface lithology may generally be grouped into two categories: roadway prism fill and glaciolacustrine deposits.

Table 2. TP22-01 Test Pit Log

Depth (feet bgs) Material Description Sample No.

0 – 3 Brownish gray, dry to moist, poorly-graded GRAVEL with silt and sand (fill), medium dense. Sand is fine to coarse and gravels are subrounded to angular. Nonplastic.

3 – 4½ Gray to dark gray, moist to wet SILT with sand, soft to medium stiff.

Sand is fine to medium. Low plasticity. S-1

4½ – 5 Brown to gray, wet, poorly-graded GRAVEL with sand and cobbles, dense to very dense. Gravels were subangular to subrounded.

Nonplastic.

S-2

Roadway prism fill consisted of medium dense, brownish gray, dry to moist poorly-graded GRAVEL with silt and sand and extended from the ground surface to 3 feet bgs. Particle size in fill soils ranged from fine to coarse and angularity from subrounded to angular. Roadway prism fill material may be described as nonplastic.

Glaciolacustrine soils consisted of soft to medium stiff, gray to dark gray, moist to wet, nonplastic to low plasticity SILT with sand and dense to very dense, brown to gray, wet, nonplastic poorly-graded GRAVEL with sand and cobbles. Boulders were observed in vicinity to the exploration of up to 4 ½ ft in diameter. Gravel and cobble-sized particles include slate rock typically 4-inch to 6-inch in diameter and subangular to subrounded in shape.

Groundwater was observed at the time of excavation at 5 feet bgs and rising, likely to match surface water elevation in Sucker Creek.

Lab testing results may be found in Attachment C – Laboratory Test Results.

DESIGN RECOMMENDATIONS AND CONSTRUCTION CONSIDERATIONS

AOP Site 1 – Sucker Creek

The existing pair of 42-inch diameter CMP culverts at this location will be replaced by a 156-inch diameter AOP pipe culvert with riprap and headwalls. Subsurface investigation indicates shallow subsurface soils are consistent with mapped glaciolacustrine deposits mentioned in the Geology section of this report. Glaciolacustrine deposits are described as well-stratified, laminated to massive silt and clay, with some sand and gravel. Unconsolidated glaciolacustrine deposits may include surface layers of muck, consisting of soft silt with fine sand and organics, and peat. Given the presence of boulders of up to 4 ½ feet in diameter, the Contractor should be prepared with appropriately sized equipment.

AOP Site 2 – Unnamed Creek

The existing pair of 36-inch diameter CMP culverts at this location will be replaced by a 132-inch diameter AOP pipe culvert with riprap and headwalls. No subsurface investigation was performed at this site; however, like the Sucker Creek AOP location, the geologic map shows the site to be on glaciolacustrine deposits, Qgl. Glaciolacustrine deposits are described as well-stratified, laminated to massive silt and clay, with some sand and gravel. Unconsolidated glaciolacustrine deposits may include surface layers of muck, consisting of soft silt with fine sand and organics, and peat. Based on surface observations conducted during the site visit on July 12, 2022 and review of field notes and site photographs from a site visit in 2019 by WFLHD Hydraulics Group, mucky soil conditions are anticipated in the shallow subsurface. Review of the 30 percent plan sheets indicates the AOP base will be approximately 11 feet below existing grade, which may be beneath any surficial muck layers and into granular material.

AOP Site 3 – Rainbow Lake

The existing 48-inch diameter CMP culvert at this location will be replaced by a 132-inch diameter AOP pipe culvert with riprap and headwalls. No subsurface investigation was performed at this site; however, like the Sucker Creek AOP location, the geologic map shows the site to be on glaciolacustrine deposits, Qgl. Glaciolacustrine deposits are described as well-stratified, laminated to massive silt and clay, with some sand and gravel. Unconsolidated glaciolacustrine deposits may include surface layers of muck and peat. Given the lack of a subsurface investigation and uncertainty regarding the subsurface conditions, we recommend that the Contractor be prepared to encounter boulders up to 4 ½ feet in diameter.

Foundations

Shallow or deep foundations are not anticipated given the proposed AOP culverts are pipes and not open-bottom. Based on correspondence with the WFL Hydraulics Group and the 30-percent plan set, AOP pipe culverts will bear on 6-inch bedding course underlain by unyielding native material or compacted backfill. If spread footings are utilized, the nominal bearing resistance on native dense, granular materials, such as gravels, and rock is 4 ksf with resistance factors of

0.45 and 0.85 for bearing and sliding, respectively. If soft fine-grained or loose sand materials are encountered, the soft or loose materials should be removed down to suitable bearing materials described above. Additional depth to suitable bearing elevations due to scour may be recommended by the Hydraulics Engineer. Overexcavated materials should not be replaced with foundation fill due to scour potential; footings should rest directly on dense gravel or rock, or be replaced with structural concrete up to the design footing elevation. Foundation settlements at each of the AOP sites are expected to be less than an inch provided the recommendations described herein are followed.

Lateral Earth Pressures

The following recommendations for lateral earth pressures apply to each of the three AOP sites.

Lateral earth pressures of backfill material acting on AOP pipe culverts are based on the Structural Backfill specification (FP-14 Subsection 704.04) and do not include load or resistance factors. It is assumed that compacted backfill creates at-rest lateral earth pressures behind pipe culverts.

Table 3. Recommended Lateral Earth Pressure Parameters

Parameter Design Value

Backfill Moist Unit Weight 130 pcf Backfill Angle of Internal Friction 34 degrees

Backfill Interface Friction Angle, δ 26 degrees Active Earth Pressure Coefficient, Ka 0.28

Active Equivalent Fluid Pressure 36 psf/ft At-Rest Earth Pressure Coefficient, K0 0.44

At-Rest Equivalent Fluid Pressure 57 psf/ft Passive Earth Pressure Coefficient, Kp 3.54

Passive Equivalent Fluid Pressure 460 psf/ft Base Soil Moist Unit Weight 125 pcf

Base Soil Angle of Internal Friction 35 degrees Coefficient of Sliding Along the Base2, tan δ 0.65

Equivalent Height of Soil for Vehicle Loading of Abutment End Walls3, heq 3.5 ft Equivalent Height of Soil for Vehicle Loading of Abutment Wing Walls4, heq 2.0 ft

Notes:

1 Design values based on a drained condition behind the wall.

2 A resistance factor of 1.0 is recommended for sliding resistance of semigravity walls at the strength limit state (AASHTO Table 11.5.7-1)

3 Interpolated from Table 3.11.6.4-1 in AASHTO LRFD Bridge Design Specifications.

4 From Table 3.11.6.4-2 in AASHTO LRFD Bridge Design Specifications.

Dewatering

Dewatering recommendations described herein apply to each of the three AOP sites. Culvert construction will require excavations extending below the stream beds. Groundwater levels are expected to fluctuate seasonally and match surface water levels. However, during the dry summer months, we anticipate most of the stream channels will be dry. Therefore, the need for dewatering will depend on construction timing and the specific site conditions. If required, bypass pumping or piping may be necessary to transport surface water through the work zone.

During periods of sustained rain or snowfall, groundwater may infiltrate into the excavations and dewatering may be necessary. Excavations should be protected from surface water.

REFERENCES

American Association of State Highway and Transportation Officials (2020), AASHTO LRFD Bridge Design Specifications, 9th Edition, Washington, D.C.

Chen, Michael (2022), Aggregate Pavement Design Memo, Federal Highway Administration – Western Federal Lands Highway Division, Vancouver, Washington.

Wilson, Frederic H., Hults, Chad P., Schmoll, Henry R., Haeussler, Peter J., Schmidt, Jeanine M., Yehle, Lynn A., and Labay, Keith A. (2012), Geologic Map of the Cook Inlet Region, Alaska, Including parts of the Talkeetna, Talkeetna Mountains, Tyonek, Anchorage, Lake Clark, Kenai, Seward, Iliamna, Seldovia, Mount Katmai, and Afognak 1:250,000-scale Quadrangles, United States Geological Survey.

CLOSING

Please contact Hayden Gluck at (360) 619-7591 or hayden.gluck@dot.gov with any questions regarding this memorandum.

CC: James Neighorn – Hydraulics Engineer Benn Oltmann – Structural Team Lead Thomas Parker – Environmental Protection Specialist

Mike Baron – Construction Operations Engineer Kevin Parker – Highway Design Engineer Justin Bowling – Geomatics Vera Anderson – Right-of-Way/Utilities Engineer

Doug Anderson – Geotechnical Team Lead Geotechnical File

Attachments:

Attachment A – Site Photographs Attachment B – Vicinity Map, Project Map, Exploration Location Maps Attachment C – Laboratory Test Results mailto:hayden.gluck@dot.gov

ATTACHMENT A – SITE PHOTOGRAPHS

A-1. Existing Rainbow Lake Culvert Inlet A-2. Existing Rainbow Lake Culvert Outlet A-3. Existing Rainbow Lake Culvert Outlet to Rainbow Lake, Facing Toward Rainbow Lake A-4. Unnamed Creek AOP Site, Existing Culvert Inlet A-5. Vegetation Within the Vicinity of Unnamed Creek AOP Site A-6. Unnamed Creek AOP Site, Existing Culvert Outlet A-7. Sucker Creek AOP Site, Existing Culvert Inlets A-8. Boulders Observed at Sucker Creek AOP Site A-9. Sucker Creek AOP Site, Existing Culvert Outlets A-10. Groundwater Observed at 5 feet bgs in Sucker Creek AOP Site Test Pit A-11. Test Pit Profile for Sucker Creek AOP Site Test Pit

Photo A-1. Existing Rainbow Lake Culvert Inlet

Photo A-2. Existing Rainbow Lake Culvert Outlet

Photo A-3. Existing Rainbow Lake Culvert Outlet to Rainbow Lake, Facing Toward Rainbow Lake

Photo A-4. Unnamed Creek AOP Site, Existing Culvert Inlet

Photo A-5. Vegetation Within the Vicinity of Unnamed Creek AOP Site

Photo A-6. Unnamed Creek AOP Site, Existing Culvert Outlet

Photo A-7. Sucker Creek AOP Site, Existing Culvert Inlets

Photo A-8. Boulders Observed at Sucker Creek AOP Site

Photo A-9. Sucker Creek AOP Site, Existing Culvert Outlets

Photo A-10. Groundwater Observed at 5 feet bgs in Sucker Creek AOP Site Test Pit

Photo A-11. Test Pit Profile for Sucker Creek AOP Site Test Pit

ATTACHMENT B – SITE MAPS

Figure B-1: Project Location Map Figure B-2: Project Vicinity Map Figure B-3: Test Pit Exploration Map

610 East Fifth Street

Vancouver, WA 98661

Project No. Project Location Map FigureAK FWS KNA 74525(1) Scale

Swan Lake and Swanson River Road Kenai Peninsula, Alaska B-1

See Scale File Name:

Figure B-1.pptx Date:

September 21, 2022

Project Location

Vancouver, WA 98661

Project No. Vicinity Map FigureAK FWS KNA 74525(1) Scale

Swan Lake and Swanson River Road Kenai Peninsula, Alaska B-2

See Scale File Name:

Figure B-2.pptx Date:

September 21, 2022

R iv er si de R oa d

Sucker Creek AOP

Unnamed Creek AOPSwanson River Road (End of Project)

Swanson River Road (Beginning of Project)

Rainbow Lake AOP

Vancouver, WA 98661

Project No. Test Pit Location Map – AOP #2 FigureAK FWS KNA 74525(1) Scale

Swan Lake and Swanson River Road Kenai Peninsula, Alaska B-3

See Scale File Name:

Figure B-3.pptx Date:

September 21, 2022

R iv er si de R oa d

TP22-01

ATTACHMENT C – LABORATORY TEST RESULTS

Station:

Western Federal Lands

Project No.: AK FWS KNA 74525(1) Sample ID: W-22-0791-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other Submitted By: Hayden Gluck

Quantity Represented:

Item No.:

Field Sample No.: S-1

Lot No.:

Date Sampled: 7/14/2022

Depth: 3.5'-3.75' Hole No.: TP22-01

Project Name: SWAN LAKE ROAD PROJECT

Unit of MeasureResult

Specific Gravity @ 20°C 2.685

Methods: T 100 - AASHTO Test Date: 9/9/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0791-GS

Con tro lle d C op y

Unit of MeasureResult

See Attached Report Document

Methods: AASHTO T 88 - Interim Test Date: 9/8/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0791-GS

Con tro lle d C

AASHTO T 88

Particle Size Analysis of Soils Laboratory ID #

➖➖➖ Results ➖➖➖

6" sieve ( 152.4 mm) % Passing - %

5" sieve ( 127 mm) % Passing - %

4" sieve ( 101.6 mm) % Passing - %

3.5" sieve ( 88.9 mm) % Passing - %

3" sieve sieve ( 76 mm) % Passing - %

2.5" sieve ( 63.5 mm) % Passing - %

2" sieve (50.0 mm) % Passing 100.0 %

1.5" sieve (37.5 mm) % Passing 91.1 %

1" sieve (25.0 mm) % Passing 91.1 %

3/4" sieve (19.0 mm) % Passing 90.2 %

1/2" sieve (12.5 mm) % Passing 88.1 %

3/8" sieve (9.5 mm) % Passing 86.8 %

No. 4 sieve (4.75 mm) % Passing 83.4 %

No. 10 sieve (2.0mm) % Passing 78.6 %

No. 40 Sieve (0.425mm) % Passing 67.2 %

No. 200 Sieve (0.075mm) % Passing 40.8 % interpolated .020 mm % Passing 22.6 % interpolated .010 mm % Passing 17.2 % interpolated .005 mm % Passing 11.7 % interpolated .002 mm % Passing 5.3 % interpolated .001 mm % Passing - %

W-22-0791-GS

Attachment - Page 1 of 1

Drying Temperature 140 ° F

% Moisture 11.54 %

Methods: T 265 - AASHTO Test Date: 7/28/2022 Tested By: Jerrad Isch

Comments:

Test Validated By: Jerrad Isch Validated Date: 8/4/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0791-GS

Con tro lle d C

Liquid Limit From T 89 Not Run

Plastic Limit from T 90 Non-Plastic

Plasticity Index Not Applicable

Methods: T 89 & T 90 - AASHTO Atterberg Limit Test Date: 8/2/2022 Tested By: Don Rowe

Comments:

Test Validated By: Jerrad Isch Validated Date: 8/4/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0791-GS

Con tro lle d C

Classification A-4 (0)

Gravel (2.00-mm and larger) 21.4 %

Coarse sand (2.0 to 0.42-mm) 11.4 %

Fine Sand (0.42 to 0.074-mm) 26.4 %

Silt-clay (0.002 and smaller) 40.8 %

Methods: M 145 - AASHTO (AASHTO M 145 is not an AAP accredited test) Test Date: 9/9/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0791-GS

Con tro lle d C

Station:

Western Federal Lands

Project No.: AK FWS KNA 74525(1) Sample ID: W-22-0792-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other Submitted By: Hayden Gluck

Quantity Represented:

Item No.:

Field Sample No.: S-2

Lot No.:

Date Sampled: 7/14/2022

Depth: 5.0'-5.25' Hole No.: TP22-01

Project Name: SWAN LAKE ROAD PROJECT

Unit of MeasureResult

Specific Gravity @ 20°C 2.664

Methods: T 100 - AASHTO Test Date: 9/9/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0792-GS

Con tro lle d C

See Attached Report Document

Methods: AASHTO T 88 - Interim Test Date: 9/8/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0792-GS

Con tro lle d C

AASHTO T 88

Particle Size Analysis of Soils Laboratory ID #

➖➖➖ Results ➖➖➖

6" sieve ( 152.4 mm) % Passing - %

5" sieve ( 127 mm) % Passing - %

4" sieve ( 101.6 mm) % Passing - %

3.5" sieve ( 88.9 mm) % Passing - %

3" sieve sieve ( 76 mm) % Passing - %

2.5" sieve ( 63.5 mm) % Passing - %

2" sieve (50.0 mm) % Passing - %

1.5" sieve (37.5 mm) % Passing - %

1" sieve (25.0 mm) % Passing 100.0 %

3/4" sieve (19.0 mm) % Passing 95.9 %

1/2" sieve (12.5 mm) % Passing 94.3 %

3/8" sieve (9.5 mm) % Passing 90.9 %

No. 4 sieve (4.75 mm) % Passing 87.1 %

No. 10 sieve (2.0mm) % Passing 81.7 %

No. 40 Sieve (0.425mm) % Passing 68.2 %

No. 200 Sieve (0.075mm) % Passing 26.4 % interpolated .020 mm % Passing 11.8 % interpolated .010 mm % Passing 8.6 % interpolated .005 mm % Passing 5.4 % interpolated .002 mm % Passing 2.7 % interpolated .001 mm % Passing - %

W-21-0792-GS

Attachment - Page 1 of 1

Drying Temperature 140 ° F

% Moisture 19.19 %

Methods: T 265 - AASHTO Test Date: 7/28/2022 Tested By: Jerrad Isch

Comments:

Test Validated By: Jerrad Isch Validated Date: 8/4/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0792-GS

Con tro lle d C

Liquid Limit From T 89 Not Run

Plastic Limit from T 90 Non-Plastic

Plasticity Index Not Applicable

Methods: T 89 & T 90 - AASHTO Atterberg Limit Test Date: 8/2/2022 Tested By: Don Rowe

Comments:

Test Validated By: Jerrad Isch Validated Date: 8/4/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0792-GS

Con tro lle d C

Classification A-2-4 (0)

Gravel (2.00-mm and larger) 18.3 %

Coarse sand (2.0 to 0.42-mm) 13.5 %

Fine Sand (0.42 to 0.074-mm) 41.8 %

Silt-clay (0.002 and smaller) 26.4 %

Methods: M 145 - AASHTO (AASHTO M 145 is not an AAP accredited test) Test Date: 9/9/2022 Tested By: Don Rowe

Comments:

Test Validated By: Don Rowe Validated Date: 9/9/2022

Version 1

All reported results apply to the sample as received.

Page 1 of 1Sample ID: W-22-0792-GS

Con tro lle d C