219-400 Pvt-Geot Report for GOGA - Tennessee Vally TH Parking Lot.pdf

Pavement Engineering and Geotechnical Report

Golden Gate National Recreation Area

Tennessee Valley Parking Lot Improvements

FHWA Project No. CA FTNP GOGA 993(1)

Marin County, California

Yeh Project No.: 219-400

June 30, 2021

Prepared for:

Atkins 7604 Technology Way, Suite 400

Denver, CO 80237 Attn: Mr. Frank Schultz, P.E.

Prepared by:

Yeh and Associates, Inc.

391 Front Street, Suite D

Grover Beach, California 93433 Phone: 805-481-9590

391 Front Street, Suite D Grover Beach, CA 93433

(805) 481-9590 www.yeh-eng.com

Colorado California Denver | Colorado Springs | Durango | Glenwood Springs | Grand Junction | Greeley Grover Beach | Ventura

Pavement Engineering and Geotechnical Report

Golden Gate National Recreation Area

Tennessee Valley Parking Lot Improvements

FHWA Project No. CA FTNP GOGA 993(1)

Marin County, California

Yeh Project No.: 219-400

June 30, 2021

Prepared by:

Jonathan D. Blanchard, GE2312 Geotechnical Engineer

Reviewer:

Robert LaForce, PE Senior Project Manager http://www.yeh-eng.com/

Geotechnical Report Project No. 219-400 GOGA Tennessee Valley Parking Lot Improvements June 30, 2021 iii

Table of Contents

1. PURPOSE AND SCOPE OF STUDY

2. PROJECT UNDERSTANDING AND SITE DESCRIPTIONS

3. GEOTECHNICAL INVESTIGATION

3.1 DRILLING

3.2 LABORATORY TESTING

4. SITE CONDITIONS

4.1 GEOLOGIC SETTING

4.2 TERRAIN AND VEGETATION

4.3 CLIMATE

4.4 SUBSURFACE CONDITIONS

5. CONCLUSIONS AND RECOMMENDATIONS

5.1 EARTHWORK - GENERAL

5.1.1 GENERAL GRADING

5.1.2 EARTHWORK FACTORS

5.1.3 EROSION AND SLOPE DRAINAGE

5.1.4 REUSE OF ONSITE SOIL

5.2 PAVEMENT DESIGN

5.2.1 STRUCTURAL SECTION

5.2.2 HOT MIX ASPHALT

5.2.3 PAVEMENT MAINTENANCE

6. NOTES TO CONSTRUCTION

7. REFERENCES

List of Figures

FIGURE 1: VICINITY MAP

FIGURE 2: REGIONAL GEOLOGIC MAP

List of Tables

TABLE 1: FIELD EXPLORATION SUMMARY

TABLE 2: SUMMARY OF EXISTING PAVEMENT THICKNESSES

TABLE 3: SUMMARY OF LABORATORY TESTS FOR TENNESSEE VALLEY PARKING LOT

TABLE 4: SUMMARY OF STRUCTURAL SECTION RECOMMENDATIONS FOR TENNESSEE VALLEY ROAD

iv

List of Plates Plate 1: Field Exploration Plan

List of Appendices Page

Appendix A – Boring Logs Legend for Soil Classification ........................................................................................................ A-1 Legend for Rock Classification ...................................................................................................... A-2 Borehole Logs for Tennessee Valley, 20T-01 to 03 ............................................................... A-3 to 5 Boring Location Photos ................................................................................................................ A-6 Appendix B – Results of Laboratory Testing Summary of Laboratory Test Results ............................................................................................ B-1 Atterberg Limits ............................................................................................................................ B-2 Proctor Compaction ...................................................................................................................... B-3 R-value........................................................................................................................................... B-4 Appendix C – Pavement Design Calculations AASHTO (1993) Spreadsheet calculations........................................................................... C-1 and 2

1. PURPOSE AND SCOPE OF STUDY

Yeh and Associates was retained by Atkins to provide geotechnical recommendations for the design of various access and road improvements as part of the Federal Highway Administration projects for the Golden Gate National Recreation Area (GOGA) in Marin County and San Francisco, California. The location of the site is shown on Figure 1.

The geotechnical evaluation consisted of a program of project coordination, reviewing data, site reconnaissance, field exploration, laboratory testing, and engineering analyses as a basis for providing the recommendations in this report. This report provides recommendations for the design of earthwork and pavements.

2. PROJECT UNDERSTANDING AND SITE DESCRIPTIONS

The project generally consists of paving and reconfiguration of the existing Tennessee Valley Trailhead parking lot, improved ADA and equestrian access, and drainage improvements. Tennessee Valley Trailhead provides coastal access to the Marin Headlands west of Highway 1 near the community of Tamalpais Valley in Marin County, California. The trailhead is located at the terminus of Tennessee Valley Road, approximately 1-3/4 miles west from Highway 1 and provides access to several trails leaving from the parking lot, equestrian facilities, and multiuse paths. The west coast of the Marin Headlands is located approximately 1.5 miles west of the parking lot. The existing trailhead parking lot is gravel surfaced, approximately ¾ acres in size and located on the relatively narrow floor of Tennessee Valley with additional roadside parking. The surrounding terrain is mostly rolling hills with grasslands, chaparral, and oaks. The existing parking lot is located at an elevation of approximately 200 feet above sea level.

The proposed improvements will consist of paving the existing parking lot within its existing general footprint, improving ADA access and parking, adding pedestrian walkways and crosswalks, formalizing roadside parking, and drainage improvements.

Figure 1: Vicinity Map

3. GEOTECHNICAL INVESTIGATION

The geotechnical exploration for this project included a program of drilling and laboratory testing.

Prefield activities were coordinated with Atkins, FHWA, and the National Park Service as summarized in our Geotechnical Memorandum (Yeh 2019). A field exploration plan showing the locations of borings drilled at the site is presented on Plate 1. Logs of the borings are presented in Appendix A.

Laboratory test results are presented in Appendix B. Table 1 summarizes the field exploration and drilling subcontractor used for each site.

Table 1: Field Exploration Summary

Site

Date of Drilling (2020) Boring- Nos. Drilled by: Rig

Completed Field Exploration

Tennessee Valley Road Trailhead January 9 20T-01 to 03 Cascade Drilling

Tracked Dietrich D50 with 8-inch hollow stem auger Three borings to 5 feet

3.1 DRILLING

The drilling subcontractors for this project was Cascade Drilling of Richmond, California. Three borings were drilled to depths of approximately 5 feet on January 9, 2020. Yeh’s field geologist scraped the sides of boreholes and recorded the thickness of the existing aggregate base, logged the subsurface conditions encountered during the drilling, secured soil samples for subsequent laboratory testing and observed the backfill of the borings. The sample intervals, a description of the subsurface conditions encountered, field tests, and blow counts (N-Values) recorded during the drilling are presented on the logs. The borings were backfilled with the native soil after drilling.

Drive Samples. Sampling within the borings was performed by driving a modified California split spoon sampler into the subgrade below the surface course aggregate and drilling the boring to the target depth to collect a bulk sample from the augers. The modified California sampler had a 3-inch outside diameter, 2-3/8-inch inside diameter, and was used with 1-inch-high brass liners. Drive samples were collected using a 140-pound automatic trip hammer in accordance with ASTM D-1586 (the Standard Penetration Test) procedures. Blow counts shown on the logs are the recorded field values and have not been corrected. Bulk samples of the subgrade soil were collected from the augers at the depth intervals noted on the logs.

Pocket Penetrometer. Pocket penetrometer tests were performed in the field on the trimmed end of selected samples to help estimate the undrained shear strength of cohesive materials. The penetrometer was pushed to the designated penetration and the shear strength was read from the spring scale on the device. The undrained shear strength results from the pocket penetrometer tests are (noted by pp) are shown on the logs.

3.2 LABORATORY TESTING

Tests for moisture content, unit weight, percent passing the 200 sieve, particle size distribution by mechanical sieve analysis, Atterberg limits, and unit weight versus moisture content relationship by the modified Proctor test were performed at our laboratories in Ventura and Grover Beach, California. R-value tests were performed by either Cooper Testing Laboratory in Palo Alto, California.

The results of laboratory tests are presented in Appendix B. Testing was performed in accordance with ASTM and American Association of State Highway and Transportation Officials (AASHTO) methods as noted on the lab reports. After the completion of the laboratory testing, the field descriptions were confirmed or modified as necessary and boring logs were prepared.

4. SITE CONDITIONS

4.1 GEOLOGIC SETTING

This project site is in the Coast Ranges geomorphic province, which extends from the Transverse Ranges in southern California to the Klamath Mountains in northern California and into Oregon. The province is characterized by north-northwest trending mountain ranges bounded by the Pacific Ocean to the west and the Central Valley to the east. The basal units are predominantly composed of Jurassic and Cretaceous age rocks with Tertiary to Holocene age rocks commonly overlying the older formations along the flanks and foothills of those ranges. Quaternary sediments are deposits along intervening drainages, valleys, and coastal areas.

Figure 2: Regional Geologic Map from Geologic Map of Golden Gate National Recreation area (NPS 2016)

The bedrock geology in the site vicinity (NPS, 2016) is mapped as Jurassic to Cretaceous age Franciscan Complex (Kjf). The Franciscan formation is a tectonic mixture of variably sheared claystone, graywacke, and serpentinite which includes blocks of relatively solid rock in a matrix of clay or serpentinite mélange. The Franciscan Complex is extensively exposed in the hills and headlands throughout the project locations. Quaternary sediments overly the Franciscan Complex at the project sites are mapped as alluvium (Qa) at the Tennessee Valley site.

The project site is in a seismically active area of California with several earthquake producing fault zones located near the project site. Active faults include the San Andreas Fault Zone offshore to the west and the Hayward Fault zone across San Francisco Bay to the east. No structures requiring seismic data are planned as part of this project.

4.2 TERRAIN AND VEGETATION

The project site is in the coastal region of Marin County, California. The terrain within Marin Headlands is generally steep coastal bluffs with intervening drainages, coastal valleys, rugged hills, and mountains within the interior. The project site is inland from beaches and is primarily surrounded by grass lands and chaparral covered slopes.

4.3 CLIMATE

Caltrans classifies the climate around Tennessee Valley as the Low Mountain Region. Freeze-thaw conditions are not a consideration for this project. Climate data was collected for the vicinity of Tamalpais Valley, California (www.weather-us.com). The average annual rainfall is approximately 40 inches. The reported average monthly temperatures range from a winter low of approximately 45 degrees to summer high of 72 degrees.

4.4 SUBSURFACE CONDITIONS

The approximate locations of the borings are shown on Plate 1. A description of the existing pavement and subgrade conditions encountered is summarized in Table 3.

Table 2: Summary of Existing Pavement Thicknesses

Site Boring No.

Asphalt Thickness (inches)

Surface Course Thickness (inches) Subgrade Comment

Tennessee Valley Road Trailhead

20T-01 -- 10 CLAY (CH)

20T-02 -- 42 Sandy CLAY (CH) Surface course aggregate is clayey sand with gravel (SC)

20T-03 -- 30 Sandy CLAY (CH)

The subgrade conditions encountered at Tennessee Valley generally consisted of a variable thickness of gravel base material overlying alluvium. The alluvium generally consisted of stiff fat clay, medium dense clayey sand with gravel, and hard sandy clay encountered to approximately 5 feet below the http://www.weather-us.com/ ground surface. Groundwater was not encountered in the borings. The following table provides a summary of geotechnical properties that were estimated from laboratory tests performed on selected samples. Soil moisture conditions will vary seasonally in response to stormwater runoff, infiltration, rainfall and other factors.

Table 3: Summary of Laboratory Tests for Tennessee Valley Parking Lot Unit Dry Unit Wt. Moisture Content R-value Proctor1

Gravel base -- 16 -- γdmax = 120 wopt = 14% Alluvium 93-114 15-21 15

5. CONCLUSIONS AND RECOMMENDATIONS

5.1 EARTHWORK - GENERAL

5.1.1 GENERAL GRADING

The recommendations of this report assume that pavement and fill materials will be placed in general accordance with Standard Specifications FP-14. Compliance with those specifications is needed for the recommendations in this report to remain applicable. Fill materials should not contain organic matter or other deleterious material. Graded slopes should be designed to inclinations of 1v:2h or flatter. Temporary excavations should be sloped or shored to conform with OSHA requirements.

5.1.2 EARTHWORK FACTORS

The subgrade soil generally consisted of clay and a variable thickness of surface course aggregate as described in the previous sections of this report and shown on the boring logs. An average earthwork factor2 of 0.9 can be used for excavated onsite soil or subgrade that will be recompacted or reused as fill. It is recognized that disturbance to drive samples occurs due to compaction of samples during driving and loosening of soil when recovering the sampler from the drill hole and during trimming in the laboratory. Differences in the soil density also occur in areas where the existing pavement subgrade and embankment fill materials were compacted during previous grading, and from inherent differences in soil type and consistency of the subgrade. The estimated earthwork factors do not account for losses due to removal of vegetation or unsuitable material, are approximate and should be checked and adjusted as the grading work progresses.

1 γdmax is maximum dry unit weight from laboratory compaction test. wopt = optimum moisture content for compaction from the test result.

2 The earthwork factor represents the ratio of the existing in-situ unit weight of the soil before construction to the unit weight of the same soil after compaction. For example, an earthwork factor of 0.95 represents a 5 percent loss in the volume of soil following compaction. An earthwork factor of 1.05 represents a 5 percent gain in volume of the soil or pavement following compaction due to bulking of a relatively dense material.

5.1.3 EROSION AND SLOPE DRAINAGE

Graded slopes and surfaces will be vulnerable to erosion. Surface drainage should be provided to reduce the potential for standing water and for concentrated flows of runoff onto slopes. Curbs should be provided where there is a potential for erosion to undermine the edge of pavement, such as commonly occurs along the base of cut slopes. Overside drains, curbs, and ditches should be provided to drain pavements and carry water to the base of slopes. Energy dissipation devices should be provided at the outlet of pipes and along ditches to reduce the potential for erosion. Topsoil, erosion control matting (if needed), and appropriate vegetation should be placed on graded slopes to reduce the potential for erosion. Maintenance and repairs to gullied or eroded areas should be performed promptly while vegetation is being established.

5.1.4 REUSE OF ONSITE SOIL

Excavated onsite soil, cleansed of organic material, oversized rock, and other deleterious material, should be suitable for reuse as compacted fill for general embankment construction. Excavated material should not be considered suitable for reuse as select material such as base course aggregate, pipe zone, pipe bedding, or drainage material.

5.2 PAVEMENT DESIGN

The structural section recommendations for pavement design were developed based on Chapter 11 of the CFLHD Project Development and Design Manual (PDDM), and design methods in the AASHTO (1993) Guide for the Design of Pavement Structures. The spreadsheet calculations for our recommended traffic loading and thickness recommendations are presented in Appendix C. Traffic data is not available for the project site and will not be collected for these sites. The new structural sections were based on the minimum traffic load of 50,000 ESAL assuming 2.5 percent truck traffic and 2.5 percent bus traffic.

5.2.1 STRUCTURAL SECTION

The existing gravel parking lot for the Tennessee Valley Road Trailhead will be paved for this project.

The existing gravel appears to be aggregate base and can be reconditioned and reused to provide subgrade support for the new pavement. The parking lot should be graded according to the plans, and prior to paving the existing gravel should be scarified to a depth of at least 9 inches, moisture conditioned, and compacted in-place to at least 95 percent relative compaction to provide at least 8 inches of compacted material below the new pavement. Gravel that is repositioned or regraded as part of the parking lot improvements should also be compacted to at least 95 percent relative compaction. The recommended structural section for Tennessee Valley is provided in the following table.

Table 4: Summary of Structural Section Recommendations for Tennessee Valley Road

Location

Existing Pavement/Subgrade

Conditions Encountered R-value

Recommended Pavement Section Comment

Tennessee Valley Parking Lot and

Miwok Stables Access Road

10 to 40 inches gravel base over clay subgrade 15 3 inches HMA over

8 inches aggregate base

Base course can consist of existing aggregate surfacing or supplemental aggregate per FP-14 Section 703-06.

Accessibility Parking -- 15 6 inches PCC over 4 inches aggregate base

Base course can consist of existing aggregate surfacing or supplemental aggregate per FP-14 Section 703-06.

5.2.2 HOT MIX ASPHALT

Hot mix asphalt (HMA) will consist of Type 1 Asphalt Concrete per Section 403 of the Standard

Specifications that will be a job mix formula submitted by the contractor that conforms to the California

Department of Transportation (Caltrans) standards. The State of California adopted a program of

Asphalt Binder Grade Selection that classifies this project area as the Low Mountain Region and recommends binders for this area based on Caltrans data as either PG 64-16 or 64-28M. The binder for this project can be PG 64-16 for dense graded HMA, or a binder approved in the job mix formula consistent with Caltrans design guidelines and specifications.

5.2.3 PAVEMENT MAINTENANCE

The pavement condition should be periodically evaluated to help plan and scope the need for maintenance and rehabilitation following the initial construction of the pavement. Maintenance of asphalt concrete pavements should typically include periodic fog, chip or slurry seals to reduce the potential for weathering and overlaying with additional HMA when needed to strengthen and further the life of the pavement. Deflection surveys can be performed to evaluate the structural capacity of pavements and the need for future overlays.

6. NOTES TO CONSTRUCTION

1. Hot mix asphalt will be developed as a job mix formula submitted by the contractor that is consistent with the California Department of Transportation Standard Specifications. The new parking lot will be associated with tight turning movements by slow moving vehicles. It is our experience that an asphalt concrete pavement containing nominal size ½-inch aggregate will tolerate turning movements with less raveling of the pavement surface than those with coarser aggregates.

2. A prime coat is required by FP-14 between the top of the base course and hot mix asphalt. The prime coat is sometimes deleted when it is not considered necessary for weather proofing during construction. However, the prime coat will also add adhesion and help bond the hot mix asphalt pavement to the base course, particularly when thin lifts (less than 3 inches) are placed on the base course. We recommend that the prime coat not be deleted for HMA lifts thinner than 3 inches.

7. REFERENCES

American Association of State Highway and Transportation Officials (AASHTO 1993), AASHTO Guide for Design of Pavement Structures, Washington D.C., copyright 1993.

Atkins (2021), Progress Plans for 95% submittal: GOGA Tennessee Valley Parking Lot, FHWA Project No. CA FTNP GOGA 993(1); print date April 29, 2021.

Atkins (2019a), Project Delivery Plan, Federal Highway Administration, Central Federal Lands Highway Division, Project Delivery Plan, U.S. National Park Service, Golden Gate National Recreation Area and City of San Francisco, Federal Project No. CA FTNP FOPO 110(1) & GOGA 205(1), consultant report prepared for FHWA CFLHD, submitted April 1, 2019.

Atkins (2019b), Design Trip Report, Federal Highway Administration, Central Federal Lands Highway Division, Project Delivery Plan, U.S. National Park Service, Golden Gate National Recreation Area, County & City of San Francisco, Federal Project No. CA FTNP FOPO 110(1) & GOGA 205(1), consultant report prepared for FHWA CFLHD, submitted April 1, 2019.

U.S. Department of Transportation, Federal Highway Administration, (FHWA 2014), Federal Lands Highway, Project Development and Design Manual (PDDM), transmittal of December 2014.

U.S. Department of Transportation, Federal Highway Administration, Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects FP-14, U.S., approved September 10, 2012.

U.S. National Park Service (NPS 2016), Geologic Map of Golden Gate NRA, Fort Point NHS, and Muir Woods NM, California; Sheets 1 and 2, Geologic Resources Inventory, Natural Resources Stewardship and Science.

Yeh and Associates, Inc. (2021), Geotechnical Memorandum: Preliminary Pavement Recommendations, Tennessee Valley Road Trailhead Parking Lot, Golden Gate National Recreation Area (GOGA), CA FTNP FOPO 110(1) & GOGA 205(1), Marin County, California, prepared for Atkins, YA Project No. 219-400, submitted April 28, 2020.

Yeh and Associates, Inc. (2019), Geotechnical Memorandum: Field Exploration Program for Stinson Beach and Tennessee Valley Road Trailhead, Golden Gate National Recreation Area (GOGA), CA FTNP FOPO 110(1) & GOGA 205(1), Marin County, California, prepared for Atkins, YA Project No.

219-400, submitted December 19, 2019.

PLATE

PROJECT NAME:

PROJECT NUMBER: REVISION DATE:

FIELD EXPLORATION PLAN

Base Map: Atkins progress plans, Site Vicinity Map, April 29, 2021

M iw ok T ra il

M iw ok T ra il

Miwok Stable Access Road

Te nnes se e V alle y R oad

Te nnes se e V alle y R oad

Te nnes se e V alle y T ra il

Te nnes se e V alle y T ra il

Proposed Parking Lot

Proposed Parking Lot

Limits of improvements 20T-01

20T-02

20T-03

LEGEND:

Boring location drilled in January 2020

All locations and dimensions are approximate

Golden Gate Na onal Recrea on Area

Tennessee Valley Parking Lot Improvements Marin County, CA

219-400 5.26.2019

North feet

APPENDIX A - FIELD EXPLORATION

DATE

6/16/2020

PROJECT NAME

GOGA Beach Trail Access Improvements

Shrinkage Limit (ASTM D427)

Swell Potential (ASTM D4546)

Unconfined Compression - Soil (ASTM D2166) Unconfined Compression - Rock (ASTM D7012)

Unconsolidated Undrained Triaxial

(ASTM D2850)

Vane Shear (AASHTO T 223-96 [2004])

-200

VS

UW

UU

UC

Permeability (ASTM 5084)

Unit Weight (ASTM D4767, ASTM D7263)

200 Wash (ASTM D1140)

SILTY, CLAYEY SAND

Group Names

SC-SM

Graphic / Symbol Graphic / Symbol Group Names

Standard California Sampler (2.5" O.D.)

C

CL

CP

CR

CU

Corrosion, Sulfates, Chlorides (CTM 643; ASTM

D4972, ASTM G187, ASTM D4327)

Compaction Curve (ASTM D1557)

Direct Shear (ASTM D3080)

Expansion Index (ASTM D4829)

PP

PM

PL

PI

PA

P

OC

M

GRAVELLY ORGANIC SILT

GRAVELLY ORGANIC SILT with SAND

ORGANIC SILT

Well-graded SAND with CLAY and GRAVEL (or SILTY CLAY and GRAVEL)

SILTY, CLAYEY SAND with GRAVEL

CLAYEY SAND with GRAVEL

SILTY SAND with GRAVEL

GROUP SYMBOLS AND NAMES

DRILLING METHOD SYMBOLS

OL

EI

GC

GP

GC-GM

SANDY ORGANIC SILT

Lean CLAY with SAND Lean CLAY with GRAVEL

SANDY lean CLAY with GRAVEL

ORGANIC lean CLAY

GRAVELLY ORGANIC lean CLAY GRAVELLY ORGANIC lean CLAY with SAND

Fat CLAY

Elastic SILT with GRAVEL SANDY elastic SILT

SANDY elastic SILT with GRAVEL GRAVELLY elastic SILT GRAVELLY elastic SILT with SAND

ORGANIC elastic SILT

SANDY ORGANIC SILT with GRAVEL

CH

MH

OH

OL/OH

Rock Core Grab Sample

TV

SW

SL

SG

SE

R

Poorly graded SAND with SILT and GRAVEL

SANDY lean CLAY

GRAVELLY lean CLAY

ORGANIC lean CLAY with SAND ORGANIC lean CLAY with GRAVEL SANDY ORGANIC lean CLAY

SANDY ORGANIC lean CLAY with GRAVEL

Fat CLAY with SAND Fat CLAY with GRAVEL SANDY fat CLAY

SANDY fat CLAY with GRAVEL GRAVELLY fat CLAY GRAVELLY fat CLAY with SAND

ORGANIC fat CLAY ORGANIC fat CLAY with SAND ORGANIC fat CLAY with GRAVEL SANDY ORGANIC fat CLAY

Elastic SILT with SAND

Well-graded GRAVEL

Poorly graded GRAVEL with SILT

GRAVELLY lean CLAY with SAND

DS

SP-SC

SW

SP

Piston Sampler

SW-SM

SILTY, CLAYEY GRAVEL with SAND

CLAYEY GRAVEL with SAND

SILTY GRAVEL with SAND

Modified California Sampler (3" O.D.)

GRAVELLY SILT with SAND

SILT

ORGANIC SILT with SAND ORGANIC SILT with GRAVEL

Liquid Limit, Plastic Limit, Plasticity Index

(ASTM D4318)

Consolidation (ASTM D2435)

Collapse Potential (ASTM D5333)

Consolidated Undrained Triaxial (ASTM D4767)

Moisture Content (ASTM D2216)

Organic Content (ASTM D2974)

Particle Size Analysis (ASTM D422-63 [2007])

Point Load Index (ASTM D5731)

Standard Penetration Test (SPT) (2" O.D.)

OL

SC

GW

GW-GM

CL

CL-ML

ML

COBBLES and BOULDERS

BOULDERS

PT

SILTY GRAVEL

CLAYEY GRAVEL

SILTY, CLAYEY GRAVEL

SILTY SAND

CLAYEY SAND

SILTY CLAY

SILTY CLAY with SAND SILTY CLAY with GRAVEL

SANDY SILTY CLAY

SANDY SILTY CLAY with GRAVEL

GRAVELLY SILTY CLAY

GRAVELLY SILTY CLAY with SAND

SILT with SAND SILT with GRAVEL

SANDY SILT

SANDY SILT with GRAVEL

SANDY ORGANIC fat CLAY with GRAVEL GRAVELLY ORGANIC fat CLAY GRAVELLY ORGANIC fat CLAY with SAND

Elastic SILT

ORGANIC elastic SILT with GRAVEL SANDY elastic ELASTIC SILT

COBBLES

Well-graded GRAVEL with SAND

Well-graded GRAVEL with SILT

Well-graded GRAVEL with CLAY and SAND (or SILTY CLAY and SAND)

Well-graded SAND with CLAY (or SILTY CLAY)

Poorly graded GRAVEL

Poorly graded GRAVEL with CLAY (or SILTY CLAY)

Poorly graded SAND with SILT

Poorly graded SAND with CLAY (or SILTY CLAY)

Poorly graded SAND with CLAY and GRAVEL (or SILTY CLAY and GRAVEL)

Lean CLAY

ORGANIC elastic SILT with SAND

SANDY ORGANIC elastic SILT with GRAVEL GRAVELLY ORGANIC elastic SILT GRAVELLY ORGANIC elastic SILT with SAND

GW-GC

GP-GM

GP-GC

GM

Well-graded SAND with SILT

SW-SC

SP-SM

GRAVELLY SILT

ORGANIC SOIL

ORGANIC SOIL with SAND ORGANIC SOIL with GRAVEL

SANDY ORGANIC SOIL

SANDY ORGANIC SOIL with GRAVEL

GRAVELLY ORGANIC SOIL

GRAVELLY ORGANIC SOIL with SAND

OH

SM

Auger Drilling

FIELD AND LABORATORY TESTS

WATER LEVEL SYMBOLS

Dynamic Cone or Hand Driven Diamond CoreRotary Drilling

Static Water Level Reading (long-term)

Shelby Tube

Bulk Sample Other (see remarks)

Static Water Level Reading (short-term)

First Water Level Reading (during drilling)

SHEET

SAMPLER GRAPHIC SYMBOLS

PEAT

Well-graded GRAVEL with SILT and SAND

Well-graded GRAVEL with CLAY (or SILTY CLAY)

Well-graded SAND

Well-graded SAND with GRAVEL

Well-graded SAND with SILT and GRAVEL

Poorly graded GRAVEL with SAND

Poorly graded GRAVEL with SILT and SAND

Poorly graded GRAVEL with CLAY and SAND (or SILTY CLAY and SAND)

Poorly graded SAND

Poorly graded SAND with GRAVEL

Pressure Meter

Pocket Penetrometer

Pocket Torvane

R-Value (CTM 301)

Sand Equivalent (CTM 217)

Specific Gravity (AASHTO T 100)

REPORT TITLE

LEGEND FOR SOIL CLASSIFICATION

Page A-1 of 6

ROCK GRAPHIC SYMBOLS

IGNEOUS ROCK

SEDIMENTARY ROCK

METAMORPHIC ROCK

GRAIN/CRYSTAL SIZE AND SHAPE

Grain Size (inches) Description Criteria

<0.003 Very Fine Very Fine: Not distinguishable to unaided eye. Few visible hand lens.

0.003 – 0.02 Fine Few distinguishable with eye or seen with difficulty but can be seen with hand lens.

0.02 – 0.08 Medium Most visible with eye and distinguishable with aid of hand lens.

0.08 – 0.2 Coarse Visible and distinguishable with eye and hand lens.

>0.2 Very Coarse Clearly visible and distinguishable by eye.

DEGREE OF WEATHERING

Term Description Grade Fresh No visible sign of rock material weathering; slight discoloration on major discontinuity surface is possible. I

Slightly Weathered

Discoloration indicates weathering of rock material and discontinuity surfaces. All rock material may be discolored by weathering and the external surface may be somewhat weaker than in its fresh condition. II

Moderately Weathered

Less than half the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is present either as a discontinuous framework or as corestones. A minimum 2-inch (50 mm) diameter sample cannot be broken readily by hand across the rock fabric.

III

Highly Weathered

More than half of the rock is decomposed and/or disintegrated to soil. Fresh or discolored rock is present either as a discontinuous framework or as corestones. A minimum 2-inch (50 mm) diameter sample can be broken readily by hand across the rock fabric.

IV

Completely Weathered

All rock material is decomposed and/or disintegrated to soil. The original mass structure is still largely intact.

Material can be granulated by hand. V

Residual Soils

All rock material is converted to soil. The mass structure and material fabric are destroyed but the apparent structure may remain intact. There may be a large change in volume, but the soil has not been significantly transported. Material can be easily broken-down by hand. Use Soil Description and Identification Guidelines to describe residual soil.

VI

RELATIVE STRENGTH OF INTACT ROCK SPEICIMENS

Grade Description Field Identification Approximate Uniaxial

Compressive Strength*

R0 Extremely Weak Specimen can be indented by thumbnail. 35 – 150 psi

R1 Very Weak Specimen crumbles under sharp blow with point of geological hammer, and can be peeled with a pocket knife. 150 – 725 psi

R2 Weak Shallow cuts or scrapes can be made in a specimen with a pocket knife. A firm blow with a geological hammer point creates shallow indents. 725 – 3,500 psi

R3 Medium Strength

Specimen cannot be scraped or cut with a pocket knife. Specimen can be fractured with a single firm blow with a geologic hammer point. 3,500 – 7250 psi

R4 Strong Specimen requires more than one firm blow of the geologic hammer point to fracture. 7,250 – 14,500

R5 Very Strong Specimen requires many firm blows from the hammer end of the geologic hammer to fracture. 14,500 – 36,250

R6 Extremely Strong

Specimen can only be chipped with firm blows from the hammer end of the geologic hammer. >36,250

*Rock strength is subjective based on general qualitative field observations and may exclude layers or crystals within the rock. Rock strength will likely vary more or less from that described.

*Widely spaced discontinuities may not be apparent in borings

DISCONTINUITY SPACING OF JOINTS,

FRACTURES, BEDDING, SHEARS AND FAULTS

Description Typical Spacing of Discontinuity*

Extremely wide >20 feet

Very wide 6 to 20 feet

Wide 2 to 6 feet

Moderate 8 inches to 2 feet

Close 2 to 8 inches

Very Close ¾ to 2 inches

Extremely Close < ¾ inches

DISCONTINUITY CONDITIONS

Description Field Identification

Excellent Very rough surfaces, no separation, hard discontinuity wall (>R2).

Good Slightly rough surfaces, separation less than ~0.04 inches, hard discontinuity wall (>R2).

Fair Slightly rough surface, separation greater than ~0.04 inches, soft discontinuity wall (<R3).

Poor Slickensided surfaces, or soft gouge less than ~0.2 inches thick, or open discontinuities between ~0.04 and 0.2 inches.

Very Poor Soft gouge greater than ~0.2 inches, or open discontinuities greater than ~0.2 inches.

REPORT TITLE

LEGEND FOR ROCK CLASSIFICATION

PROJECT NAME

PROJECT NUMBER DATE

GOGA Trail - Beach Access Improvements

219-400 6/15/2020

Page A-2 of 6

21 94

10'' AGGREGATE BASE.

Fat CLAY (CH); stiff; light yellowish brown; moist;

(ALLUVIUM).

Bottom of borehole at 5.0 ft bgs

Boring elevation estimated from Google Earth.

A 1 R (R-Value = 15)

2.0PP

BORING NUMBER

20T-01

SURFACE ELEVATION

207 ft. +/-

LOGGED BY

W. Hoon

DRILLER

Cascade Drilling

TOTAL DEPTH OF BORING

5.0 ft

GROUNDWATER

READINGS

FINAL BY

N. Simon

DRILL RIG

Dietrich D50

BEGIN DATE

1-9-20

COMPLETION DATE

1-9-20

DRILLING METHOD

8" Hollow Stem Auger

HAMMER TYPE

140 lb Autotrip BOREHOLE LOCATION (Lat/Long or North/East and Datum)

BOREHOLE LOCATION (Offset, Station, Line)

DURING DRILLING

Not encountered

AFTER DRILLING (DATE)

WEATHER NOTES

Clear, sunset/dusk

LOCATION DESCRIPTION

Tennessee Valley: Northwest corner of parking lot, 51 feet west of end of pavement

BACKFILLED WITH

Native

E

LE

V A

T

IO

N ft

S am pl e

Lo ca tio n

REVISION DATE

1/11/2021

M at er ia l G ra ph ic s

B lo w s pe r in

PROJECT NAME

GOGA Beach Trail Access Improvements

PROJECT NUMBER

219-400

SHEET

M oi st ur e C on te nt

D E

P T

H ft

BORING NUMBER

20T-01

D ry

U ni t W ei gh t (p cf

DESCRIPTION

R ec ov er y

D ri lli ng

M et ho d

C as in g

D ep th

R Q

D

S am pl e

N um be r

Remarks

S he ar S tr en gt h

(k sf

B lo w s pe r fo ot

B

R

S T

A N

D A

R D

-4

_L A

B A

N D

L O

G S

.G P

J C

A

LI

F O

R N

IA

Y

E H

L

IB

R A

R Y

Y

E H

V

A P

R

IL

G

LB

/2

0/

Page A-3 of 6

16 114

42'' AGGREGATE BASE.

CLAYEY SAND with GRAVEL (SC); medium dense; dark gray; moist; fine GRAVEL; fine to coarse SAND;

(ALLUVIUM).

Bottom of borehole at 5.0 ft bgs

Boring elevation estimated from Google Earth.

B

CP ( D, MAX = 120 pcf, wOPT = 14%)

-200 (19% G, 40% S, 40% F)

PI (33 LL, 20 PL, 13 PI)

2.5 to

4.5PP

BORING NUMBER

20T-02

SURFACE ELEVATION

204 ft. +/-

LOGGED BY

W. Hoon

DRILLER

Cascade Drilling

TOTAL DEPTH OF BORING

5.0 ft

GROUNDWATER

READINGS

FINAL BY

N. Simon

DRILL RIG

Dietrich D50

BEGIN DATE

1-9-20

COMPLETION DATE

1-9-20

DRILLING METHOD

8" Hollow Stem Auger

HAMMER TYPE

140 lb Autotrip BOREHOLE LOCATION (Lat/Long or North/East and Datum)

BOREHOLE LOCATION (Offset, Station, Line)

DURING DRILLING

Not encountered

AFTER DRILLING (DATE)

WEATHER NOTES

Clear, dark

LOCATION DESCRIPTION

Tennessee Valley: SW corner of Parking Area, 81' SE from edge of lot

BACKFILLED WITH

Native

E

LE

V A

T

IO

N ft

S am pl e

Lo ca tio n

REVISION DATE

1/11/2021

M at er ia l G ra ph ic s

B lo w s pe r in

PROJECT NAME

GOGA Beach Trail Access Improvements

PROJECT NUMBER

219-400

SHEET

M oi st ur e C on te nt

D E

P T

H ft

BORING NUMBER

20T-02

D ry

U ni t W ei gh t (p cf

DESCRIPTION

R ec ov er y

D ri lli ng

M et ho d

C as in g

D ep th

R Q

D

S am pl e

N um be r

Remarks

S he ar S tr en gt h

(k sf

B lo w s pe r fo ot

B

R

S T

A N

D A

R D

-4

_L A

B A

N D

L O

G S

.G P

J C

A

LI

F O

R N

IA

Y

E H

L

IB

R A

R Y

Y

E H

V

A P

R

IL

G

LB

/2

0/

Page A-4 of 6

15 93

30'' AGGREGATE BASE.

SANDY lean CLAY (CL); hard; dark brown; moist;

(ALLUVIUM).

Bottom of borehole at 5.0 ft bgs

Boring elevation estimated from Google Earth.

C

3 PI (27 LL, 18 PL, 9 PI)>=4.5PP

BORING NUMBER

20T-03

SURFACE ELEVATION

216 ft.+/-

LOGGED BY

W. Hoon

DRILLER

Cascade Drilling

TOTAL DEPTH OF BORING

5.0 ft

GROUNDWATER

READINGS

FINAL BY

N. Simon

DRILL RIG

Dietrich D50

BEGIN DATE

1-9-20

COMPLETION DATE

1-9-20

DRILLING METHOD

8" Hollow Stem Auger

HAMMER TYPE

140 lb Autotrip BOREHOLE LOCATION (Lat/Long or North/East and Datum)

BOREHOLE LOCATION (Offset, Station, Line)

DURING DRILLING

Not encountered

AFTER DRILLING (DATE)

WEATHER NOTES

Clear, dark

LOCATION DESCRIPTION

Tennessee Valley: Middle of turn around near stable area, 56 feet west of gate at Miwok Trail

BACKFILLED WITH

Native

E

LE

V A

T

IO

N ft

S am pl e

Lo ca tio n

REVISION DATE

1/11/2021

M at er ia l G ra ph ic s

B lo w s pe r in

PROJECT NAME

GOGA Beach Trail Access Improvements

PROJECT NUMBER

219-400

SHEET

M oi st ur e C on te nt

D E

P T

H ft

BORING NUMBER

20T-03

D ry

U ni t W ei gh t (p cf

DESCRIPTION

R ec ov er y

D ri lli ng

M et ho d

C as in g

D ep th

R Q

D

S am pl e

N um be r

Remarks

S he ar S tr en gt h

(k sf

B lo w s pe r fo ot

B

R

S T

A N

D A

R D

-4

_L A

B A

N D

L O

G S

.G P

J C

A

LI

F O

R N

IA

Y

E H

L

IB

R A

R Y

Y

E H

V

A P

R

IL

G

LB

/2

0/

Page A-5 of 6

Drill Locations Project No. 219-400 Golden Gate National Recreational Area Improvements Project April 28, 2021

T-Series, Tennessee Valley Trailhead, Marin County, California

20T-01 (looking southwest 12.30.19) 20T-02 (looking west 12.30.19)

20T-03 (looking west)

Page A-6 of 6

APPENDIX B - RESULTS OF LABORATORY TESTING

20T-01 1 1.0 MCAL 114 94 21 -- -- -- -- -- -- -- -- -- -- -- -- -- -- Fat CLAY (CH)

20T-01 A 1.5 BULK -- -- -- -- -- -- -- -- -- -- -- -- -- -- 15 -- -- SANDY fat CLAY with GRAVEL (CH)

20T-02 B 1.0 BULK -- -- 16 -- -- -- -- -- -- -- -- -- 120 14 -- -- -- CLAYEY SAND with GRAVEL (SC)

20T-02 2 3.5 MCAL 131 114 16 19 40 40 13 33 -- -- -- -- -- -- -- -- -- CLAYEY SAND with GRAVEL (SC)

20T-03 3 2.5 MCAL 108 93 15 -- -- -- 9 27 -- -- -- -- -- -- -- -- -- SANDY lean CLAY (CL)

Sample Information

SUMMARY OF LABORATORY TEST RESULTS

Boring No.

Sample No.

USCS ClassificationDepth (ft)

Atterberg

M ax

. D ry

U ni t W ei gh t, d, M

A X, (p cf

To ta l U ni t W ei

(p cf

D ry

U ni t W ei d, (p cf

M oi st ur e Co nt en t (

Pl as tic ity

In de x (P

I)

Re si st iv ity cm

G ra ve l (

Sa nd

Li qu id L im it

(L L)

Fi ne s pH R- Va lu e

O pt im um

M oi st ur e Co nt en t (

Compaction

A dd iti on al T es tin g

(m g/ kg

(m g/ kg

Cl

SO

Ex pa ns io n In de x

Gradation Corrosion

Sample Type

Y E

H S

U M

M A

R Y

O F

T E

S T

R E

S U

LT

S

-4

A .G

P J

C A

LI

F

O R

N

IA

Y E

H L

IB

R

A R

Y

Y E

H V

A

P R

IL

0)

.G

LB

/2

8/

PROJECT MANAGER

J. Blanchard

CHECKED BY

J. Blanchard

SHEET

PREPARED BY

R. Hooke

PROJECT NO.

219-400

PROJECT NAME

GOGA Beach Trail Access Improvements

REVISION DATE

4-28-21

Page B-1 of 4

0 10 20 30 40 50 60 70 80 90 100 110

LIQUID LIMIT, LL

ML or OL

MH or OH

CL or OL

CH or OH

ATTERBERG LIMITS

PL

A

ST

IC

IT

Y

IN

D

EX

, P

I

CL-ML

"A" LINE

Y E

H A

T T

E R

B E

R G

-4

A .G

P J

C A

LI

F

O R

N

IA

Y E

H L

IB

R

A R

Y

Y E

H V

A

P R

IL

0)

.G

LB

/2

8/

SHEET

PROJECT NO.

219-400

PROJECT MANAGER

J. Blanchard

PREPARED BY

R. Hooke

CHECKED BY

J. Blanchard

REVISION DATE

4-28-21

PROJECT NAME

GOGA Beach Trail Access Improvements

3.5

2.5

Sample ID Depth (ft)

Test Symbol

Fines

(%) LL PL

20T-02

20T-03

Boring Number

MC

(%) PI Classification

CLAYEY SAND with GRAVEL (SC)

SANDY lean CLAY (CL)--

Page B-2 of 4

0 5 10 15 20 25 30 35 40 45

MOISTURE-DENSITY RELATIONSHIP

Curves of 100% Saturation for Specific Gravity Equal to:

WATER CONTENT, %

Symbol

20T-02

Boring Number

Sample

ID

B

D

RY

U N

IT

W

EI

G

H T, p cf

Optimum Moisture Content

ASTM

Test

Method

1557B

Maximum Dry Unit Weight

(pcf)

120 14

Y E

H C

O M

P A

C T

IO

N

-C

U R

V E

-4

A .G

P J

C A

LI

F

O R

N

IA

Y E

H L

IB

R

A R

Y

Y E

H V

A

P R

IL

0)

.G

LB

/2

8/

SHEET

PROJECT NO.

219-400

PROJECT MANAGER

J. Blanchard

PREPARED BY

R. Hooke

CHECKED BY

J. Blanchard

REVISION DATE

4-28-21

PROJECT NAME

GOGA Beach Trail Access Improvements

2.80

2.70

2.60

Page B-3 of 4

Boring: 20T-01 Reduced By: RU Sample: A Checked By: PJ

Depth: 1-4 Date: 1/27/2020

A B C D E 290 120 70 598 336 237

7515 4222 2978

2.48 2.70 2.51 133 73 30 120 124 132

2.80 4.36 3.56 23 14 13 23 16 13

16.4 18.7 21.0

131.9 127.4 129.6

113.3 107.4 107.1

Specimen Designation

Corrected R-Value Moisture Content (%)

Wet Density (pcf) Dry Density (pcf)

Exudation Load (psf) Height After Compaction (in)

Stabilometer @ 2000 Turns Displacement

R-value

Exudation Pressure (psi)

Expansion Pressure (psf)

Compactor Foot Pressure (psi)

R-Value

CTM 301

CTL Job No.:

Client:

Project Number:

687-087 Yeh & Associates 219-400

Soil Description:

Remarks:

Project Name: GOGA Trail Access Dark Brown Sandy CLAY w/ Gravel R-Value

Expansion Pressure

0 100 200 300 400 500 600 700 800

Ex pa ns io n pr es su re , p sf

R‐ va lu e

Exudation Pressure, psi

Exudation Pressure vs R‐Value

Exudation Pressure vs. Expansion Pressure

Page B-4 of 4

APPENDIX C - PAVEMENT DESIGN CALCULATIONS

Flexible Pavement Thickness Design - Spreadsheet

Client Name: Atkins Project Number: 219-400 Project Name: GOGA Tennesse Valley Trailhead Parking Lot Improvements Date: by: J. Blanchard checked: R. LaForce Case:

Ref.

Mr Correlation: 1 Min W18: 50000 for HMA 10000 for aggregate surface

(a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n) (o) (p) (q)

R-value Wt18, EDAL's Design ESAL's

Design Life

(1) Reliablility(2) Req'd SN(3) W18

(4) log(W18) ZR Std. Dev.

So

(5) po pt

(6) ∆psi S1

MR

(psi) log(W18) difference

1 Tennessee Valley 15 3 50000 25 75 2.36 50000 4.699 -0.674 0.49 4.2 2.0 2.2 3.89 4195 4.698 0.001 2 0.49 4.2 2.0 2.2 2.56 2569 3 0.49 4.2 2.0 2.2 2.56 2569 4 0.49 4.2 2.0 2.2 2.56 2569 5 0.49 4.2 2.0 2.2 2.56 2569

1) per FHWA (2008) PDDM, Ch. 11 use 25 years for 4R, 20 years for 3R

2) per FHWA (2008) PDDM, Ch. 11 use 75% for < 2,500 ADT; 85% for 2500-5000 ADT, 90% for >5000 ADT (CFL uses 75%)

3) find req'd SN by using goal-seek to set "difference" column to zero by changing the value in the "SN" column in the same row

4) per FHWA (2008) PDDM, Ch. 11 use min. 50,000 ESAL/W18 or 10,000 for aggregate surface roads.

5) per FHWA (2008) PDDM, Ch. 11 use 0.49 for flexibile pavement design, use 0.39 for rigid pavement design

6) per FHWA (2008) PDDM, Ch. 11 3.0 for ADT>5000; 2.5 for ADT 500-5000; 2.0 for ADT <500

I. AASHTO R-value Conversion and data summary: II. AASHTO CBR conversion and data summary:

Sample: 20T-01 A Sample:

~Post Mile: Tenn. Vly Soil: CHg Avg Soil:

R-value 15 15.0 CBR CBR = 2.8 2.8 MR = 1500xCBR (psi):

Subgrade MR (psi) 4195 4195 Equivalent R-value:

Equations/Definitions: #DIV/0!

Col. (f), Req'd SN = Structural number of pavement needed for subgrade and traffic condition

Col. (e), W18 = predicted number of 18-kip single axle loads to end of service life

ESALn = EDAL0 n(1 + i )n-1 x 365

Col. (h), log (W18) = log of W18 from column (g) where:

ESAL = equilvalent 18-kip single axle loads over life of project

Col. (p), log (W18) = EDAL0 = equivalent daily 18-kip single axle loads at start of project (t=0) i = annual rate of increase in traffic where: n = number of years to ESALn , typically design life of project W18 = predicted number of 18-kip single axle loads to end of service life for a value of SN

ZR = standard normal deviate from Lookup value in Table III specified reliability in Col. (e) SO = prescribed combined standard error of the traffic prediction and performance prediction

∆PSI = difference between initial design (po) and terminal (pt) servicibility indices; col (k) - (l) MR = resilient modulus (psi), commonly correlated to R-value, CBR or soil type (see Tables I and II )

IV. Calculation of design equivalent number of single axle loads (ESALs) Reliability ZR

50 0 Traffic Data 1 2 3 4 5 60 -0.253 Case: Tennesse Stinson China Funston Long Notes 70 -0.524 Current ADT 100 per DAF 75 -0.674 Annual Growth, i 2% default per PDDM 80 -0.841 Lanes (each direction) 1 85 -1.307 Design Life, n 25 for 4R 90 -1.282 91 -1.34 Traffic Mix (#/100) 92 -1.405 Passenger Cars (2) 0.950 93 -1.476 Buses - Cl. 4 0.025 94 -1.555 Lt. Duty Trucks - Cl. 5 0.025 95 -1.645 Hvy Duty Trucks - Cl. 6 0.000 96 -1.751 Semi-Logging Trucks - Cl. 9 0.000 97 -1.881 Check sum: 1.000 0.000 0.000 0.000 0.000 98 -2.054 99 -2.327 Load Equiv./Truck Factor

99.9 -3.09 Passenger Cars (2) 0.0004

99.99 -3.75 Buses - Cl. 4 1.25 avg value

Lt. Duty Trucks - Cl. 5 0.5 avg value Hvy Duty Trucks - Cl. 6 1.5 max value

Semi-Logging Trucks - Cl. 9 2.3 max value

Direction distribution/lane factor: 0.6 0.6 0.6 0.6 0.6 default per CFL

Traffic Load EDAL0 4 0 0 0 0 daily axle loads ESALn 64770 0 0 0 0 lifetime axle loads n(1 + i )n-1 40 0 0 0 0 Factored

EDAL 3 0 0 0 0 distributed Design ESALn 38862 0 0 0 0 > 50000 HMA, >10,000 ASR

March 11, 2020

Case

III. Lookup Values

AASHTO Guide for Design of Pavements Structures, American Association of State Highway officials, Washington D.C., copyright 1993.

ENTER "1" for NCHRP 128 (CDOT) or "2" for AASHTO 1993

FHWA, Federal Lands Highway Project Development and Design Manual , Chapter 11 – Pavements, U.S. Department of Transportation, issued March 2008.

𝑐𝑐𝑐𝑐𝑐𝑐 𝑐𝑐 • 𝑐𝑐𝑐𝑐𝑐𝑐 (𝑑𝑑) • 365 days/year

𝑍𝑍𝑅𝑅𝑆𝑆𝑂𝑂 + 9.36 log(𝑆𝑆𝑆𝑆 + 1) − 0.20 + log ∆𝑃𝑃𝑃𝑃𝑃𝑃

4.2 −1.5

0.4+ 1094

𝑃𝑃𝑆𝑆+1 5.19

+ 2.32 log𝑀𝑀𝑅𝑅 − 8.07

Page C-1 of 2

Structural Section Thickness Calculations

Client Name: Atkins Project Number: 219-400 Project Name: GOGA Tennesse Valley Trailhead Parking Lot Improvements Date: 3/11/2020

Tennessee Valley 0 0 0 0 Notes

ESALs 50000 Min. SN req'd: 2.36 0.00 0.00 0.00 0.00 Rsg= 15 0 0 0 0

Material Layer Coef.

ai Drain Coef. mi

Thickness, Di

(inches) SNi Comments

Surface Course New HMA 0.44 1 3 1.32 Cold Recycle CIPR 0.3 1 0 Aggregate base ABC 0.14 1 8 1.12 Base Course FDR - pulverized 0.12 1 0 Select Borrow 0.06 1 0 Subgrade

Total SN: 2.44

Equations/Definitions:

Req'd SN = Structural number of pavement needed for subgrade and traffic condition (from page 1 )

SN = Calculated structural number summed for all layers SNi = Calculated structural number for the layer thickness, drainage condition, and material type noted where:

ai = prescribed layer coefficient for material type noted

Di = layer thickness in inches mi = drainage coefficient

𝑆𝑆𝑆𝑆 = 𝑎𝑎1𝐷𝐷1 + 𝑎𝑎2𝐷𝐷2𝑚𝑚2 + 𝑎𝑎3𝐷𝐷3𝑚𝑚3 + . . .

Page C-2 of 2