AZ FLAP 202(1)_Geotech and Pavements Report.pdf

Geotechnical Engineering Report and

Final Pavements Recommendation

AZ FLAP 202(1) Red Cloud Mine Road

Yuma County, Arizona

Yeh Project No.: 217-421

September 12, 2019

Prepared for:

Jacobs Engineering Group, Inc.

Attn: Berwyn Wilbrink, P.E.

101 N 1st Avenue, Suite 2600

Phoenix, Arizona 85003

Prepared by:

Yeh and Associates, Inc.

570 Turner Drive, Suite D Durango, Colorado 81303

Phone: 970-382-9590 Fax: 970-382-9583 i

Table Of Contents

1. PURPOSE AND SCOPE OF STUDY

1.1 PURPOSE OF WORK

1.2 SCOPE OF WORK

2. PROPOSED CONSTRUCTION

3. GEOLOGICAL SETTING AND SITE CONDITIONS

4. SUBSURFACE INVESTIGATION

4.1 FIELD EXPLORATION

4.2 LABORATORY TESTING

5. SUBSURFACE CONDITIONS

5.1 PROPOSED RECONSTRUCTION OF EXISTING ALIGNMENT OF RED CLOUD MINE ROAD

5.1.1 EXISTING AND PROPOSED ALIGNMENT ON TERRACE SURFACES

5.1.2 EXISTING AND PROPOSED ALIGNMENT WITHIN ALLUVIAL WASHES

5.2 PROPOSED REALIGNMENT OF RED CLOUD MINE ROAD

6. GEOTECHNICAL AND PAVEMENT RECOMMENDATIONS

6.1 EARTHWORK DESIGN

6.1.1 GENERAL GRADING

6.1.2 REUSE OF ON-SITE SOIL

6.1.3 WATER-SOLUBLE SULFATE AND CORROSION PROPERTIES OF ON-SITE SOIL

6.1.4 EROSION AND SLOPE DRAINAGE

6.1.5 EARTHWORK FACTORS

6.1.6 EXCAVATION

6.1.7 SUBGRADE PREPARATION

6.1.8 GRADED SLOPE DESIGN

6.2 FOUNDATION PREPARATION FOR CATTLE GUARDS AND WINGWALLS

6.3 PAVEMENT DESIGN RECOMMENDATIONS

6.3.1 DESIGN TRAFFIC VOLUME AND SUBGRADE

6.3.2 STRUCTURAL SECTION

6.3.3 BINDER AND MIX RECOMMENDATIONS

7. LIMITATIONS

8. REFERENCES

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APPENDICES

List Of Figures

FIGURE 2-1 - PROJECT LOCATION MAP

FIGURE 2-2 - PROJECT LIMITS

FIGURE 3-1 - GEOLOGIC MAP

FIGURE 3-2 - DESERT PAVEMENT ON TERRACE, ADJACENT TO ALLUVIAL WASH

FIGURE 3-3 - EXISTING ROAD - CROSSING ALLUVIAL WASH

List Of Tables

TABLE 4-1 - SUMMARY OF BORINGS

List Of Appendices

BORING LOCATION MAPS ...................................................................................................... A

BORING LOGS ........................................................................................................................ B

LABORATORY TEST METHODS AND RESULTS .......................................................................... C

PAVEMENT DESIGN CALCULATIONS ....................................................................................... D

NRCS SOIL MAP AND SOIL DESCRIPTIONS .............................................................................. E

PHOTOS OF DRILLING OPERATIONS ....................................................................................... F

AZ FLAP 202(1) Red Cloud Mine Road YA Project No. 217-421 Geotechnical Engineering and Final Pavement Recommendations September 12, 2019

1. PURPOSE AND SCOPE OF STUDY

This report presents the results of the Yeh and Associates, Inc. (Yeh) geotechnical engineering investigation and pavement design analysis for the proposed reconstruction, realignment and paving of approximately 3.1 miles of Red Cloud Mine Road in Yuma County, Arizona. The study was performed in accordance with our Scope of Work dated August 18, 2017 and with Yeh’s

Geotechnical Investigation Plan, dated April 15, 2019.

1.1 Purpose of Work

The purpose of this report is to provide geotechnical investigation results and engineering recommendations for use by Jacobs Engineering Group, Inc. (Jacobs) and the project team for the proposed reconstruction and partial realignment of 3.1 miles of Red Cloud Mine Road. The proposed project is located north of the Yuma Proving Grounds and partially on the Imperial

National Wildlife Refuge (INWR) in the southwestern corner of Arizona. Project AZ FLAP 202(1) is an extension of the improvements already planned/designed for the AZ FLAP 439(1) Martinez

Lake Road project to the south. The project is generally described as a full 4R reconstruction project, with reconstruction; horizontal and vertical realignment; widening; surfacing; and drainage improvements being planned.

1.2 Scope of Work

Our scope of work included the following:

• Geotechnical investigation of existing alignment to include pavement and subgrade borings

• Geotechnical investigation of proposed realignment

• Laboratory testing of select samples

• Pavement cost analyses – relative cost assessments of viable options

• Preliminary Pavement Recommendations

• Recommendations for culvert and headwall/wingwall geotechnical design parameters;

vented structure bearing requirements; subexcavation requirements; general earthwork requirements; and corrosivity/swell potential of soil/rock materials.

• Draft and Final Geotechnical and Pavement Engineering Report

2. PROPOSED CONSTRUCTION

This project consists of reconstruction and minor widening of 3.1 miles of Red Cloud Mine Road between the road’s intersection with Martinez Lake Road and the Imperial National Wildlife

Refuge (INWR). The project site is located in Yuma County, Arizona, approximately 35 miles north of the city of Yuma via US Highway 95 and Martinez Lake Road, as illustrated in Figure 2-

1.

Figure 2-1 - Project Location Map (no scale)

The project begins at the intersection of Red Cloud Mine Road with Martinez Lake Road. From the intersection, the proposed project generally follows the existing alignment of Red Cloud

Mine Road to the northwest for approximately 2 miles. Near the intersection with Snipe Road, the proposed alignment diverges eastward from the road’s existing location and traverses a series of terraces and drainages for a distance of approximately 1.1 miles. The project limits are shown in Figure 2-2. The existing Red Cloud Mine Road consists of two lanes, and varies in width from 24 to 28 feet. The road is surfaced with road base or native granular materials.

Proposed improvements include reconstructing and realigning the roadway to provide an asphalt surfaced roadway 28 feet in width, with two 12-foot lanes and 2-foot shoulders. Existing horizontal geometry will be adjusted slightly to improve the 25-mph corridor to a desired 30 mph corridor. The vertical geometry will be revised to provide adequate stopping sight distance and to raise the roadway out of the floodplains such that the 5-year storm event can pass under, and all greater events can pass safely over the new roadway prism.

Figure 2-2 - Project Limits (no scale)

3. GEOLOGICAL SETTING AND SITE CONDITIONS

The project area is located primarily within the limits of the United States Geologic Survey

(USGS) Imperial Reservoir Quadrangle topographical map (USGS, 2018). At its northern end, the project extends onto the Red Hill SW Quadrangle map (USGS, 2018). Red Cloud Mine

Road within the project limits is located within the Colorado River valley, and generally skirts the eastern perimeter of Martinez Lake as it approaches the INWR. Ground elevations are approximately 200 feet above Mean Sea Level (MSL). Surficial deposits are Quaternary in age, and are delineated and described in the Arizona Geologic Survey’s Geologic Map of Arizona

(Richard, S.M., et al., 2000). Figure 3-1 shows the geologic map for the project area; unit descriptions follow.

Figure 3-1 - Geologic Map (no scale)

Qr Holocene River Alluvium – Unconsolidated to weakly consolidated sand and gravel in river channels and sand, silt and clay on floodplains. Also includes young terrace deposits fringing floodplains

Q Quaternary Surficial Deposits, Undivided – Unconsolidated to strongly consolidated alluvial and eolian deposits. This unit includes: coarse, poorly sorted alluvial-fan and terrace deposits on middle and upper piedmonts and along large drainages; sand, silt and clay on alluvial plains and playas; and wind-blown sand deposits.

Tv Middle Miocene to Oligocene Volcanic Rocks – Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks.

Ti Middle Miocene to Oligocene Shallow Intrusions – Granite to diorite representing solidified magma chambers that were the likely source of overlying and nearby volcanic rocks of map unit Tv.

The existing alignment for Red Cloud Mine Road lies within the limits of map unit Qr. Where the proposed roadway diverges uphill (east) of the existing alignment, surficial deposits of map unit

Q are expected to be encountered. North, south and east of the project area, Tertiary rocks (Tv and Ti) protrude from the sediments to form low ranges of hills.

National Resources Conservation (NRCS) soil maps for the project area indicate that two map units are present. Within the alluvial washes the soil is mapped as Carrizo very gravelly sand

(Map Unit 3), while the upland terraces consist of Map Unit 21 – Ligurta-Cristobal complex. Map unit descriptions and a soil map downloaded from the NRCS Web Soil Survey are provided in

Appendix E. Soil properties and chemical qualities are discussed in Sections 5 and 6.1.2 of this report.

The natural, undisturbed ground surface on the upland terraces is sparsely vegetated and generally covered with “desert pavement”, consisting of angular to sub-angular gravel to cobble and small boulder-sized fragments of volcanic rock. Figure 3-2 shows the native landscape typical of the area. Where the existing alignment traverses the broad alluvial washes, the roadsides are dominated by dense stands of tamarisk trees, as shown in Figure 3-3.

Figure 3-2 - Desert Pavement on Terrace, Adjacent to Alluvial Wash

Figure 3-3 - Existing Road - Crossing Alluvial Wash

4. SUBSURFACE INVESTIGATION

4.1 Field Exploration

Yeh conducted a geotechnical investigation for the Red Cloud Mine Road project on April 23, 24 and 25, 2019. A truck-mounted CME 75 drill rig was used to advance the borings into the existing roadway prism using an 8 inch hollow-stem auger (HSA). For borings along the section of proposed realignment, a low impact ATV mounted drill rig with a 4 inch solid-stem auger

(SSA) was utilized. Resilient Drilling Services of Mesa, Arizona, was the drilling contractor;

traffic control was provided by Quail Construction, LLC, of Yuma, Arizona.

Approximate coordinates and elevations for the borings were recorded using a hand-held GPS unit; the locations were projected onto the roadway alignment provided by Jacobs. Locations of the borings are shown on the Exploratory Boring Location Maps in Appendix A. Boring Logs are included in Appendix B, and photographs of the drilling operations are provided in Appendix F.

Sixteen (16) borings, RC-01 through RC-16, were drilled into the existing roadway prism using the HSA. Boring depths ranged from 11.5 to 16.5 feet, with the exception of Boring RC-09, which met with auger refusal at 4 feet. One HSA boring, RC-17 was located on Snipe Road. Six

(6) holes were drilled along the proposed realignment of Red Cloud Mine Road within the

Imperial National Wildlife Reserve. Borings RC-18A and RC-18 through RC-21 were drilled with the SSA. Borings depths attained with the SSA ranged from 3 to 17 feet. The HSA was also used for boring RC-22 at the northern terminus of the project. The remainder of the proposed realignment, south of the INWR, lies on land owned by the State of Arizona. Permission to enter and disturb the ground surface was not granted by the State.

With the exception of two (2) inches of asphalt pavement at Boring RC-01, no asphalt surfacing was present. Groundwater was encountered in seven (7) borings; requisite well permits were obtained from the Arizona Department of Water Resources for each of these locations. No bedrock was encountered in any of the borings. Results of the investigation are summarized in

Table 4-1. Maps of the boring locations are provided in Appendix A.

Table 4-1 - Summary of Borings

Roadway Boring No. Station Offset

Hollow- Stem or

Solid-Stem Auger

Total Depth (ft)

Location - Upland or

Wash

Depth to Ground-water (ft)

Red Cloud Mine Road -

Existing Alignment

RC-01 108+90 5' Rt. HSA 11.5 Terrace RC-02 117+05 5' Rt. HSA 11.5 Terrace RC-03 128+15 11' Rt. HSA 11.5 Terrace RC-04 132+60 13' Lt. HSA 16.5 Wash 5.6 RC-05 137+40 10' Rt. HSA 16.5 Wash 6.0 RC-06 142+35 16' Lt. HSA 16.5 Wash RC-07 148+20 10' Rt. HSA 16.5 Terrace RC-08 154+30 16' Lt. HSA 16.5 Terrace RC-09 158+20 8' Rt. HSA 4.0 Terrace RC-10 166+50 20' Rt. HSA 16.5 Wash 11.0 RC-11 173+10 13' Lt. HSA 16.5 Wash RC-12 179+90 11' Rt. HSA 16.5 Wash 7.0 RC-13 186+30 17' Lt. HSA 16.0 Wash 9.0 RC-14 194+45 15' Rt. HSA 16.5 Wash 7.0 RC-15 197+15 13' Lt. HSA 16.5 Wash 9.0 RC-16 205+55 45' Lt. HSA 11.5 Terrace

Snipe Road RC-17 402+95 12' Rt. HSA 11.5 Terrace

Red Cloud Mine Road - Realignment

RC-19 38+00 @ CL SSA 17.0 Wash RC-18 42+70 @ CL SSA 10.0 Wash

RC-18A 42+70 50' Lt. SSA 3.0 Terrace RC-20 47+70 @ CL SSA 4.0 Terrace RC-21 51+00 38' Rt. SSA 12.0 Terrace RC-22 55+20 @ CL HSA 11.5 Terrace

Soil samples were collected from all of the borings during drilling. Samples were collected from auger cuttings and at intermittent depths from HSA borings utilizing either a standard 2 inch

O.D. split spoon sampler or a 2.5 inch O.D. “Modified California” sampler. The samplers were advanced by a 140 pound automatic (or “auto”) hammer with a 30 inch drop height. The number of blows required to drive the sampler 12 inches, or a fraction thereof, after an initial penetration of 6 inches for the standard sampler, constitutes the N-value as shown on the boring logs. N-values can be correlated to the relative density of cohesionless soils.

4.2 Laboratory Testing

Samples recovered during the subsurface investigation were transported to Yeh’s laboratory in

Durango, Colorado. The samples and field logs of the borings were reviewed by the Project

Engineer and a program of laboratory testing was assigned. Specialized testing for chloride content, was provided by Green Analytical Laboratories of Durango, Colorado. Hveem

Resistance “R” Value testing was performed at Yeh’s Denver laboratory.

The laboratory tests were performed on selected samples from the borings in general accordance with the American Association of State Highway and Transportation Officials

(AASHTO) and American Society of Testing and Materials (ASTM) procedures. Laboratory tests on samples included sieve analysis, Atterberg limits, natural moisture content, and R-Value. In addition, selected samples were subjected to chemical analyses to evaluate soil corrosivity: pH, water-soluble sulfate content, water-soluble chloride content, and resistivity. The laboratory test results are included in Appendix C and are shown on the boring logs in Appendix B.

Results from the Atterberg limits determination and sieve analysis were used to classify the soils according to AASHTO and the Unified Soil Classification System (USCS) standards. Atterberg limits were performed in general accordance with AASHTO T89 and T90, and sieve analyses were performed in general accordance with ASTM D421. Soil classifications are shown on the boring logs in Appendix B and on the summaries in Appendix C.

The moisture content of a soil can be useful for characterizing a soil’s in situ consistency, compressibility, and structural adequacy. High moisture contents can also be an indicator of the recent depth to groundwater. Moisture content tests were performed in general accordance with

ASTM D2216.

R-Value tests were performed on five (5) bulk samples. The tests were performed in general conformance with ASTM D 2844. R-Value test results are provided in Appendix C.

Eight (8) samples were tested for chemical properties to evaluate the potential of the soil to be aggressive to concrete and to corrode buried metal. The tests included pH (ASTM D 4972 /

AASHTO T 289), soluble sulfate content (AASHTO T 290), and soil resistivity (AASHTO T 288).

Water-soluble chloride measurements (EPA 300.0) were performed by Green Analytical

Laboratories, Inc. The test results are summarized in Appendix C and presented on boring logs in Appendix B.

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5. SUBSURFACE CONDITIONS

5.1 Proposed Reconstruction of Existing Alignment of Red Cloud Mine Road

The proposed project follows the current alignment of Red Cloud Mine Road for a distance of approximately 2 miles from the intersection with Martinez Lake Road, northward to the intersection with Snipe Road. In this area, 16 exploratory borings were drilled through the existing roadway surface. One additional boring, RC-17, was located on Snipe Road. The existing alignment transitions into and out of broad, low-angle alluvial washes, including Los

Angeles Wash, that drain westward into Martinez Lake.

5.1.1 Existing and Proposed Alignment on Terrace Surfaces

Eight borings, RC-01; RC-02; RC-03; RC-07; RC-08; RC-09; RC-16 and RC-17, were located on terrace areas outside of the washes. Asphalt pavement was encountered only at Boring RC-

01, drilled near the transition from asphaltic to gravel surfacing. Subsurface conditions generally consist of poorly sorted sands and gravels, with silt and occasional zones of cobble. No groundwater or bedrock was encountered in the terrace borings. Penetration Resistance values in the upper 10 feet of subgrade ranged from 8 to 27 blows per foot (bpf) except in gravel zones, where values of 35 to 78 bpf were recorded.

Four samples of subgrade collected from depths of less than 5 feet below the ground surface were tested for purposes of classification. Gradation test results show the soils have 6 to 22 percent fines (passing the No. 200 standard sieve). Sand portions ranged from 42 to 63 percent, while the gravel content (retained on the #4 standard sieve) ranged from 24 to 51 percent.

Atterberg limits testing showed only the sample from RC-01, obtained from beneath the asphalt pavement, exhibited plasticity. The Liquid Limit (LL) was 25 percent and the Plasticity Index (PI) was 7. The other samples tested were all Non-Plastic. Under the AASHTO system, the soils were classified as A-1-a (0) or A-1-b (0), with the exception of RC-01, which was an A-2-4 (0) soil. In the Unified Soil Classification System (USCS), the soils were SM-SC (silty sand with gravel), SM (poorly graded sand with silt and gravel), GP-GM (poorly graded gravel with silt and sand) and SP-SM (poorly graded sand with silt and gravel).

The natural moisture contents for two samples were 4.7 and 1.1 percent. Chemical properties were measured for one sample from Boring RC-08. The pH was 7.8. Water-soluble sulfate and chlorides were high, at 0.53 percent and 0.797 percent, respectively, and the resistivity was low, 1 1 at 77 Ohm-cm. Hveem Resistance “R” Values of 76 and 74 were measured for samples from

RC-02 and RC-16.

5.1.2 Existing and Proposed Alignment within Alluvial Washes

Borings RC-04, RC-05, RC-06, RC-10, RC-11, RC-12, RC-13, RC-14 and RC-15 were located where the existing and proposed Red Cloud Mine Road passes through alluvial washes.

Subsurface conditions generally consist of silty gravels and silty sands, with 2.0 to 2.5 feet of what appears to be granular fill in places. Groundwater was encountered in 7 of the 9 borings, at depths of 5.6 to 11.0 feet beneath the roadway surface. Penetration resistance values were lower than those for the terrace areas. Values were between 2 and 15 bpf, except where gravel was a significant component of the soil, as in Borings RC-11, RC-12 and RC-13, where readings of 29 to 38 bpf were recorded.

Five bulk samples of subgrade soils were tested for purposes of classification. Gradation test results show the soils to have between 19 and 63 percent fines, 34 to 52 percent sand, and 3 to

43 percent gravel. A sample from Boring RC-12 had a LL of 24 percent and a PI of 3. The remaining samples were Non-Plastic. Two samples had AASHTO classifications of A-1-b (0), one was A-2-4 (0), and two were A-4 (0). Under the USCS system, one sample was classified as GM (silty gravel with sand), two were SM (silty sand with gravel), and two were ML (sandy silt). One split spoon sample collected below the recorded water level at Boring RC-13 at a depth of 10 feet using the Standard Penetration Test was tested. This sample had a natural moisture content of 27.8 percent, 71 percent fines and 29 percent sand. The sample was Non-

Plastic, and was classified as A-4 (0) under AASHTO and ML under the USCS system.

The natural moisture contents for four samples, all collected from above the groundwater surface, were between 4.5 and 8.1 percent. Chemical properties were measured for four samples. The pH ranged from 7.3 to 8.2. Measurements for water soluble sulfate ranged from

0.034 percent to 0.51 percent; water soluble chloride ranged from 0.0421 percent to 0.1020 percent. Resistivity ranged from 180 to 580 Ohm-cm. R-Values measured for two samples were

60 and 67.

5.2 Proposed Realignment of Red Cloud Mine Road

The section proposed for realignment is approximately 1.1 miles in length. Borings RC-19, RC-

18, RC-18A, RC-20, RC-21 and RC-22 were drilled along the northern portion of the proposed new alignment within the bounds of the INWR. The southern portion of the proposed new

1 2 alignment lies within an area where surface ownership is under the control of the State of

Arizona. Access for drilling was not granted within that area, but surface and subsurface conditions are not expected to differ significantly from those encountered in the borings drilled to the north.

Eight subgrade samples were collected from three borings, RC-18; RC-19; and RC-20, at different depths for purposes of classification. For RC-18 and RC-19, the fines content ranged from 38 to 74 percent. Sand comprised between 25 and 60 percent, and gravel ranged from 1 to

21 percent. Samples from RC-21 were coarser, with 4 to 14 percent fines, 58 to 91 percent sand, and 5 to 28 percent gravel. AASHTO Classifications for all RC-18 and RC-19 samples were A-4 (0); USCS classes were ML (sandy silt) and SM (silty sand). For RC-21, all samples were classified as A-1-b (0) under AASHTO, with USCS classes of SM (silty sand), SP-SM

(poorly graded sand with silt) and SP (poorly graded sand).

Natural moisture contents ranged from 0.7 to 2.9 percent, with the exception of the RC-19 sample from 4 to 8 feet beneath the surface, where the moisture content was 20.2 percent. Soil pH and water soluble sulfates were measured for two samples; pH values were 7.2 and 8.3, with 0.26 to 0.32 percent sulfate. Water soluble chlorides for the one sample tested were 0.5710 percent. The R-Value for a composite sample at RC-19 was 65.

6. GEOTECHNICAL AND PAVEMENT RECOMMENDATIONS

The recommendations of this report assume that grading, paving and fill materials will be placed and constructed in general accordance with the Federal Highway Administration’s Standard

Specifications (FP-14). Compliance with those specifications is needed for the recommendations in this report to remain applicable.

6.1 Earthwork Design

6.1.1 General Grading

All site grading should conform to the applicable sections of FP-14. Fill materials should not contain organic matter or other deleterious material. Excess fill or cut material should be hauled offsite for proper disposal, unless an onsite location has been specifically identified for placement of excess fill on the project plans. Temporary excavations should conform to OSHA requirements.

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6.1.2 Reuse of On-site Soil

On-site soil removed from excavations and cleansed of topsoil, organics, clay lenses or clods, and oversized rock can be reused as borrow for general embankment fill and unclassified borrow. Fill materials should not contain organic matter or other deleterious material. The soil samples tested were typically more than 10 percent below the optimum moisture content for compaction. Moisture conditioning of the excavated soil will be necessary to make the material suitable for compaction.

6.1.3 Water-Soluble Sulfate and Corrosion Properties of On-site Soil

The chemical properties of on-site soils may make them unacceptable for use as Structural

Backfill in contact with steel and concrete structures. Water-soluble sulfate values were high, generally between 0.19 and 0.53 percent. Water soluble chloride levels were also elevated, in most cases ranging from 0.102 to 0.797 percent. Corresponding resistivity measurements were low, between 77 and 580 Ohm-cm. The low resistivity levels and high sulfate and chloride contents require that the soil should be treated as an aggressive environment for concrete and metal (Sabatini, et al. 2002, subsection 4.12.4.9). Local NRCS Soils Maps and maps addressing

Corrosion of Concrete and Steel are provided in Appendix E. The Arizona Department of

Transportation specifications include the following: “Backfill material shall have a value of resistivity not less than 2,000 ohm-centimeters.” (Arizona DOT, 2008).

We recommend that a Project Special Provision be developed to address the issue of high water-soluble sulfates and water-soluble chlorides and low resistivity in the natural on-site soils.

When applicable, a layer of Structural Backfill or aggregate base course could be used as a separator between concrete and native material. Options for corrosion mitigation could include sacrificial metal (heavier gauge construction material) in design of structural elements and use of materials resistant to corrosion such as galvanized or epoxy coatings; cathodic protection systems, and sulfate resistant concrete. A qualified corrosion engineer should review this data to evaluate the appropriate level of corrosion protection for subgrade utilities and buried metal and concrete structures proposed for the area.

6.1.4 Erosion and Slope Drainage

The project site is within a desert environment with sparse vegetation and minimal to no topsoil.

Graded slopes will be vulnerable to erosion. Surface drainage on the terrace areas should be maintained to allow the sheet flow of water similar to existing conditions and without

1 4 concentrating flow or runoff. Concentrated flows of runoff should not be allowed to run over slopes. Drains and drainages should be designed with appropriate erosion control and scour resistance surfaces.

6.1.5 Earthwork Factors

The Earthwork factor was estimated for the subsurface conditions encountered. Where on-site soil will be excavated for reuse as embankment fill, an average earthwork factor of 0.95 should be used. The earthwork factor is approximate and should be checked and adjusted as-needed as the grading work progresses to properly balance earthwork operations.

6.1.6 Excavation

Sandy and silty soils containing varying amounts of gravel were encountered in the proposed cut areas along Red Cloud Mine Road. Excavation of the soils should be possible with conventional heavy earthmoving equipment and should not require heavy ripping or blasting.

The excavated soil is likely to contain gravel and cobble size materials and occasional boulders.

Oversized materials and zones of unsuitable soil will need to be removed from the excavated soil before it is considered suitable for reuse as compacted fill.

6.1.7 Subgrade Preparation

The roadbed should be prepared for placement of aggregate base or embankment fill materials in accordance with FP-14. Prior to placing fill or base course materials, the subgrade should be scarified to a depth of 8 inches, conditioned to a moisture content suitable for compaction, and compacted in-place to at least 95 percent relative compaction. The subgrade along the new road alignment should generally consist of medium to dense sandy material that should be suitable for the support of the new roadway and embankment fill. Where the existing alignment crosses alluvial washes, the subgrade should be reviewed following the initial excavation to evaluate whether or not additional soft or compressible soil is in place. If needed, subexcavation should be provided to remove soft or compressible soil prior to placing the embankment fill, culvert pipes or cattle guards.

6.1.8 Graded Slope Design

The proposed project will involve embankment construction, excavation for cuts, and widening of existing cut and embankment slopes through undulating terrain with intervening drainages.

Graded slopes should be designed to inclinations of 1v:2h or flatter.

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6.2 Foundation Preparation for Cattle Guards and Wingwalls

A series of cattle guards are proposed for providing low-flow drainage beneath Red Cloud Mine

Road where it crosses the alluvial washes. On-site soils are fine-grained, and may be prone to compression under load. We recommend that the structures be placed on a pad constructed of soil cement material, 8 inches in thickness. This will serve to diminish opportunities for differential settlement, and also provide a physical barrier between the concrete and the on-site soils.

We recommend that the foundation areas for wingwalls be subexcavated 2 feet beyond the footing perimeter to a depth of 8 inches. Following removal of this material, the top 6 inches of the remaining in-place material should then be scarified, reconditioned to a moisture content suitable for compaction, and compacted in-place to at least 95 percent relative compaction.

Material removed from the excavation should be replaced with 8 inches of soil cement as a barrier to contact with the on-site soils.

6.3 Pavement Design Recommendations

The minimum pavement design thickness for the reconstructed Red Cloud Mine Road is recommended based on design standards provided in Chapter 11 of the Federal Lands

Highway Project Development and Design Manual (PDDM) and the AASHTO (1993) Guide for the Design of Pavement Structures. Preliminary pavement structural sections were evaluated and presented in the Yeh July 23, 2019 memorandum. Based on our evaluation and subsequent discussions with Jacobs, it was determined that hot asphaltic concrete pavement

(HACP) over Aggregate Base was the appropriate alternative for this project. Where the roadway crosses the alluvial washes, design plans show that the roadway prism will be constructed with upstream and downstream side slopes “armored” by soil-cement. In these areas, an 8 inch soil-cement cap is proposed to replace the 6 inches of aggregate base. Soil-cement will be obtained from a commercial source in order to avoid problems with high sulfate concentrations in local soils.

6.3.1 Design Traffic Volume and Subgrade

The design traffic volume was estimated using the average daily traffic (ADT) provided by

Jacobs in preliminary roadway plans dated December 4, 2018 and procedures in the PDDM.

Jacobs reported that the current (2018) seasonal ADT for Red Cloud Mine Road is approximately 500 vehicles per day with less than 1 percent trucks. The projected ADT for 2038

1 6 was 700. These data were used to estimate the number of 18-kip equivalent single axle loads

(ESALs) considering a design life of 25 years. The value used in design was 92,000 ESALs.

Soils encountered in the subsurface investigation of Red Cloud Mine Road were generally classified as AASHTO A-1 and A-4, with some A-2-4 soils present. All soils tested are considered to provide good to excellent subgrade support for the roadway. R-values obtained from bulk samples ranged from 60 to 76. The recommended structural section thicknesses were estimated considering a resilient modulus (Mr) of 13,200 psi for the granular subgrade soils encountered.

6.3.2 Structural Section

Red Cloud Mine Road will be reconstructed with minor horizontal and vertical changes from the intersection with Martinez Lake Road to the intersection with Snipe Road. In addition, a complete realignment of Red Cloud Mine Road is proposed for a distance of 1.1 miles, north from Snipe Road. Based on the geotechnical investigation, subgrade soils encountered throughout the project are expected to provide adequate structural support in both cut and fill applications.

The recommended structural section for both of these areas is based on the traffic loading conditions assuming a 25-year design life for a 4R project; a Reliability Level (R) of 75;

Combined Standard Error (SO) of 0.49; Initial and Terminal Serviceabilities of 4.2 and 2.0, respectively; and a minimum structural number of 1.74. The minimum structural section required by the pavement design software is 3 inches of HACP on 4 inches of Aggregate Base. The thickness of Aggregate Base required for the project has been increased to 6 inches, as shown on the plans.

6.3.3 Binder and Mix Recommendations

The State of Arizona has adopted a program of Asphalt Binder Grade Selection that classifies this project area as a Desert Region. The recommended binder for this area is PG 70-10

(LTPPBind). This project is in a rural area, and we understand the location of existing commercial asphalt plants may result in relatively long haul distances to the construction site.

Loss of temperature and segregation of the hot asphalt mix can occur during transport. We recommend that the project specifications require the use of a material transfer device at the point of placement to ensure uniform temperatures and prevent segregation of the mix during placement.

1 7

7. LIMITATIONS

This study was conducted in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design of the proposed roadway reconstruction project. Recommendations herein are intended to be used for design by a qualified transportation engineer. The preliminary analyses and recommendations presented in this report are based upon our data obtained from limited field observations, widely spaced borings, laboratory testing, our understanding of the proposed construction and other information as discussed in this report. It is possible and likely that subsurface conditions may vary from those encountered in the borings. We should also review the design for conformance to the recommendations in the report when the scope of the proposed construction becomes established.

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

This report was prepared in substantial accordance with the generally accepted standards of practice for geotechnical engineering as exist in the site area at the time of our investigation. No warranties, express or implied, are intended or made. The recommendations in this report are based on the assumption that the Contracting Officer will conduct an adequate program of construction testing and observation to evaluate compliance with our recommendations.

1 8

8. REFERENCES

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

Arizona Department of Transportation, Standard Specifications for Road and Bridge Construction, 2008.

Sabatini, P.J. et al., 2002, Geotechnical Engineering Circular No. 5, Evaluation of Soil and Rock Properties, U.S. Department of Transportation, Office of Bridge Technology, Federal Highway Administration, Report No. FHWA-IF-02-034.

FP-14, Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects. U.S. Department of Transportation, Federal Highway Administration, Federal Lands Highway, 2014.

Richard, S.M.; Reynolds, S.J.; Spencer, J.E.; and Pearthree, P.A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35.

U.S. Department of Transportation, Federal Highway Administration, Federal Lands Highway Project Development and Design Manual (PDDM), Chapter 11 – Pavements, Government Printing Office, Washington, D.C., December 2014.

U.S. Geological Survey (USGS), 2018, Imperial Reservoir Quadrangle, Arizona – California, 7.5-minute Series, 1:24,000.

U.S. Geological Survey (USGS), 2018, Red Hill SW Quadrangle, Arizona – California, 7.5-minute Series, 1:24,000.

1 9

APPENDICES

BORING LOCATION MAPS ...................................................................................................... A

BORING LOGS ........................................................................................................................ B

LABORATORY TEST METHODS AND RESULTS .......................................................................... C

PAVEMENT DESIGN CALCULATIONS ....................................................................................... D

NRCS SOIL MAP AND SOIL DESCRIPTIONS .............................................................................. E

PHOTOS OF DRILLING OPERATIONS ....................................................................................... F

Appendix A

BORING LOCATION MAPS

1 Boring Location Map - Existing Alignment

2 Boring Location Map - Realignment on INWR

Appendix B

BORING LOGS

Project Number: 217-421

AZ FLAP 202 (1) Red Cloud Road

Lithology Symbols(see Boring Logs for complete descriptions)

Asphalt USCS Low Plasticity Sandy Clay

Fill with Gravel as major soil

Fill with Sand as major soil

USCS Silty Gravel USCS Poorly-graded Gravel with Silt

USCS Poorly-graded Sandy Gravel USCS Silt

USCS Sandy Silt USCS Clayey Sand USCS Silty Sand USCS Poorly-graded Sand with Silt

Lab Test Standards Other Lab Test Abbreviations pH Soil pH (AASHTO T289-91) S Water-Soluble Sulfate Content (AASHTO T290-91, ASTM D4327)

Chl Water-Soluble Chloride Content (AASHTO T291-91, ASTM D4327)

S/C Swell/Consolidation (ASTM D4546) UCCS Unconfined Compressive Strength (ASTM D2166) R-Value Resistance R-Value (ASTM D2844) DS (C) Direct Shear cohesion (ASTM D3080) DS (phi) Direct Shear friction angle (ASTM D3080) Re Electrical Resistivity (AASHTO T288-91) PtL Point Load Strength Index (ASTM D5731)

Notes

Moisture Content ASTM D2216 Dry Density ASTM D7263 Sand/Fines Content ASTM D421, ASTM C136, ASTM D1140

Atterberg Limits ASTM D4318 AASHTO Class. AASHTO M145, ASTM D3282

USCS Class. ASTM D2487 (Fines = % Passing #200 Sieve Sand = % Passing #4 Sieve, but not passing #200 Sieve)

Auger Cuttings

Modified California Sampler (2.5 inch OD, 2.0 inch ID)

Standard Penetration Test

(ASTM D1586)

Sample Types

Legend for Symbols Used on Borehole Logs

Project:

Yeh and Associates, Inc.

C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

1. "Penetration Resistance" on the Boring Logs refers to the uncorrected N value for SPT samples only, as per ASTM D1586. For samples obtained with a Modified California sampler, drive depth is 12 inches, and "Penetration Resistance" refers to the sum of all blows. Where blow counts were > 50 for the 3rd increment (SPT) or 2nd increment (MC), "Penetration Resistance" combines the last and 2nd-to-last blows and lengths; for other increments with > 50 blows, the blows for the last increment are reported.

2. The Modified California sampler used to obtain samples is a 2.5-inch OD, 2.0-inch ID (1.95-inch ID with liners), split-barrel sampler with internal liners, as per ASTM D3550. Sampler is driven with a 140-pound hammer, dropped 30 inches per blow.

3. "ER" for the hammer is the Reported Calibrated Energy Transfer Ratio for that specific hammer, as provided by the drilling company.

A-2-4 (0)

SM-SC22 72554244.7

7-10-7

4-4-4

6-8-10

0.0 - 0.2 ft. 2 inches Asphalt.

0.2 - 3.0 ft. silty SAND with gravel, tan-brown, dry to damp, medium dense.

3.0 - 6.5 ft. loose to medium dense.

6.5 - 11.5 ft. medium dense.

Bottom of Hole at 11.5 ft.

Total Depth: 11.5 ft

Ground Elevation: Approximate surface elevation

Coordinates: N: E:

Location: Sta. 108+90, 5' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-01 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

E S

T E

M P

LA

T

E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

S an d C on te nt

G ra ve l C on te nt

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta nc e

A-1-b (0) SP-SM11 NPNV R-Value=7662274.8

8-10-12

6-8-9

4-4-3

0.0 - 0.5 ft. 6 inches of treated aggregate base course.

0.5 - 11.5 ft. SAND Poorly graded with silt and gravel, dark brown, damp, dense.

Light brown, dry, medium dense.

Bottom of Hole at 11.5 ft.

Total Depth: 11.5 ft

Ground Elevation: Approximate surface elevation: 204

Coordinates: N: E:

Location: Sta. 117+05, 5' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-02 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

E S

T E

M P

LA

T

E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

S an d C on te nt

G ra ve l C on te nt

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

Fine sand in sample barrel from 10' to 11'

28-50

9-8-10

18-9-13

0.0 - 5.0 ft. sandy GRAVEL silty, tan-brown, dry, very dense.

5.0 - 11.5 ft. silty GRAVEL sandy, scattered cobbles, tan, dry, medium dense.

Bottom of Hole at 11.5 ft.

Total Depth: 11.5 ft

Ground Elevation: Approximate surface elevation: 203

Coordinates: N: E:

Location: Sta. 128+15, 11' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-03 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

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J

Y E

H A

S S

O C

IA

T

E S

T E

M P

LA

T

E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

7-6-6

4-3-3

6-4-2

3-4-5

0.0 - 2.0 ft. silty GRAVEL sandy, brown, damp, dense, (Fill).

2.0 - 5.6 ft. silty SAND, dark brown, moist, loose.

5.6 - 16.5 ft. silty SAND, wet, loose.

Bottom of Hole at 16.5 ft.

Total Depth: 16.5 ft

Ground Elevation: Approximate surface elevation: 208

Coordinates: N: E:

Location: Sta. 132+60, 13' L

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

5.6 ft

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-04 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

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T E

M P

LA

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D T

L

IB

R

A R

Y .G

LB

/6 /1

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

GM19 NPNV pH=8.1

S=0.034% Chl=0.0421% Re=580ohm·cm

Boring caved in at 4 feet. Estimated water depth based on sample moisture is 6 feet

38434.8

6-9-6

1-1-1

2-4-4

0.0 - 2.0 ft. silty GRAVEL with sand, brown, damp, dense, (Fill).

2.0 - 5.0 ft. silty SAND, brown, damp, medium dense.

5.0 - 16.5 ft. silty SAND, brown, moist to wet, very loose to loose.

Bottom of Hole at 16.5 ft.

Total Depth: 16.5 ft

Ground Elevation: Approximate surface elevation: 191

Coordinates: N: E:

Location: Sta. 137+40, 10' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

6.0 ft

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-05 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

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J

Y E

H A

S S

O C

IA

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M P

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E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

S an d C on te nt

G ra ve l C on te nt

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

4-6-6

6-5-5

4-4-6

2-2-4

0.0 - 10.0 ft. silty GRAVEL sandy, tan-brown, damp, loose to medium dense.

10.0 - 16.5 ft. silty SAND, brown, moist to wet, loose.

Bottom of Hole at 16.5 ft.

Total Depth: 16.5 ft

Ground Elevation: Approximate surface elevation: 190

Coordinates: N: E:

Location: Sta. 142+35, 16' L

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-06 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

E S

T E

M P

LA

T

E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

14-17-18

5-10-11

11-10-12

0.0 - 6.0 ft. silty GRAVEL sandy, tan, damp, medium dense.

6.0 - 11.0 ft. sandy CLAY, brown, dry, very stiff.

11.0 - 16.5 ft. clayey SAND, tan, dry, medium dense.

Bottom of Hole at 16.5 ft.

Total Depth: 16.5 ft

Ground Elevation: Approximate surface elevation: 209

Coordinates: N: E:

Location: Sta. 148+20, 10' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-07 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

E S

T E

M P

LA

T

E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

A-1-a (0) GP-GM7 NPNV pH=7.8

S=0.53% Chl=0.797% Re=77ohm·cm

42511.1

20-7-8

3-5-7

4-9-11

6-8-9

0.0 - 5.0 ft. GRAVEL poorly graded, with silt and sand, tan, dry, medium dense to dense.

5.0 - 10.0 ft. silty SAND with gravel, tan, dry, medium dense.

10.0 - 16.5 ft. silty SAND, tan, dry, medium dense.

Bottom of Hole at 16.5 ft.

Total Depth: 16.5 ft

Ground Elevation: Approximate surface elevation: 227

Coordinates: N: E:

Location: Sta. 154+30, 16' L

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-08 Yeh and Associates, Inc.

E le va tio n (f ee t)

D ep th (f ee t)

S am pl e

T yp e/ A dv an ce m en t M et ho d

B O

R

IN

G L

O G

S P

T C

D O

T S

T Y

LE

-4

R

E D

C

LO

U D

.G P

J

Y E

H A

S S

O C

IA

T

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M P

LA

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E .G

D T

L

IB

R

A R

Y .G

LB

/6 /1

S an d C on te nt

G ra ve l C on te nt

M oi st ur e C on te nt

D ry

D en si ty

(p cf

)Blows per 6 in Li th ol o gy

Soil Samples

Material Description

P en et ra tio n

R es is ta

Auger refusal on first attempt at 3.5', offset 4' north and refused at 4'

25-23-15

0.0 - 4.0 ft. silty GRAVEL and cobbles, tan, dry, dense to very dense.

Bottom of Hole at 4.0 ft.

Total Depth: 4.0 ft

Ground Elevation: Approximate surface elevation: 226

Coordinates: N: E:

Location: Sta. 158+20, 8' R

Groundwater Levels:

Logged By: B. Bunker

Final By: B. Bunker

Symbol Depth Date

Weather Notes:

Inclination from Horiz.: Vertical

Night Work:

Boring Began: 4/23/2019

Boring Completed: 4/23/2019

Drilling Method(s): Hollow-Stem Auger

Driller: Resilient Drilling Services

Drill Rig: CME 75

Hammer: Automatic (hydraulic), ER: %

Project Name:

PAGE

AASHTO

& USCS

Classifi-cations

F in es C on te nt

P la st ic ity In de x

Project Number: 217-421 C o n s u l t i n g E n g i n e e r s & S c i e n t i s t s

Li qu id Li m it

Field Notes and

Other Lab Tests

AZ FLAP 202 (1) Red Cloud Road

Atterberg Limits

Boring No.: RC-09 Yeh and…