2011_June_17_Final_GeoTech_Investigation_CR_5.pdf

Yeh and Associates, Inc.

Consulting Engineers & Scientists

5 7 0 0 E a s t E v a n s A v e n u e , D e n v e r , C O 8 0 2 2 2 1 5 2 5 B l a k e A v e n u e , G l e n w o o d S p r i n g s , C O 8 1 6 0 1

5 7 0 T u r n e r D r i v e , S u i t e D , D u r a n g o , C O 8 1 3 0 3

June 17, 2011 Project No. 29-202A

Mr. Bahram Seifipour, P.E.

HDR Engineering 303 East 17th Avenue, Suite 700 Denver, Colorado 80203-1256

Dear Mr. Seifipour, Our field investigation for this report was based on plans furnished by the client dated October 15, 2010. All field work, including drilling, was completed between November 4th and November 23rd, 2010. Updated plans, County Road 5 F.I.R. Meeting Plans dated January 26, 2011, were provided by the client post drilling. We recommend additional test hole drilling be performed on fill wall locations shown on the January 2011 plan set that were not investigated. Additional test hole drilling would provide specific wall subsoil information that could be utilized for wall design including, but not limited to, bearing capacities, groundwater depths, global stability and lateral earth pressures. The table below indicates walls that were investigated for this report and new walls that were not investigated.

Original Wall No.

(HDR plan set dated

10/15/2010)

New Wall No.

(HDR FIR plan set dated 1/26/2011)

Wall Investigated?

1 1A YES

- 1B NO

- 1C NO

3 3A YES

- 3B NO

4 4 YES

5 5 YES

6 6 YES

7 7 YES

- 8B NO

9 11 YES

- 9 YES

- 10 NO

Sincerely, YEH AND ASSOCIATES, INC.

Keith E. Asay Project Engineer

FINAL

Geotechnical Investigation

County Road 5

Fill Walls, Bridge at MP 32 and Intersection with County Roads 3

Rio Blanco County, Colorado

Project No. 29-202A June 17, 2011

Prepared for:

Rio Blanco County

Mr. Bahram Seifipour, P.E.

HDR Engineering 303 East 17th Avenue, Suite 700

Denver, Colorado 80203-1256

Prepared by:

Yeh and Associates, Inc.

1525 Blake Avenue

Glenwood Springs, Colorado 81601 Phone: 970-384-1500 Fax: 970-384-1501

Rio Blanco County Road 5 Fill Walls, Bridge, Stock Passes and Intersection Project No. 29-202A i

TABLE OF CONTENTS

PURPOSE AND SCOPE

PREVIOUS INVESTIGATIONS AND STUDIES

PROPOSED CONSTRUCTION

SITE CONDITIONS

SITE GEOLOGY

SUBSURFACE INVESTIGATION

SUBSURFACE CONDITIONS

Existing Fill Sand and Gravel Clay Bedrock Groundwater

SITE DEVELOPMENT

FOUNDATION RECOMMENDATIONS

Fill Wall Foundations Stock Pass Foundations Bridge Foundation (Piceance Creek at approximate mile post 31.9)

LATERAL EARTH PRESSURE

PAVEMENT DESIGN

Intersection Subgrade Materials Traffic Loading Determination of Resilient Modulus (MR) of Subgrade for Design Hot Mix Asphalt Pavement Designs Hot Mix Asphalt Type Subgrade Preparation Drainage Considerations

WATER SOLUBLE SULFATE

ADDITIONAL INVESTIGATIONS

LIMITATIONS

ii

Figures

Figure 1 – Site Location Figures 2 through 8 – Approximate Test Hole Locations

Appendices Appendix A – Logs and Legend of Exploratory Borings Appendix B – Laboratory Test Results Summary of Laboratory Test Results Table Appendix C – Pavement Design

PURPOSE AND SCOPE

This report presents the results of our geotechnical investigation for proposed road improvements on County Road 5 (Piceance Creek Road) in Rio Blanco County, Colorado

(Figure 1). The purpose of this study was to evaluate geotechnical characteristics of the onsite soils and pavement subgrade and to provide geotechnical recommendations for fill walls, bridge foundations, stock pass foundations, intersection pavements at County Road 3, and other geotechnical issues at the subject site.

The site investigation consisted of geologic reconnaissance and exploratory test hole drilling to investigate subsurface conditions. Test hole drilling was observed by representatives of Yeh and Associates. Samples obtained during the field exploration were examined by the project personnel and representative samples were subjected to laboratory testing to determine the engineering characteristics of materials encountered. Based on our investigation, Yeh and

Associates completed an engineering analysis of the subsurface conditions. Our report summarizes our field investigation, the results of our analysis, and our conclusions and recommendations based on the proposed construction, site reconnaissance, subsurface investigation, and results of the laboratory testing.

PREVIOUS INVESTIGATIONS AND STUDIES

Yeh and Associates conducted several investigations and reviewed previous reports and studies by others in preparation of this report. Previous reports and studies are as follows:

• “Preliminary Geotechnical Investigation and Pavement Report” by

CTL|Thompson, Inc., Project No. GS 05270-115, dated March 23, 2009.

• “Preliminary Geologic Hazard Investigation” by CTL|Thompson, Inc., Project No.

GS 05270-115, dated January 15, 2009.

• “Road and Bridge Department Impact Fee Support Study” by RPI Consulting, LLC, Final Report dated April, 2008.

• “Final Geotechnical Investigation and Pavement Design” by Yeh and Associates, Inc., Project No. 29-202, dated August 6, 2010, Revised April 25, 2011.

• “Final Geotechnical Investigation, County Road 5, Projects 1 and 2B”, Project

No. 29-202A, dated March 15, 2011.

PROPOSED CONSTRUCTION

For this project, seven fill walls are planned. Fill walls will be constructed for roadway widening purposes. Plans dated October 15, 2010 provided by the client were used for this investigation. The table below summarizes fill wall locations and dimensions.

Table 1 – Fill Wall Locations Fill Wall

Designation Location Type Maximum Height

1A, originally 1 mp 8.59 to mp 8.87, left MSE* 15 feet 3A, originally 3 mp 12.85 to mp 12.98, left MSE 12 feet

4 mp 15.63 to mp 15.74, left MSE 8 feet 5 mp 17.63 to mp 17.69, left MSE 15 feet 6 mp 17.9 to mp 17.99, left MSE 20 feet 7 mp 25.35 to mp 25.40, left MSE 10 feet

11, originally 9 mp 34.56 to mp 34.67, right MSE 7 feet *Mechanically stabilized earth wall system

An existing bridge located at Piceance Creek (approximate mile post 31.9) will be replaced by a new bridge structure. Based on plans provided by the client, the new structure will be 51 feet wide (out to out) and 100 feet long (to bridge abutment centerlines). The proposed bridge deck elevation is planned at around 5991.57 feet (average). It is our understanding that a deep steel H-Pile foundation system will be utilized.

One intersection planned for improvements is included in this report. The intersection of

County Road 5 with County Road 3 was investigated. The County Road 3 intersection is located at mile post 17.8. Preliminary plans provided by the client indicated a fill wall on the south side of the intersection at the County Road 3 location. Profile plans indicated fills of up to

5 feet for County Road 5 and up to 7 feet for County Road 3 are planned.

Acceleration/deceleration lanes for turning lanes as well as medians will be constructed at the intersection.

SITE CONDITIONS

County Road 5 was paved at the time of investigation. Existing road widths varied between approximately 24 and 32 feet. Existing pavement appeared to be in satisfactory condition. Longitudinal and transverse cracks were observed at varying locations particularly in the northern section of this road. The cracking appeared to be minor and was previously filled.

Existing grades on County Road 5 vary between flat and 7 percent that generally slope down to the south and east. For most of the length, the roadway follows the Piceance Creek drainage and in many areas was located at the base of very steep to near vertical slopes at the transition to the valley floor. A majority of the roadway appeared to be constructed by utilizing cut slopes on the uphill side and embankment fill slopes on the downhill side. Ranches, vacant land and gas/oil production access roads were located along the project site.

The existing bridge at Piceance Creek, mile post 31.9, was approximately 31 feet long by 28 feet wide. Water level (creek level) was approximately 13 feet below the existing bridge deck elevation. Existing bridge abutments were constructed with steel sections and corrugated metal lagging.

SITE GEOLOGY

The project area is located in the Piceance Basin of western Colorado, a complex of numerous anticlines and synclines and a major gas production area. The Piceance Basin is located in the Colorado Plateau province and the topography of the basin is made up of high plateaus and ridges and deep valleys. The asymmetrical, arc-shaped basin is about 100 miles long by 50 miles wide, is oriented northwest-southeast and is deepest on the east edge. It is bounded structurally on the north by the Uinta Mountains, on the northeast by the Axial Uplift, on the east by the Grand Hogback/White River Uplift and the Elk Mountains, on the south by the

Uncompahgre Uplift and on the west by the Douglas Creek Arch/Rangely Dome. Exposed in the project area were Tertiary age sedimentary rocks including the brown and gray sandstone, siltstone and marlstone of the Uinta Formation and the upper members of the Green River

Formation, which includes localized layers of marlstone, siltstone, and sandstone. Bedrock is exposed in the project area in slopes and cliffs adjacent to the roadway. Surficial deposits include colluvium and alluvial gravels and artificial fill. Possible geohazards in the project area include, but are not limited to, rockfall, expansive and/or collapsible soils, subsidence, hydrocompaction, and debris flow. The scope for this investigation did not include evaluation of geologic hazards for this site.

SUBSURFACE INVESTIGATION

Proposed fill walls were investigated by drilling exploratory test holes at 200 foot to 300 foot spacing. Two additional test holes were drilled at the bridge location to supplement previous subsoil information. The intersection was investigated by drilling a minimum of four test holes within the existing intersection right-of-way, on pavement or shoulders. Two fill wall test holes were utilized as pavement test holes at the County Road 3 intersection. Yeh and

Associates chose the spacing requirements and field located all test hole boring locations. Test hole depths varied based on the wall heights at test hole locations, depth to bedrock and a minimum of 10 feet for pavement test holes. The table below summarizes test hole information.

Table 2 – Test Hole Designations Structure/Location Test Hole Number

Fill Wall 1A, originally 1 TH-1 through TH-6 Fill Wall 3A, originally 3 TH-11 through TH-14

Fill Wall 4 TH-15 through TH-17 Fill Wall 5 TH-18, TH-19, PH-1, PH-2 Fill Wall 6 TH-20 through TH-22 Fill Wall 7 TH-23 and TH-24

Fill Wall 11, original Wall 9 TH-28 through TH-30 Piceance Creek Bridge B-1 and B-2

County Roads 5 and 3 Intersection TH-18, TH-19, PH-1, PH-2

The locations of the test holes are presented on Figures 2 through 8. Test hole depths varied between 10 and 77 feet. All test holes were drilled either on the existing roadway shoulder or on/through existing pavement. All test holes were advanced using either a CME 45 or CME 55 truck or track drill rig with 4-inch continuous flight auger to pre-determined depths where a modified California or split spoon sampler was used to record blow counts and obtain samples. Bulk samples were also obtained at depths indicated.

To perform the modified California penetration resistance tests, a 2.0-inch inside diameter sampler was seated at the bottom of the test hole, then driven up to 12 inches with blows of an standard hammer weighing 140 pounds and falling a distance of 30 inches utilizing a “auto hammer” or “cat’s head” (ASTM D1586). The number of blows (Blow Count) required to drive the sampler 12 inches or a fraction thereof, constitutes the N-value. The N-value, when properly evaluated, is an index of the consistency or relative density of the material tested.

Test hole logs and legend are presented in Appendix A.

SUBSURFACE CONDITIONS

Subsoils encountered in the test holes consisted of varying amounts of existing asphalt over a gravelly sand layer underlain by fill, sand, gravel, silt and/or clay. Medium hard weathered sandstone bedrock was encountered at the surface in test hole TH-22 and at 70 feet in test hole B-2. Hard to very hard sandstone bedrock was encountered at depths of 11.5 feet, 32 feet, 19 feet and 7 feet in test holes TH-17, TH-20, TH-21 and TH-22, respectively. Practical drill rig refusal was encountered in test hole TH-17 at 12 feet. Hard to very hard bedrock shale with sandstone was encountered in test holes B-1 and B-2 at depths of 39 feet and 75 feet, respectively.

Existing Asphalt and Base/Chip Seal

Existing asphalt and base/chip seal was encountered during this investigation. Asphalt thicknesses measured were approximately 9 inches, 6 inches, 5 inches, 5 inches, 6 inches and

6 inches in test holes TH-1, TH-20, TH-21, PH-1, B-1 and B-2, respectively. Corresponding base/chip seal thicknesses measured were approximately no base, 15 inches, 11 inches, 16 inches, 12 inches and 9 inches, respectively. In test hole TH-24, which was drilled on the shoulder next to the asphalt edge, the section was difficult to differentiate, however, the total section (asphalt and base/chip seal) measured 15 inches.

Existing Fill

Existing fill was encountered in test holes TH-1 through TH-6, TH-18, TH-19, PH-1, PH-

2, TH-23, TH-24, B-1 and B-2. Fill depths varied between 1 foot and 13 feet and consisted of gravel, sand, silt and/or clay. On occasion, the age of the fill made differentiation from naturally deposited soils difficult. Seven fill samples tested had 15 to 57 percent fines. Atterberg limit testing on these samples exhibited liquid limits of non-liquid to 32 percent and plastic indices of non-plastic to 9 percent. One composite bulk fill sample from test holes PH-1 and TH-18 was subjected to Hveem (R-value) testing (ASTM 2844) resulted in an R-value of 38 at an exudation pressure of 300 psi. Fill samples classified as SM, SC, and CL-ML according to the Unified Soil

Classification System (USCS) and A-1-b, A-2-4 and A-4 according to the American Association of State Highway and Transportation Officials (AASHTO).

We believe that existing fill was constructed by cut and fill methods for original roadway construction and may have been placed in an uncontrolled manner. Typically, any uncontrolled fill under planned improvements should be moisture conditioned and recompacted. However, we believe the existing fill below new pavements should not result in poor pavement performance.

Sand and Gravel

Thirty-one sand and gravel samples were subjected to laboratory testing. Testing indicated 9 to 49 percent fines, liquid limits of non-liquid to 31 percent and plastic indices of non-plastic to 12 percent. Six of these samples exhibited low compression (-0.3 to -1.2 percent) when wetted under an applied pressure of 1,000 psf. These sand samples were silty, clayey, occasionally gravelly, poorly graded and well graded with silt. The gravel sample had 15 percent fines, was non-liquid and non-plastic and was silty and sandy. The gravel and sand classified as GM, SM, SC, SP and SW-SM (USCS) and A-1-a, A-1-b, A-2-4, A-4 and A-6

(AASHTO).

Clay

Seven clay samples were subjected to laboratory testing. Testing indicated 50 to 70 percent fines, liquid limits of 27 to 38 percent and plastic indices of 7 to 18 percent. Three of these samples exhibited low compression (-0.2 and -2.2 percent) when wetted under an applied pressure of 1,000 psf. The clay classified as CL and CL-ML (USCS) and A-4 and A-6

(AASHTO).

Bedrock

One weathered sandstone bedrock sample tested had 11 percent fines. Complete test results of laboratory testing are found in Appendix B and are summarized in the Summary of

Laboratory Test Results.

Groundwater

Groundwater was encountered during drilling at depths of 13 feet, 13 feet, 19 feet in

TH-1 through TH-3, respectively; at 18 feet, 10 feet and 10 feet in test holes TH-28 through

TH-30, respectively; and at 13.5 feet and 15 feet in test holes B-1 and B-2, respectively. All other test holes were dry. The test holes were backfilled after completion of drilling.

Groundwater will likely be encountered during foundation construction at fill walls 1A

(originally Wall 1), and Wall 11 (originally Wall 9) and at the bridge location. Dewatering and/or diversion may be required in these areas prior to and during construction. Variations in groundwater conditions may occur seasonally. The magnitude of the variation will be largely dependent upon the amount of spring snowmelt, duration and intensity of precipitation, site grading changes, and the surface and subsurface drainage characteristics of the surrounding area.

SITE DEVELOPMENT

Based on plans provided, fills of up to 20 feet are planned for fill walls. Construction also includes intersection upgrades with new pavement and a new bridge structure. Upgrades may include widening of roadways for shoulders, medians and turn lanes. We anticipate fill placement would be required for roadway widening and structure upgrades. Based on plans provided, intersection grades will be raised 5 to 10 feet. We recommend fill material below pavements meet a minimum R-value of 25. We anticipate rock and/or soil cut slopes may also be necessary for widening or realignment. We anticipate cut slopes in soil may be excavated with conventional equipment. Bedrock cut slopes would likely require heavier equipment, rock-splitting and/or blasting. On-site soils and bedrock could be used in site grading fills. We recommend the materials be processed to a maximum particle size of 6 inches and less.

Areas to receive fill should be stripped of vegetation, organic soils and debris. Topsoil is not recommended for fill material. Fill should be placed in thin, loose lifts of 8 inches thick or less. The on-site soils free of organic matter, debris and rocks larger than 6 inches can be used in fills. We recommend fill materials be moisture conditioned to within 2 percent of optimum moisture content and compacted to at least 95 percent of maximum standard Proctor dry density (ASTM D 698). For fill below a depth of 15 feet, we recommend the materials be moisture conditioned within 2 percent of optimum moisture content and compacted to at least

100 percent of maximum standard Proctor dry density (ASTM D 698). Placement and compaction of fill should be observed and tested by a representative of the geotechnical engineer.

We recommend that permanent soil cut slopes be constructed at a slope no steeper than 2H:1V. Temporary excavation slopes should be constructed no steeper than 1H:1V.

Permanent cut slopes in bedrock can be constructed at a 3/4H:1V. Permanent bedrock cut slopes may be constructed steeper on a case by case study after inspection and characterization of the bedrock by the geotechnical engineer. Permanent fill slopes should be constructed no steeper than 2.5H:1V. If fill slopes are planned steeper than 2.5H:1V, the slopes should be evaluated for stability and may require the installation of a retaining wall system or constructed as a geogrid reinforced soil slope (RSS). Surface water should be directed away from the crest of slopes. The slopes should be protected from erosion by revegetation or other means. The risk of slope instability increases if seepage is encountered in cut slopes. Flatter slopes may be required if significant seepage is encountered in cut slopes.

Prior to fill placement, we believe that all fills placed on slopes or existing embankments steeper than 4H:1V, should be “benched”. We recommend the slopes be benched prior to fill placed as recommended in the 2011 CDOT Standard Specifications section 203.06. Benching shall be well keyed and, where practical, a minimum bench width of 8 feet should be constructed. Each horizontal cut shall begin at the intersection of the original ground and the vertical sides of the previous bench.

FOUNDATION RECOMMENDATIONS

Our soil investigation for foundation design included drilling 23 test holes for 7 fill walls and 2 test holes for a new bridge structure for a total of 25 test holes. Due to access, all fill wall test holes were drilled either on existing pavement or on the existing roadway shoulder. The 2 holes at the bridge location were drilled to supplement prior test hole drilling and were drilled near the existing abutments and on existing pavement. Foundation recommendations for fill walls, stock pass structures and the new bridge structure are presented below.

Fill Wall Foundations

Fill Wall heights are planned to be up to 20 feet for walls. Bottom of wall elevations were estimated to be between 2 and 16 feet below existing roadway shoulder elevations. All elevations were estimated from plans provided. Low collapsing soils were encountered during our geotechnical investigation. Our experience suggests that MSE wall construction generally is not adversely affected by collapsing soils and walls could be supported by shallow foundations.

If the client desires a lower risk foundation alternative or if a cast-in-place (CIP) wall system is selected, we recommend ground modification such as subexcavation be performed below shallow foundations or a deep foundation system such as a drilled friction pier, bedrock pier or micropiles be utilized. Typically, micropiles are designed and installed by a specialty contractor.

We should be contacted to provide additional recommendations for subexcavation or deep foundations. Recommended design and construction criteria for MSE wall foundations are presented below.

1. Foundations should be constructed on undisturbed natural soils or properly compacted fill. Loose, disturbed soils encountered at foundation level should be removed and replaced with compacted fill or the foundation should be extended to undisturbed soils. Groundwater was encountered in test hole drilling for fill wall 1A (originally wall 1) and fill wall 11 (original wall 9). Dewatering, diversion and/or foundation subgrade stabilization may be required in these areas prior to and during construction.

2. MSE walls can be designed for maximum allowable soil pressures listed in the table below.

3. Resistance to sliding at the bottom of the wall system can be calculated based on a coefficient of friction values listed in the table below.

4. All foundation excavations should be observed by a representative of the geotechnical engineer prior to placement of leveling pad.

Wall Allowable Soil Pressure(psf) Coefficient of Friction Fill Walls 1A (original 1), 4, 5, and 11 (original 9) 2,500 0.35

Fill Walls 3A (original 3) and 7 3,000 0.35 Fill Wall 6 4,000 0.35

Stock Pass Foundations

Fifteen stock passes are proposed for construction within the CR 5 F.I.R. meeting plans dated January 26, 2011. Two out of the fifteen stock pass structures have been previously investigated under our “Final Geotechnical Investigation and Pavement Design, County Road 5, dated August 6, 2010. These two structures are located at Fourteen Mile Creek (stock pass 1, mp 8.8) and Jessup Gulch (stock pass 5, mp 15.9). The County Road 3 intersection (mp 17.8) test hole borings were drilled in the vicinity of the stock pass 6 structure.

Due to soft, saturated, low bearing capacity fill and sand soils at anticipated footing depths, we believe foundation movement could occur for moderately loaded structures due to these soils. As an alternative, subexcavating these softer, moister soils with a granular material could reduce the risk of potential movement as well as increasing bearing capacity. We recommend the removal and replacement of on-site soils to a depth of 3 feet below proposed foundation levels and extend 5 feet beyond the edge of footings, mats or box culvert foundations. We recommend a structural fill such as a CDOT Class 1 or CDOT Class 6 roadbase material be used for the subexcavation. A separator fabric and/or geogrid reinforcement may also be required in the subexcavated fill section. See the SITE

DEVELOPMENT section for placement and compaction recommendations. Groundwater was encountered at these structure locations during our investigation. Dewatering and/or groundwater diversion will likely be required for subexcavation and foundation construction.

Recommendations for footing and/or mat foundations are presented below.

1. Foundations constructed on existing fill, sand or properly placed fill can be designed for a maximum allowable soil pressure of 1,500 psf. Resistance to sliding at the bottom of the footing can be calculated based on a coefficient of friction of 0.30.

Passive pressure against the side of the footing can also be considered for the sliding resistance if it is properly compacted. Passive pressure can be estimated based on an equivalent fluid density of 300 pcf for a level backfill.

2. Foundations constructed on compacted, subexcavated soils can be designed for a maximum allowable soil pressure of 2,500 psf. Resistance to sliding at the bottom of the footing can be calculated based on a coefficient of friction of 0.35. Passive pressure against the side of the footing can also be considered for the sliding resistance if it is properly compacted. Passive pressure can be estimated based on an equivalent fluid density of 350 pcf for a level backfill.

3. The soils below footings or box culverts should be protected from freezing. We recommend the bottom of footings and box culverts be constructed at least 36 inches below finished exterior grade or as required by project specifications and/or local municipal code.

4. All foundation excavations should be observed by a representative of the geotechnical engineer prior to placement of concrete.

Bridge Foundation (Piceance Creek at approximate mile post 31.9)

Due to soft, lower bearing capacity near surface soils, we believe the bridge should be supported on a driven pile foundation. We believe the piles should be founded in weathered bedrock or bedrock. Groundwater will likely be encountered at about an elevation of between

5976 feet and 5978 feet. General recommendations for design and construction of driven piles are presented below.

1. For Allowable Stress Design (ASD) criteria, steel H-pile driven into gravel may be designed for a service stress of 9 ksi for Grade 36 steel or 12 ksi for Grade 50 steel.

For design of piles in tension, we recommend using 50 percent of the allowable vertical load capacity (ultimate value) plus the weight of the pile. Appropriate reduction or safety factors should be applied. We recommend a minimum pile tip elevation for the north abutment of between 5949 feet and 5952 feet. We recommend a minimum tip elevation for the south abutment of 5921 feet.

2. Using Load Resistance Factor Design criteria (LRFD), a combined end bearing and skin friction ultimate capacity of 27 ksi for Grade 36 steel or 36 ksi for Grade 50 steel, times the cross sectional area of the pile can be used by driving the piles into gravel.

The bearing capacity assumes a weighted load factor of 1.5 and a resistance factor of 0.5. Settlement of the structure using the LRFD method should be checked against loadings obtained based on service limit states.

3. Driven piles should be installed per CDOT Standard Special Provision, Section 502 dated November 3, 2008.

4. Based on the results of our field exploration, laboratory testing and our experience with similar properly constructed driven pile foundations, we estimate individual pile settlement will be less than ½ inch when designed according to the criteria presented in this report.

5. The upper 3 feet of pile penetration should be neglected for lateral load resistance calculation. For lateral loading analysis using LPILE program, the following parameters may be used:

Material Soil Model

Friction Angle, φ (deg)

Cohesion, c (psf)

Horizontal Modulus of Subgrade

Reaction, kh (pci) ε50

Total Unit

Weight, γ (pcf)

Saturated Unit

Weight, γ (pcf)

Silt and clay

Stiff Clay without free water

0 500 30 0.020 120 125

Granular Soil above groundwater

Reese Sand 28 0 90 -- 130 135

Granular Soil below groundwater

Reese Sand 28 0 60 -- 130 135

6. Groups of piles required to support concentrated loads will also require appropriate reductions of the axial and lateral capacities based on the effective envelope of the pile group. The minimum spacing requirements between piles should be three diameters from center to center. For vertical and lateral loading, recommended P multipliers are 0.5 for tangent piles increasing linearly to 1.0 for piles placed at 3 diameters or greater. Additional capacity reduction factors can be provided if required for conditions other than those anticipated.

LATERAL EARTH PRESSURE

Retaining walls should be designed to resist lateral earth pressure. We recommend all retaining walls and stock passes be backfilled with CDOT class 1 structural fill. Walls can be designed using an equivalent fluid density of 35 pcf for a horizontal, Class 1 structure backfill.

This equivalent fluid density assumes a horizontal, on-site material backfill. This value assumes the backfill materials are not saturated. Wall designs should consider the influence of surcharge loading such as traffic, construction equipment and/or sloping backfill.

Retaining walls should be constructed with a drainage system to drain away any excess water immediately behind the wall. The drainage system may consist of free-draining gravel, pipes, drain board and/or weep holes are commonly used for the wall drainage.

PAVEMENT DESIGN

A pavement section is a layered structure designed to disperse dynamic traffic loads to the subgrade. The performance of the pavement structure depends on the traffic loadings and physical properties of the subgrade materials. As described below, soils are represented for flexible pavement design purposes by means of a soil support value that is empirically related to strength.

County Road 3 Intersection

For this project (CR 5, F.I.R. Meeting Plans, dated January, 26, 2011), one intersection is planned for upgrades. Upgrades may include, but are not limited to, fill walls for widening, shoulders, medians, turn lanes and new pavement. From plans provided, proposed grades in the intersection will be raised between 5 and 10 feet. Table 3 below indicates the intersection included in this investigation.

Table 3 - Roadway Sections Roadway Stationing Mile Post(s)

County Road 5 (Project 2A) 2649+49.99 to 2695+00.00 mp 17.31 – 18.12

County Road 3 300+00 to 306+70.00 mp 17.8

Subgrade Materials

Based on the results of our previous and current field explorations and laboratory testing, the pavement subgrade material generally consisted of existing gravel, sand, silt and clay fill and natural sand, gravel, silt, clay and bedrock. These soils classified as A-1, A-2, A-4 and A-6 in accordance with the American Association of State Highway and Transportation

Officials (AASHTO) and as GM, GP-GM, SM, SC, CL, and CL-ML in accordance with the

Unified Soil Classification System (USCS).

For the intersection included in this investigation, one composite bulk sample was grouped from samples obtained from test holes PH-1 and TH-18 and were subjected to laboratory classification and Hveem (R-value) testing (ASTM 2844). Laboratory testing indicated that the bulk sample classified as A-2-4 and as an SM. R-value results on this bulk sample indicated a value of 38 at an exudation pressure of 300 psi. The measured R-value exceeded the design R-values of 9 and 26 from our previous investigation. The pavement section for County Road 3 will be designed utilizing the R-value of 38.

Traffic Loading

For CR 3, traffic loading provided by Rio Blanco County, entitled “Traffic Data”, dated

November 7, 2008 was utilized (Table 4). The 5-day average daily traffic volume (ADT) number was converted to a 7-day ADT. Based on a growth factor of 1.55, we calculated the 20 year, 18-kip Equivalent Single Axle Load (ESAL) for County Road 24 using traffic type percentages from the report by RPI Consulting (Appendix C). ESAL values for County Road 5 were presented in our previous investigation and are shown below. Complete calculations of the design ESAL for flexible pavements are shown in Appendix C.

Table 4 - Design Life Equivalent 18-kip Single Axle Load (ESAL)

Roadway 20-Year Flexible ESAL

County Road 5 (Project 2A) 2,700,000

County Road 3 1,958,685

Determination of Resilient Modulus (MR) of Subgrade for Design

From the design and measured R-values, the resilient moduli for the projects were calculated using the CDOT 2011 Pavement Design Manual (see Table 5). The R-value and calculated resilient modulus listed below were used to determine the design thicknesses for the various flexible pavement sections for the roadways.

Table 5 – Resilient Modulus for Pavement Thickness Design

Roadway R-value Resilient Modulus (psi)

County Road 5 (Project 2A) 26 6,010

County Road 3 38 8,896

Hot Mix Asphalt Pavement Designs

For County Road 5 and County Road 3, a pavement design for full depth, composite, composite with subbase, and composite with subbase and geogrid (CR 5 only) were calculated using the DARWin version 3.1 computer program following the 2011 CDOT Pavement Design

Manual and Tensar “Spectra Pave” software. The various sections utilized a combination of hot mix asphalt (HMA), aggregate base course (ABC, R-value > 77) and CDOT Class 3 subbase.

The geogrid should consist of Tensar BX1200 or equivalent, as recommended below. The parameters used for pavement design for each segment are presented in Tables 6 and 7. A

Class 3 subbase must have a minimum R-value of 65 and/or a maximum of 20 percent passing the No. 200 sieve. Pavement section thicknesses are presented below in Tables 8 and 9.

Table 6 – Flexible Pavement Design Parameters (CR 5 and CR 3 Intersection) Asphalt Pavement Design Parameters

Initial Serviceability 4.5 Reliability Level, % 90

Terminal Serviceability 2.5 Overall Standard Deviation 0.44

Construction Stage 1 Resilient Modulus, psi 6,010

20 Year Design ESALs 2,700,000 HMA Str. Layer Coefficient 0.44

ABC Str. Layer Coefficient 0.12 Subbase Str. Layer Coefficient 0.10

Table 7– Flexible Pavement Design Parameters (CR3 Roadway)

Asphalt Pavement Design Parameters

Initial Serviceability 4.5 Reliability Level, % 90

Terminal Serviceability 2.5 Overall Standard Deviation 0.44

Construction Stage 1 Resilient Modulus, psi 8,896

20 Year Design ESALs 1,958,685 HMA Str. Layer Coefficient 0.44

ABC Str. Layer Coefficient 0.15 Subbase Str. Layer Coefficient 0.10

The Darwin and Tensar “Spectra Pave” Program outputs for the recommended pavement thickness designs are provided in Appendix C and are summarized below.

Table 8 – Recommended Pavement Sections (CR 3 Roadway)

Roadways Pavement Type Design

Life (years)

Thickness (inches)

CR 5

(Project 2A)

Full Depth HMA 20 10” HMA

HMA + ABC 20 6” HMA + 14” ABC

HMA + ABC +

Subbase 20 6” HMA + 6” ABC + 9”

Subbase

HMA + ABC +

Geogrid* + Subbase 20

6” HMA + 4” ABC +

BX1200 +

4” Subbase *Tensar BX1200 Geogrid (minimum) or equivalent

Table 9 – Recommended Pavement Sections (CR 3 Roadway)

Roadways Pavement Type Design Life (years) Thickness (inches)

CR 3

Full Depth HMA 20 8” HMA

HMA + ABC 20 6” HMA + 6” ABC

HMA + ABC +

Subbase 20 6” HMA + 4” ABC + 4”

Subbase

HMA + ABC +

Geogrid* + Subbase 20 NA

Hot Mix Asphalt Type

Because of the heavy loads and often slow moving (<45 mph) nature of anticipated traffic for this project, we recommend that the asphalt mix for this project meet the specifications for Grading SX (100) in accordance with the specifications. The number of SuperPave Gyratory revolutions (Ndes) for the asphalt mixes should be at 100 gyrations. We recommend that unmodified performance grade asphalt binder meeting the CDOT requirements for performance grade PG 58-28 be used in the lower layers and that the top lift contain Performance Graded

Asphalt PG 76-28. PG 58-28 is a 98% reliability binder for both binder rutting resistance and thermal cracking for the Meeker area based on data from the FHWA Binder Selection Program, LTPPBind. Based on recommendations from the same binder selection program, PG 76-28 is a

98% reliability binder for the top lift, and will give the new pavement additional resistance to rutting. The lower lifts should meet the requirements for SX (100) and be placed at thicknesses of two and three inches. The top 2-inch lift should conform to SX (100) with PG 76-28 binder.

Aggregates for hot mix asphalt should be of uniform quality, composed of clean, hard, durable particles of crushed stone, gravel, or slag. Excess of fine material should be wasted before crushing. The specifications of gradation for the Grading SX are shown below:

Table 10 – Gradation for Grading SX Grading SX

Sieve Size Passing by Weight, % 3 /4” 100 1 /2” 90-100 3 /8” * #4 * #8 28-58

#30 * #200 2-10

*See details in CDOT Standard Specifications.

Subgrade Preparation

Prior to placing aggregate base course and asphalt pavement, the entire subgrade area should be scarified to a depth of 12 inches and recompacted to the specified relative compaction with a moisture content in accordance with the CDOT Standard Specifications for

Road and Bridge Construction. In locations where the in-place subgrade contains more than 40 percent minus No. 200 sieve material, a separator fabric conforming to CDOT Separator

Geotextile Class B should be installed prior to placing the subbase. Based on our investigation, a separator may be necessary along CR5 and for CR 3. Imported fill material should be compacted in thin lifts to within 2 percent of optimum moisture content in accordance AASHTO

T 99 or T 180. As noted above, the ABC should have a minimum R-value of 77. For all layers, drainage needs to be addressed during construction to prevent ponding of water and provide for ease of construction. The pavement subgrade and each layer ABC should be proof rolled with a heavily loaded pneumatic-tire vehicle. Areas which deform more than 0.5 inch under heavy wheel loads should be removed, replaced if necessary and reworked to achieve a stable subgrade prior to paving. We recommend that proof rolling and compaction tests be performed under the direct supervision of a representative of the geotechnical engineer.

Drainage Considerations

The collection and diversion of surface drainage away from paved areas is critical to the satisfactory performance of the pavement. Proper drainage design should include prevention of ponding of water on or immediately adjacent to pavement areas. Concentrated runoff should be avoided in areas susceptible to erosion. Slopes and other stripped areas should be protected against erosion by re-vegetation or other methods.

WATER SOLUBLE SULFATE

Based laboratory test results, we anticipate a Class 0 exposure for concrete due to the presence of water-soluble sulfate. Based on ACI 201.2R-01, “Guide to Durable Concrete,” concentrations between 0.0 and 0.1 percent represent Class 0 exposure (low). For cast-in-place structures such as pavements placed on onsite soils, ACI recommends any type of cement can be used for improvements at this site. Structural fill and aggregate base course are assumed to have Class 0 exposure or no effect on concrete.

ADDITIONAL INVESTIGATIONS

Our field investigation for this report was based on plans furnished by the client dated

October 15, 2010. All field work (drilling) was completed between November 4th and November

23rd, 2010. Updated plans (CR 5 F.I.R. Meeting Plans dated January 26, 2011) were provided by the client post drilling. We recommend additional test hole drilling be performed on fill wall locations shown on the January 2011 plan set that were not investigated. Additional test hole drilling would provide specific subsoil information that would be utilized for wall design including, but not limited to, bearing capacities, groundwater depths and lateral earth pressures. The table below indicates walls investigated for this report and new walls that were not investigated. The table reflects the revised numbering based on the January 26, 2011 plan set.

Table 11 – Wall Numbering

Original Wall No.

(HDR plan set dated

10/15/2010)

New Wall No.

(HDR FIR plan set dated

1/26/2011) Wall Investigated?

1 1A YES

- 1B NO

- 1C NO

3 3A YES

- 3B NO

4 4 YES

5 5 YES

6 6 YES

7 7 YES

- 8B NO

9 11 YES

- 9 YES

- 10 NO

LIMITATIONS

This study was conducted in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design purposes. The conclusions and recommendations submitted in this report are based upon the data obtained from exploratory test holes, field reconnaissance and anticipated construction. The nature and extent of subsurface variations across the site may not become evident until excavation is performed.

If during construction, fill, soil, or water conditions appear to be different from those described herein, this office should be advised at once so reevaluation of the recommendations may be made. We recommend on-site observation of excavations and pavement subgrade by a representative of the geotechnical engineer.

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 or 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.

The 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 Yeh and Associates will conduct an adequate program of construction testing and observation to evaluate compliance with our recommendations.

YEH AND ASSOCIATES, INC. Reviewed by:

Keith E. Asay Richard D. Johnson, P.E.

Staff Engineer Senior Geotechnical Engineer

Reviewed by:

Robert F. LaForce, P.E.

Senior Materials Manager

APPENDIX A

LOGS AND LEGEND OF EXPLORATORY BORINGS

Project Number: 29-202A

Project: Rio Blanco County Road 5

Legend for Symbols Used on Borehole Logs

GEOTECHNICAL ENGINEERING CONSULTANTS

Notes:

1. Test holes were drilled on November 4-5, 17-19 and 23, 2010 using 4-inch continuous flight auger.

2. Test hole descriptions are subject to explanations contained in this report.

3. Elevations were estimated by Yeh & Associates from plans provided by HDR Engineering, Inc.

SANDSTONE, slightly moist, medium hard to very hard, brown, rust, gray.

INTERBEDDED CLAYSTONE (SHALE) / SANDSTONE, slightly moist, medium hard to very hard, brown, rust, gray.

Weathered SANDSTONE, slightly moist, medium hard, brown, rust, gray.

SAND, clayey, moist, loose to medium dense, brown, rust, low plasticity (SC).

GRAVEL, silty to sandy, slightly moist to wet, loose to medium dense, yellow-brown, brown, gray, rust (GM).GRAVEL, clayey, with sand, wet, medium dense, gray (GC).

SAND, silty to gravelly, slightly moist to wet, very loose to dense, light brown to dark brown, rust, gray, red-brown, yellow-brown, non to low plasticity (SM).

YEH AND ASSOCIATES, INC.

Figure No. A-1

Bulk sample was obtained from auger cuttings at the depths indicated.

Modified California Sampler. The symbol 16/12 indicates that 16 blows from a 140 pound hammer falling 30 inches was used to drive 2-inch I.D. sampler 12 inches.

Split Spoon Sampler. The symbol 15/12 indicates that 15 blows from a 140 pound hammer falling 30 inches was used to drive 1.5-inch I.D. sampler 12 inches.

Soil Lithology

Bedrock Lithology

Other Symbols

Asphalt

Indicates practical drill rig refusal. Indicates approximate ground water level at time of drilling

Sample Types

Fill with Sand as major soil, slightly clayey to clayey, silty , with gravel, slightly moist to moist, loose to medium dense, brown, rust, gray, non to low plasticity (SM, SC).

Fill with Silt as major soil, clayey, sandy, moist, stiff, brown

(ML).

Fill with Gravel as major soil, silty, sandy, slightly moist, medium dense, brown (GP).

CLAY, silty to sandy, slightly moist to wet, very soft to stiff, brown, dark brown, brown-black, rust, gray, low to medium plasticity (CL, CL-ML).

Fill with Clay as major soil, silty, sandy, with gravel, moist, medium stiff, brown, rust, low plasticity (CL, CL-ML).

GRAVEL, sandy, slightly moist to wet, loose to medium dense, brown, red-brown and yellow-brown (GW-GM).

SAND, slightly silty, slightly gravelly to gravelly, slightly moist to wet, very loose to medium dense, brown, rust, gray (SP, SW, SP-SM, SW-SM).

SILT, sandy, clayey, with gravel, slightly moist to wet, stiff, brown, dark brown, gray, (ML).

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

C E

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TH

A S

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9-

2A

L O

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.G P

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G D

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/2 4/

Figure No. A-2

39/12

4/12

3/12

7/12

10/12

26/12

22/12

TH-01

Approximate elevation: 6729 ft Approximate elevation: 6725 ft

10/12

12/12

4/12

3/12

5/12

15/12 11/12

TH-02

Approximate elevation: 6725 ft

22/12

9/12

12/12

5/12

25/12

TH-03

Approximate elevation: 6725 ft

9/12

6/12

4/12

7/12

18/12 11/12

14/12

27/12

TH-04

Approximate elevation: 6725 ft

12/12

6/12

7/12

13/12

20/12

TH-05

Approximate elevation: 6726 ft

7/12

9/12

15/12

16/12

TH-06

Wall 1A (Originally Wall 1)

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

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9-

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/1 5/

Approximate elevation: 6584 ft

10/12

10/12

9/12

24/12

TH-11

Approximate elevation: 6583 ft

10/12

6/12

4/12

7/12

TH-12

10/12

7/12

10/12

9/12

Approximate elevation: 6585 ft

TH-13

17/12

7/12

Approximate elevation: 6587 ft

6/12

9/12

TH-14

Figure No. A-3

Wall 3A (Originally Wall 3)

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

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Rio Blanco County Road 5 Wall 4

Approximate elevation: 6455 ft

8/12

10/12

9/12

10/12

TH-15

Approximate elevation: 6450 ft

7/12

12/12

15/12

7/12

TH-16

Approximate elevation: 6446 ft

4/12

3/12

TH-17

Figure No. A-4

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

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9-

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/1 5/

Rio Blanco County Road 5 Wall 5 and Intersection CR 5 & CR 3

7/12

8/12

8/12

PH-1

Aprpoximate elevation: 6387 ft Approximate elevation: 6380 ft

26/12

10/12

7/12

PH-2

Approximate elevation: 6387 ft

14/12

2/12

5/12

6/12

10/12

TH-18

Approximate elevation: 6385 ft

12/12

6/12

5/12

7/12

6/12

1/12

TH-19

Figure No. A-5

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

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9-

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Rio Blanco County Road 5 Wall 6

Approximate elevation: 6388 ft

7/12

7/12

29/12

6/12

8/12

12/12

50/12

TH-20

Aprpoximate elevation: 6398 ft

24/12

14/12

12/12

50/4

50/4

50/0.5

TH-21

20/12

50/1

50/1.5

TH-22

Approximate elevation: 6408 ft

Figure No. A-6

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

C E

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9-

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Rio Blanco County Road 5 Wall 7

Approximate elevation: 6132 ft

28/12

21/12

11/12

32/12

TH-23

Approximate elevation: 6136 ft

5/12

8/12

10/12

7/12

14/12

TH-24

Figure No. A-7

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

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Rio Blanco County Road 5 Bridge near mile marker 32

12/12

8/12

17/12

1/12

50/3

50/1.5

NW bridge corner B-1

Approximate elevation: 5991 ft

7/12

5/12

4/12

4/12

1/7

6/15

26/12

50/8 50/3

SE bridge corner B-2

Approximate elevation: 5991 ftApproximate elevation: 5991 ft

23/12

25/12

6/12

5/12

7/12

NE bridge corner

BTH-37

8/12

6/12

4/12

SW bridge corner

BTH-38

Approximate elevation: 5991 ft

Figure No. A-8

GEOTECHNICAL ENGINEERING CONSULTANTS

D ep th (f t)

YEH AND ASSOCIATES, INC.

Project Number: 29-202AFE N

C E

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5/12

6/12

16/12

6/12

TH-28

Approximate elevation: 5909 ft Approximate elevation: 5905 ft

13/12

16/12

4/12

5/12

9/12

TH-29

Approximate elevation: 5903 ft

21/12

9/12

5/12

TH-30

Rio Blanco County Road 5 Wall 11 (Originally Wall 9)

Figure No. A-9

APPENDIX B

LABORATORY TEST RESULTS

Applied Normal Pressure, ksf

1 9

2 14

Job No:

SW

Graph Number

Boring Number

Depth (ft)

Natural Dry Density

(pcf)

Moisture Content

Swell(+) / Consolidation(-)

Clay, sandy (CL) Checked By:

Soil Description

SWELL /

CONSOLIDATION

GRAPH

TH-1 91 25.2 -0.6 Clay, sandy (CL) Drawn By:

RDJ

29-202A Project Name: Rio Blanco County Road 5 Figure B-1YEH & ASSOCIATES, INC.

TH-2 85 35.8 -2.2

-12.0

-11.0

-10.0

-9.0

-8.0

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

WATER ADDED

Graph 2

-12.0

-11.0

-10.0

-9.0

-8.0

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

WATER ADDED

Graph 1

1 14

2 9

Job No:

SW

Graph Number

Boring Number

Depth (ft)

Natural Dry Density

(pcf)

Moisture Content

Swell(+) / Consolidation(-)

Sand, clayey (SC) Checked By:

Soil Description

SWELL /

CONSOLIDATION

GRAPH

TH-12 97 17.8 -0.2 Clay, silty, sandy (CL- ML) Drawn By:

RDJ

29-202A Project Name: Rio Blanco County Road 5 Figure B-2YEH & ASSOCIATES, INC.

TH-14 106 14.1 -0.5

-8.0

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

WATER ADDED

Graph 2

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

1 4

2 9

Job No:

RDJ

29-202A Project Name: Rio Blanco County Road 5 Figure B-3YEH & ASSOCIATES, INC.

TH-18 90 18.8 -0.6 Sand, silty (SM) Checked By:

Soil Description

SWELL /

CONSOLIDATION

GRAPH

TH-18 104 15.8 -0.4 Sand, silty (SM) Drawn By: SW

Graph Number

Boring Number

Depth (ft)

Natural Dry Density

(pcf)

Moisture Content

Swell(+) / Consolidation(-)

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

WATER ADDED

Graph 2

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

1 4

2 4

Job No:

SW

Graph Number

Boring Number

Depth (ft)

Natural Dry Density

(pcf)

Moisture Content

Swell(+) / Consolidation(-)

Sand, silty (SM) Checked By:

Soil Description

SWELL /

CONSOLIDATION

GRAPH

TH-21 113 9.6 -1.2 Sand, silty, gravelly (SM) Drawn By:

RDJ

29-202A Project Name: Rio Blanco County Road 5 Figure B-4YEH & ASSOCIATES, INC.

PH-1 102 18.2 -0.3

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

WATER ADDED

Graph 2

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

0.1 1 10 100

C on so lid at io n(

Sw el l(+

#4 99

¾ " -

½" -

⅜" 100

2" -

1 ½" -

1" -

Sieve Size

Passing

3" -

2 ½" -

Pe rc en t P as si ng

20040103/8" 41/2"3/4"3"12" 6" 1" 30 508 16

Sieve Analysis Hydrometer Analysis

Sieve Opening in Inches…