J.05_K-2C_Draft_Geotech_DHS_20090701.pdf

TABLE OF CONTENTS

1. INTRODUCTION

2. PROJECT DESCRIPTION

3. SCOPE OF SERVICES

3.1 Field

3.2 Laboratory

3.3 Engineering

4. SITE CHARACTERIZATION

4.1 Surface

4.2 Subsurface

4.3 Laboratory

5. DISCUSSION

6. RECOMMENDATIONS

6.1 General

6.2 Gate Foundations

6.3 Laeral Earth Pressures and Slopes

6.4 Earthwork

6.4.1 Site Clearing

6.4.2 Excavation

6.4.3 Workability

6.4.4 Foundation Preparation

6.4.7 Materials

6.4.7 Placement and Compaction

6.5 Construction Observation and Testing

6.6 Surface Drainage

6.7 Corrosivity

APPENDIX

Vicinity Map A-1 Site Plans A-2 Glossary of Terms A-10 Boring Log Notes A-12 Boring Logs A-13 Laboratory Data A-31

DRAFT GEOTECHNICAL EXPLORATION

US-MEXICO BORDER GATE IMPROVEMENTS

EL PASO SECTOR, K-2C SEGMENT

EL PASO COUNTY, TEXAS

FOR

MICHAEL BAKER JR., INC.

TEC 08T002.02 RPT.02D

JULY 1, 2009

1. INTRODUCTION

This report presents the results of our geotechnical exploration for the proposed gates in Segment K-2C along the levee in El Paso County, Texas. The approximate location of the site is shown on the Vicinity Map in the Appendix. This geotechnical exploration was performed by TEC to provide information and recommendations regarding:

Near-surface soil and groundwater conditions on site, Index, engineering, and corrosivity characteristics of site soils, and Geotechnical criteria for design of proposed gates and levee stability evaluation.

2. PROJECT DESCRIPTION

Nine gates are planned in the 7-mile length of segment K-2C on the levee at existing openings in the fence. They will be steel and supported by drilled-shaft foundation, which are planned to be 3½ feet in diameter and 35 feet deep. The stability of the levee will also be evaluated as part of the gate project. Additional details regarding the gate locations are shown on the Site Plans in the Appendix. It is understood that the soil profile along the levee, within the depth of the planned foundations, is expected to consist of levee fill underlain by a relatively thin layer of clay soils (2 to 5 feet thick) that are underlain by fine-grained sands with silts and clays. Also, some concern was expressed about encountering artesian conditions during construction based on US Army Corps of Engineers experience in Texas.

3. SCOPE OF SERVICES

Three categories of services were performed for this geotechnical exploration: (1) field, (2) laboratory, and (3) engineering. TEC and its subcontractors performed these services in general accordance with current project standards of practice for engineering and testing.

3.1 Field

The fieldwork consisted of obtaining utility clearances, interfacing with others involved in the site or project, site exploration by geotechnical and field engineers, and drilling and sampling with an all-terrain drill rig. Auger and rotary methods were used to advance a boring at each location to a planned depth of 75 feet; the boring locations are shown on the Site Plans. Soil and groundwater conditions limited the boring depths at eight of the nine locations, and the borings ranged from 57½ to 76½ feet deep. Drilling fluids for rotary drilling and cement-bentonite grout backfill for the borings complied with project criteria. The field engineer obtained ring, split-spoon, shelby tube, and bulk samples at selected intervals and logged the borings.

3.2 Laboratory

A laboratory-testing program was developed by the geotechnical engineer to obtain data used in development of recommendations for geotechnical criteria for design. The program consisted of moisture content, dry density, gradation, plasticity index, direct shear, triaxial, permeability, pH, resistivity, and soluble chlorides and sulfates tests.

3.3 Engineering

Field and laboratory data were evaluated by TEC to formulate recommendations for geotechnical criteria for design of the planned gates.

4. SITE CHARACTERIZATION

Information regarding surface features, subsurface soil and groundwater conditions, and laboratory test results is presented in this section. This information was gathered by TEC for geotechnical engineering purposes only. This site characterization does not and was not intended to address the existence or likelihood of contamination on or around the site. Specialized methods and procedures, which were not part of this scope of services, are required for an adequate environmental site assessment.

4.1 Surface

The gates will be at gaps in the fence that follows the levee, between the levee and the adjacent, unlined, irrigation canal. Most of the construction related to the fence had been completed. The fence was steel with a concrete foundation, and had been constructed on a bench. Erosion control had been placed on the levee bank, below the fence.

4.2 Subsurface

As shown on the logs in the Appendix, levee fill and non-plastic to high plasticity, alluvial soils were observed in the borings. The soil profile was similar to what was anticipated, as described in Project Understanding, however, a thin clay layer was not observed below the fill in each boring.

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 2

The levee fill consisted of alluvial soils that appeared to have been borrowed from the river floodplain. The change from levee fill to native soils was not apparent in the borings, but is believed to be near the elevation of the adjacent river plain, and was estimated to be 9 to 13 feet deep in the field. Soils observed in the borings included fat clays (CH), lean clays (CL), silty clays (CL-ML), silts (ML), clayey sands (SC), silty clayey sands (SC-SM), silty sands (SM), poorly and well-graded sands with silt (SP-SM and SW-SM), and poorly and well-graded gravels with silt and sand (GP-GM and GW-GM) that were layered and interbedded. No regular or consistent pattern was discerned, horizontally or vertically. Clayey sands, silty clayey sands, and silty sands were predominant. Relative densities and consistencies ranged from loose to dense and soft to very stiff, respectively, but generally, ranged from loose to medium and medium to stiff. Calcareous cementation was minimal to light.

Groundwater was observed in the borings at depths of 13 to 21 feet; the depth to groundwater generally decreased from north to south. No evidence of artesian conditions was observed during exploration. Groundwater conditions in the area were not studied for this exploration and may be significantly different during construction than those encountered in this exploration. Kiewit reported that groundwater levels in the levee are tied to and follow water levels in the adjacent, unlined canal relatively quickly.

4.3 Laboratory

Index test indicated soils included fat clays (CH), lean clays (CL), silty clays (CL-ML), silts (ML), clayey sands (SC), silty clayey sands (SC-SM), silty sands (SM), and poorly graded sands (SP).

Laboratory tests on relatively undisturbed ring and tube samples indicated in situ dry densities range from 72 to 116 pcf and moisture contents range from 4.1 to 51 percent. Flexible-wall tests indicated the permeability of levee soils ranged from 8.0x10-6 to 8.1x10-4 centimeters/second (cm/s). Direct shear and triaxial tests indicated friction angle and cohesion of levee and native soils at near consolidated-drained conditions, generally, ranged from 23 to 39 degrees and 0.0 to

0.6 kips per square foot (ksf), respectively. Two samples had friction angles of 18 degrees, and another sample had a cohesion of 1.5 ksf. Chemical tests indicated pH and resistivity of soils ranged from 8.2 to 8.4 standard units and 290 to 550 ohm-cm, respectively. Concentrations of soluble sulfates and chlorides ranged from 460 to 1,200 and 135 to 840 parts per million (ppm), respectively.

5. DISCUSSION

The recommendations presented herein are based on our understanding of the project as presented in Project Description and the assumption that subsurface conditions encountered in the borings adequately represent conditions near and between the borings. Because project criteria regarding grading, number and type of structures, foundation loads, etc. can change and

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 3

because subsurface conditions near and between the borings are not always similar to those encountered during exploration, the geotechnical engineer must be contacted for review and possible revision of the recommendations presented herein when related project criteria are altered during design or construction or when subsurface conditions substantially different from those described in the boring logs are encountered during construction.

6. RECOMMENDATIONS

This section presents recommendations regarding geotechnical criteria for design of the planned gates and the levee stability evaluation. They are based on Terrane’s interpretations and opinions of the field and laboratory data from this exploration. They should not be considered the only valid interpretation of the data, and other qualified professionals may develop their own interpretations and opinions regarding the data from this exploration for design of the planned gates and levee stability evaluation. Regardless of how the data from this exploration is interpreted and what opinions are developed, design conditions must be confirmed by the geotechnical engineer or his qualified representatives by adequate observation and testing during construction. The firm that provides construction observation and testing services must assume the role of geotechnical engineer for this project.

6.1 General

Levee and native soils should be considered to have a high degree of heterogeneity, laterally and vertically, with respect to engineering properties, and bracketing design conditions with likely limits of engineering properties is recommended.

With respect to permeability, the permeability of levee soils is estimated to range from 10-3 to 10-

6 cm/s. The permeability of soils in the levee is expected to vary laterally and vertically, and, based on its age and number flood events during its life without breaches being reported, continuous sections through the levee with permeabilities in the higher range are not thought likely. The global permeability of the levee is estimated to range from 10-4 to 10-5 cm/s.

With respect to shear strength, there is a marked difference between the clay and sand soils. In consolidated-drained conditions, cohesion is estimated to be zero for clays and sands, and generally, the friction angle is estimated to range from 22 to 28 degrees for clays and 30 to 36 degrees for sands.

With respect to density, soils can be separated into four categories based on their type and origin – levee clays, native clays, levee sands, and native sands. Though density varied over a wider range, the following estimated ranges of dry, moist, and effective submerged unit weights are considered reasonable brackets for analysis:

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 4

Levee Clays: Dry, 90 to 105 pcf; moist, 105 to 120 pcf, and submerged, 55 to 65 pcf;

Native Clays: Dry, 80 to 95 pcf; moist, 105 to 115 pcf, and submerged, 50 to 60 pcf;

Levee Sands: Dry, 90 to 105 pcf; moist, 100 to 115 pcf, and submerged, 55 to 65 pcf;

Native Sands: Dry, 95 to 110 pcf; moist, 100 to 115 pcf, and submerged, 60 to 70 pcf.

Engineering properties of the levee and native sands are expected to control design of the gate foundations because of the relative thinness and infrequency of clay strata and the long-term loading conditions being considered for design. Where there is a clay stratum beneath the levee, the lower friction angles of the clays may control stability analysis of the levee for some loading conditions. After construction, the drilled-shaft foundations for the gates are expected to improve mass stability of the levee locally.

6.2 Gate Foundations

Lateral capacity is expected to control design of the drilled-shaft foundations for the gates. The following criteria are recommended for lateral analysis with inclusion of surcharges and loads as required for structural analysis:

Model the levee soils as cohesionless, loose sands above the water table with a k-value of 25 pounds per cubic inch (pci), a friction angle of 30 to 36 degrees, and a moist unit weight of 100 to

115 pcf, and

Model the native soils as cohesionless, medium sands below the water table with a k-value of 60 pci, a friction angle of 30 to 36 degrees, and a submerged unit weight of 60 to 70 pcf.

Though axial capacity is not considered likely to be a controlling design factor for the foundations, recommendations for axial capacity can be developed using the uplift capacity of a drilled shaft, which would not count on any end bearing, be conservative in most situations, and not require that drilled shafts end in a specified bearing material. The uplift capacity can be developed by methods in NAVFAC DM-7.2 for drilled-shaft foundations, which yield the following equation for determining uplift capacity as a function of shaft depth and diameter and soil weight:

T = (W + 0.26D2dw)/FS where, T = Design uplift capacity (lbs) D = Depth of pier below finished grade (ft) d = Diameter of pier (ft) w = Unit weight of soil (pcf)* W = Weight of pier (lbs) FS = Factor of safety**

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 5

* 110 pcf for levee soils and 60 pcf for native soils are recommended.

** A minimum FS of 2.0 is recommended.

Drilled-shaft construction should be installed by a qualified contractor with suitable experience.

Conditions observed during this exploration and prior construction, indicate that groundwater is likely to be encountered at drilled-shaft locations. Accordingly, the contractor should be prepared to properly construct drilled shafts below a water table. For each drilled shaft, exposed soil conditions and cleaning should be reviewed and bearing soil confirmed by the geotechnical engineer or his qualified representative prior to placing reinforcing steel and concrete. A qualified structural engineer should determine the size, quantity, and location of reinforcement. The geotechnical engineer or his representative should observe placement of steel and concrete.

6.3 Lateral Earth Pressures and Slopes

Lateral earth pressures may be needed for design of some elements for the gates. Table 7.1 presents equivalent fluid pressures for active and passive pressures, perpendicular to the levee slope, for the range of slopes expected in the construction area. Additional analysis should be performed for saturated conditions. However, reducing the value in Table 7.1 by half and adding 60 psf/ft to the remainder will provide a reasonable estimate of equivalent fluid pressure for saturated conditions.

A coefficient of friction of 0.4 between footings and bearing soils may be used to resist lateral loads. If passive earth pressures are used in conjunction with base friction to resist lateral loads, reduce the coefficient of friction to 0.3. Retaining wall backfill should be free-draining, granular material with less than 5 percent fines, and a drainage system should be installed to prevent water accumulation in the retaining wall backfill.

Table 7.1 Active and Passive Lateral Earth Pressures

Active Passive Slope (deg)

Pressure (psf/ft)

Slope (deg)

Pressure (psf/ft)

-40 20 -34 69 -20 24 -30 109 0 28 -20 182

+20 36 -10 255 +30 47 0/+10 350/420 +34 69 +20 500

In all cases, Occupational Safety and Health Administration (OSHA) Standards must be followed.

For temporary slopes, soils should be considered “Type C” without additional evaluation by a

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 6

“competent person”. OSHA allows a maximum slope 1½:1 (H:V) and does not allow benching in “Type C” soils. Permanent slopes should be limited to 2:1 (H:V) or flatter.

6.4 Earthwork

The recommendations for geotechnical criteria in this report for design of planned modifications are predicated on fulfillment of the following earthwork recommendations:

6.4.1 Site Clearing: Existing vegetation, debris, and other deleterious materials must be removed from areas requiring prepared subgrade prior to construction. After clearing, the exposed subgrade should be scarified and compacted to a depth of 10 inches. After clearing and preparation, the surface should be relatively flat for subsequent work.

6.4.2 Excavation: Generally, conventional equipment is expected to be suitable for shallow excavations (less than 5 feet). However, caving and relatively flat, stable slopes should be anticipated. Specialized methods and equipment should be anticipated for drilled-shaft construction because of cohesionless soils and shallow groundwater. In all cases, Occupational Safety and Health Administration (OSHA) Standards must be followed. Without evaluation by a “competent person”, soils in the project area should be considered “Type C” soils.

6.4.3 Workability: At elevated moisture contents, the site soils may "pump" and become unworkable. This may require changes or additions in equipment and procedures such as grading the site to prevent ponding after site clearing, scarification and drying, over-excavation and replacement, or use of lightweight equipment.

6.4.4 Foundation Preparation: Specialized treatment of undisturbed, native soils in drilled-shaft foundation areas is not required. Soils disturbed by subsequently should be removed and replaced with additional concrete.

6.4.7 Materials: Clean, site soils or similar imported soils approved by the geotechnical engineer may be used for fill or backfill; however, fine-grained soils (silts and clays) are not recommended for use within 2 feet of finished grade for the levee road. Aggregate and concrete should conform to governmental or qualified professional’s specifications.

Imported soils should have a plasticity index of 15 or less, conform to the gradation presented in Table 6.1, and have no more than 0.10 percent soluble sulfates.

6.4.7 Placement and Compaction: All fill and backfill materials should be uniformly moisture conditioned to within 3 percent of optimum moisture content, placed in relatively horizontal loose lifts not exceeding the effective depth of compaction equipment (commonly 8 to 10 inches), and uniformly compacted to at least 95 percent of standard

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 7

proctor maximum dry density. Aggregate for pavement should be compacted to at least 100 percent of standard proctor maximum dry density.

6.5 Construction Observation and Testing

Recommendations for geotechnical criteria in this report for design and evaluation are predicated on adequate observation and testing during construction by the geotechnical engineer or his representatives, which, at a minimum, should include:

Review of site clearing and all foundation excavations to evaluate whether actual conditions are consistent with those encountered during exploration, Observation and testing of placement and compaction of all fill and backfill materials and geogrid, if needed, to evaluate compliance with specifications, and

Field and laboratory sampling and testing of portland cement concrete to evaluate compliance with specifications regarding slump, temperature, entrained air, and strength.

Adequate observation and testing during the construction phase are critical to the performance of constructed improvements and confirmation of the design-level recommendations presented herein. Accordingly, the firm that performs construction observation and testing must assume the role of geotechnical engineer for this project.

6.6 Surface Drainage

Construction and final site grades should be designed to prevent water from ponding in areas on or adjacent to foundations, retaining walls, slabs-on-grade, and pavement. Infiltration of water into soils supporting planned improvements must be prevented or reduced to the extent possible.

Slopes and drainage should be provided to prevent long-term ponding within 5 feet of planned improvements.

6.7 Corrosivity

Site soils should be considered to have high corrosion potential with respect to buried metals because of their low resistivity. Coatings, cathodic protection, and/or non-corrosive materials should be considered for buried metals. Site should be considered to have moderate corrosion potential with respect to portland cement concrete because of their sulfate contents ranged from 150 to 1,500 ppm. American Concrete Institute (ACI) recommends Type II, IP(MS), or IS(MS) for sulfate contents in this range.

MICHAEL BAKER JR., INC. - TEC 08T002.02 RPT.02D 8

VICINITY MAP

SCALE: 1:282,000 DRAWN BY: Y.C.

DATE: 6/26/09

APPROVED BY:

SITE

F. COSTELLO, P.E. REVISED:

EL PASO SECTOR, K-2C SEGMENT

N

REF: DELORME STREET ATLAS

DRAWING NUMBER

08T002.02-1

SITE PLAN

SCALE: 1” = 400’ DRAWN BY: Y.C.

DATE: 6/25/09

APPROVED BY:

REF: MICHAEL BAKER JR., INC.

DRAWING NUMBER

08T002.02-2

# Boring number and location

DATE: 6/25/09

APPROVED BY:

DRAWING NUMBER

08T002.02-3

DATE: 6/25/09

APPROVED BY:

F. COSTELLO, P.E. REVISED:

EL PASO SECTOR, K-2C SEGMENT

08T002.02-4

DATE: 6/25/09

APPROVED BY:

F. COSTELLO, P.E. REVISED:

EL PASO SECTOR, K-2C SEGMENT

08T002.02-5

DATE: 6/25/09

APPROVED BY:

F. COSTELLO, P.E. REVISED:

EL PASO SECTOR, K-2C SEGMENT

08T002.02-6

DATE: 6/25/09

APPROVED BY:

F. COSTELLO, P.E. REVISED:

EL PASO SECTOR, K-2C SEGMENT

08T002.02-7

DATE: 6/25/09

APPROVED BY:

08T002.02-8

DATE: 6/25/09

# Boring number and location

APPROVED BY:

08T002.02-9

A-10

GLOSSARY OF TERMS

ALLOWABLE BEARING CAPACITY: The allowable pressure at the base of the footing in excess of that at the same level due to the surrounding surcharge.

ASTM: American Society for Testing and Materials.

BACKFILL: Material replaced in a confined space, usually a man-made excavation.

BASE COURSE: A layer of specified material, usually granular, of planned thickness constructed on the subgrade for the purpose of serving one or more functions such as distributing load, providing drainage, minimizing frost action, etc.

BENCH: A horizontal surface in a sloped deposit.

CALICHE: A desert soil formed by the near surface crystallization of calcite and/or other soluble minerals by upward-moving solutions.

COLLAPSE POTENTIAL: Ability of a soil to undergo significant decrease in volume upon an increase in moisture content.

COMPRESSIBILITY: The property of a soil or rock pertaining to its susceptibility to decrease in volume when subjected to load.

DIFFERENTIAL SETTLEMENT: The difference in downward movement between two adjacent foundation elements.

ENGINEERED FILL: Specified material placed and compacted under full-time observation of the geotechnical engineer or his qualified representative in accordance with project specifications.

EQUIVALENT FLUID PRESSURE: Horizontal pressure of soil, or soil and water, in combination which increases linearly with depth and are equivalent to those that would be produced by a fluid of a selected unit weight.

EXISTING GRADE: Elevation of ground surface at time of exploration.

EXPANSION POTENTIAL: The ability of a soil to increase its volume upon contact with water.

FILL: Material placed by man to raise the surface of the land.

A-11

GLOSSARY Continued

FINISHED GRADE: The final grade of ground surface, floor slab, pavement, etc.

HEAVE: Upward movement of ground or structural element.

MAG: Maricopa Association of Governments.

MAXIMUM DRY DENSITY: The maximum dry density obtainable in the laboratory for a given compactive effort.

MOISTURE CONTENT: The ratio of the mass of water contained in the pore spaces of soil or rock material, to the solid mass of particles in that material, expressed as a percentage.

OPTIMUM MOISTURE CONTENT: The moisture content at which a soil can be compacted to a maximum dry unit weight by a given compactive effort.

PLASTICITY: The property of a soil that allows it to be deformed beyond the point of recovery without cracking or appreciable volume change.

ROCK: Natural solid mineral matter occurring in large masses or fragments.

SCARIFY: To mechanically loosen or break the existing soil structure.

SETTLEMENT: Downward movement of ground or structural element.

SOIL: Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may not contain organic matter.

STRIP: Remove from present location.

SUBBASE: A layer used in pavement or slab-on-grade system between the subgrade and base course, or between the subgrade and portland cement concrete pavement.

SUBGRADE: The soil prepared and compacted to support a structure or a pavement system.

TERRANE: 1. A geologic formation or group of formations. 2. The area of surface over which a particular rock or group of rocks is prevalent. 3. An area or region considered in relation to its fitness or suitability for some specific purpose.

A-12

BORING LOG NOTES

These notes and boring logs are intended for use with this geotechnical report for the purposes described therein. The logs indicate our interpretation of subsurface conditions at the described locations on the date noted. Subsurface conditions may vary, and groundwater levels may change because of seasonal or other factors. Accordingly, the boring logs should not be made a part of the construction plans or be used to define construction conditions.

The borings were positioned by measuring from and visually referencing existing site features. The approximate positions are shown on the Site Plan.

"Boring Size/Type" refers to the diameter and type of boring. "HSA" denotes hollow-stem auger;

"HA" denotes hand auger, “MR” denotes mud rotary, and "SSA" denotes solid-stem auger.

"Sample Type" refers to the sampling method and equipment used during exploration where:

N indicates a 2.00-inch-outside-diameter, split-spoon sampler driven by a 140-pound hammer dropped 30 inches, R indicates a 2.42-inch-inside-diameter ring sampler driven by a 140-pound hammer dropped 30 inches, T indicates a 3.00-inch-outside-diameter, galvanized, steel tube driven by the hydraulic rams of the drill rig, and G indicates a grab sample from auger cuttings.

"Blows/Foot" refers to the number of blows required to drive the sampler one foot or a specified distance. Refusal is 50 blows per foot for R samples and 100 blows per foot, 50 blows for six inches, or 25 blows without advancing for N samples.

"Dry Density" refers to unit weight of the soil in pounds per cubic foot as determined in the laboratory. "NR" indicates that no sample was recovered, and "*" indicates that the sample was too disturbed for density testing.

"Moisture Content" refers to the moisture content of the soil in percent by weight as determined in the laboratory.

"Description and Classification" refer to the materials encountered in the boring. Generally, the descriptions and classifications are based on visual examination in the field. Further examination and testing were performed on selected samples in the laboratory. The terms and symbols used in the boring logs are in general accordance with the Unified Soil Classification System and the American Society for Testing and Materials.

Log of Boring 1

Project: El Paso Sector, K-2C Location: El Paso, TX TEC Job No: 08T002.02 Date: May 31, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 19 ft Other:

Depth (feet)

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

G

R

T

7.5

16.6

8.0

10.0

19.4

Clayey Sand (SC); light brown, fill

Lean Clay with Sand (CL); brown, fill

Silty Sand (SM); brown, fill

Clayey Sand (SC); light brown

Silty Sand (SM); light brown lean clay (CL) stringer groundwater some organic matter brown, some organic matter, CL stringer with fine gravel, dark brown, some organic matter, CL stringers with fine gravel, gray, with CL stringers

A-13

Log of Boring 1 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

NR

Silty Sand (SM) cont’d three attempts to sample unsuccessful because of soil in auger auger chatter 46-50 ft, gravel and cobbles likely auger chatter thin lens CL with fine gravel, with CL stringers

Stopped @ 61½ feet, auger near seizure from saturated sands

A-14

Log of Boring 2

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 6, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 21 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

11.5

15.8

4.9

22.5

22.2

Sandy Lean Clay Sand (CL); light brown, fill

Sandy Silt (ML); light brown, fill

Silty Sand (SM); light brown, fill

Poorly Graded Sand (SP); light brown switch to mud rotary auger chatter on gravel gray

CL stringers

A-15

Log of Boring 2 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

25.3

36.6

Fat Clay (CH); gray, some organics

Clayey Sand (SC); gray, trace organics

Silty Sand (SM); gray

CL stringer, gray-brown, some organics

Clayey Sand (SC); gray, light cementation

Stopped @ 76½ feet

A-16

Log of Boring 3

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 5, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 21 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

8.8

12.7

10.2

6.3

21.6

23.7

Silty Clayey Sand (SC-SM); light brown, fill brown gray, clayey sand (SC) stringer significant drilling fluid loss

A-17

Log of Boring 3 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

26.7

Silty Clayey Sand with Gravel (SC-SM); gray bit chatter on gravel

Silty Sand with Gravel (SM); gray

Refusal @ 58½ feet

A-18

Log of Boring 4

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 4, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 18 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

76-95

15.5

31.2

18-51

24.8

18.7

26.7 some organics

Lean and Fat Clay (CL & CH); brown bit chatter, possibly on gravel gray-brown poorly graded sand with silt and gravel (GP-GM) stringer with gravel, dark gray no gravel, gray-brown

A-19

Log of Boring 4 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

22.5

16.8 with gravel no gravel bit chatter

Refusal @ 70 feet

A-20

Log of Boring 5

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 7, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 18 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

9.0

16.3

30.7

24.3

24.3

22.9

Sandy Silty Clay (CL-ML); light brown, fill

Silty Clayey Sand (SC-SM); brown, fill chatter on gravel with gravel, gray

A-21

Log of Boring 5 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

43.0

17.1

Silty Sand (SM); gray

Peat (PT); tree core Organic Silt (OL); gray

Silty Sand with Gravel (SM); some organics heavy chatter, slow advancement to sample depth

Refusal @ 62½ feet

A-22

Log of Boring 6

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 1, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 17 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

89-92

17.6

23.2

16.7

4.1

22.2

Sandy Silty Clay (CL-ML); light brown, fill

Fat Clay (CH); brown, fill brown, CL stringers gray-brown, CL stringer dark gray, CL stringers, organic smell

A-23

Log of Boring 6 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

GP-GM stringer dark gray

Well-Graded Gravel with Silt and Sand (GW-GM); gray

Refusal @ 57½ feet

A-24

Log of Boring 7

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 2, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 13 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

9.0

22.7

37.7

21.4

31.1

23.6

Sandy Lean Clay (CL); light brown, fill

Silty Clay with Sand (CL-ML); light brown, fill

Lean Clay with Sand (CL); brown, some organics

Silty Sand (SM); light brown, organic stringers, groundwater

Lean Clay with Sand (CL); light brown

A-25

Log of Boring 7 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

32.8

17.7

Lean Clay with Sand (CL) cont’d dark brown

Well-Graded Sand with Silt and Gravel (SW-SM); dark gray, bit chatter

Refusal @ 58 feet

A-26

Log of Boring 8

Location: El Paso, TX TEC Job No: 08T002.02 Date: June 3, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA, 3½”/MR Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 16 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

34.6

28.5

39.9

34.1

26.2

27.8

Sandy Lean Clay (CL); light brown, fill

Fat Clay with Sand (CH); brown, fill

Sandy Lean Clay (CL); brown, fill

Fat Clay with Sand (CH); brown, some organics

Silty Clayey Sand (SC-SM); brown, with organics and iron, groundwater

Silty Sand (SM); dark gray, some organics with gravel, white CL stringers, bit chatter

Silty Clayey Sand (SC-SM); gray, CL stringers

A-27

Log of Boring 8 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90

22.7

16.5

Silty Clayey Sand (SC-SM) cont’d

Silty Sand (SM); gray, CL stringers moderate to heavy chatter

Refusal @ 66½ feet

A-28

Log of Boring 9

Location: El Paso, TX TEC Job No: 08T002.02 Date: May 29, 2009

Drill Rig: CME 750XL Boring Size/Type: 8”/HSA Elevation (ft): Not determined Logged by: K. Watts

Drilled by: TERCO Groundwater: 15 ft

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__5 __10 __15 __20 __25 __30 __35 __40

13.4

12.9

17.6

Fat Clay (CH); brown

Silty Sand (SM); brown dark brown with gravel, CL stringers auger chatter

A-29

Log of Boring 9 Cont’d

Sample Type

Blows/ Foot

Dry Density

(pcf)

Water Content

Description and Classification

__45 __50 __55 __60 __65 __70 __75 __80 __85 __90 brown, CL lens auger chatter on gravel and cobbles

Stopped @ 61½ feet, auger near seizure from saturated sands

A-30

1) Soil classification tests by PSI, Inc. in conjunction with direct shear or triaxial tests. A-31

SUMMARY OF INDEX PROPERTY TESTS - TEC 08T002.02 RPT.02

MOISTURE-DENSITY RELATIONSHIP PARTICLE SIZE ANALYSIS – ASTM D422

(percent passing by weight)

ATTERBERG

LIMITS

ASTM D4318

BORING

OR PIT

NO.

DEPTH

(ft)

USCS

SOIL

TYPE 3” 2” 1” ½” #4 #8 #40 #200 LL PL PI

MAXIMUM

DENSITY

(pcf)

OPTIMUM

MOISTURE

ASTM

METHOD

NOTES

1 0-3 SC 100 97 92 91 86 36 21 12 9 118.8 11.8 D698-A

5-6 CL 100 80 26 15 11

12½-14½ SM 26 NP 1

17½-19 SM 100 99 94 34 NP

2 2-5 CL 100 97 96 95 63 25 15 10 113.3 12.8 D698-A

5-6 ML 100 77 NP

15-17 SP 2 NP 1

3 2½-5 SC-SM 100 97 96 95 30 22 16 6 115.6 13.3 D698-A

5-6 SM 100 34 NP

12½-14½ SM 43 NP 1

4 0-5 SC-SM 100 99 96 95 94 49 24 17 7 110.0 13.3 D698-A

5-6 SM 100 93 91 46 NP

12½-14½ CH 94 74 28 46 1, 1st point

12½-14½ CL 97 39 28 11 1, 2nd point

12½-14½ CL 98 41 21 21 1, 3rd point

5 0-5 SC 100 98 98 95 49 24 16 8 113.0 14.4 D698-A

2½-4½ SC 49 26 16 10 1

5-6 CL-ML 100 98 97 93 68 28 22 6

1) Soil classification tests by PSI, Inc. in conjunction with direct shear or triaxial tests. A-32

SUMMARY OF INDEX PROPERTY TESTS - TEC 08T002.02 RPT.02

MOISTURE-DENSITY RELATIONSHIP PARTICLE SIZE ANALYSIS – ASTM D422

(percent passing by weight)

ATTERBERG

LIMITS

ASTM D4318

BORING

OR PIT

NO.

DEPTH

(ft)

USCS

SOIL

TYPE 3” 2” 1” ½” #4 #8 #40 #200 LL PL PI

MAXIMUM

DENSITY

(pcf)

OPTIMUM

MOISTURE

METHOD

6 0-7½ SC-SM 100 99 95 92 86 27 23 18 5 115.0 14.0 D698-A

5-6 CL-ML 100 74 25 20 5

7-9 CH 99 57 26 31 1

7 0-5 SC 100 98 92 91 84 35 25 13 12 114.2 12.1 D698-A

5-6 CL 100 99 98 57 26 13 13

7-9 CL-ML 81 28 21 7 1

8 0-7½ SC 100 99 96 96 94 43 29 14 15 111.8 14.0 D698-A

5-6 CL 100 96 95 95 93 54 25 11 14

7½-9½ CH 86 76 31 45 1

9 0-5 SC-SM 100 99 93 81 77 71 28 20 16 4 116.0 11.9 D698-A

5-6 SC-SM 100 98 36 19 15 4

10-12 CH 96 64 19 45 1

27½-29 SC-SM 100 93 86 85 76 27 18 13 5

1) Permeability test by Alpha G&M, Inc.; B/P is back pressure; C/S is consolidation stress; End Sat. is end saturation with assumed specific gravity of 2.65.

2) Direct shear (DS) or triaxial test (TT) by PSI, Inc.; DS CD at 1, 2, and 4 ksf; TT CU w/PP at about 1, 2, and 4 ksf.

3) Direct shear test by AMEC; DS CD at 1, 2, and 3 ksf.

4) Soil classification based on visual, field classification.

A-33

SUMMARY OF ENGINEERING PROPERTY TESTS - TEC 08T002.02 RPT.02

INITIAL CONDITIONS PERMEABILITY STRENGTH

BORING

OR PIT

NO.

DEPTH

(ft)

USCS

SOIL

TYPE

DRY

DENSITY

(pcf)

WATER

CONTENT

ASTM

TEST

K (cm/s)

B/P (psi)

C/S (psi)

End Sat.

ASTM

TEST

c (ksf)

Ø (deg) q (psi)

R-

VALUE

D1844

1 5-6 CL 101 7.5 D5084-C 8.0x10-6 75 5 97 1

12½-14½ SM 113 8.0 D3080 0.2 35 2

2 5-6 ML 96 11.5 D5084-C 5.8x10-5 75 5 103 1

15-17 SP 116 4.9 D3080 0.3 33 2

3 5-6 SM 103 8.8 D5084-C 7.0x10-5 75 5 101 1

12½-14½ SM 108 12.7 D3080 0.4 29 2

4 5-6 SM 87 15.5 D5084-C 3.9x10-4 75 5 97 1

12½-14½ CL 76-95 18-51 D4767 0.4 24 2

5 2½-4½ SC 112 9.0 D3080 0.0 39 1

5-6 SM 97 16.3 D5084-C 2.0x10-5 75 5 102 1

6 5-6 CL-ML 72 17.6 D5084-C 1.6x10-5 75 5 95 1

7-9 CH 89-92 23.2 D4767 0.2 18 2

7 5-6 CL 96 9.0 D5084-C 8.1x10-4 75 5 99 1

7-9 CL-ML 112 22.7 D4787 0.2 35 2

8 5-6 CL 102 13.7 D5084-C 1.3x10-5 75 5 97 1, remolded

7½-9½ CH 83 34.6 D3080 0.6 18 2

10-11 CL 115 28.5 D3080 1.5 30 3, 4

1) Permeability test by Alpha G&M, Inc.; B/P is back pressure; C/S is consolidation stress; End Sat. is end saturation with assumed specific gravity of 2.65.

2) Direct shear (DS) or triaxial test (TT) by PSI, Inc.; DS CD at 1, 2, and 4 ksf; TT CU w/PP at about 1, 2, and 4 ksf.

3) Direct shear test by AMEC; DS CD at 1, 2, and 3 ksf.

4) Soil classification based on visual, field classification.

A-34

SUMMARY OF ENGINEERING PROPERTY TESTS - TEC 08T002.02 RPT.02

INITIAL CONDITIONS PERMEABILITY STRENGTH

BORING

OR PIT

NO.

DEPTH

(ft)

USCS

SOIL

TYPE

DRY

DENSITY

(pcf)

WATER

CONTENT

ASTM

TEST

K (cm/s)

B/P (psi)

C/S (psi)

End Sat.

ASTM

TEST

c (ksf)

Ø (deg) q (psi)

R-

VALUE

D1844

9 5-6 SC-SM 89 13.4 D5084-C 2.2x10-5 75 5 95 1

10-12 CH 108 12.9 D4787 0.6 23 2

A-35

SUMMARY OF CHEMICAL PROPERTY TESTS - TEC 08T002.02 RPT.02

BORING

NO.

DEPTH

(ft)

USCS

SOIL

TYPE

ORGANIC

MATTER

SOIL

pH ARIZ 236b

(S.U.)

RESISTIVITY

ARIZ 236b (ohm-cm)

SOLUBLE

SALTS

ENG. SOIL

SOLUBLE

SULFATES

AZ 733

(ppm)

SOLUBLE

CHLORIDES

AZ 736

(ppm)

NOTES

1 0-3 SC 8.4 320 740 300 1

2 2-5 CL 8.3 460 1,017 278 1

3 2½-5 SC-SM 8.4 400 886 433 1

4 0-5 SC-SM 8.2 370 930 696 1

5 0-5 SC 8.2 380 1,145 516 1

6 0-7½ SC-SM 8.2 480 460 200 1

7 0-5 SC 8.2 290 1,200 550 1

8 0-7½ SC 8.2 550 575 135 1

9 0-5 SC-SM 8.3 280 1,100 840 1

1) Soluble sulfates and chlorides tests by Motzz Laboratory, Inc.