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Park West CC(02-2)-SY050323GEOTECHNICAL INVESTIGATION OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS Presented To: MAJESTIC REALTY COMPANY ATLANTA, GEORGIA GEOTECNN~CAL AND ] [~ ~:~ O U P EN¥1RONMENTAL CO NS[JLTANTS March 23, 2005 Project No. 12045 Majestic Realty Company 3490 Piedmont Road N.E., Suite 210 Atlanta, Georgia 30305 ATTN: Mr. Stan Conway GEOTECHNICAL INVESTIGATION OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS Gentlemen: Transmitted herewith are copies of the referenced report. Should you have any questions concerning our findings or if you desire additional information, do not hesitate to call. Sincerely, REED ENGINEERING GROUP, LTD. Den'in G. Williams . _ ..:. ............. Principal Enginem DGW~apv copies submitted: (2) Majestic RealW Comp~y~r. St~ Conway (1) Cadence McSh~e Co~oratio~r. Gle~ A. De. am (1) Hardy McCullah/MLM Architects, Inc./ Mr. Hardy McCullah, AIA 2424 STUTZ DRIVE, SUITE 400 DALLAS, TX 75235 tel 214.350 5600 fax 2~4.350.0019 wwwt eed-en§inee~ ing corn TABLE OF CONTENTS PAGE INTRODUCTION .................................................................................................... 1 Project Description ..................................................................................... 1 Authorization ............................................................................................... 1 Purpose and Scope ...................................................................................... FIELD AND LABORATORY INVESTIGATIONS ............................................ 2 General ......................................................................................................... 2 Field Investigation ....................................................................................... 2 Laboratory Testing ...................................................................................... 3 GENERAL SITE CONDITIONS .......................................................................... Physiography ................................................................................................ 4 Geology .......................................................................................................... 5 Stratigraphy .................................................................................................. 5 Ground Water ............................................................................................. 6 Texas Health and Safety Code and TCEQ Comment .............................. 6 Seismic Site Classification ........................................................................... 7 ANALYSIS AND RECOMMENDATIONS .......................................................... 7 Potential Vertical Movement ..................................................................... 7 Foundation Design ....................................................................................... 10 Grade Beams/Tilt-Wall Panels ................................................................... 11 Floor Slab ...................................................................................................... 12 Retaining Walls ............................................................................................ 17 Earthwork .................................................................................................... 19 Pavement ...................................................................................................... 21 Construction Observation and Testing Frequency ................................... 25 -i- TABLE OF CONTENTS (Continued) ILLUSTRATIONS PLATE PLAN OF BORINGS ............................................................................................... 1 BORING LOGS ....................................................................................................... 2-18 KEYS TO TERMS AND SYMBOLS USED ......................................................... 19&20 LABORATORY TEST RESULTS ........................................................................ 21-25 ABSORPTION PRESSURE-SWELL TEST RESULTS ..................................... 26 INTERPRETIVE GEOLOGIC CROSS-SECTION ............................................ 27 SPECIFICATIONS PAGE WATER INJECTION W/"SELECT" OR CRUSHED LIMESTONE FILL CAP ....................................................................................... 1 WATER INJECTION W/LIME-MODIFIED CAP ............................................. 1 INTRODUCTION Project Description This report presents the results of a geotechnical investigation performed for two new buildings to be located northwest of the intersection of Airline Drive and Beltline Road in Coppell, Texas. The general orientations of the buildings are shown on the Plan of Borings, Plate 1 of the report Illustrations. The project consists of construction of two office/warehouse buildings on an approximate 16.5- acre tract. The buildings will be approximately 137,000 and 153,000 square feet, and will have finished floor elevations of 519.0 and 519.5. Associated site paving will also be included in the development. Authorization This investigation was authorized by signature of our Proposal No. 12-10 (Revised) on February 15, 2005. Purpose and Scope The purpose of this investigation has been to evaluate the general subsurface conditions and provide recommendations for: · design of the foundation systems; · floor slabs; · below-grade and retaining walls; · pavement subgrade; and site preparation and earthwork compaction criteria. Project No. 12045 - 1 - March 23, 2005 The investigation has included drilling sample borings, performing laboratory testing, analyzing engineering and geologic data and developing geotechnical recommendations. The following sections present the methodology used in this investigation. Recommendations provided herein are site~specific and were developed for the project discussed in the report Introduction. Persons using this report for other than the intended purpose do so at their own risk. FIELD AND LABORATORY INVESTIGATIONS General The field and laboratory investigations have been conducted in accordance with applicable standards and procedures set forth in the 2004 Annual Book of ASTM Standards, Volumes 04.08 and 04.09, "Soil and Rock." These volumes should be consulted for information on specific test procedures. Field Investigation Subsurface conditions were evaluated by 17 sample borings drilled to depths of I0 to 25-1/2 feet in March 2005. The locations of the borings are shown on Plate 1 of the report Illustrations. Borings were located in the field using a GPS (Global Positioning System) unit. The accuracy of this unit is estimated to be within plus or minus one meter. Borings were advanced between sampling intervals by means of a track-mounted drilling rig equipped with continuous flight augers. Samples of cohesive soils were obtained with 3-inch diameter Shelby tubes (ASTM D-1587). - 2 - March 23, 2005 Project No. 12045 Cohesionless soils (sands and gravels) were sampled in conjunction with the Standard Penetration test (SPT) (ASTM D-1586). Delayed water level observations were made in the open boreholes to evaluate ground water conditions. The borings were backfilled at completion of field operations. Sample depth, description of materials, field tests, water conditions and soil classification [Unified Soil Classification System CUSCS), ASTM D-2488] are presented on the Boring Logs, Plates 2 through 18. Keys to terms and symbols used on the logs are included as Plates 19 and 20. Elevations shown on the boring logs are approximate, and have been interpolated to the nearest foot based on topographic information on site plans provided by Hardy McCullah/MLM Architects, Inc. Laboratory Testing All samples were returned to the laboratory and visually logged in accordance with the USCS. The consistency of cohesive soils was evaluated by means of a pocket penetrometer. Results of the pocket penetrometer readings are presented on the boring logs. Laboratory tests were performed to evaluate index properties, confirm visual classification, and evaluate the undrained shear strength of selected samples. Tests and ASTM designations are provided in Table 1. Project No. 12045 - 3 - March 23, 2005 TABLE 1. TESTS CONDUCTED AND ASTM DESIGNATIONS Type of Test ASTM Designation Atterberg Limits D-4318 Moisture Content D-2216 Partial Gradation D-1140 Soil Suction D-5298 Unconfined Compression (Soil) D-2166 The results of these tests are summarized on Plates 21 through 25. The expansive characteristics of the severely weathered shale were also evaluated by means of one absorption pressure-swell test~. Results of the swell test are presented graphically on Plate 26. GENERAL SITE CONDITIONS Physiography The site is relatively flat with short grass that covers the surface and trees that line the two roads. There are no visible channels or structures on the site, and access was unlimited. Some fill was encountered on the west side of the site. The fill is anticipated to be associated with development of the adjacent site to the west. Johnson, L.D., & Snethen, D.R. (1978). "Prediction of Potential Heave of Swelling Soil." Geotechnical Testing Journal, ASTM 1 (3), 117-124. Project No. 12045 - 4 - March 23, 2005 Geology The site is located within terraced alluvial soils overlying the Cretaceous Eagle Ford Formation. The terraced alluvial soils are associated with Quaternary deposition in the floodplain of the Elm Fork Trinity River and its tributaries in the geologic past. Unweathered shale of the Eagle Ford Formation typically consists of dark gray, soft clay shale that weathers to form highly plastic CH clay. Stratigraphy A geologic cross-section was developed for visual assistance and is included in the report Illustrations as Plate 27. Stratigraphic lines shown on the cross-section are interpreted fi.om the boring logs. Actual conditions will vary. Subsurface conditions encountered in the borings consist of fill and terraced alluvial soils over severely weathered shale to slightly weathered to unweathered shale of the Cretaceous Eagle Ford Formation. The fill was encountered in three borings and consisted of one to two feet of very dark brown to dark brown, highly plastic clay. The alluvial soils consisted Of highly plastic clays and highly to moderately plastic silty clays and sandy clays grading to clayey sands and sands below depths of 13 to 23-1/2 feet. The upper clays were very dark brown to dark brown grading to yellowish-brown and gray to brownish-yellow and gray. The sands were brownish-yellow to pale yellow and gray. Four of the deeper borings were terminated within the alluvial soils. Project No. 12045 - 5 - March 23, 2005 Below depths of 12 to 23-1/2 feet in Borings B-I, B-2, B-5 B-9, and B-10, olive-yellow and gray to yellowish-brown and gray, fissile clay was encountered. The fissile clay represents severely weathered shale, and is noted as such on the logs. Two borings encountered light gray to grayish-brown, slightly weathered shale below the alluvial sands at depths of 24-1/2 and 25 feet. Ground Water Ground water seepage was encountered in all of the deeper borings at depths of 13 to 19 feet (Elev. 504 to 497). Based on post-drilling water level observations, ground water was present at depths of 6 to 11-1/2 feet (Elev. 510 to 506) in March 2005. The ground water is perched above the relatively impermeable, unweathered shale in the overlying alluvial soils. The depth to, and amount of ground water, will fluctuate with variations in seasonal and yearly rainfall. Texas Health and Safety Code and TCEQ Comment Pursuant to the Texas Health and Safety Code, Chapter 361, §361.538 and 30 Texas Administrative Code 330, §330.953, Reed Engineering Group, Ltd. has performed appropriate soil tests as required by these regulations to demonstrate that the subject property does not overlie a closed municipal solid waste landfill. The site observations and subsurface data do not indicate the presence of buried municipal solid waste at this site. Based on these data, development of this site should not require a Development Permit, as described in §361.532 and §§330.951-330.963, Subchapter T. Project No. 12045 - 6 - March 23, 2005 Seismic Site Classification The site has been classified with respect to seismic design criteria contained in the 2000 International Building Code (IBC), Section 1615.1.5. The criteria require characterization of the upper 100 feet of subsurface materials. Based on the IBC criteria, the site may be classified as Site Class C per Table 1615.1.1. ANALYSIS AND RECOMMENDATIONS Potential Vertical Movement An analysis of the magnitude of soil movement (i.e., expansion and/or shrinkage) associated with changes in soil moisture was performed. This analysis included: · identification of the zone of activity; · evaluation of the expansive properties of the materials encountered in the borings; · anticipated changes in the environmental factors that impact soil behavior associated with the construction of the proposed development; and · development of a model to evaluate the anticipated soil movement. Subsurface conditions consist of highly plastic alluvial soils over alluvial sands and severely weathered shale. Ground water was encountered at a depth of 13 to 19 feet below existing grade, or approximate Elev. 504 to 497. Materials above and below the ground water were found to be currently moist. The zone of activity for this site and geologic environment is associated with the depth of seasonal drying of the upper soils, which is, in turn, limited by the ground water. Project No. 12045 - 7 - March 23, 2005 Historical records within the area indicate the ground water is present at about the elevation noted in this study. Therefore, accounting for the capillary zone above the phreatic surface, the maximum zone of activity is considered to be at an approximate depth of 12 feet below grade. The actual depth of activity will be dependent upon the specific climatic conditions for any particular year. In other words, the seasonal depth varies fi.om year to year dependent upon the length and severity of either drought or excessive rainfall. (This is similar to the "100-year flood" concept used in hydraulic studies.) The seasonal variation can be evaluated by use of the Thomthwaite Index, Im2. Calculation of Im for Dallas/Fort Worth based on weather data at D/FW Airport through 1999 is presented in the following graph. 5 -10 -15 Variation of Thomthwaite Index D/FW Airport, 1974 - 1999 197419751976 1977 1978 19791980 1981 1982 19831984 1985 19861987 19881999 1990 1991 199219931994199519961997 1998 1999 Year 2 Thomthwaite, C.W. (1948). "An Approach Toward a Rational Classification of Climate." Geographical Review, 38(I), 54-94. Project No. 12045 - 8 - March 23, 2005 The expansive properties of the upper soils were evaluated by use of the absorption pressure- swell test and the classification tests. Models used to evaluate the magnitude of movement consisted of correlation with pressure-swell tests3'4 and an empirical method developed by McDowell5 and modified by the Texas Department of Transportation, TxDOT 124-E6. Based on this analysis for existing site conditions and considering the seasonal average, the magnitude of movement is estimated to be on the order of three to five inches dependent upon location. Without environmental changes associated with the proposed construction, the movement will be seasonal, i.e., upwards at the end of the dry season and into the wet season, and downwards (shrinkage) at the end of the wet season and into the dry season as the soils dry. Considering the preceding discussion, it is intuitive to conclude that the magnitude of soil movement can be reduced by limiting the seasonal changes in soil moisture. If the soils are dry at the time of construction, they must be kept dry throughout the life of the project. On the other hand, if the soils are moist, they should be kept moist for the economic life of the structures. Based on extensive experience, it is easier to keep the soils moist than dry. Keeping the soils moist can be accomplished by the addition of landscape irrigation, construction of impermeable surfaces such as the floor and site paving and prudent watering during extended periods of drought. 3 Johnson, L.D., & Snethen, D.R. (1978). "Prediction of Potential Heave of Swellnig Soil." Geotechnical Testing Journal, ASTM 1 (3), 117-124. 4 Fredlund, D., and Rahardjo, H.(1993). "Soil Mechanics for Unsaturated Soils," John Wiley & Sons, Inc., New York, N.Y. s McDowell, C. "The Relation of Laboratory Testing to Design for Pavements and Structures on Expansive Soils." Quarterly of the Colorado School of Mines, Volume 54, No. 4, 127-153. 6 "Method for Determining the Potential Vertical Rise, PVR." (1978). Texas Department of Transportation, Test Method Tex- 124-E. - 9 - March 23, 2005 Project No. 12045 Foundation Design Foundation support for concentrated column loads should be provided by reinforced concrete, underreamed (belled) piers. The piers should be founded at a depth of 15 feet below existing (March 2005) grades or on top of sand or ground water, whichever occurs first. The piers should be designed for an allowable bearing pressure of 4.5 kips per square foot (ksf) dead load or 6.5 ksftotal load, whichever governs. Piers proportioned in accordance with the allowable bearing value will have a minimum factor of safety of three considering a shear or plunging failure. The weight of the pier concrete below final grade may be neglected in determining foundation loads. Elastic settlement of properly constructed underreamed piers should be limited to approximately ½ to 1 inch. Piers will be subjected to uplift associated with swelling within the upper clays. The piers should contain reinforcing steel throughout the pier to resist the tensile uplift forces. Reinforcing requirements may be estimated based on an uplift pressure of 1.3 ksf acting over the top 8 feet of pier surface area. The calculated uplift value is considered a working load. Appropriate factors of safety should be applied in calculating the percent of reinforcement. "Mushrooming", or widening of the upper portion of the pier shaft, will significantly increase the uplift pressure from the upper clays. "Mushrooms" should be removed fi'om the piers prior to backfill operations. Pier caps should not be used with the piers unless a minimum void of 6 inches (factor of safety of 1.1) is created below the portion of the cap extending beyond the shaft diameter. - 10 - March 23, 2005 Project No. 12045 Uplift resistance for underreamed piers will be provided by the weight of the soil overlying the bell and the dead load from the structures. A minimum bell-to-shaft diameter ratio of two to one (2:1) is recommended to resist uplift associated with swelling of the upper soils. A maximum bell-to-shaft diameter ratio of 3:1 is recommended to limit possible caving of the bells. Ground water was encountered during the field investigation. Dewatering pier excavations should not be required if close coordination of drilling and concrete placement is performed. Pier excavations should be dry and free of deleterious materials prior to concrete placement. In no case should the pier shaft excavation remain open for more than four hours prior to concrete placement. Continuous observation of the pier construction by a representative of this office is recommended. Observation is recommended to confirm the bearing stratum and that the excavation is dry prior to placement of concrete. Grade Beams/Tilt-Wall Panels Grade beams or tilt-wall panels underlain by clay should be constructed with a minimum void of 6 inches (Factor of Safety of 1.1) beneath them. A void is recommended to limit potential foundation movements associated with swelling of the underly/ng soils. The void can be created below grade beams by use of wax-impregnated cardboard forms or beneath tilt panels by over-excavating the required void space prior to panel erection. Retainer boards along the outside of the grade beam or tilt-wall panel will not be necessary. - 11 - March 23, 2005 Project No. 12045 Grade beams should be double-formed. Earth-forming of beams below ground is not recommended because of the inability to control the beam excavation width. Fill on the outside of perimeter grade beams and/or tilt walls should be placed in a controlled manner. Backfill should consist of site-excavated clays, or equal, placed and compacted in accordance with the Earthwork section. If bedding soils must be used adjacent to the perimeters of the buildings, the clay/bedding soil interface should be sloped to drain away from the buildings. Compaction criteria are included in the Earthwork section. Floor Slab A number of factors affect the performance of the floor slab, to include traffic and wheel loads, quality of the concrete, joint treatment and condition of the subgrade. The two factors which affect the condition of the subgrade are related to post-construction movement and strength of the subgrade. The following sections address the potential for movement and alternatives to reduce the potential and/or probability of the movement occurring. The strength of the subgrade is addressed in the Modulus of Subgrade Reaction subsection. Potential movements associated with heave from a dry condition to a moist condition are estimated to be on the order of three to five inches. Additional movement is possible if the clays become saturated, such as can happen from utility leaks and excessive ponding adjacent to the perimeter walls. -12- March 23,2005 Project No. 12045 Two types of floor systems are considered feasible; a suspended floor and a ground-supported (or "floating") slab. The suspended floor is considered the most expensive but does provide the highest degree of confidence that post-construction movement of the floor will not occur. If this alternative is desired, a minimum void of 10 inches (approximate F.S. of 2) is recommended. Use of a ground-supported floor is feasible, provided the risk of some post-construction floor movement is acceptable. The potential movement can be reduced by proper implementation (i.e., construction) of remedial earthwork recommended in the following paragraphs. The risk of the potential movement occurring can be reduced by implementation of positive grading of surface water away from the buildings and backfilling immediately adjacent to the structures with on-site clays. Considering finished floor elevations of 519.0 and 519.5 for the two buildings and existing grades, the most economical means of limiting the potential for post-construction floor movement is to preswell the upper clays then provide a surface seal with either 12 inches of "select" or limestone fill or 6 inches of lime-stabilized clay. The general procedures are presented in the following paragraphs. Strip vegetation and dispose of in accordance with the project specifications. Cut and fill balance with on-site soils to within 12 inches of finished subgrade, or to subgrade if the lime-stabilized option will be used to cap the pad. Place and compact soils in accordance with recommendations in the Earthwork section. Note: If insufficient on-site fill exists to achieve the proposed subgrade for the "select" or crushed limestone fill options, all imported fill for use below the buildings should consist of "select" or crushed limestone fill. Balance on-site soils to provide a uniform thickness of"select" or crushed limestone. - 13 - March 23, 2005 Project No. 12045 3. Preswell the upper clays via pressure injection with water to a depth of 10 feet. Guideline specifications for performance of the injection are included in the report Specifications. Two guideline Specifications are included, one for the "select" or limestone cap, and one for the lime-stabilized option. 4. Place and compact the surface moisture barrier, consisting of either: · 12 inches of"select" fill, or ,, 12 inches of compacted limestone fill, or · stabilize the top 6 inches of injected soil with a minimum of 6 percent hydrated lime. Placement recommendations for "select" and limestone fill are included in the Earthwork section. Lime stabilization should be conducted in accordance with the Texas Department of Transportation (TxDOT) "Standard Specifications for Construction of Highways, Streets and Bridges," 1993 Edition, Item 260. Lime-stabilized soils should be compacted to a minimum of 95 pement of Standard Proctor density, ASTM D-698. Injections should be extended a minimum of five feet beyond the general building lines. The injection should be increased to 10 feet beyond the buildings at entrances to limit the potential for differential movement between the structures and sidewalks or entrance pavement. The performance of an injected subgrade is dependent upon the quality of the workmanship. Therefore, water pressure injection is no__~t recommended unless a representative of this office is present full-time to observe all injection operations. Project No. 12045 - 14 - March 23, 2005 The actual number of injection passes required will be dependent upon the soil moisture conditions at the time of construction. For estimating purposes and considering relatively dry conditions at the time of construction, a minimum of three injection passes should be anticipated. The surface moisture seal ("select" or limestone fill or stabilized clay) should be placed as soon as possible after completion of injection operations to limit moisture loss within the upper clays. Potential floor movements considering a properly preswelled subgrade are anticipated to be on the order of ½ to 1 inch. Positive drainage of water away from the structures must be provided and maintained after construction. Architectural detailing of interior finishes should allow for approximately ¥2 to 1 inch of differential floor movement. A minimum six-mil thick polyethylene sheet is recommended below the floor to limit migration of moisture through the slab from the underlying clays. This is of particular importance below sections of the floor covered with carpeting, paint or tile. Penetrations and lapped joints should be sealed with a waterproof tape. Ground-supported floors over expansive soils may be subject to settlement if the underlying clays dry during the life of the structures. Natural desiccation will be limited to the outer four to five feet along the perimeters. However, roots from trees and shrubs can grow below the structures and increase the zone of desiccation. This process typically requires 8 to 10 years to develop. An effective means of limiting plant root growth is construction of a vertical moisture barrier adjacent to the foundations or extension of paving to the perimeter of the buildings. The Project No. 12045 -15- March 23, 2005 barrier should consist of a minimum six-inch wide, five-foot deep lean concrete wall. As an alternate, the barrier may consist of BioBarrier. BioBarrier is a geotextile fabric with permanently attached nodules containing trifluralin. Trifluralin prevents root tip cells from dividing, which is the method by which roots grow. More information on this product can be obtained on the Web at www.biobarrier.com. Trees and shrubs should be planted outside the barrier. Modulus of Subgrade Reaction - The proceeding sections discussed alternatives to reduce the potential and or probability of post-construction floor movement. Two alternatives were provided to seal the moisture into the subgrade to reduce construction related moisture loss. The alternatives included lime stabilization of approximately 6 inches of clay and placement of 12 inches of "select" fill or crushed limestone. Considering either the "select" fill or lime-stabilized options, it is recommended the floor slabs be designed using a modulus of subgrade reaction, k, of 150 pounds per cubic inch (pci). This value is applicable considering placement of a minimum of 12 inches of "select" fill or lime stabilization of 6 inches of subgrade with a minimum of 6 percent hydrated lime over the prepared subgrade. To achieve the recommended modulus, compaction of the "select" fill and lime-stabilized clay to the specified density will be required. Materials disturbed by the construction equipment immediately prior to placement of the concrete will reduce the allowable modulus. Project No. 12045 - 16 - March 23, 2005 A modulus of subgrade reaction of 200 pci is recommended if the pad is capped with a minimum of 12 inches of crushed limestone fill. The limestone should be compacted as outlined in the Earthwork section. Various alternatives are available to increase the effective modulus of subgrade reaction. One alternative consists of stabilization of the top six inches of "select" fill with a minimum of six percent cement. Another alternative consists of placement and compaction of a minimum of 5 inches of crushed concrete or flexible base (TxDOT Item 248, Type A, Grade 2 or better) on top of compacted "select" fill or lime-stabilized clay. Either of the two alternatives would increase the k value to approximately 200 pci. Other combinations to increase the allowable modulus are feasible and will be addressed if desired. Retaining Walls Lateral earth pressures against retaining walls will be a function of the backfill within the "active zone" of earth pressure. The "active zone" can be estimated as an included angle of 35© t~om the vertical, extended upward bom the base of the wall. Considering backfill using site-excavated materials, lateral earth pressures can be estimated based on an equivalent fluid pressure of 60 pounds per cubic foot (pcf) for active conditions, or 80 pcf for at-rest conditions. Alternatively, imported "select" fill may be used as backfill in the active zone. Considering "select" fill, lateral earth pressures can be estimated based on an equivalent fluid pressure of 35 pcf, active conditions, or 50 pcf at-rest conditions. - 17 - March 23, 2005 Project No. 12045 Rotation, or lateral movement on the top of the wall, equal to 0.02 times the height of the wall will be necessary for on-site soil backfill for the "active" condition. Lateral movement of the top of the wall equal to 0.001 times the height of the wall will be necessary for the "active" pressure condition for "select" fill backfill. The lateral earth pressures are applicable for horizontal surface grades and non-surcharged, drained conditions. A drainage system should be installed behind the base of the retaining walls to limit development of excess hydrostatic pressures. The drainage system should consist, as a minimum, of 12-inch by 12-inch pocket drains spaced 15 feet on-center, installed near the base of the wall. Fill in the pocket drains should consist of durable crushed stone such as ASTM C-33, Size 67 or coarser, wrapped in filter fabric (ADS 600 or equivalent). Backfill around the gravel drain should consist of site-excavated soils or "select" fill. A compacted clay cap is recommended within the upper two feet of the surface to limit surface-water infiltration behind the walls. Retaining walls may be founded on spread or continuous footings placed a minimum of 18 inches into undisturbed, on-site soils or compacted and tested fill. Footings should be proportioned for a maximum bearing pressure of 3,000 pounds per square foot (Psf). Movement of the footings and walls should be anticipated. Softer, flexible walls are recommended. Solid concrete walls should be battered into the soil to limit outward rotational movement caused by differential footing movement. - 18 - March 23, 2005 Project No. 12045 Passive resistance to lateral movement can be estimated based on an equivalent fluid pressure of 450 pcf for on-site materials. This value is applicable for footings founded on undisturbed, on-site soils or compacted and tested fill. In addition to passive resistance, a coefficient of friction between the base of the footing and the underlying soil equal to 0.45 may be used. The lateral earth pressure values do not incorporate specific factors of safety. If applicable, factors of safety should be integrated into the structural design of the wall. It is also recommended that any earth slope greater than eight feet in height be considered a major slope and evaluated for global stability. This also applies to slopes combined with retaining walls that have a combined height in excess of eight feet. All fill slopes should be vegetated as soon as possible. Use of erosion control fabric is recommended during construction of the slopes. Global stability analysis was not within the scope of the present investigation. This office can assist in the analysis if desired. Earthwork All vegetation and topsoil containing organic material should be cleared and grubbed at the beginning of earthwork construction. Areas of the site that will underlie fill or within the buildings should be scarified to a depth of 6 inches and recompacted to a minimum of 92 percent and a maximum of 98 percent of the maximum density, as determined by ASTM D- 698, "Standard Proctor". The moisture content should range from +1 to +5 percentage points above optimum. Project No. 12045 - 19 - March 23, 2005 Site-excavated soils should be placed in maximum eight-inch loose lifts and compacted to the moisture and density requirements outlined above. The final 6 inches of subgrade below pavement should be compacted to a minimum of 95 percent of Standard Proctor, at or above optimum moisture. Proper backfilling around the building perimeters will reduce the potential for water seepage beneath the structures. Fill against the perimeter of the foundations should consist of site- excavated clays, or equal, placed and compacted in accordance with the recommendations outlined above. "Select" fill is defined as uniformly blended clayey sand with a Plasticity Index (PI) of between 4 and 15. Select fill should be placed in maximum 8-inch loose lifts and compacted to at least 95 pement of the Standard Proctor density, at a moisture content between -2 to +3 percentage points of optimum moisture. The select fill should be placed within approximately seven working days over the injected subgrade to limit moisture loss within the underlying soils. Imported limestone fill may be used in lieu of clayey sand as "select" fill. Limestone fill should be placed in maximum loose lifts of 9 inches and compacted to at least 95 percent Standard Proctor. All limestone fragments larger than six inches should be broken down or removed from the fill prior to compaction. Limestone placed within six inches of the final grade should be reduced in size to three inches or less. - 20 - March 23, 2005 Project No. 12045 Pavement The specific pavement section will be dependent upon: 1. traffic loads and frequency; 2. pavement type and strength; 3. desired pavement life and ending condition; and 4. strength and condition of the subgrade. Information regarding the specific traffic loads and frequency is not available. Therefore, analysis was performed for a range of traffic conditions, and design thickness versus traffic load diagrams were developed. The pavement type is anticipated to be concrete. Analysis was performed for both 3,000 pounds per square inch (psi) and 4,000-psi compressive strength concrete. Based on correlations between compressive strength and flexural strength and incorporating a factor of safety of 1.33, an allowable working stress of 370 and 425 psi was used for the 3,000- and 4,000-psi concrete, respectively. Control of the water-cement ratio at the design value during placement and use of quality construction will be necessary to achieve the required flexural strength. A 20-year life was used for the analysis. Total pavement life was based on a si~x-day week. Analysis was performed in accordance with procedures developed by the American Association of State Highway Officials (AASHO). Project No. 12045 - 21 - March 23, 2005 The upper surface soils consisted of CH clays. When these soils are moist, they are relatively soft. For purposes of pavement analysis, the subgrade was assumed to be recompacted in accordance with the density and moisture recommendations in the Earthwork section and in a moist condition. An effective modulus of subgrade reaction, k, of 100 pci was used for the analysis. The effective k value of the subgrade can be increased to approximately 150 pci by stabilization of the upper 6 inches with a minimum of 6 percent hydrated lime. Lime should be placed and compacted in accordance with Item 260 of the current edition of TxDOT "Standard Specifications for Construction of Highways, Street and Bridges." The lime-stabilized subgrade should be compacted to a minimum of 100 percent of ASTM D-698 density (Standard Proctor). Generally, it is more cost-effective to increase the pavement thickness and construct over a compacted, non-stabilized subgrade. However, stabilization does provide an all-weather working platform for the contractor, and this may be beneficial from a construction perspective, especially if construction will occur during the wetter part of the year. Stabilization is also recommended if the traffic speed exceeds 30 miles per hour (mph). Considering the above discussion, analysis was made for both unlimited repetitions of cars and light trucks and for multiple repetitions of loaded tractor-trailers. Analysis indicates a pavement thickness of 4.5 inches of 3,000-psi concrete will be adequate for car and light truck traffic. A minimum five-inch section over a scarified and recompacted subgrade is recommended. Project No. 12045 - 22 - March 23, 2005 Pavements subject to multiple repetitions of tractor-trailer traffic were analyzed using both 3,000- and 4,000-psi concrete. Trailers were assumed to be loaded to the maximum allowable weight, 80 kips, consisting of two sets of tandem axles loaded to 32 kips and one 16-kip axle. Recommended sections for various rates of lxuck traffic, based on number of repetitions per day for a six-day week, are provided in the following tables. TABLE 2. (K=100 PCl) NUMBER OF TRUCK REPETITIONS VS. PAVEMENT THICKNESS 3,000-PSI COMPRESSIVE STRENGTH Pavement Thickness No. of Repetitions (inches) (per day) 6 (minimum recommended for fire lanes) 9 7 22 8 52 9 110 TABLE 3. (K=100 PCl) NUMBER OF TRUCK REPETITIONS VS, PAVEMENT THICKNESS 4,000-PSI COMPRESSIVE STRENGTH Pavement Thickness No. of Repetitions (inches) (per day) 6 13 7 33 8 82 9 163 Project No. 12045 - 23 - March 23, 2005 Analysis of Tables 2 and 3 indicates an approximate 50 to 80 percent increase in the number of track repetitions can be obtained by increasing the concrete strength from 3,000 psi to 4,000 psi. An increase of 100 to 150 percent is realized by increasing the thickness of the pavement by 1 inch. Although not provided herein, analysis of the allowable repetitions was also performed considering a stabilized subgrade. For any given pavement thickness and strength of concrete, an increase in the number of repetitions equal to 20 to 33 percent of the non-stabilized repetitions is realized. Considering the relative costs associated with stabilizing the subgrade, a greater increase in repetitions (i.e., pavement life) is realized by increasing the pavement thickness or strength versus stabilization of the subgrade. Pavements should be lightly reinforced if shrinkage crack control is desired. Reinforcing for 5- and 6-inch pavements should consist of the equivalent of #3 bars (metric # 10) at 18 inches on- center. Pavement sections should be saw cut at an approximate spacing in feet of 2.5 to 3 times the pavement thickness expressed in inches. (For example, a 5-inch pavement should be saw cut in approximate 12.5- to 15-foot squares.) The actual joint pattern should be carefully designed to avoid irregular shapes. Recommended jointing techniques are discussed in detail in "Joint Design for Concrete Highway and Street Pavements," published by the Portland Cement Association7. "Joint Design for Concrete Highway and Street Pavements" (1980). Portland Cement Association, Skokie, IL. Project No. 12045 - 24 - March 23, 2005 The above sections are based on the stated analysis and traffic conditions. Additional thickness or subgrade stabilization may be required to meet the City of Coppell development code. Construction Observation and Testing Frequency It is recommended thc following items (as a minimum) be observed and tested by a representative of this office during construction. Observation: Testing: Fill placement and compaction. Pressure-injection operations. Pier construction and concrete placement. Earthwork · One test per 5,000 square feet per lift within fills below the buildings. · One test per 10,000 square feet per lift within fills in the paving area. · One test per 150 linear feet per lift in utility and grade beam backfill. · One test per 100 linear feet per lift in retaining wall backfill. · Post-injection borings, one boring per 10,000 square feet of injected area. The purpose of the recommended observation and testing is to confirm the proper foundation bearing stratum and the earthwork and building pad construction procedures. Project No. 12045 - 25 - March 23, 2005 0 · al:l ~NI"II:IIV Project No. 12045 Date: 03-08-05 BORING LOG B-! Office/Narehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brown, stiff to very stiff, w/trace of ironstone nodules 6; calcareous particles (CH) CLAY, dark grayish-brown, very stiff, w/silt 8 trace of ironstone nodules ~, calcareous particles (CH) SILTY CLAY, yellowish-brown ~, gray, very stiff t.o hard, w/trace of ironstone nodules (CH) CLAY, yellowish-brown 8 light gray, very stiff to hard, w/trace of silt seams, fissile (severely weathered shale) (CH) w/silt below lg' 4" bentonite seam ~ 20' Total Depth = 25 feet Seepage encountered @ 14' during drilling. Water @ 23" after 3 minutes. Water @ 12-1/2' ~ end of day. Nater ~ 8' & blocked @ 18' on 03-09-05. GROUP Location: See Plate 1 Pocket Peeetrometer Readings Tons Per Sq. Ft. -~ Standard Penetration Tests BIoHs per Foot - ~ PLATE 2 6EOTEQ-~ICAL CONSULTANTS -- Project Nc. 12045 Date: 03-09-05 BORTN$ LOG B-2 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas reed engineering GROUP Location; See Plate 1 DESCRIPTION OF STRATA CLAY, very dark brown, stiff to hard, w/trace of gravel (CH) Pocket Penetrometer Read,DS Tons Per Sq. Ft. -~ Standard Penetration Tests Blows per Foot - + CLAY, dark grayish-brown, hard, w/trace of calcareous particles, fragments R, fine sand (CH - CL) SILTY CLAY, brownish-yellow S gray, very stiff, w/some calcareous particles ~, trace of iron stains ~, calcareous fragments (CH) CLAY, pale yellowish-brown & light gray, very stiff to hard, w/trace of iron stains, fissile (severely weathered shale) (CH) CLAY, brownish-gray, w/silt seams, fissile (severely weathered shale) (CH) Total Depth = 25 feet Seepage encountered ~ ID' during drilling. Dry @ completion. Water e 14' ~ end of day. Water @ 8-1/2' ~; blocked @ 9' on 03-15-05. PLATE 3 6EOTECHNICAL CON~JLTANTS -- Project No. 12045 Date: 03-08-05 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brown, stiff to very stiff, w/trace of ironstone nodules (CH) CLAY, grayish-brown, hard, w/silt trace of calcareous particles 6 ironstone nodules (CL) CLAY, yellowish-brown & gray, very stiff to hard, w/trace of calcareous particles & ironstone nodules (CH) englpeerlng GROUP Location: See Plate 1 SANDY CLAY, brownish-yellow, very stiff (CL) SAND, pale yellow @ gray, fine (SP) Total Depth = 25 feet Seepage encountered ~ 17' during drilling. Water ~ 14' after 5 minutes. Water @ 13' ~ end of day. Water ~ I0' & blocked B 14-1/2' on 03-09-05. BORIN6 LOG B-3 PLATE 4 ~EOTECHNICAL CONSULTANTS Project No. 12045 Date: 03-09-05 BORING LOG B-4 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brownish-gray, stiff, w/trace of ironstone nodules 8, fine gravel (CH) CLAY, dark brownish-gray, hard, w/some fine sand ~, trace of fine gravel (CH) SILTY CLAY, yellowish-brown ~ gray, very stiff, w/fine sand 8 trace of iron stains 8 calcareous deposits (CL) SAND, brownish-yellow, dense, fine, w/some clay (SP) SHALE, light gray, soft, slightly weathered Total Depth = 25-1/2 feet Seepage encountered {~ 13-t/2' during drilling. Water ~ IO-I/2' after 5 minutes. Water @ 10-I/2' @ end of day. Water @ 9' blocked ~ 13-~/2' on O3-15-05. GROUP Location: See Plate Pocket Penetrometer Readings Tons Per Sq. Ft,-4 Standard Penetration Tests Blows per Foot - + ~ I 2 3 4 4.5+ 4.5-~ + IO 2O 30 40 50 60 PLATE 5 ~EOTECI-~IICAL CONSULTANTS Project No, 12045 [:late: 03-09-05 BORING LOG B-5 Office/Warehouse Buildings Airline Drive and BelUine Road Coppell, Texas DESCR[PT[0N OF STRATA CLAY, very dark brown, stiff to hard (CH) CLAY, dark grayish-brown, hard, w/trace of calcareous particles ~ fine sand (CH - CL) SILTY CLAY, brownish-yellow, very stiff, w/some calcareous particles S trace of ironstone nodules (CL) SAND, brownish-yellow, medium dense, fine w/clay seams (SP) CLAY yellowish-brown fissile (severely weathered shale) (CH) SHALE, grayish-brown, soft, slightly weathered Total Depth = 25-1/2 feet Seepage encountered @ 73' during drilling. Water ~ 9-1/2' after 5 minutes. Water ~ 10' @ end of day. Water @ 9-1/2' ~; blocked @ 15' on 03-15-05. GROUP Location: See Plate I Pocket Penetrometer Readings Tons Per Sq. Ft.-{ Standard Penetration Tests Blows per Foot - + PLATE 6 GEOTEQ'~IIP.,AL CONSULTANTS -- Project No, 12045 Date: 03-09-05 BORING LOG B-6 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brownish-gray, stiff, w/trace of ironstone nodules (CH) CLAY, dark grayish-brown, hard, w/trace of ironstone nodules (CH) SILTY CLAY, pale yellow ~ dark brown, very stiff, w/some calcareous particles & trace of iron stains (CL) CLAYEY SAND, brownish-yellow, fine (sc) SAND, brownish-yellow, medium dense, fine (SP) Total Oepth ,, 25-1/2 feet Seepage encountered @ 13-1/2' during drilling, Water @ 11-1/2° after 3 minutes, Water 8 9' @ end of day, Water B 9-1/2' blocked @ I0' on 03-15-05, reed engineering GROUP Location: See Plate 1 Tons Per Sd. Ft.-$ - Standard Penetration Tests ~ I 2 3 4 45+ PLATE 7 6EOTECI4qfCAL C(3NSULTANI~ -- Proiect No. 12045 Date: 03,-09-05 BORING LOG B-7 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas OESCRiPT[ON OF STRATA CLAY, very dark brownish-gray, stiff to very stiff (CH) CLAY, very dark grayish-brown, hard, w/silt & trace of calcareous fragments, particles & calcareous deposits (CL) SILTY CLAY, gray & yellowish-brown, very stiff, w/some fine sand & trace of ironstone nodules ~, calcareous particles (CH) SANDY CLAY, light yellowish-brown yellowish-brown, very stiff (CL) SAND, brownish-yellow, medium dense, fine, w/clay seams (SP) Total Depth = 25-1/2 feet Seepage encountered ~ 17' during drilling. Water ~ 21' after 5 minutes. Water @ 11-1/2' @ end of day. Water ~ I0' S blocked @ 10-1/2' on 03-t5-05. GROUP Location: See Plate Pocket Penetrometer Readings Tons Per Sq. Ft. -3 Standard Penetration Tests BIo~s per Foot - + PLATE 8 6IEOTECHNICAL CONSULTANTS -- Proiect No. 12045 Date: 03-09-05 BORING LOG B-8 Office/Narehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPT[ON OESTRATA CLAY, dark brown & brownish-yellow, very stiff, w/trace of calcareous particles & gravel (Fill) (CH) CLAY, very dark brownish-grey, very stiff, w/trace of ironstone nodules & gravel (CH) SILTY CLAY, yellowish-brown, hard, w/some calcareous deposits, fragments ~ trace of iron stains (CL) CLAY, brownish-yellow ~ gray, stiff, w/trace of calcareous particles (CH) SAND, brownish-yellow ~, gray, medium dense, fine, w/clay seams (SP) Total Depth = 25-I/2 feet Seepage encountered @ 18' during drilling. Water ~ 13' @ encl of day, Water 0 IH/2' blocked ~ 12' on 03-~5-05. GROUP Location: See Plate 1 Pocket Penetrometer Readings Tons Per Sq. Ft,-t Standard Penetration Tests Blows per Foot - f PLATE 9 6EOTE{:~INICAL C~NSIJLTANTS -- Project No. 12045 Date: 03-09-05 BORING LOG B-9 Office/iNarehouse Buildings Airline Drive and Beltline Road Coppetl, Texas reed engineering GROUP Location: See Plate I DESCRIPTION OF STRATA CLAY, very dark brown, stiff to very stiff, w/trace of ironstone nodules & calcareous particles (CH) Pocket Penetrometer Readings Tons Per Sq. Ft. -~ Standard Penetration Tests Blows per Foot - ~ CLAY, dark brown [CH) SILTY CLAY, gray to yellowish-brown, very stiff, w/trace of calcareous particles & iron stains (CH) CLAY, olive-yellow 6 gray, very stiff to hard, w/bentonite & silt seams, fissile (severely weathered shale) (CH) Total Depth = 25 feet Seepage encountered @ 19' during drilling. Water ~ 24-1/2' after 3 minutes. Water @ ~ end of day, Dry ~; blocked @ 9' on 03-15-05. PLATE tO GEOTECHNICAL C~NSULTANTS -- Project No, 12045 Date: 03-08-05 BORING LOG B-lO Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark gray & yellowish-brown, very stiff, w/trace of calcareous fragments (Fill) (CH) CLAY, very dark grayish-brown, very stiff, w/trace of calcareous particles gravel (CH) SILTY CLAY, brownish-yellow G gray, hard, w/trace of iron stains (CL) CLAY, olive-yellow ~ gray, very stiff to hard, fissile (severely weathered shale) (OH) w/silt after 24' Total Depth = 25 feet Seepage encountered e 14' during drilling. Dry ~ completion, Water Q 21' ~ end of day. Water e 10 G blocked @ 17' on 03-09-05. reed engineering GROUP Location: See Plate 1 Pocket Penetrometer Readings Tons Per Sq. Ft. -{ Standard Penetration Tests Blows per Foot - {* PLATE 11 GEOTECHNICAL (~NSULTANTS -- Project No. 12045 Date: 03-09-05 BORING LOG B-11 Office/Narehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCR[PT[ON OF STRATA CLAY, very dark grayish-brown, very stiff, w/some gravel S trace of calcareous particles (Fill) (CH) CLAY, very dark brownish-gray, very stiff, w/trace of fine to coarse gravel ~ ironstone nodules (Fill) (CH) GRAVELLY CLAY, very dark brownish-gray, very stiff, w/concrete fragments (Fill) (6P) CLAY, very dark grayish-brown, hard, w/trace of calcareous particles ~, fragments (CH) CLAY, brownish-yellow & light gray, very stiff, w/trace of calcareous particles & iron stains, fissile (severely weathered shale) (CH) Total Depth -= 10 feet Dry @ completion, reed er~gineerlng GROUP Location: See Plate 1 Pocket Penetfometer Readings Tons Per Sq. Ft.-~ Standard Penetration Tests Bioxs per Foot - + PLATE 12 6EOTEQ-E4]CAL CONSULTANTS -- Project No. 12045 Date: 03-09-05 BORING LOG B-12 reed engineering GROUP Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas Location: See Plate DESCRIPTION OF STRATA CLAY, very dark brownish-gray, very stiff, w/trace of fine gravel (Fill) (CH) CLAY, very dark brownish-gray, very stiff, w/trace of iron nodules (CH) SILTY CLAY, grayish-brown, hard, w/trace of calcareous particles (CL) Pocket Penetrometer Readings Tons Per Sq, Ft. -~ Standard Penetration Tests BlOWs per Foot - + Total Depth = 10 feet Dry @ completion. PLATE 13 GEOTEC~IICN. CONSULTANTS -- Project No. 12045 Date: 03-08-05 BORING LOG B-13 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brown & yellowish-brown, w/trace of calcareous particles [Fill) (CH) CLAY, very dark brownish-gray, very stiff, w/trace of ironstone nodules (CH) CLAY, yellowish-brown & gray, very stiff, w/some calcareous particles ~ trace of iron stains (CH) Total Depth = 10 feet Dry ~ completion. GROUP Location: See Plate 1 Pocket Penetrorneter Readings Tons Per Sq. Ft. -~ Standard Penetration Tests 8lows per Foot - ~* PLATE 14 SEOTEO'I~IICAL CONSIJLTANTS -- Project No. 12045 Date: 03-08-05 BORING LOG B-14 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, dark brownish-gray, very stiff (CH) -- w/trace of calcareous particles after 3' CLAY, dark brown, hard, w/trace of calcareous particles (CL) SILTY CLAY, brownish-yellow ~ gray, very stiff, w/trace of calcareous particles & iron stains (CL) Total Depth = 10 feet Dry O completion. reed englr~eering.~ GROUP Location: See Plate Pocket Penetroroeter Readings Tons Per Sq. Ft. --~ Standard Penetration Tests Blows per Foot - ~' + D 20 30 40 50 60 PLATE 15 ~EOTEI:=-INIP_~_ CONSULTANTS -- Project No. 12045 Date: 03-09-05 BORING LOG B-15 Office/Harehouse Buildings Airline [:)rive and Beltline Road Coppell, Texas DESCRIPTION OF STRATA CLAY, very dark brownish-gray, stiff to very stiff (CH) CLAY, very dark grayish-brown to grayish-brown, hard, w/some fine sand, 6 trace of calcareous particles & ironstone nodules (CL) SILTY CLAY, brownish-yellow, very stiff, w/trace of calcareous particles, fragments & iron stains (CL) Total Depth = 10 feet Dry ~ completion. GROUP Location: See Plate 1 Pocket Penetrometer Readings Tons Per Sq. Ft.-4 Standard Penetration Tests Blows per Foot - ~ PLATE 16 GEOTECHNIRN. CONSULTANTS -- Project No. 12045 Date: 03-08-05 BOR[N$ LOG B-16 Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas GROUP Location: See Plate DESCR[PT[ON OF STRATA CLAY, very dark brownish-gray, stiff to very stiff, w/trace of gravel (CH) CLAY, dark yellowish-brown, very stiff, w/trace of calcareous particles (CH) Pocket Penetrometer Readings Tons Per Sq. Ft,-~ Standard Penetration Tests Blows per Foot - + SILTY CLAY, brownish-yellow, very stiff to hard, w/trace of calcareous particles (CL) Total Depth = 10 feet Dry ~ completion. PLATE 17 6EOTEQ-INICAL CONSULTANTS -- Project No. 12045 Date: 03-09-05 BORING LOG B-17 reed engineering GROUP Office/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas Location: See Plate DESCRIPTION OF STRATA CLAY, very dark brownish-gray, very stiff, w/trace of ironstone nodules ~ calcareous fragments (CH) SILTY CLAY, dark brownish-gray, hard, w/some sand 8 trace of ironstone nodules (CL) SILTY CLAY, brownish-yellow, very stiff, w/calcareous particles ~, trace of ironstone nodules (CL) Pocket Penetrometer Readings Tons Per Sq. Ft. -! Standard Penetration Tests Blows per Foot - + Total Depth = I0 feet Dry @ completion. PLATE 18 I~OTI:Q-~IIOAL I~NSULTANTS -- Proiect No. 12045 Oate: 03-08-05 Of fica/Warehouse Buildings Airline Drive and Beltline Road Coppell, Texas reed engineering GROUP reed engineering__ GROUP  Fill Location: See Plate 1 Type of Fill DESCRIPTION OF STRATA CLAY, very dark brown, stiff to very stiff, w/[race of ironstone nodules ~; calcareous particles (cH) CLAY, dark grayish-brown, very stiff, w/silt ~; trace of ironstone nodules ~ calcareous particles (CH) SILTY CLAY, yellowish-brown ~; gray, very stiff to hard, w/trace of ironstone nodules (CH) CLAY, yellowish-brown ~ light gray, very stiff to hard, w/trace of silt seams, fissile (severely weathered shale) (CH) w/silt below 19' 4" bentonite seam ~ 20' Total Depth = 25 feet Seepage encountered e 14' during drilling. Water ~ 23' after 3 minutes. Water @ 12-1/2'~ end of day. Water ~ blocked 9 16' on 03-09-05. BORING LOG B-1 UNDISTURBED ~ STANDARD [She~y Tu~e & PENETRATION NX-Core) TEST DISTURBED PENETROMETER TEST ti~ 1 2 3 4 45+ 45++ ~i- I0 20 30 40 50 60 PLATE 2 C~O'rECH~!~C~L CONSULTANTS- CLAY (CL) [LL<5O) CLAY (CH} (LL>50) SILT (ML) (LL<50) SILT (MH) (LL>50) CLAYEY SAND (SC) SILTY SAND (SM) SAND (SP-SN) CLAYEY GRAVEL (DC) GRAVEL (GP-$W) (weathered) SHALE (unweathered) (weathered) LINESTONE (unweathered) (weathered) SANDSTONE (unweathered) Water level at time of drilling. Subsequent water level and date. KEYS TO SYMBOLS USED ON BORING LOGS PLATE 19 6EOTECHNICAL CONSULTANTS -- reed engineering GROUP SPT N-Values Retative (blows/foot) Density 0 - 4 ......................... Very Loose 4 -10 ......................... Loose tO-30 ........................ Hedium Dense 30-50 ....................... Dense 50 + ......................... Very Dense SOIL PROPERTIES Pocket Penetrometer (T.S.F.) Consistency <0.25 ..................... Very Soft 0,25-0.50 .............. Soft 0.50-1.00 ............... Hedium Stiff 1.00-2.00 ............... Stiff 2.00-4.00 ............. Very Stiff 4.00 + ................... Hard ROCK PROPERTIES HARDNESS DIAGNOST;C FEATURES very Soft .......................... Can be dented with moderate finger pressure. Soft .................................... Can be scratched easily with fingernail, Moderately Hard ............. Can be scratched easily with knife but not with fingernail. Herd ................................... Can be scratched with knife with some difficulty; can be broken by light to moderate hammer blow. Very Hard ......................... Cannot be scratched with knife; can be broken by repeated heavy hammer blows. DIAGNOSTIC FEATURES Slightly Weathered ..............Slight discoloration inwards from open fractures. Weathered ............................. Discoloration throughout; weaker minerals decomposed; strength somewhat less than fresh rock; structure preserved. Severely Weathered ........... Host minerals somewhat decomposes; much softer than fresh rock; texture becoming indistinct but fabric and structure preserved. Completely Weathered..,,... Minerals decomposed to soil; rock fabric and structure destroyed (residual soil). KEY TO DESCRIPTIVE TERNS ON BORINO LOGS PLATE 20 ~EOTEO'INICAL CDNSULTAHTS . GEOTECHNICAL INVESTIGATION OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS Boring No. B-1 B-2 B-3 B-4 Summary of Classification and Index Property Tests Total Moisture Liquid Plastic Plasticity Soil Depth Content Limit Limit Index Suction (feet) (%) (%) (%) (PI) (psf) 1.5 - 3.0 32.0 ...... 4,240 3.0 - 4.5 30.4 ...... 6,290 4.5 - 6.0 30.3 71 26 45 5,100 9.0 - 10.0 29.3 ...... 10,810 14.0 - 15.0 31.3 ...... 9,350 19.0 - 20.0 27.9 ...... 6,280 Percent Passing No. 200 Sieve 1.5 3.0 32.3 ...... 5,340 -- 3.0 - 4.5 27.1 ...... 31,080 -- 4.5 - 6.0 25.4 ...... 31,970 -- 9.0 - 10.0 30.9 70 27 43 10,310 87 14.0- 15.0 32.8 ...... 9,730 -- 19.0 - 20.0 31.4 ...... 9,950 -- 1.5 3.0 32.9 71 24 47 3,670 3.0 - 4.5 30.9 ...... 6,390 4.5 6.0 27.7 ...... 11,590 9.0 - 10.0 28.9 73 25 48 14,040 14.0- 15.0 23.8 ...... 12,260 19.0 - 20.0 15.5 ...... 3,740 1.5 3.0 25.7 ...... 7,900 -- 3.0 4.5 17.1 ...... 43,800 -- 4,5 6,0 20.8 70 21 49 41,230 -- 9.0 - 10.0 25.2 ...... 10,670 -- SUMMARY OF LABORATORY TEST RESULTS PLATE 21 Boring No. B-5 B-6 B-7 B-8 GEOTECHNICAL INVESTIGATION OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS (Continued) Summary of Classification and Index Property Tests Total Moisture Liquid Plastic Plasticity Soil Depth Content Limit Limit Index Suction (feet) (%) (%) (%) (PI) (psf) 1.5 3.0 25.7 ...... 6,070 3.0 4.5 18.8 55 22 33 34,090 4.5 6.0 18.7 ...... 31,180 9.0 - 10.0 19.4 ...... 8,620 Percent Passing No. 200 Sieve 1.5 3.0 29.9 ...... 5,060 -- 3.0 4.5 29.3 ...... 7,030 -- 4.5 6.0 20.5 77 23 54 57,980 -- 9.0 - 10.0 27.2 ...... 16,540 -- 14.0 - 15.0 20.0 ...... 1,970 48 1.5 3.0 29.9 ...... 3,670 -- 3.0 4.5 27.3 ...... 8,320 -- 4.5 6.0 23.5 81 23 58 37,180 ~- 9.0 - 10.0 29.6 72 26 46 15,210 86 14.0 - 15.0 18.8 ...... 12,380 -- 19.0 - 20.0 18.6 ...... 4,410 -- 1.5 3.0 30.4 ...... 7,540 3.0 4.5 29.1 ..... 9,550 4.5 6.0 29.5 75 25 50 7,740 9.0 - 10.0 27.2 ...... 11,700 14.0 - 15.0 30.3 ...... 10,700 SUMMARY OF LABORA;~Ii~¥1~iEI~II~I~;iI~.Lt~I~ESTIGATION PLATE 22 Boring No. B-9 B-lO OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS (Continued) Summary of Classification and Index Property Tests Total Moisture Liquid Plastic Plasticity Soil Depth Content Limit Limit Index Suction (feet) (%) (%) (%) (PI) (psf) 1.5 3.0 35.5 77 28 49 4,910 3.0 4.5 32.4 ...... 5,890 4.5 6.0 30.1 ...... 12,370 9.0 - 10.0 28.8 71 25 46 8,480 14.0 - 15.0 32.0 ...... 8,830 19.0 - 20.0 28.2 ...... 9,950 1.5 3.0 21.9 ...... 7,210 3.0 4.5 31.7 ...... 7,390 4.5 6.0 29.7 ...... 5,310 9.0 - 10.0 29.7 ...... 11,930 14.0 - 15.0 31.8 ...... 10,190 19.0 - 20.0 28.3 66 25 41 14,830 SUMMARY OF LABORATORY TEST RESULTS Percent Passing No. 200 Sieve PLATE 23 Summary of Unconfined Compression Tests Dry Unconfined Moisture Unit Compressive Sample Boring Depth Content Weight Strength Legend No. (feet) (%) (pcf) (ksf) A B-1 14.0 - 15.0 31.4 92.2 3.1 B B-2 14.0 - 15.0 30.7 93.3 3.2 C B-3 19.0 -20.0 17.6 114.7 1.9 D B-4 9.0 - 10.0 20.9 104.7 3.2 E B-6 14.0 - 15.0 16.9 118.1 1.5 F B-7 14.0 - 15.0 19.9 110.8 5.6 6 5 4 1 0 0,00 0.20 0.40 0.60 0.80 1.00 strain (%) SUMMARY OF LABORATORY TEST RESULTS PLATE 24 Summary of Unconfined Compression Tests Dry Moisture Unit Sample Boring Depth Content Weight Leqend No. (feet) (%) (pcf) A B-8 14.0 - 15,0 28,4 94.6 B B-9 14.0 - 15.0 29.9 93.3 C B-10 14.0 - 15.0 31.1 90.6 Unconfined Compressive Strength (ksf) 2.5 3.0 4.3 5 4 0 0.00 0.05 0.10 0,15 0.20 0.25 0.30 0.35 0.40 strain (%) SUMMARY OF LABORATORY TEST RESULTS PLATE 25 Project No. Boring No. Depth (ft) Liquid Limit Plasticity Index Cs alpha Percent Swell Absorption Pressure Swell Test 12045 Moisture Content (%) B-10 Penetrometer (tsf) 19-20 Dry Unit Weight (pcf) 66 Specific Gravity 41 Void Ratio 0.034 Saturation (%) 0.67 Spec. Volume 1.6 Swell Pressure (psf) Initial 32.2 4.5 89.9 2.72 0.889 98 0.69 1.940 Final 33.8 3.25 88.4 2.72 0.919 100 0.71 25O 2 0 100 1000 Restraining Swell Pressure (psf) 0.925 0.920 0.915 0.910 .~ .o 0.905 ~ 0.900 ~ 0.895 0.890 0.885 10000 0.72 0.70 0.68 31.0 33.0 Moisture Content {%) ABSORPTION PRESSURE SWELL TEST 35.0 PLATE 26 ELEVATION (feet) o ~ o 'T' (1eej) NOI.I.~A3'I~ GUIDELINE SPECIFICATIONS SOIL MODIFICATION WATER INJECTION W/"SELECT" OR CRUSI~ED LIMESTONE FILL CAP FOR OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTLINE ROAD COPPELL, TEXAS Site Preparation Prior to the start of injection operations, the building pad should be brought to finished subgrade, minus select or crushed limestone fill, and staked out to accurately mark the areas to be injected. Allowance should be made for three to five inches of swelling that may occur as a result of the injection process. Materials 1. The water shall be potable, with added surfactant, agitated as necessary to ensure uniformity of mixture. A nonionic surfactant (wetting agent) shall be used according to manufacturer's recommendations; but in no case shall proportions be less than one part (undiluted) per 3,500 gallons of water. Equipment 1. The injection vehicle shall be capable of forcing injection pipes into soil with minimum lateral movement to prevent excessive blowback and loss of slurry around the injection pipes. The vehicle may be a robber tire or trac machine suitable for the purpose intended. 2. Slun-y pumps shall be capable of pumping at least 3,000 GPH at 100 - 200 pounds per square inch (psi). Application 1. The injection work shall be accomplished after the building pad has been brought to finished subgrade, minus select or crushed limestone fill, and prior to installation of any plumbing, utilities, ditches or foundations. 2. Adjust injection pressures within the range of 100 - 200 psi at the pump. Project No. 12045 ~ 1 - March 23, 2005 Water Injection Specifications w/"Select" Fill Cap Space injections not to exceed five feet on center each way and inject a minimunl of five feet outside building area. Inject 10 feet beyond building at entrances. Inject to a depth of 10 feet or impenetrable mater/al, whichever occurs first. Impenetrable mater/al is the maximum depth to which two injection rods can be mechanically pushed into the soil using an injection machine having a minimum gross weight of 5 tons. Injections to be made in 12-inch to 18-inch intervals down to the total depth with a minimum of 7 stops or intervals. The lower portion of the injection pipes shall contain a hole pattern that will uniformly disperse the slurry in a 360° radial pattern. Inject at each interval to "refusal." Refusal is reached when water is flowing freely at the surface, either out of previous injection holes or from areas where the surface soils have fractured. Fluid coining up around, or in the vicinity, of one or more of the injection probes shall not be considered as soil refusal. If this occurs around any probe, this probe shall be cut off so that water can be properly injected through the remaining probes until refusal occurs for all probes. In any event, no probe shall be cut off within the first 30 seconds of injection at each depth interval. Multiple injections with water and surfactant will be required. The second injection shall be orthogonally offset fi:om the initial injection by 2-1/2 feet in each direction. Subsequent injections shall be offset such that existing probe holes are not utilized. A minimum of 48 hours shall be allowed between each injection pass. Injections will be continued until a pocket penetrometer reading of 3.0 tsfor less is obtained on undisturbed soil samples throughout the injected depth. The engineer of record can waive this requirement if, in his opinion, additional injections will not result in additional swelling. At the completion of injection operations, the exposed surface shall be scarified and recompacted to a density between 92 and 98 percent of maximum ASTM D-698 density, at or above optimum moisture. A minimum of 12 inches of select or crushed limestone fill shall be placed over the injected subgrade as soon as is practical after completion of injection operations. Select or crushed limestone fill should be placed in maximum loose litts of 8 inches and compacted to at least 95 percent of maximum density, ASTM D-698, at a moisture content between -2 to +3 percentage points of optimum. Project No. 12045 March 23, 2005 -2- Water Injection Specifications w/"Select" Fill Cap Observation and Testing 1. A full-time representative of Reed Engineering Group, Ltd. will observe injection operations. 2. Undisturbed soil samples will be obtained continuously throughout the injected depth, at a rate of one test hole per 10,000 square feet of injected area for confirmation. Sampling will be performed a minimum of 48 hours after the completion of the final injection pass. ! Pr~ectNo. 12045 -3- March 23, 2005 Water Injection Specifications w/"Select" Fill Cap GUIDELINE SPECIFICATIONS SOIL MODIFICATION WATER INJECTION W/LIME-MODIFIED CAP FOR OFFICE/WAREHOUSE BUILDINGS AIRLINE DRIVE AND BELTL1NE ROAD COPPELL, TEXAS Site Preparation Prior to the start of injection operations, the building pad should be brought to finished subgrade and staked out to accurately mark the areas to be injected. Allowance should be made for three to five inches of swelling that may occur as a result of the injection process. Materials 1. The water shall be potable, with added surfactant, agitated as necessary to ensure uniformity of mixture. A nonionic surfactant (wetting agent) shall be used according to manufacturer's recommendations; but in no case shall proportions be less than one part (undiluted) per 3,500 gallons of water. Equipment 1. The injection vehicle shall be capable of foming injection pipes into soil with minimum lateral movement to prevent excessive blowback and loss of slurry mound the injection pipes. The vehicle may be a robber tire or trac machine suitable for the purpose intended. 2. Slurry pumps shall be capable of pumpLng at least 3,000 GPH at 100 - 200 pounds per square inch (psi). Application 1. The injection work shall be accomplished after the building pad has been brought to finished subgrade and prior to installation of any plumbing, utilities, ditches or foundations. 2. Adjust injection pressures within the range of 100 - 200 psi at the pump. 3. Space injections not to exceed five feet on center each way and inject a minimum of five feet outside the building footprint. Inject 10 feet beyond building at entrances. Project No. 12045 - 1 - March 23, 2005 Water Injection Specifications w/Lime-Modified Cap Inject to a depth of 10 feet or impenetrable material, whichever occurs first. Impenetrable material is the maximum depth to which two injection rods can be mechauically pushed into the soil using an injection machine having a minimum. gross weight of 5 tons. Injections to be made in 12-inch to 18-inch intervals down to the total depth with a minimum of 7 stops or intervals. The lower portion of the injection pipes shall contain a hole pattern that will uniformly disperse the slurry in a 360° radial pattern. Inject at each interval to "refusal". Refusal is reached when water is flowing freely at the surface, either out of previous injection holes or fi-om areas where the surface soils have fi-actured. Fluid coming up around or in the vicinity of one or more of the injection probes shall not be considered as soil refusal. If this occurs around any probe, this probe shall be cut off so that water can be properly injected through the remaining probes until refusal occurs for all probes. In any event, no probe shall be cut off within the first 30 seconds of injection after refusal at each depth interval. (The 30-second criterion is not the maximum time for each depth interval but a minimum time. Additional time may be required to achieve refusal, dependent upon the contractor's equipment.) Multiple injections with water and surfactant will be required. The second injection shall be orthogonally offset from the initial injection by 2-1/2 feet in each direction. Subsequent injections shall be offset such that existing probe holes are not utilized. A minimum of 48 hours shall be allowed between each injection pass. Injections will be continued until a pocket penetrometer reading of 3.0 tsf or less is obtained on undisturbed soil samples throughout the injected depth. The engineer of record can waive this requirement if, in his opinion, additional injections will not result in additional swelling. At the completion of injection operations, the exposed surface shall be scarified and blended with a minimum of 6 percent hydrated lime, or 27 pounds of lime per square yard to a depth of 6 inches. The subgrade shall then be recompacted to a density of between 95 and 100 percent of maximum ASTM D-698 density at or above optimum moisture. Project No. 12045 March 23, 2005 -2- Water Injection Specifications w/Lime-Modified Cap Observation and Testing 1. A full-time representative of Reed Engineer/ng Group, Ltd. will observe injection operations. Undisturbed soil samples will be obtained continuously throughout the injected depth, at a rate of one test hole per 10,000 square feet of injected area for confirmation. Sampling will be performed a minimum of 48 hours after the completion of the final injection pass. Project No. 12045 March 23, 2005 -3- Water Injection Specifications w/Lime-Modified Cap