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WA9302-SY 940225 REPORT CItY OF COPPELL y~OC~S~'a~ 0 ~ COPPELL, TEXAS C..Opy k} S4t-~t C. GEOTECHNICAL INVESTIGATION FOR PROPOSED AT GRADE WATER STORAGE TANK COPPELL, TEXAS REPORT NO. C-94-0102 GEE CONSULTANTS, INC. GEOTECHNICAL, ENGINEERING AND ENVIRONMENTAL CONSULTANTS _ DALLAS, TEXAS February 25, 1994 [EOTECHNICALE I GEE Consultants, inc. - E I NVIRONMENTAL 2540 Glenda Lane · Suite 108 · Dallas, Texas 75229 · (214) 620-9791 · Fax (214) 620-9794 February 25, 1994 Mr. Ken Griffin, P.E. City of Coppell 255 Parkway Boulevard Coppell, Texas 75019 RE: Report No. C-94-0102 Geotechnical Investigation Proposed At-Grade Water Storage Tank Coppell, Texas Dear Mr. Griffin: Submitted herein is a report summarizing the results of the geotechnical investigation performed at the above referenced project. _ We trust the recommendations derived from this investigation will provide an adequate and economical foundation design. As your project develops, we would be pleased to assist you with the construction materials testing and inspection services. We thank you for the opportunity to provide you with our professional services. If we can be of further assistance, please do not hesitate to contact us. Very truly yours, GEE Consultants, Inc. Gary G. Huang, Ph.D. Richard W. Gee Project Manager President _ff'~v~o. ......... - Geotechnical Engineering Division ~'.~.~./" ~:;.,i!'~:~ "~'~%1 GGH:RWG/lej ~ atc.~,a WAYNE ,3~ Enclosure .'., b>. % s ~ TABLE OF CONTENTS Introduction ......................................... 1 - Site And Project Description ............................... 2 Description of Subsurface Conditions ......................... 3 Subsurface Water Conditions .............................. 3 - Limitations ......................................... 4 Analyses and Recommendations ............................. 5 APPENDIX Field and Laboratory Investigations ......................... A-1 Guidelines for Concrete Pavement .......................... A-4 Pavement Joint Cross-Sections Lime Stabilization Recommendations ......................... A-7 Plan of Borings Logs of Boring Symbols and Terms used on Boring Logs Unified Soil Classification System City of Coppell February 25, 1994 GEOTECHNICAL INVESTIGATION FOR PROPOSED AT-GRADE WATER STORAGE TANK COPPELL, TEXAS REPORT NO. C-94-0102 I. INTRODUCTION This report transmits the findings of the geotechnical investigation performed at the above referenced site. The purpose of this investigation was to define and evaluate the general subsurface conditions at the test boring locations. Specifically, the study was planned to determine the following: 1. Subsurface stratigraphy at the locations of exploratory bofings. 2. Classification of engineering and physical characteristics of the soils encountered at the test boring locations. 3. Foundation design recommendations and allowable loading pressures. 4. Estimated vertical soil movement at the test boring locations. 5. Construction requirements for the placement of necessary shallow earth fills. 6. Pavement thickness and subgrade preparation recommendations This study was performed in accordance with the authorization of Mr. James Witt, City Manager for the City of Coppell. To accomplish the intended purposes, a three phase _ study program was conducted which included; a) a field exploration consisting of four (4) exploratory test bofings with samples obtained at selected intervals, b) a laboratory testing program designed to evaluate the physical and strength characteristics of the _ subsurface soils, and c) an engineering analysis of the field and test data for foundation recommendations. No additional analysis was requested or performed. A brief _ GEE Consultants, Inc. Report No. C-94-0102 Page I City of Coppeli February 25, 1994 description of the various field and laboratory tests and their respective results is included in the Appendix of this report. II. SITE AND PROJECT DESCRIPTION The site for the proposed at-grade water storage tank is located near the southeast corner of Village Parkway and Kimbal Kourt in Coppell, Texas. The site surface is relatively level and covered with mowed weeds. There is an existing water tank about 250 feet west of the proposed water tank, center to center. A shallow drainage ditch about two (2) feet deep was noted on the north and west boundaries of the proposed site. A deeper concrete lined drainage ditch is located along the south boundary. A few small trees were observed at each corner of the site. Present planning indicates that an at-grade concrete water storage tank is proposed for this site. The diameter and height of the tank will be one hundred fifty-two (152) feet and about forty (40) feet, respectively. The finished floor elevation of the proposed water tank is to be at or above existing and surrounding grade. It is our understanding that an existing water tank west of the proposed site is supported on piers with a slab supported at grade and is performing well from a structural standpoint. Consequently, a pier and beam foundation system will be considered as a first choice to - support the structural loads. An integral slab and grade beam foundation will be considered provided soil conditions warrant this system to be a feasible alternative. _ GEE Consultants, Inc. Report No. C-94-0102 Page 2 City of Coppell February 25, 1994 If this information and/or assumptions are incorrect, GEE Consultants, Inc., should be notified for additional comments regarding the soil related design parameters given herein. No other information was available at the time of this investigation. III. DESCRIPTION OF SUBSURFACE CONDITIONS The study area lies within the boundaries of the Eagle Ford Formation. This geologic unit is an upper Cretaceous age sedimentary rock of marine origin. It consists of predominantly gray shale in various degree of weathering with bentonite seams and calcareous deposits. The upper soils are alluvial deposits of the Elm Fork, a tributary of the Trinity River. The near surface materials encountered in the test borings consisted of fill, clay, sandy clay, gravelly sand, and shaley clay underlain by gray shale at depths of 25 to 30 feet. The fill consists of silty clay and limestone gravel. The silty clay fill is stiff to very stiff in consistency. The limestone fill is in a firm condition. The underlying gray clay is in medium _ to very stiff condition. A soft sandy clay layer was encountered at test boring location B-1 at a depth of fifteen (15) feet below the existing grade. A relatively moist and soft layer was also noted at boring location B-2 at a depth of 10 feet. Detailed descriptions of the various - strata encountered are presented on the individual Logs of Boring in the Appendix of this report. ' IV. SUBSURFACE WATER CONDITIONS At the time of the field exploration, groundwater or seepage was encountered at a depth of fifteen (15) to twenty-one (21) feet below presently existing grade in deep test borings B-l, _ GEE Consultants, Inc. Report No. C-94-0102 Page 3 City of Coppell February 25, 1994 B-2 and B-3. The sub surface water regime is subject to change with variations in climatic conditions. Future construction activities may also alter the surface and subsurface drainage characteristics of the site. Therefore, the depth to groundwater should be verified just prior to construction. If there is a noticeable change from the conditions reported herein, GEE Consultants, Inc. should be immediately notif'~ed to review the effect it may have on the design recommendations. It is not possible to accurately predict the magnitude of subsurface water fluctuations that might occur based upon short-term observations. V. LIMITATIONS The professional services performed, the findings obtained, and the recommendations prepared were accomplished in accordance with currently accepted geotechnical engineering principles and practices. The possibility always exists that the subsurface conditions at the site may vary somewhat from those encountered in the boreholes. The number and spacing of test borings were chosen in such a manner as to decrease the possibility of undiscovered abnormalities, while considering the nature of loading, size, and cost of the project. If there are any unusual conditions differing significantly from those described herein, GEE Consultants, Inc. should be notified to review the effects on the performance of the designed foundations. The recommendations given in this report were prepared exclusively for the use of the City of Coppell, Texas or its consultants. The information supplied herein is applicable only for the design of the previously described structure to be constructed at the location indicated at this site and should not be used for any other structure, location, or for any other purpose. GEE Consultants, Inc. Report No. C-94-0102 Page 4 Cit~, of Coppell February 25, 1994 GEE Consultants, Inc. is not responsible for the conclusions, opinions, or recommendations made by others based on the information submitted herein. VI. ANALYSES AND RECOMMENDATIONS A. Soil Movements The near surface soils encountered at the study area exhibited plasticity indices ranging from 21 to 49. The soils encountered at the test boring locations should be considered moderately to highly expansive and some heaving may occur with changes in moisture content, when the tank is empty. Based on test method TEX-124E and assuming an initial dry condition and final wet condition, the Potential Vertical Rise (PVR) at the test boring locations is estimated to be on the order of 2.25_+ inches. Also, the elastic and consolidation settlement due to the structural loading and relatively soft layers encountered at some locations should be anticipated during and after construction when - the tank is fully loaded. The total settlement for an integral slab and grade beam and forty (40) feet of water loading is estimated to be about 4.5 inches at the tank center and 2.25 inches at the edge for a flexible foundation. Therefore, the differential vertical - settlement is estimated to be on the order of 2.25 inches. Test boreholes revealed relatively soft layers at test boring locations B-1 and B-2. Therefore, localized total settlement may exceed 2.25 inches in those areas. The differential vertical settlement - indicated above is highly dependent on the loading, stiffness of the foundation, thickness and depth of the underlying clay soils, and the groundwater elevation at the time the water tank is constructed and loaded. More settlement will occur in areas where loads ' are greater and groundwater elevation rises significantly during or after construction. GEE Consultants, Inc. Report No. C-94-0102 Page 5 City of Coppell February 25, 1994 B. Pier Foundation Recommendations The structural loads of the proposed water tank may be supported by auger excavated, straight-sided, cast-in-place reinforced concrete piers founded at least three (3) feet into the sound gray shale stratum, encountered at test boring locations at a depth of 25 to 30 feet below presently existing grade. These piers should be designed and proportioned using an allowable end bearing pressure of 25,000 pounds per square foot and a skin friction value of 3,000 pounds per square foot of shaft area in direct contact with the gray shale below the recommended minimum penetration. A frictional value of 2,000 pounds per square foot of shaft area in direct contact with the gray shale may be used to calculate the resistance of the foundation systems against uplift loads. · Foundation systems proportioned and placed in accordance with the recommendations provided in this report will have a factor of safety in excess of 2.5 against shear type failure. Using the allowable values listed herein and the Theory of Elasticity with the anticipated maximum loads, settlement of structural piers is expected to be less than -- one-half (1/2) inch; most of the settlement will occur as elastic settlement during construction and within a short period of time after the water tank is fully loaded. -- A six (6) inch void space should be provided between the concrete grade beams and underlying surface soils. It is important that some type of soil retainer be provided to prevent the soils adjacent to the grade beams from sloughing into the void space. GEE Consultants, Inc. Report No. C-94-0102 Page 6 Cit~; of Coppell February 25, 1994 Additionally, care should be taken to insure that backfill soils placed adjacent to grade beams within the foundation area are compacted to between 95 and 105 percent of the maximum density as defined by the Standard Proctor Test (ASTM D 698). C. Pier Foundation Construction Normal construction procedures for this area of Texas should be employed in the installation of the drilled, cast-in-place, straight-shaft piers. Concrete and reinforcing steel should be placed immediately after the excavation has been completed and inspected. Inspection should include verification of: a) Bearing stratum b) Minimum penetration c) Cleanliness and removal of all smear zones d) Correct handling of groundwater seepage In no event should an excavation be allowed to remain open for more than four (4) hours. Concrete should not be placed if standing water exists within the excavated pier hole. Based on bore hole information, it appears that temporary casing may be required to prevent groundwater infiltration and sloughing of sandy and gravelly soils. A positive head of concrete should be maintained within the casing as it is being removed, to assure that water outside the casing is properly displaced by concrete. Concrete placed in the excavation in excess of ten (10) feet in depth should be prope~y tremied to prevent separation of the aggregates. GEE Consultants, Inc. Report No. C-94-0102 Page 7 City of Coppell February 25, 1994 D. Floor Slab Systems In order to completely immune the floor slab from differential vertical soil movement due to possible movement of the subgrade soils, the slab should be structurally supported and physically separated from the subgrade by a void of not less than six (6) inches. The soils underlying the slab should be sloped to drain toward the outside of the structure and water should not be allowed to pond in the void space. Alternatively, at greater risk of experiencing floor slab distress, the floor slab can be supported at existing grade and should be designed to withstand previously estimated soil movement. The estimated vertical slab movement when the tank is empty due to heave, may be reduced to approximately 1.25_+ inch with utilization of a minimum 36 inches of "select fill" placed on top of existing grade. The "select fill" should not be placed below the existing or surrounding ground surface and should not extend outside the perimeter of the foundation. E. Integral Slab and Grade Beam Foundation Alternative ' Based on our analysis it is our opinion that a shallow foundation is feasible as long as differentiated settlement in excess of 1.0 inch can be tolerated. The structural loads of the proposed water tank may be supported by an integral slab and grade beam (waffle ' type) foundation system. The slab should be designed stiff enough to withstand the previously mentioned estimated total and differential vertical soil movement of 4.5 and 2.25 inches, respectively. Subgrade should be prepared according to the recommendations of this report. Grade beams founded at least eighteen (18) inches _ below the existing or final grade may be designed using an allowable soil bearing GEE Consultants, Inc. Report No. C-94-0102 ' Page 8 City of Coppell February 25, 1994 pressure of 3,000 pounds per square foot. A factor of safety against shear failure is in excess of 3.0. Also, a moisture barrier of polyethylene sheeting or similar material should be placed between the slab and subgrade soils to retard moisture migration through the slab. It should be understood that a greater risk of experiencing foundation distress will be associated with the utilization of a waffle slab than when compared to a pier supported foundation. To completely prevent any potential distress (cracks on the floor and/or walls) to the proposed structure may be considered as not economically practical. However, with a properly engineered structure designed the constructed in accordance with the highest standards of the industry, the potential for distress will be reduced considerably. F. Pavement Recommendations Organic materials and any vegetation should be removed from the site to achieve final subgrade elevation. Prior to beginning pavement construction, soils at the ground surface in the proposed driveway and parking area should be scarified and grubbed to a depth of at least six (6) inches. After the completion of rough grading within pavement areas, samples should be obtained for lime series laboratory tests to determine the proper amount of lime necessary to stabilize the subgrade soils. GEE Consultants, Inc. Report No. C-94-0102 Page 9 City of Coppert February 25, 1994 The exposed surface should then be re-scarified and mixed with appropriate amount of lime. The soil and lime mixture should be compacted to a minimum of 95 percent of the maximum dry density as defined by ASTM D 698 (Standard Proctor Test) at a moisture content within two percent of the optimum moisture value. Lime stabilization should be performed in accordance with the procedures included in the Appendix of this report. The following pavement sections are a minimum recommended for this project (15 year life design): Areas of Light Traffic (Auto Parking) 5.0 inches Portland Cement Concrete* (12 foot joint spacing) 6.0 inches Lime Stabilized Subgrade Areas of Channelized Traffic ** 6.0 inches Portland Cement Concrete * (12 ft joint space) 6.0 inches Lime Stabilized Subgrade ' * See "Guidelines for Concrete Parking Areas" in the Appendix of this report. Periodic maintenance of the concrete pavement will be required. ' ** Fire lane and city streets should be designed in accordance with applicable City requirements. The light duty pavement is designed for 200 to 300 vehicles per day; two (2) to three (3) of which may be heavy commercial trucks. The channelized heavy traffic pavement _ is designed to sustain 300 to 500 vehicles per day, including five (5) to seven (7) heavy commercial vehicles. GEE Consultants, Inc. Report No. C-94-0102 Page 10 City of Coppell February 25, 1994 G. Site Preparation All existing structures, pavements, surface vegetation, loose fill, debris, or any objectionable material within the study area should be removed prior to the placement of any fill material and construction of slab-on-grade. The site surface should be proof- rolled with a sufficiently heavy roller (20 to 25 tons) to evidence any soft, compressible areas. Any soft areas in the exposed subgrade, after stripping and proof-rolling, should be removed and replaced under controlled conditions. All exposed surfaces should then be scarified; watered, as required; and re-compacted to between 95 and 105 percent of the maximum dry density as defined by ASTM D 698 (Standard Proctor Test) at a moisture content between optimum and five (5) percent above the optimum moisture value. The site may then be filled to grade using on-site materials or "select fill" material, free from deleterious matter. Fill materials should be placed in six (6) to eight (8) inch loose lifts at a moisture content between optimum and five (5) percent above the optimum moisture content (within three (3) percent of the optimum moisture value for "select fill"); and each lift compacted to between 95 and 105 percent of the maximum dry density as defined by ASTM D 698 (Standard Proctor Test). Each lift should be inspected and approved by a qualified engineering technician, supervised by a geotechnical engineer, before another lift is added. The above recommendations for subgrade improvement within the proposed building pad _ areas would not necessarily be required if a suspended floor system is utilized. GEE Consultants, Inc. Report No. C-94-0102 Page 11 City of Coppell February 25, 1994 H. Select Fill "Select fill" as referred to in this report should consist of clayey sands free of organic materials and having a plasticity index (PI) between 4 and 15, a liquid limit of 40 or less, and 15 to 45 percent passing a No. 200 U.S. Sieve. Placement and compaction of the "select fill" should be performed in accordance with the above mentioned Site Preparation section. I. Surface Drainage and Vegetation Drainage should be maintained away from the foundation, during and after construction. - Trees and large shrubs can, by transpiration, remove moisture from the clays and cause shrinkage of these soils. Therefore, any shrubs or trees planted for landscaping should be located at least one-half their anticipated mature height away from the structure. J. Roof Drain Downspouts or collector systems for roof drains must have provisions for removing storm-water runoff away from the structure. Care must be maintained at all times to ensure that surface watering or storm-water runoff not be allowed to accumulate next to or below the proposed structure. _ K. Below Grade Drainage Systems Any structural floor system must have the underlying exposed soils graded to drain to a collection point with provisions for de-watering the collection point. _ GEE Consultants, Inc. Report No. C-94-0102 Page 12 Cit~ of Coppell February 25, 1994 We recommend any step-down, below grade walls, etc. be provided with under-drains or wail drains with gravity or other suitable de-watering device to remove accumulated water from the system. _ GEE Consultants, Inc. Report No. C-94-0102 Page 13 City of Coppert February 25, 1994 APPENDIX GEE Consultants, Inc. Report No. C-94-0102 City of Coppell February 25, 1994 FIELD AND LABORATORY INVESTIGATIONS PROPOSED WATER STORAGE TANK COPPELL, TEXAS REPORT NO. C-94-0102 I. FIELD INVESTIGATION Soil conditions at the study area were explored by four (4) intermittent sample borings which _ were drilled on January 20, 1994. The locations of these borings are shown on the sheet entitled Plan of Borings of this report. - Descriptions of the various strata encountered in each of the borings and the depths at which samples were obtained are presented on the individual Logs of Boring. ' Standard penetration tests (ASTM D 1586) were performed on the subsurface soils. This test is conducted by recording the number of blows required for a 140-pound weight falling 30 inches to drive a split spoon sampler one (1) foot into the soils. The disturbed samples were removed from the sampler, logged, sealed, and transported to the laboratory for further identification and classification. Relatively undisturbed specimens of cohesive soils were obtained with thin-walled Shelby tube _ samplers (ASTM D 1587). The soil specimens were extruded from the tubes in the field, logged, sealed, and packaged to maintain "in-situ" conditions. The samples were then transported to our laboratory for further identification, classification, and testing. GEE Consultants, Inc. Report No. C-94-0102 Page A-I City of Coppell February 25, 1994 Logs of all borings have been included in the Appendix of this report. The logs show visual descriptions of all soil strata encountered using the Unified Soil Classification System. Sampling information, pertinent field data, and field observations are also included. - H. LABORATORY SOIL TESTS Laboratory soil tests were performed on samples recovered from the borings to verify visual classification and determine the pertinent engineering properties of the soils encountered. Atterberg limits and moisture content tests were performed on representative soil samples in order to classify them according to the Unified Soil Classification System. Unit dry weight, unconfined compressive strength, and moisture content tests were performed on selected cohesive soil samples in order to estimate the shear strength as well as the deformation of the soil. Consolidation tests were performed on selected saturated soil samples in order to calculate consolidation settlements for the different soil strata. The results of all the laboratory and field tests are presented on the following pages or tabulated on the Logs of Boring. - GEE Consultants, Inc. Report No. C-94-0102 Page A-2 City of Coppell February 25, 1994 Consolidation Test Results - Initial Initial Dry Unit Preconsolidation Compression Boring Depth Void Moisture Weight Pressure Index No. (ft) Ratio Content(%) (pcf) (tsf) (cc) B-1 15 - 16.5 0.543 20.4 108.4 0.58 0.052 B-2 10 - 11.5 0.974 34.4 87.3 3.4 0.352 B-3 10-11.5 0.753 25.0 96.8 1.2 0.174 GEE Consultants, Inc. Report No. C-94-0102 Page A-3 CitlV of Coppeli February 25, 1994 GUIDELINES FOR CONCRETE PAVEMENT PROPOSED AT-GRADE WATER STORAGE TANK COPPELL, TEXAS REPORT NO. C-94-0102 I. CHARACTERISTICS OF CONCRETE A. All concrete should have a specified 28~day compressive strength of 3,000 psi - (pounds per square inch). Concrete should be manufactured and delivered in accordance with ASTM C 94; Standard Specifications for Ready Mixed Concrete. B. Four (4) to six (6) percent air should be entrained in the concrete. C. The maximum coarse aggregate size should not be greater than one-fourth the slab ' depth. D. Maximum slump should be four (4) inches + one (1) inch. E. Periodic maintenance of the pavement will be required. II. SUBGRADE PREPARATION A. Prior to beginning paving operations, all vegetation should be removed to a depth of at least six (6) inches. GEE Consultants, Inc. Report No. C-94-0102 Page A4 City of Coppell February 25, 1994 B.The exposed surface should then be scarified and re-compacted to between 95 and 105 percent of the maximum dry density as determined by ASTM D 698 (Standard Proctor Test) at a moisture content between optimum and five (5) percent above the optimum moisture value. C. In the event that additional fill is necessary to bring the parking and drive areas to grade, (prior to stabilization) it should be placed in six (6) to eight (8) inch loose lifts. Fill should then be compacted to between 95 and 105 percent of the maximum dry density as determined by ASTM D 698 (Standard Proctor Test) at a moisture content between optimum and five (5) percent above the optimum moisture content. D. Lime stabilization should then be performed in accordance with subsequent recommendations. E. The subgrade should be in a moist condition at the time concrete is deposited thereon. F. Using coarse sand (sand cushion) as a leveling material is not recommended. Surface runoff water may be piped through the coarse material and adversely affect the underlying subgrade. -- GEE Consultants, Inc. Report No. C-94-0102 Page A-5 City of Coppell February 25, 1994 HI. JOINTS A. Recommended joint spacings are provided in the Pavement Recommendations section of this report. .- B. Control joints or contraction joints should be formed by one of the following methods: sawed, hand-formed or formed by premolded filler. Joint depth should be equal to one-fourth of the slab thickness. Hand-formed joints should have a - maximum edge radius of 1/4 inch. Sawing of joints should begin as soon as the concrete has hardened sufficiently to permit sawing without excessive ravelling. All joints should be completed before uncontrolled shrinkage cracking occurs. Joints ' should be continuous across the slab unless interrupted by full-depth premolded joint filler, and should extend completely through the curb. Joint openings wider than 1/4 inch should be cleaned and sealed before opening parking area to traffic. C. Expansion joints or isolation joints should be used to isolate fixed objects abutting or within the paved area. They should contain premolded joint filler for the full depth of the slab and should be sealed prior to opening to traffic. D. Utilization of an integral curb is recommended. GEE Consultants, Inc. Report No. C-94-0102 Page A-6 JOINT CROSS-SECTIONS STRUCTURE ISOLATION JOINT SAWED JOINT ~ 1/4 IN. MAX. TYP. EXPANSION MATERIAL BUTT,FACED CONSTRUCTION JOINT PREMOLDED FILLER JOINT ' ' . PREMOLDED FILLER 7LUSH WITH SURFACE THICKENED EDGE ISOLATION JOINT TRANSVERSE CONSTRUCTION JOINT · . ..;..;..: ......'..., ;';o..., J~.. , ..... ,......: .;: '.: SMOOTH GREASED ~ . DOWEL BAR WHERE WHEEL LOADS WlLL CROSS THF JOINT. NOTE: ALL JOINTS SHOULD BE CLEANED AND SF..~ PRIOR TO OPENING TO TRAFF1C. J~ [Job Proposed At-Grade Water IScale: N.T.S NGDN'EERD~G File ' Name: ~'i .y of Coppel I No: C9401_02 City of Coppell February 25, 1994 LIME STABILIZATION RECOMMENDATIONS PROPOSED AT-GRADE WATER STORAGE TANK COPPELL, TEXAS REPORT NO. C-94-0102 - I. APPLICATIONS The hydrated lime should be applied only in the area where the first mixing operations can be completed during the same working day. The hydrated lime can be placed by either - the dry method or the slurry method. However, the dry method of placing hydrated lime has been prohibited by some municipalities since the lime is dispersed very easily by the wind. Consequently, the lime should not be applied when wind conditions are such that ' dispersed lime becomes objectionable to traffic or adjacent property owners. A motor grader should not be used to spread the lime. The material should be sprinkled until the proper moisture content has been obtained. If the situation presents itself such that the hydrated lime cannot be placed by the dry method, then the slurry method should be used. The hydrated lime should be mixed with water in trucks or in tanks and applied as a thin water suspension or slurry. The _ distributor truck or tank should be equipped with an agitator which will keep the lime and water in a uniform mixture. By calculating the number of square yards in each area and by knowing the amounts (pounds) per truck load, the rate of application can be checked - very closely. -- GEE Consultants, Inc. Report No. C-94-0102 Page A-7 City of Coppell February 25, 1994 The amount of required lime placed by either the dry method or the slurry method should _ be determined by performing lime series testing after rough grading operations are completed. _ IL MIXING The material and hydrated lime should be thoroughly mixed by a rotary mixer or other device to obtain a homogeneous, friable mixture of material and lime, free from all clods - or lumps and left to cure from one (1) to four (4) days. From our experience, we have found that a curing period of 48 hours to 72 hours is adequate. During the curing period, the material should be kept moist. Ill. FINAL MIXING After the required curing time, the material should be uniformly mixed with a rotary ' mixer capable of reducing the size of the particles so that when all non-slaking aggregates (asphalt particles) retained on the No. 4 U.S. Sieve are removed, the remainder of the material should meet the following requirements when tested dry by laboratory sieves: Minimum passing 13/4 inch sieve: 100% _ Minimum passing No. 4 U.S. Sieve: 60% During the interval of time between application and mixing, the hydrated lime should not be exposed to the open air for a period of over six (6) hours. IV. COMPACTION Compaction of the mixture should begin immediately after final mixing, and in no case - later than three (3) calendar days after final mixing. The material should be aerated or _ GEE Consultants, Inc. Report No. C-94-0102 Page A-8 Cit~ of Coppell February 25, 1994 ' sprinkled as necessary to provide the optimum moisture content. Compaction should begin at the bottom and continue until the entire depth of the mixture is uniformly compacted. All irregularities, depressions, or weak spots which develop must be corrected immediately by scarifying the areas affected, adding or removing material, and _ reshaping and re-compacting by sprinkling and rolling. The surface should be maintained in a smooth condition - free from undulations and ruts. - The subgrade should be compacted to a minimum of 95 percent of the maximum dry density as defined by ASTM D698, at a moisture content within plus or minus two (2) percent of the optimum moisture value. After the required compaction is reached, the - subgrade should be brought to the required lines and grades; and finished by rolling with a pneumatic tire or other suitable roller sufficiently light to prevent haldine cracking. The compacted section should be moist-cured for a minimum of three (3) days. To prevent objectionable damage from traffic, the completed section should not be opened to traffic for two (2) days after completion. _ GEE Consultants, Inc. Report No. C-94-0102 Page A-9 PROPOSED WATER TANK SITE -- % 1d°b COPPELL WATER TANK Scale: f'=loo' Name: EOTECHNICAL GEE ConSultantS, Inc, Client File NGINEERING CITY OF COPPELL c941_02 Name: No: -- NVIRONMENTAL Project No' C-94-010g Date: 01/g5/94 Page · No: 1 OF 1 m Number Location Page 1 of 2 Log of Boring ~ B- 1 s~ P~A~ or ~om~cs c-94q02 Project COPPELL WATER TANK, COPPELL, TEXAS ~ Type __ ~ ~ra, Surface Elevation ~. ~ ~ ~ STRATUM DESCRIPTION . ;;;;;; 8 BRO~ ~D G~Y SILTY CLAY 19 37 16 21 - ]',',',]', - ~ffi c~c~eous nodules -- """""" 57 - wiffi limestone ~a~ents - ..;;;; ' """""" (FILL) _ ,,,,,, 32 3.0 17 ,,,,,, T~ ~D G~Y LIMESTONE G~VEL ,,,,,, - ~ffi silty clay - """ (FILL) _~,,,,,,,,:,,I 6.5 -- 1.5 26 102 10. 2.0 G~Y CLAY 21 108 45 15 30 _ - ~ffi c~c~eo~ nod~es - ~ffi iron s~m 15 0.5 ~~ 20 - 15.5 - T~ ~D G~Y S~DY CLAY ' 'Q' 6. 65 20.0 12 ~O~ ~' BRO~ G~VELLY S~D '~' ~ CONTINUED ON NEXT PAGE OD ...................................... Completion D~th ~ Water Obse~ations ' ~.5' 1/2 WA~R ENCO~~D AT 15 ~ GEE Consultants. Inc. Number Location Page 2 of 2 Log of Boring B-1 I SEE PLAN OF BORINGS C-94-102 Project COPPELL WATER TANK, COPPELL, TEXAS :~ Type iO ~ iNTERMFFTENT SAMPLING ~ ~,~ Surface Elevation ~ ~ N/A ~ o o $TRATtJM DESCRIPTION H' 50/ 25.0 20 5" 30 100/ GRAY SHALE _s ~." - ~ I__ _ 35 ~ 100/ _ _ _ 40" 100/ -' 4" _ _ _ 45 100/ " 3" _ _ 46.5 END OF BORING Completion Depth ~/~ Water Observations 46.5' 1/2 WATER ENCOUNTERED AT 15 FT GEE Consultants, Inc. -- Number Location Page 1 of 2 Log of Boring B-2 SEE PLAN OF BORINGS C-94-102 Project COPPELL WATER TANK, COPPELL, TEXAS Type INTERMITTENT SAMPLING . ~ ,,~o STRATUM DESCRIPTION ::::: 13 BRO~ ~D G~Y SILTY CLAY 19 ::::: "" 38 23 ,,,, T~ ~D G~Y LIMESTONE G~VEL -- ,,,, ~.~ "" (FILL) 0.75 i0.0 ~5 8~ ~ 20 4~ ]]~0 G~Y CLAY 2.0 ' · 25 20.0 22 .... T~ AND G~Y S~DY CLAY ~ CO~INUED ON NEXT PAGE Completion D~th Date Water Obse~ations ' ~.5' 1/20/94 WA~R ENCO~~D AT 21 ~ GEE Consultants, Inc. -- Number Location Page 2 of 2 Log of Boring B-2 SEE PLAN OF BORINGS C-94-102 Project COPPELL WATER TANK, COPPELL, TEXAS .~ Type INTERMITTENT SAMPLING ~ ~ ,; Surface Elevation ' ~ ~~, STRATUM DESCRIPTION p.~ 45 25.0 ;:;;;;: TAN AND GRAY SHALEY CLAY 30 :p~;";":";~50/ 30.0 22 35 100/ GRAY SHALE 40--- ~ 100/ --' 5" _ 45 100/ $ 4" · ................................................................................... 46.5 END OF BORING Completion Depth ~/~7g Water Observations ' 46.5' 1/2 WATER ENCOUNTERED AT 21 Fr GEE Consultants, Inc. Number Location Page 1 of 2 Log of Boring B-3 SEE PLAN OF BORINGS C-94-102 Project COPPELL WATER TANK, COPPELL, TEXAS Type INTERMITTENT SAMPLING Surface Elevation ~:~ ~ .~ ~ ~.~ I STRATUM DgSCRIPTION 1 BROWN AND GRAY SILTY CLAY 25 - with limestone fragments 3 (FILL) ...... 6.0 26 52 17 35 ' ""' 1.5 GRAY SILTY CLAY AND LIMESTONE ...... GRAVEL ,,,,,, - with calcareous nodules ,,,,,, - with iron stains ,,,,,, 1.0 """ (FILL) ,,.,:::: 11.5 1.7 GRAY CLAY 7 _ - . : 19.0 20 - ' 26 23 ' TAN AND GRAY SANDY CLAY Completion Depth ~/~ Water Observations ' / WATER ENCOUNTERED AT 19 FF GEE Consultants, Inc. 46.5 12 Number Location Page 2 of 2 Log of Boring B-3 I snn ~,LAN Or BOmNCS C-94-~02 Project COPPELL WA~R T~, COPPELL, ~S ~ T~e ~~~ S~L~G ~ ~ Surface Elevation ~_~ STRATUM DESCRIPTION ~ ~ ~=~ ~ '>>>>>>~41 25.0 ' ~<~< T~ ~D GRAY SH~EY CLAY 28.0 30 ~ 50/ 35 100/ G~Y SHOE 40 100/] _ 45- ' 1~/ ~ 4.. I~ ............................................................................ 46.5 END OF BO~NG Completion Depth ~ Water Obseffations ' ~.5' 1/2 WA~R ENCO~~D AT 19 ff GEE Consultants, Inc. Number Location Page 1 of 1 Log of Boring B-4 SEE PLAN OF BORINGS C-94-102 Project COPPELL WATER TANK, COPPELL, TEXAS ~ Type ~ INTERMITTENT SAMPLING ~ ~ ~ ' Surface Elevation ' "' "~ ~ 0m ~ ~ i~ ~ STRATUM DESCRIPTION '~ ~' ~ '= ~ ~ °~' 1;;;: 14 21 '""' BROWN SILTY CLAY ',,,,, - with calcareous nodules -- ""' 12 ""' (FILL) ..... 32 15 ' '] ',',: 3.5 ' "' GRAY LIMESTONE GRAVEL ' "' - with clay 5- ,,,,,,,,,, (FILL) _ 5.5 . 24 103 -- 2.0 GRAY CLAY 10- 1.75 29 48 15 33 __ Completion Depth ~/;~ Water Observations 11.0' 1/2 NO WATER ENCOUNTERED GEE Consultants, Inc. SYMBOLS AND TERMS: USED ON BORING LOGS SOIL OR ROCK TYPES SAND SANDY SHALE SILT SILTY LIMESTONE_S~__~ CLAY CLAYEY ASPHALT ~__~SPOON AUGER ~E~ CONSISTENCY OF COHESIVE SOILS UNCONFINED COMPRESSIVE STRENGTH DESCRIPTIVE TERM (TON/SQ. FOOT) ' VERY SOFT Less Than 0.25 SOFT 0.25-0.50 FIRM 0.50-1.00 STIFF 1.08-2.08 VERY STIFF 2.00-4.08 HARD More Than 4.88 RFIATTVF DFNgTTY OF CONFgTONI Fg~ ~13T[ g STD. PENETRATION RESISTENCE DESCRIPTIVE TERM RELATIVE DENSITY -- BLOWS/FOOT 0-10 LOOSE 0 TO 40% 10-30 MEDIUM DENSE 40 TO 30-50 DENSE 70 TO OVER 50 VERY DENSE gB TO 100% SOIL STRUCTURE CALCAREOUS Containing deposits o~ calcium carbonate: generally nodular SLICKENSIDED Having inclined planes o~ weakness that are slick and glossy in appearance LAMINRTED Composed o~ thin layers o~ varying color and texture -- FISSURED Containing shrinkage cracks ~requentlg ~illed with ~ine sand or silt: usuall9 more or less vertical INTERBEDDED Composed o~ alternate layers o~ di{{erenf soil types pHygTCAI PROPERTTFg OF ROCK NARDHESS AND DFGRFF OF CEMENTATION VERY SOFT OR PLASTIC Can be nemolded in hand: corresponds in consistency up to very sti~ in soils ' SOFT Can be scratched with fingernail MODERRTELY HARD Can be scratched easily with knife: cannot be scratched uifh fingernail HARD Difficult to scratch with knife VERY HRRD Cannot be scratched with kni{e POORLY CEMENTED OR FRIABLE Easily crumbled CEMENTED Bound together by chemically precipitated material occurring -* in the interstices between allogenic particles o~ rock -- quartz, calcite, dolmife, siderite and iron oxide ape common cementing materials pHySTCAI PROPERTTFS OF ROCK DE~RFF OF WFATHFRTN~ ' UNWEATHEREO Rock in its natural state before being exposed to atmospheric agents SLIGHTLY WEATHERED Noted predominatly bg color change with no disintegrated rock _ WEATHERED Complete color change with zones of slightly decomposed rock EXTREMELY WEATHERED Complete color change with consistency, texture, and generat appearance approaching soil GEE CONSULTANTS, INC. SOIl, CLASSIFICATION SYSTEM MAJOR DIVISIONS SYM- TYPICAL NAMES BOLS GW Well graded gravels, gravel - sand mixtures, CLEAN Little or no fines. GRAVELS GRAVELS (Little or (More than no fines) Poorly graded gravels or gravel - sand 50% of GP coarse mixtures, Little or no fines. fraction is LARGER than the No. 4 GRAVELS GM SiJty gravels - sand- silt mixtures. U.S. Sieve WITH FINES ' COARSE size) (Appreciable GRAINED amt. of SOILS fines ) GC Ctayey gravels, gravel - sand - clay mixtures. (More than 50% of material is LARGER than SW Well graded sands, gravefly sands, Little or no fines. No. 200 U.S. CLEAN SANDS Sieve size) SANDS (Little or (More than no fines) 50% Of SP Poorly graded sands or gravefly sands, little or no fines. coarse ' fraction is SMALLER than the No, 4 SANDS SM Si[ty sands, sand-silt mixtures. U.S. Sieve WITH FINES - size) (Appreciable amt. of fines ) SC Clayey sands, sand-clay mixtures. Inorganic silts and very fine sands, rock ML flour, sitty or clayey fine sands or clayey silts with slight p[assticity. SILTS AND CLAYS Inorganic clay of Low to medium plasticity, (Liquid limit CL gravefly clays, sandy clays, sitty clays, lean LESS than 50) clays. -- FINE GRAINED SOILS OL Organic silts and 0ganic si[ty clays of low (More than plasticity. 50% of material is SMALLER than MH Inorganic silts, micaceous or diatonmceous No, 200 U, S, fine sandy or silly soils, elastic silts. Sieve size) SILTS AND CLAYS (Liquid limit CH Inorganic clays of high plasticity, fat clays. GREATER than 50) OH Organic clays of medium to high plasticity, organic silts. HIGHLY ORGANIC SOILS PT Peat and other highly organic soils. BOUNDARY CLASSIFICATIONS: Soils possessing characteristics of two groups are designated by combinations of group symbols. - GEE Consultants, Inc.