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Amberpoint 1A-CS070711 iii HaIff Associates 8616 Northwest Plaza Drive Dallas, Texas 75225-4292 (214) 346-6200 Fax (214) 214-361-5573 LETTER OF TRANSMITTAL TO: Mr. Ken Griffin, P.E. City of Coppell Engineering Dept. 255 Parkway Blvd, P.O. Box 478 Coppell, TX 75019 DATE: 07/11/07 AVO: 25027 PROJECT: Staples Expansion, Lot 1 AR, Block A Amberpoint Bus. Park at Coppell Coppell, TX FROM: Cody Graham, E.I.T. cgraham @halff.com VIA: Courier WE ARE SENDING YOU [gI Attached: D Shop Drawings [gI Prints D Copy of letter D Change order D Under separate cover: D Plans D Drawings D Submittal D Other: D Specifications THESE ARE TRANSMITTED as checked below: [gI For approval D For your use D As requested D For review/comment D Approval as submitted D Approved as noted D Returned for corrections D Other: D Resubmit _ copies for approval D Submit _ copies for distribution D Return _ corrected prints ITEMS SENT: 7 - Copies of signed and sealed Engineering Construction Plans tor Staples Fulfillment Center Expansion. 7 - Copies of signed and sealed Early Grading Package for Staples Fulfillment Center Expansion. 1 - Comment response letter. 1 - Letter requesting variance of pavement standards. 1 - Copy of Terracon Geotechnical Eng. Report #94075192 for subject project. COMMENTS: Ken, attached is our signed and sealed engineering submittal for the above project. Please call 214.346.6315 if you have any questions or problems, as we are trying to have approved plans this week. Thanks! SIGNED: Cody Graham, E.I.T. PREPARED BY: Halff Associates COPIES: [gI File [gI Owner D Contractor D Other: 1:\25000s\25027\admin\lot\lOT 07-11-07 KG.doc III HaIff Associates ENGINEERS. ARCHITECTS. SCIENTISTS. PLANNERS. SURVEYORS 8616 NORTHWEST PLAZA DRIVE DALLAS, TEXAS 75225 (214) 346-6200 FAX (214) 739-0095 July 11,2007 AVO 25027 Kenneth M. Griffin, P.E. Director of Engineering/Public Works City of Coppell Engineering Department 255 Parkway Blvd. Coppell,Texas 75019 Re: Staples Fulfillment Center Expansion, Lot lAR, Block A, Amberpoint Bus. Park at Coppell Request Variance for Site Pavement to Waive Lime Stabilized Subgrade Dear Mr. Griffin: On behalf of Staples, Inc. we are requesting a variance from the standard City of Coppell pavement specification for the Staples Fulfillment Center Expansion project at Amberpoint Business Park Lot lAR, Block A. We request a variance for the proposed car parking areas to use 5-inches of 4,000 psi concrete placed over unstablized subgrade; in lieu of the Coppell standard of 5-inches of Class "C" concrete (3,600 psi) over lime stabilized subgrade. We request a variance for the proposed truck traffic areas to use 7-inches of 4,000 psi concrete placed over unstablized subgrade; in lieu of the Coppell standard of 6-inches of Class "C" concrete (3,600 psi) over lime stabilized subgrade. If you have any questions or require additional information, please call me at (214) 346-6244. Sincerely, HALFF ASSOCIATES, INC. JJt/!L//ffi~ Mark W. McGraw, P.E. Project Manager cc: John Whitney, Staples, Inc., w/enc. enc: Terracon Geotechnical Engineering Report No. 94075192, dated June 5,2007 DALLAS . FORT WORTH . HOUSTON . McALLEN . AUSTIN . FRISCO . SAN ANTONIO . FLOWER MOUND TRANSPORTATION . WATER RESOURCES . LAND DEVELOPMENT . MUNICIPAL . ENVIRONMENTAL . STRUCTURAL MECHANICAL . ELECTRICAL . SURVEYING . GEOGRAPHIC INFORMATION SYSTEMS ARCHITECTURE . LANDSCAPE ARCHITECTURE . PLANNING III HaIff Associates ENGINEERS. ARCHITECTS. SCIENTISTS. PLANNERS. SURVEYORS 8616 NORTHWEST PLAZA DRIVE DALLAS, TEXAS 75225 (214) 346-6200 FAX (214) 739-0095 July 11,2007 Ava 25027 Michael Garza, EJ.T. Graduate Engineer City of Coppell Engineering Department 255 Parkway Blvd. Coppell,Texas 75019 Re: Staples Fulfillment Center Expansion, Lot 1AR, Block A, Amberpoint Bus. Park at Coppell Construction Plan Review Comments dated June 21, 2007 Dear Mr. Garza: We offer the following responses to your June 21, 2007 comments regarding the subject project: 1. Location map has been revised. 2. Legal has been revised. Sheet Clo01 3. More clarification for fire hydrant and water service protection was added to sheet. Sheet C2.01 4. Subgrade material has been specified. A copy of the geotechnical report and letter requesting a variance for pavement subgrade is included in this submittal. Sheet C3.01 5. Existing elevations, specifically along Sandy Lake Road, were tied in a 3/29/07 topographic survey of the site. Survey was field-checked. Existing curb and gutter elevations along Sandy Lake Road were added to this sheet for clarity. Sheet C5.01 6. Water line plugs locations have been clarified. Fire hydrant to remain is shown more clearly. DALLAS . FORT WORTH . HOUSTON . McALLEN . AUSTIN . FRISCO . SAN ANTONIO . FLOWER MOUND TRANSPORTATION . WATER RESOURCES . LAND DEVELOPMENT . MUNICIPAL . ENVIRONMENTAL . STRUCTURAL MECHANICAL . ELECTRICAL . SURVEYING . GEOGRAPHIC INFORMATION SYSTEMS ARCHITECTURE . LANDSCAPE ARCHITECTURE . PLANNING iii HaIff Associates ENGINEERS. ARCHITECTS. SCIENTISTS. PLANNERS. SURVEYORS Michael Garza, E.I.T. City of Coppell July 11,2007 Page 2 Sheet C6.01 7. Detail of grate inlet protection is shown on sheet C6.02. We do not foresee any conflict. Construction vehicles will drive beside or over grate inlet. If you have any questions or require additional information, please call me at (214) 346-6244. Sincerely, HALFF ASSOCIATES, INC. jIJ./ i// //pL Mark W. McGraw, P.E. Project Manager cc: John Whitney, Staples, Inc., w/enc. enc: Letter requesting variance to pavement subgrade. Terracon Geotechnical Engineering Report No. 94075192, dated June 5,2007 GEOTECHNICAL ENGINEERING REPORT STAPLES EXPANSION SWQ OF SANDY LAKE ROAD AND NORTH POINT DRIVE COPPELL, TEXAS REPORT NO. 94075192 June 5, 2007 Prepared for: STAPLES, INC. Framingham, Massachusetts Prepared by: lrerracon Dallas,Texas lrerracon June 5, 2007 Consulting Engineers & Scientists Staples, Inc. 500 Staple Drive Framingham, Massachusetts 01702 8901 Carpenter Freeway, Suite 100 Dallas. Texas 75247 Phone 214.630.1010 Fax 214.630.7070 www.terracon.com Attn: Mr. John F. Whitney Re: Geotechnical Engineering Report Staples Expansion SWQ of Sandy lake Road and Northpoint Drive Coppell, Texas Terracon Report No. 94075192 Dear Mr. Whitney: In accordance with your authorization, Terracon has completed its geotechnical engineering report at the above referenced site. The work was accomplished in accordance with the general scope outlined in Terracon's Proposal No. P07940733 dated May 2, 2007. The results are presented in the attached report. Please do not hesitate to contact us if there are any questions. We stand ready to assist during the design or construction phase of the project. We appreciate the opportunity to provide these services. Sincerely, lrerracon -"',...."", _--:;~ OF .,. \\, :...~ ....... S'J...'I. '" -, .' *. -r..., t ,:' CO ..' .... '($1 , t: '.*~ f . ............... ..* ~ I!. ..~~~!?~~MED.... ~ ~ -<l '. ( 9492;'" r{1~S!- 2t> 07 " ~ . /. <:). Q;;-, '40....- ".9E'NS~." ,~~ . ~J' . .. .... ,,':\,...,:- ,,\\SlmJAl f.~~-- ,,""........-- CC: Richard Nordyke/O'Brien Associates Keith LesliefTechniStructures Delivering Success for Clients and Employees Since 1965 More Than 80 Offices Nationwide llerracon TABLE OF CONTENTS Page Letter of Transmittal.... .................. ................. ................... .................. ............ ....................... i INTRODUCTION ....................... .... ....... ............. ............... ........... ......... ..... .......... .................1 PROJ ECT DESCRI PTION ......... .......... ........... ............. ................ ....................... ......... .........1 SITE EXPLORATION PROCEDU RES .......... .............. ....... ............ .................... ......... .........1 Field Exploration.. ............. ..... ......... ...................... ........... ......... ........ .............. ...........1 Laboratory Testing.............................. ......... ......................................... ..................... 2 SUBSURFACE CONDITIONS.. .... .......... ..... ....................... ...... ... ..... ......... .......... ................. 3 Soil Conditions ................................. .............. ...........................................................3 Groundwater Conditions............................................................... .............................3 ANALYSIS AN D RECOM MENDA TIONS .. ................................. ................ ....... ...................4 Geotechnical Considerations................ ........ ........................................ .....................4 Drilled Shaft Foundation System................ ......................................... ........... ...........4 Underreamed Shafts..................... ........ ...............................................................4 Soil Induced Uplift Loads ................ ....... ................................. ........ ........ ........... ..5 Drilled Shaft Construction Considerations..................................... .......................5 Grade Beams/Pier Caps ..................... ............................................ ........ .......... ...6 Seismicity ............ ............................... ........................................... ......................6 Floor System.............................. ........ ....... .......................................... ................... ...6 Structural Floor Slabs ......................... ............... ............................ ......................7 Floor Slabs on Modified Subgrade .... ..................................... ....... ................. ...... 7 Excavation and Replacement............ ...... ........................................... .................... ...8 Select Fill.. .............................................. ............................................................... ....8 Site Grading...................................................................................... ........................ 9 Utilities...... .......................................... .... ..................................... ...... ........... ......... .... 9 Surface Drainage................................. ................................................................. ...1 0 Surface Pavement Recommendations............................................. ..................... ...1 0 Pavement Subgrades ...................... ............................................................... ...1 0 Pavement Sections.................... ................. .......................................................11 Preventative Maintenance........... ...................................................................... 12 GENERAL COM MENTS.. .... ...... .... ........ ....... ................ ....... .... ... ........ .... ................ ............12 APPENDIX Figure Boring Location Diagram........................... ................ ....... ..................................................... 1 Log of Boring.. ....................... ............ ....... ............... ................ .... ......... ...... ......... ........ 2 and 5 General Notes....................................................................................................................... 6 Unified Soil Classification System.... ............. ........... ....... ....................... .... .......... ........ .........7 lrerracon GEOTECHNICAL ENGINEERING REPORT STAPLES EXPANSION SWQ OF SANDY LAKE ROAD AND NORTH POINT DRIVE COPPEll, TEXAS REPORT NO. 94075192 June 5, 2007 INTRODUCTION A new expansion of Staple warehouse with associated surface parking is planned at the site located in the southwest quadrant of Sandy Lake Road and Northpont Drive in Coppell, Texas. This report describes the subsurface conditions encountered and provides recommendations regarding the geotechnical design and construction of foundations and floor slabs for the proposed building and associated surface parking areas. In addition, general earthwork recommendations are provided. Our scope of services included drilling and sampling 4 borings, laboratory testing, and engineering analyses. PROJECT DESCRIPTION The proposed expansion consists of a tiltwall warehouse building of about 148,000 SF footprints. Surface parking is planned surrounding the warehouse. The expansion will be on the north side of the existing Staple warehouse building. The column loads of the building are anticipated to be about 150 kips, or less. Currently, the site is vacant land with weeds, native grass and some small to large sized trees. Based on NCTCOG topographic map, the existing surface elevations of the site vary from about 518 to 520 feet. The planned finished floor (FF) elevation of the building will be 521.5 feet. Therefore, about 1 Y2 to 3Y2 feet of fill will be required to prepare proposed building pad. SITE EXPLORATION PROCEDURES Field Exploration Four borings were drilled on May 17, 2007 at the approximate locations shown on the Boring Location Diagram, Figure 1, in the Appendix. The borings were located in the field by a representative of Terracon using a site plan provided by the client. The boring locations are considered to be approximate. The results of the field exploration program are presented on the Logs of Borings, Figures 2 through 5, in the Appendix. General Notes for terms and abbreviations used in the boring logs are presented on Figure 6. Field logs of the borings were prepared by the drill crew. These logs included visual classifications of the materials encountered as well as interpretation of the subsurface conditions between samples. The boring logs included with Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 llerracon this report represent the engineer's interpretation of the field logs and include modifications based on laboratory evaluation of the samples. A truck-mounted auger-drilling rig was used to advance the boring. Samples of the soils encountered in the boring were obtained using thin-walled tube sampling procedures. The samples were tagged for identification, sealed to reduce moisture loss, and taken to the laboratory for further examination, testing, and classification. Disturbed samples of soil were obtained with a split-spoon sampler in conjunction with the Standard Penetration Test (SPT). The test employs a 140-pound hammer that is dropped a distance of 30 inches, driving the split spoon sampler into the subject material. The number of blows required for 18 inches of penetration is recorded and value for the last 12 inches, or the penetration obtained from 50 blows, is reported as the Standard Penetration resistance (UN value") on the boring log. Laboratory Testing The Logs of Boring and samples were reviewed by a geotechnical engineer who selected soil samples for testing. Tests were performed by technicians working under the direction of the engineer. A brief description of the tests performed follows. Plastic and liquid limit tests (Atterberg limits) were performed on selected samples from the borings. These tests were used in conjunction with moisture content measurements to aid in classifying the soils in accordance with the Unified Soil Classification System (USCS). The USCS is summarized on Figure 7 in the Appendix. Absorption swell tests were performed on selected samples of the cohesive materials. These tests were used to quantitatively evaluate volume change potential at in-situ moisture levels. Shear strengths of cohesive soils were estimated by field pocket penetrometer and laboratory unconfined compressive strength tests performed on selected samples. The results of the laboratory tests are presented on the Logs of Borings. Results of the swell tests are presented in Table 1. Boring Depth Liquid Plasticity Initial Final Surcharge Swell Limit Index Moisture Moisture No. (feet) % % (%) (0/0) (pst) (0/0) B-1 2-4 58 38 20 23 300 0.2 B-2 19-20 - - 17 22 1,500 2.3 B-4 8-10 34 19 12 19 900 0.8 TABLE 1 . SUMMARY OF SWELL TESTS 2 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 llerracon SUBSURFACE CONDITIONS Soil Conditions The conditions encountered at the boring locations are depicted on the Logs of Boring. Descriptions of each stratum with its approximate depth and thickness are provided. The stratum depths pre referenced from the ground surface present at the time of drilling. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. A brief discussion of the stratigraphy indicated by the exploration program is presented below. Fill materials consisting of brown and dark brown sandy clays with trace amounts of sand and gravel were encountered in Borings B-1 and B-3 to a depth of 2 feet below grade. Visually, the fill is classified as CL by the USCS. The clay fills were stiff to hard in consistency. Below the fill and existing grade, dark brown, brown and tan clays with trace amounts of calcareous nodules were encountered in the borings to depths of 4 to 13 feet. These clays had Liquid Limits (LL's) ranging from 53 to 58 percent and Plasticity Indices (PI's) ranging from 33 to 38. These soils are classified as CH by the USCS. The clay soils were stiff to hard in consistency. Tan and gray silty clays with trace amounts of sand, calcareous nodules and deposits were next encountered at depths of 4 to 13 feet and they extended to depths of 14 to 22 feet. These clays had LL's ranging from 28 to 40 percent and PI's ranging from 10 to 22. These soils are classified as CL by the USCS. The clay soils were very stiff to hard in consistency. Below tan and gray silty clay, tan sandy clay with trace amounts of silt was encountered at a depth of 14 feet in Boring B-4 and it extended to a depth of 22 feet. Visually, this soil is classified as CL by the USCS. The sandy clay was very stiff in consistency. Tan sand was next encountered at depths of 17 to 22 feet below grade. This sand had some gravel, and became cemented and slightly cemented below 22 feet. The cemented sand extended to boring termination depths of 25 feet below grade. The surficial clay soils encountered at this site are considered highly to moderately active with respect to moisture induced volume changes. Active soils can experience significant volume changes (expansion or contraction) with fluctuations in their moisture content. Groundwater Conditions The borings were advanced in the dry using auger drilling techniques, which allows short- term groundwater observations to be made while drilling. Groundwater seepage was not observed in the borings during and upon completion of drilling. 3 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 lrerracon Groundwater conditions may be different at the time of construction. Groundwater conditions may change because of seasonal variations in rainfall, landscape irrigation, and runoff. ANALYSIS AND RECOMMENDATIONS Geotechnical Considerations Highly to moderately active soils were encountered in the borings. The results of the swell tests performed on selected soil samples of the clay soils indicate that at their present moisture levels the soils are considered relatively stable with regard to post construction moisture induced volume changes. This could change if the soils are allowed to desiccate prior to construction. We estimate the potential magnitude of post-construction heave at this site to be on the order 3 to 4 inches for dry subgrade conditions. Shallow or near surface footings are subject to differential movements due to moisture induced volume changes in the site soils. A positive means to reduce the potential for foundation movement would be to support the structure on a foundation system bearing below the zone of seasonal moisture variation. The use of drilled and underreamed reinforced concrete shafts situated in the overlying tan silty clay and clay at a depth of about 12 feet below existing grade, should perform satisfactorily. If floor slab movements must be limited to less than one inch, a floor system structurally suspended above the subgrade is recommended. If movement of one inch is acceptable. floor slab on subgrade soils at their current moisture levels can be used. If the soils become dry, subgrade soils should be modified as discussed in this report. It should be noted that there is a risk that 1-inch of movement can result in unsatisfactory performance. Some of the risks that can affect performance include uneven floors, floor and wall cracking, and sticking doors. Asphaltic concrete pavement or Portland cement concrete pavement can be used at this site. If asphaltic concrete is used, the subgrade should be stabilized with lime. Geotechnical recommendations for the building foundation, floor slab subgrade preparation, earthwork and pavement are presented in the following report sections. These should be reviewed when the grading plan is available. Drilled Shaft Foundation System Underreamed Shafts Drilled and underreamed shafts should be situated in the tan silty clay and clay strata at a depth of about 12 feet below existing grade. An allowable bearing pressure of 5,000 psf (pounds per square feet) is recommended. 4 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 1rerracon Underreamed shafts should have a minimum base to shaft diameter ratio of 2 to 1 to resist the uplift loads described below. In addition, the bell diameter should be a minimum of 36 inches larger than the straight shaft portion. A minimum shaft diameter of 18 inches is recommended. We recommend that underreamed shafts be maintained a minimum edge to edge spacing of one underream diameter, based on the larger of the two. Closer drilled shaft spacing should be evaluated to determine if reductions in the allowable bearing pressures should be made to control settlement. About 70 to 80 percent of the foundation settlement of properly constructed underreamed shafts is expected to occur as the shafts are loaded. The total settlement is estimated to range from % to 1 percent of the underream diameter. Differential settlements of equally loaded drilled shafts are expected to range from % to % of the total settlements. Soil Induced Uplift Loads The shafts will be subject to uplift because of heave in the overlying clay soils. The magnitude of these loads varies with the shaft diameter, soil parameters, and particularly the in-situ moisture levels at the time of construction. The shafts must contain sufficient continuous vertical reinforcing to resist the net soil induced uplift load. The uplift load can be approximated by assuming a uniform uplift of 1,200 psf over the shaft perimeter for a depth of 8 feet in the soils at their current moisture conditions. Drilled Shaft Construction Considerations The drilled shafts should be installed in accordance with ACI 336. Excavation for the shafts should be maintained in the dry. Concreting should closely follow excavation to reduce potential caving and/or seepage problems. Close coordination of excavation and concreting could be required due to groundwater seepage or caving soils. Care should be taken not to undermine the existing foundations during construction of the building expansion. The top of the drilled shafts should be cast without any top enlargement that can result in increasing the soil uplift forces acting on the drilled shafts. The enlarged top or umushroomed shaped" top drilled shafts should be cut away to the nominal shaft diameter before grade beams or panels are placed. The concrete should have a slump of 6 inches plus or minus 1 inch and be placed in a manner to avoid striking the reinforcing steel during placement. Close coordination of excavation and concreting will serve to reduce potential caving of the underreams. The drilled shaft design recommendations provided in this report are based on proper construction procedures. including maintaining a dry shaft excavation and proper cleaning of 5 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 lrerracon bearing surfaces prior to placing reinforcing steel and concrete. All drilled shaft installations should be inspected by qualified geotechnical personnel to help verify the bearing stratum, the design penetration, and perform related duties. Grade Beams/Pier Caps The drilled shafts should support all grade beams. A minimum void space of 6 inches is recommended between the bottom of grade beams and pier cap extensions, and the subgrade. This void will serve to reduce distress resulting from swell pressures generated by the clays. Structural cardboard forms are one acceptable means of providing this void beneath cast-in-place elements. Soil retainers should be used to help prevent the filling of the void with soil. The grade beams should be formed rather than cast against earth trenches. Backfill against the exterior face of grade beams should be properly compacted onsite clays. Compaction should be a minimum of 93 percent of ASTM D 698 maximum dry density. The fill soil should be placed at 2 or more percentage points above the optimum moisture content determined by that test. Seismicity Based on the 2003 International Building Code, Table 1615.1.1 Site Class Definitions, the site soils can be characterized as Site Class C. Site Class C is described as very dense soil and soft rock for the top 100 feet of the site soil and rock profile. Floor System Floor slabs placed on grade may be subject to movement as a result of moisture induced volume changes in the active soils. The soils expand (heave) with increases in moisture and contract (shrink) with decreases in moisture. The movement typically occurs as post construction heave. The potential magnitude of the moisture induced movements is rather indeterminate. It is influenced by the soil properties, overburden pressures, and to a great extent by soil moisture at the time of construction. Potential Vertical Movement calculations were performed using the Texas Department of Transportation (TxDOT) Method 124-E. The TxDOT method is empirical and is based on the liquid and plastic limits and moisture content of the subsurface soils. Potential soil movements at this site are estimated to be on the order of 3 to 4 inches if the soils become dry at the time of construction. Based on the results of the laboratory tests, the soils are currently at favorable moisture levels. At these levels potential movements are estimated to be about one inch. A structural floor slab is recommended if floor slab movements are to be limited to less than one inch. If floor slab movements of about one inch are acceptable, the floor slabs can be 6 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 llerracon supported on a subgrade at the present moisture level. It should be noted that even Y2 inch of movement in slabs can result in uneven floors, sticking doors, and cracking of floor slabs and wall partitions. If the risk of these movements is unacceptable, the floor slab should be structurally suspended. Structural Floor Slabs A floor system structurally suspended above the subgrade is recommended if movements are to be limited to less than 1 inch. A minimum void space of 10 inches is recommended beneath the slabs. The minimum void space can be provided by the use of cardboard carton forms, or a deeper crawl space. The bottom of the void should preferably be higher than adjacent exterior grades. If it is lower, it should be shaped and drained to prevent the ponding of water. A ventilated and drained crawl space is preferred for several reasons, including the following: . Ground movements will affect the project utilities, which can cause breaks in the lines and distress to interior fixtures. . A crawl space permits utilities to be hung from the superstructure, which greatly reduces the possibility of distress due to ground movements. It also can provide ready access in the event repairs are necessary. . Ground movements are uneven. A crawl space can be positively drained preventing the ponding of water and reducing the possibility of distress due to unexpected ground movements. Floor Slabs on Modified Subgrade At the time of our field operations on May 17, 2007, in-situ moisture contents in the existing soils were in a favorable condition. Potential movements from the present moisture levels are estimated to be on the order of 1 inch. This level of movement can be maintained by moisture conditioning the upper 2 feet of clay soil in conjunction with a 1 foot cap of select fill in the building pad and other areas sensitive to movement. It is also recommended that the floor slab be placed within 30 to 40 days after installation of the select fill cap. However, it is emphasized that the clays can dry rapidly when the soils are exposed to warm, dry weather. As the soils dry, the magnitude of potential movements will approach the levels previously discussed in the "Floor Systems" section above. If the subgrade soils are allowed to desiccate, then it will be necessary to moisture condition the desiccated soils to reduce the expected post-construction vertical movement to a level of one inch. A suitable method to modify subgrade soils at this site is "Excavation and Replacement", as described below. The area to be treated should be extended beyond to 7 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 llerracon building line to include entrances and adjacent flatwork sensitive to movement. The treated area should be capped with one foot of select fill. Excavation and Replacement The area to be treated should be undercut to a minimum depth of 2 feet or as required to remove desiccated soils. The exposed subgrade soil should be scarified to a depth of 8 inches and re-compacted to between 92 to 98 percent of Standard Proctor (ASTM 0 698) at a minimum of +4 percentage points above the soil's optimum moisture content. The depth of desiccated soils should be evaluated by additional soil borings or test pits prior to slab construction. The excavated soils, free of vegetation, any debris, rocks greater than 4 inches in maximum dimension and any deleterious material, should be thoroughly mixed with water as needed to raise the soil moisture content to 4 or more percentage points above optimum moisture content. The moisture conditioned fill can then be replaced in loose lifts, less than 9 inches thick, and uniformly compacted. Each lift should be compacted to between 92 and 98 percent of the Standard Proctor (ASTM 0698) maximum dry density. Care should be taken that a lift is not allowed to desiccate prior to placing a subsequent lift. The select fill cap should then be placed above the reworked subgrade within 48 hours of completing the installation of the moisture conditioned soils. The select fill serves to prevent desiccation of the moisture conditioned clays. Steps should be taken to prevent desiccation of the clays around the perimeter of the structures where the select fill cap feathers out, or they are exposed by cuts. It should be realized that slab movements of even 1/2 inch can result in distress to floor coverings, interior partitions, and finishes. Special provisions should be made to accommodate movement, if slab-on-grade construction is utilized. A properly engineered and constructed vapor barrier should be provided beneath slabs-on- grade which will be carpeted or receive moisture sensitive coverings or adhesives Select Fill Select fill material should be a very sandy clay to clayey sand with a Liquid Limit (LL) of less than 35 percent and a Plasticity Index (PI) preferably between 6 and 15. As an alternate to select fill, the pad can be capped with flexible base. The base should meet the requirements of TxOOT Item 247, Grade A, Type 1 or 2. Recycled concrete meeting these requirements is acceptable. 8 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 , Ierracon The select fill or base should be spread in loose lifts, less than 9 inches thick, and uniformly compacted to a minimum of 95 percent of ASTM 0698 within :t2 percentage points of the soil's optimum moisture content. The first lift of select fill should be placed wet of optimum to prevent drying the underlying subgrade. Positive drainage must be provided away from the structure to prevent the ponding of water in the select fill. Site Grading Preparation of the site for construction operations should include the removal and proper disposal of all obstructions and materials, which would hinder preparation of the site for construction. To the extent practical, it is recommended that trees scheduled for removal in the vicinity of proposed slab-on-grade foundations be removed as far in advance of slab construction as possible. This will tend to restore a more favorable soil moisture equilibrium which will, in turn, tend to minimize the potential for greater than anticipated post-construction ground movements. Root balls should be removed, and the soil that is placed in these areas should be placed and compacted as described above in the section "Excavation and Replacement", under the supervision of a geotechnical engineer or his representative. The on-site soils, free of vegetation, rocks greater than 4 inches in maximum dimension, and any other deleterious matter, are generally suitable for site grading. If imported fill materials are used, they should be clean soil with a Liquid Limit preferably less than 50 percent and no rock greater than 4 inches in maximum dimension. The subgrade in areas to be filled should be scarified to a minimum depth of 6 inches and uniformly compacted to a minimum of 95 percent of ASTM D 698 at or above the optimum moisture content as determined by that test. The fill materials should then be spread in loose lifts, less than 9 inches thick, and uniformly compacted to the same criteria. If filling is suspended and the subgrade becomes desiccated or rutted, it should be reworked prior to placement of a subsequent lift. When placing fill on existing slopes that are steeper than 6H to 1V, the fill should be benched into the slope. This permits placement of relatively horizontal lifts and breaks of potential slide planes. Permanent slopes should generally be 4H to 1 V or flatter. Site improvements should be held back from the crest of slopes to reduce the affects of creep or shallow slides. Utilities Care should be taken that utility trenches are not left open for extended periods, and they are properly backfilled. Backfilling should be accomplished with properly compacted on-site soils as recommended in this report, rather than granular materials. A positive cut-off at the 9 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 , Ierf'ilaX1 building line is recommended to help prevent water from migrating in the utility trench backfill. Surface Drainage All grades must be adjusted to provide positive drainage away from the structures. Water permitted to pond near or adjacent to the perimeter of the structures can result in soil movements that exceed those discussed in this report. Open ground should preferably be sloped at a minimum of 5 percent grade for at least 10 feet beyond the perimeter of the building. Flatwork and pavement could be subject to post construction movement. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. In addition, allowances in final grades should take into consideration post-construction movement of f1atwork, particularly if such movement would be critical. Consideration should be given to preswelling techniques as discussed in the previous section of this report in sensitive areas. Where paving or flatwork abuts the structures, care should be taken that joints are properly sealed and maintained to prevent the infiltration of surface water. Planters located adjacent to the structures should preferably be self-contained or at least designed to drain. Sprinkler mains should be located a minimum of 5 feet away from the building lines. If heads must be located adjacent to the structures, then service lines off the main should be provided. Roof drainage should be collected by a system of gutters and downspouts and transmitted by pipe to a storm drainage system or to a paved surface where the water can drain away without entering the building subgrade. Ideally, roof drains should discharge to storm sewers by closed pipe. Surface Pavement Recommendations Pavement Subgrades Subgrade materials at this site are anticipated to consist of clay soils. These are subject to loss in support value with the moisture increases, which occur beneath pavement sections. They react with hydrated lime, which serves to improve and maintain their support value. Lime stabilization is recommended beneath flexible (asphalt) pavement sections. Rigid (concrete) pavements may be placed on an unstabilized properly compacted subgrade as discussed in the "Pavement Section" below. A minimum of 8 percent hydrated lime (TxDOT Item 264), by dry weight, should be used. The lime should be thoroughly mixed and blended with the top 6 inches of the subgrade (TxDOT, Item 260). Stabilization should extend a minimum of one foot beyond the edge of the pavement. 10 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5. 2007 lrerracon The subgrade. stabilized or unstabilized, should be uniformly compacted to a minimum of 95 percent of ASTM D698 maximum dry density between -1 to +3 percentage points of the optimum moisture content. The subgrade should be protected and maintained in a moist condition until the pavement is placed. Pavement subgrades should be graded to prevent ponding and infiltration of excessive moisture on or adjacent to the pavement subgrade surface. Pavement Sections Both asphalt and concrete pavement sections are presented below. They are not considered equal. Over the life of the pavement, concrete sections would be expected to require less maintenance. Five inches of asphaltic concrete should be adequate in parking lots servicing only automobile traffic. The section should consist of a two-inch surface course similar to TxDOT Type D and a base course similar to Type A or B. The coarse aggregate in the surface course should be crushed limestone rather than gravel. Portland cement concrete is recommended in areas subject to truck traffic and should provide good service for other pavement areas. In employee parking lots and other areas not subject to trucks, a minimum of 5 inches of 3,OOO-psi concrete on an unstabilized subgrade is recommended. In areas subject to truck traffic, the following table (Table 2) summarizes the estimated number of allowable daily repetitions of a fully loaded tractor- trailer rig. The sections are based on the use of a minimum 28-day compressive strength of 3,500 psi and a 20-year design life. TABLE 2 - PAVEMENT SECTIONS PAVEMENT ALLOWABLE DAILY SECTION REPETITIONS 7" Concrete without lime 40 7" Concrete with lime 60 8" Concrete without lime 90 8" Concrete with lime 130 The pavements should contain a minimum of 5 :t 1 percent entrained air for a one-inch maximum aggregate size. As a minimum they should be reinforced with No.3 bars on 18 inch centers in both directions. The pavement will be subject to significant movement due to volume changes in the site soils. Flat grades should be avoided with positive drainage provided away from the pavement edges. Backfilling of curbs should be accomplished as soon as practical to prevent ponding of water. 11 Geotechnical Engineering Report Staples Expansion Coppell. Texas Terracon Report No. 94075192 June 5. 2007 lrerracon The pavements presented in Table 2 represent a minimum design thickness. Periodic maintenance must be anticipated and planned. Higher daily traffic volumes may require thicker pavement sections. Additional recommendations can be provided if actual traffic volumes are provided. Preventative Maintenance Preventative maintenance should be planned because of the highly active nature of the clays at this site. Differential soil movements can occur that can cause pavement cracking and opening of joints. Water entering joints can reduce the service life of the pavement. Preventative maintenance should be provided for through an on-going pavement management program to enhance future pavement performance. Preventative maintenance activities are intended to slow the rate of pavement deterioration and to preserve the pavement investment. Preventative maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Also, thicker pavement sections could be used to reduce the required maintenance and extend the service life of the pavement. Signs should be placed at the entrances of the parking area to limit heavy trucks being on the automobile pavements. GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide testing and observation during excavation, grading, foundation and construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental assessment of the site or identification of contaminated or hazardous materials or conditions. If the owner is concerned about the potential for such contamination. other studies should be undertaken. 12 Geotechnical Engineering Report Staples Expansion Coppell, Texas Terracon Report No. 94075192 June 5, 2007 1rerracon This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design. or location of the project as outlined in this report are planned. the conclusions and recommendations contained in this report ,shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. 13 APPENDIX lrerracon SANOY LAKE ROAD r----------------------------------, I 8 A ~I I ~ .... 8-1 I I I : PROPOSED : I EXPANSION 8-3 I I ~-- I - - - -r - - --- - - - i _\&- - - - - r - --I I i l~~_"~_L_____. I I L____ ___________~u _______~-----m--- -i----J (- (~ II I r W EXISTING OFfICE/WAREHOUSE OJ " o ::. ., o >- o .1 U' ~ o N '" ." r- o " '" I ! ~ ' ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ D r- o o N o " o LEGEND: _ ~ APPROXIMATE LOCATION or BORING U <SO o N f L..J :> - et a I- 2: o Q J: I- et o 2: ., " ) NOTE: BORING LOCATIONS ARE APPROXIMATE o 40 80; [I 1 ~-~--nl APPROXIMATE SCALE BORING LOCATION DIAGRAM 11errcx:on ST APLES EXPANSION swa OF SANDY LAKE ROAD AND NORTHPOINT DRIVE COPPELL, TEXAS FIGURE 1 Project No.' 94075192 CLIENT Staple Inc. Farmingham, Massachusetts BORING See Figure 1 LOCATION Cl DESCRIPTION 0 -' u E 0- '" Ci Approx. Surface Elevation: N/A ft \J~ FILL. SANDY LEAN CLAY, -l 0 \J~ Dark brown -l 0 2.0 ~ FAT CLAY, Dark brown 4.0 !/ 1/ SILTY LEAN CLAY, v/I/ 1/ 1/ Tan and gray //v // // V // 8.0 / / SIL TY LEAN CLAY, 1/[/ 1/ Tan 1/1/ 1/1/ 1/1/ 1/ vI/ 1/1/ 1/ 1/1// vl// vl// vl/ 1/ 1// 1// v/ /v/ /v 17.0 ..... SAND, 00. o 0 Tan o 0 0 o 0 o 0 0 o 0 o 0 0 o 0 o 0 0 o . o 0 . o 0 o 0 0 o . o 0 0 . . o 0 . o 0 . 0 . 22.0 o . . 0 . SAND. o . o 0 . . 0 Tan, with gravel, cemented o 0 . . 0 0 . 0 . . 0 o 0 . . 0 . 0 25.0 . 0 0 B.H. at 25.0' STRATIFICATION LINES REPRESENT APPROXIMATE BOUNDARIES BETWEEN SOIL AND ROCK TYPES. IN SITU. THE TRANSITION BETWEEN STRATA MAY BE ~ MORE GRADUAL '" Oil , Q. C) ('oj '" ;;; ~ WATER LEVEL OBSERVATIONS. FEET 'Sl- ~ 'it ~ g No seepage observed. LOG OF BORING NO. B-1 PROJECT: STAPLES EXPANSION SITE SWQ of Sandy Lake Road & Northpoint Dr. Coppell, Texas SAMPLES TESTS f- 0 LL 'if!. 0.. X U Zu.. U W Z ~~ ~ 0.. 'if!. 0 u.. -' f- WUl & f- 0 OJ: o '. ~ ~ .-: ~ >~ W al Ou w::!E>- woo ~ o (ii' f- w ::!E Xz U5 ~ o (I) J: (I) u.. >- f-_ f-O 0::: o:::f- Z :J U ~~ wt; :i (/) o:::Cii ~ 0::: !J!'if!. :Jz W w O~ eDti:iOcit;;~ 0 0 ~ en - 0::: Z 0::: f- en W 5 (/) :Jw o..w :J 0.. U 0.. f-O ;tf51rlO o~ >- :5 z> ::!Eo::: -' w en >- 0..-' 0::: 0 -!!:! Of- <( 0 :J f- eneD uo.. o:::!: ::!Eu 0 :J Q. ::!Een uen LL - CL ST 4.5+ - CH ST 2.75 20 113 58 38 --- 5- CL ST 4.5 - CL ST 4.5+ - CL ST 4.5+ 10 - - CF - CL ST 4.5+ 13 107 158 2.5 15 - - CF - - SP SS 30/12 20 - - CF - - SP SS 4.5/50 25 REMARKS lrerracon DATE DRILLED 5/1712007 Page 1 of 1 PROJECT NUMBER 94075192 FIGURE 2 ~ <D LOG OF BORING NO. B-2 CLIENT Staple Inc. PROJECT: STAPLES EXPANSION Farmingham. Massachusetts ._n__._ BORING See Figure 1 SITE: SWQ of Sandy Lake Road & Northpoint Dr. LOCATION Coppell, Texas SAMPLES TESTS I- 0 u.. ;Ii a.. x U Zu.. U w <l:(I? a.. ;Ii 0 Ll- Z -' I- II- ;Ii ~ ~ WOl ~ I- 0 OI 0: -.e. >~ cr en DESCRIPTION w 10 aU ~ l- I- ~I 0 w:::; >- a I- -' W :::; Xz 1-0 0: w" iii ~ l- e Ol u u.. >- 1-- ~o: ~~ 0:1- Z ::; U ~~ wI- E :r: (I? 0: in ::)7 w 0:" W c. 03:: !!ltu oei I-W 0 0 f= Ol" a..Z a: '" I- Ol W Oll- 5 Ol ::)w ::;;w ::) t9 a.. U a.. 1-0 -'z UO -z >- :5 ~a; -' Approx. Surface Elevation: N/Aft w Ol ~ a..-, <l:w Wo: 00 0: 0 og: ~ 0 ::) OlIO ua.. 0:_ :::;u 0 ::; a.. ::;;iii UOl u.. 0: FAT CLAY, ~ Dark brown - CH ST 1.5 - CH ST 2.0 0: 4.0 -- / V SIL TV LEAN CLAY, /v Tan and gray, with trace silt. and 5- CL ST 4.5+ /v calcareous deposits and nodules //v //v //v - CL ST 4.5+ / /v / V //v //V - CL ST 4.5+ 12 40 //V 22 //v / V 10 //v // - // // - CF / // 13.0 - // SIL TV LEAN CLAY, // Tan, with sand -- f- / CL ST 4.5+ 9 28 10 // 15 -- // // - // // - CF / // // - ~ SP ST 45 17 111 22.6 47 Vl/ 20 Vl/ Vl/ V Vl/ 22.0 CF . 0 0 SAND. o. . . . o 0 Tan, slightly cemented . 0 0 . . . . 0 . . . 0 . o . SP SS 30/12 . 0 . . . 25.0 . . . 25 ..- BH at 250' STRATIFICATION LINES REPRESENT APPROXIMATE REMARKS BOUNDARIES BETWEEN SOIL AND ROCK TYPES IN SITU. THE TRANSITION BETWEEN STRATA MAY BE MORE GRADUAL WATER LEVEL OBSERVATIONS. FEET DATE DRILLED Page 1 of 1 51- ~ llerracon 5/17/2007 FIGURE '!l- l? PROJECT NUMBER No seepage observed. 94075192 3 , Q. <.:l '" en on .... o ... en '" g LOG OF BORING NO. B- 3 CLIENT Staple Inc. Farmingham, Massachusetts - _" . - __. n____ _ __._____ BORING See Figure 1 LOCATION "-.J'- "-.J'- ~ ~ ~ ~ ~ ~ ~ J~ / /1/ 1/ 1/ 1/ 1/ / 1/ 1/ 1/ /1/ /1/ . . . . . . . . . ...~ . . . . . . . . . . . . . . . . . . . . . . -.- -.. ~_.. - ---- --- -------.-... - -.- SITE swa of Sandy Lake Road & Northpoint Dr. Coppell,Texas SAMPLES TESTS - _.---- . - _.- -- .- I I I I I- 0 0.. u. X U Zu. U W <(w 0.. ~ 0 u. --' I- I~ ;;!!. WV> I- 0 OI o ,D. ::P. ~ ~ ~ >~ W ID Ou I- 0 ~I w:2; >- WOo en ~ >- W ::!: Xz 1-00:: l- I- 0 u. >- 1-- ~o:: l1J~ ~Z Z :J 0 ~~ wI- I VJ 0::- w 0::C> o~ I->'I-w 0 0 f= en' o..Z I- en W IDW 00 wI- 5 VJ ::Jw ::!:w 0.. U Q. 1-0 ~iD ~o o~ >- ~ z> W VJ >- 0..-' 0:: 0 _w og: 0 ::J I- WID uo.. o::!: ::!:u 0 :J 0.. ::!:u; UV> ; ! Ol o --' Ll :.c c. to o DESCRIPTION Approx. Surface Elevation: N/A ft FILL. FAT CLAY, Brown and dark brown, with trace sand g.Q.~d gravel ~_ FAT CLAY, Brown 4.0 FAT CLAY, Tan and brown, with trace calcareous nodules 130 ---+-.-- -- - -----,._._--~..__. SILTY LEAN CLAY, Tan, with trace sand .18.0 SAND. Tan 22.0 SAND. Tan, with gravel, cemented ~50" B.H at 25.0' REMARKS STRATIFICATION LINES REPRESENT APPROXIMATE BOUNDARIES BETWEEN SOil AND ROCK TYPES. IN o SITU. THE TRANSITION BETWEEN STRATA MAY BE :g MORE GRADUAL ~ WATER LEVEL OBSERVATIONS. FEET ~ t-.--- - -- - --. . ----- N SL !' '" o o .. '" CD o --' PROJECT STAPLES EXPANSION ;fl Z ~ l- V> W a:: ::J -' <( u. CH ST 1.5 -. -1-- ___ u_ _j CH ST 2.0 . ____d..._ I---~~ -- -.- -.--- i I I ...- ---. ... ---l 10_:~~_:35~-r-l-j ..11 I !!,' i I ' I I I I I I i I 5- CH ST 18 53 33 2.75 ---- CF ---. -... CL ST , I t 119.0 29 I 4.5 13 110 15 - - CF - - SP SS 31/12 20 - - CF __ __H ." ... _. - -- -- --- --- ..-- -..- ,. i I I I -- SP SS 25. --. 4/50 .--. --- -- .. I I i DATE DRILLED 5/17/2007 Page 1 of 1 .., J' lrerracon PROJECT NUMBER 94075192 FIGURE 4 No seepage observed. ~ o ;; <Ii LOG OF BORING NO. B-4 CLIENT Staple Inc. PROJECT: STAPLES EXPANSION Farmingham, Massachusetts BORING See Figure 1 SITE: SWQ of Sandy Lake Road & Northpoint Dr. LOCATION Coppell, Texas SAMPLES TESTS I- --- -- [1- 0 u. X ;i!- U Zu. U w Z <((I) [1- 0 u. -' I- It- ;i!- wV) <C t- o OI 0' ;i!- >- ~ >~ a:: 01 DESCRIPTION W al AU > ;i!- l- t: >- a Vi. I- 0 w::a;: Vi -' W ::a;: ~~ 1-0 a:: w. ::a;: I- a V)I V) u. >- a:: I- Z ::J U ~ ;;;-~ III I- u a::ii) iicr: ~o~ :Jz a::C> W E :i (I) I-w W 0 i= a:: c.. l- V) 03: all- 00 V) I- 0 ~u.i [1-Z :J '" W _W :5 V) ::a;:w 2i Approx. Surface Elevation: N/Aft [1- u [1- 1-0 ...JZ uo -z >- :5 z> og: -' W V) >- [1--, <(w Wa:: 00 a:: 0 _w <C 0 :J I- V)al U[1- a::_ ::a;:u 0 ::J [1- :2 Vi uv) IJ.. ~ FAT CLAY, ~ Dark brown - CH ST 1.0 - CH ST 4.5+ ~ 4.0 / v SIL TV LEAN CLAY, //V / V Tan and gray, with trace sand 5- CL ST 4.5+ //V /V //V //V - CL ST 4.5+ / V /V .-. //V //V - CL ST 4.5+ 12 114 34 19 //V / V / V 10 -- / V /V - //V //V - CF //v //V / V - /V 14.0 i!~. . SANDY LEAN CLAY, CL ST 3.75 9 124 34 36 ~ Tan, with trace silt 15 ~ - ~ CF ~ % % CL ST 3.75 10 118 32 45 % 20 % 22.0 CF . . . SAND, . . . . . . . . Tan, coarse, with gravel, cemented . . . . . . . . . . SP SS 26/12 . . . . . . . 25.0 . . . 25 B.H. at 25.0' STRATIFICATION LINES REPRESENT APPROXIMATE REMARKS BOUNDARIES BETWEEN SOIL AND ROCK TYPES. IN SITU THE TRANSITION BETWEEN STRATA MAY BE MORE GRADUAL WATER LEVEL OBSERVATIONS. FEET DATE DRILLED Page 1 of 1 'Sl. ~ llerracon 5/17/2007 FIGURE 'l- ~ PROJECT NUMBER 5 No seepage observed. 94075192 Q. " ,~ '" :c <> " '" lD g GENERAL NOTES DRILLING & SAMPLING SYMBOLS: SS: Split Spoon _1_3/8"1.0., 2" D.o., unless otherwise noted ST: Thin-Walled Tube - 2" D.O., unless otherwise noted TC: TxDOT Cone Penetrometer Test CF: Continuous Flight Auger BS: Bulk Sample or Auger Sample HS: PA: HA: RC: WB: Hollow Stem Auger Power Auger Hand Auger Rock Core Wash Boring or Mud Rotary The number of blows required to advance a standard 2-inch 0.0. split-spoon sampler (SS) the last 12 inches of the total 18-inch penetration with a 140-pound hammer falling 30 inches is considered the "Standard Penetration" or "N-value". For TxDOT cone penetrometer (TC) the penetration value is reported as the number of blows required to advance the sampler 12 inches or penetration in inches after 100 blows using a 170-pound hammer falling 24 inches, reported as "blows perfoot: or inches per 100 blows and is not considered equivalent to the .Standard Penetration" or "N-value". WATER lEVEL MEASUREMENT SYMBOLS: WL: Water Level WS: WCI: Wet Cave in WD: DCI: Dry Cave in SCR: AS: After Boring ACR: While Sampling While Drilling Before Casing Removal After Casing Removal NlE: Not Encountered Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-term observations. DESCRIPTIVE SOil CLASSIFICATION: Soil classification is based on the Unified Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coars8i;jrained soils are defined on the basis of their in-place relative density and fin8i;jrained soils on the basis of their consistency. Unconfined ComDressive Strenath, Qu. Dsf < 500 500 - 1,000 1,001 - 2,000 2,001 - 4,000 4,001 - 8,000 8,000+ Standard Penetration or N-value (SS) Blows/Ft. <2 2-3 4-6 7-12 13-26 26+ RELATIVE DENSITY OF COARSE-GRAINED SOilS Standard Penetration or N-value (SS) Blows/Ft. 0-3 4-9 10 - 29 30 - 49 50+ CONSISTENCY OF FINE-GRAINED SOilS Consistency Very Soft Soft Medium Stiff Stiff Very Stiff Hard TxDOT Cone Penetrometer (TC) Blows/Ft Q-8 8-20 20-80 80 to 5"/100 5"/100 to 0"/100 Relative Densitv Very loose Loose Medium Dense Dense Very Dense RELATIVE PROPORTIONS OF SAND AND GRAVEL Descriptive Term(s} of other Percent of constituents Dry WelQht GRAIN SIZE TERMINOLOGY Maior Component of Sample Particle Size Trace With Modifier < 15 15 -29 >30 Boulders Cobbles Gravel Sand Silt or Clay RELATIVE PROPORTIONS OF FINES Descriptive Term(s) of other constituents Percent of Dry Weiaht Term Plasticitv Index Trace With Modifiers <5 5 -12 > 12 Non-plastic Low Medium High Over 12 in. (300mm) 12 in. to 3 in. (300mm to 75 mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm) Passing #200 Sieve (0.075mm) PLASTICITY DESCRIPTION o 1-10 11-30 30+ lrerracan FIGURE 6 UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests. 5011 Classification Group Symbol Group Name" GW Well-graded gravel' GP Poorly graded gravel' GM Silty gravel'G H GC Clayey gravel,.GH SW Well-graded sand' SP Poorly graded sand' SM Silty sandG.H1 SC Clayey sandG.H1 CL Lean clay"Ul ML SiltK.L.M OL Organic clay"Ul.N Organic siltK'M.o CH Fat clay"..M MH Elastic SiltK....M OH Organic clay"""'" Organic silr..Mo PT Peat Coarse-Grained Soils Gravels Clean Gravels Cu ~ 4 and 1 $ Cc $ 3' More than 50% retained More than 50% of coarse Less than 5% finesc Cu < 4 and/or 1 > Cc > 3' on the No. 200 sieve fraction retained on NO.4 sieve Gravels with Fines Fines classify as ML or MH More than 12% finesc Fines classify as CL or CH Sands Clean Sands Cu~6and1$Cc$3' 50% or more of coarse Less than 5% fineso Cu < 6 and/or 1 > Cc > 3' fraction passes No. 4 sieve Sands with Fines Fines classify as ML or MH More than 12% fineso Fines Classify as CL or CH Fine-Grained Soils Silts and Clays inorganic PI> 7 and plots on or above "A" line' 50% or more passes the Liquid limit less than 50 PI < 4 or plots below "A" line' No. 200 sieve organic Liquid limit - oven dried < 0.75 Liquid limit - not dried Silts and Clays inorganic PI plots on or above "A" line Liquid limit 50 or more Pilots below "A" line organic Liquid limit - oven dried < 0.75 Liquid limit - not dried Highly organic soils Primarily organic matter, dark in color, and organic odor Hlf fines are organic, add "with organic fines" to group name. I If soil contains ~ 15% gravel. add "with gravel" to group name. J If Allerberg limits plot in shaded area. soil is a CL-ML. silty clay. Kif soil contains 15 to 29% plus No. 200. add "with sand" or "with gravel," whichever is predominant. llf soil contains ~ 30% plus No. 200 predominantly sand, add "sandy" to group name. M If soil contains ~ 30% plus No. 200. predominantly gravel, add "gravelly" to group name. Npl ~ 4 and plots on or above "A" line. o PI < 4 or plots below "A" line. PPI plots on or above "A" line. a PI plots below "A" line. ABased on the material passing the 3-in. (75-mm) sieve BIf field sample contained cobbles or boulders. or both. add "with cobbles or boulders. or both" to group name. cGravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with sill. GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt. GP-GC poorly graded gravel with day. oSands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with sill. SW-SC well-graded sand with clay. SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay (030 )2 ECU = 0601010 Cc = 0,0 x De<) F If soil contains ~ 15% sand, add "with sand" to group name. Glf fines classify as CL-ML. use dual symbol GC-GM. or SC-SM. --1 j i I -1 I I 60 I For classification of fine-grained solis and fine-grained fraction 50 '- of coarse-grained soils - ------- Equation of "A" -line Horizontal at PI=4 to LL=25.5. 40'- then PI=0.73 (LL-20) Equation ot "U" - line Ver1ical at LL=16 to PI=7. 30 then PI=O.9 (LL-B) ~ X W o Z ~ (3 i= en ::5 a.. 20 MH or OH 10 7 --- 4 - o o 10 16 20 100 110 90 60 70 80 50 30 40 lrerracon LIQUID LIMIT (LL) FIGURE 7 Form 1 "~I9B