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ST9401-SY 950518Geotechnical Study DENTON TAP ROAD COPPELL, TEXAS Presented to c~ty of coppdw May 1995 Prepared by the Fort Worth, Texas Office of Eracon ENGINEERING AND ENVIRONMENTAL SERVICES Offices Nationwide 5701 East Loop 820 South Fort Worth, Texas 76119 817/478-8254 Metro 572-3411 5701 East Loop 820 South · Fort Worth, Texas 76119-7051 · (817) 478-8254 · Metro (817) 572-3411 · Fax (817) 478-8874 May 18, 1995 Report No. 62958-001-001 Mr. Kenneth M. Griffin, P.E. Assistant City Manager, City Engineer City of Coppell P.O. Box 478 Coppell, Texas 75019-0478 Geotechnical Study Denton Tap Road Denton Creek to Highland Drive Coppell, Texas Dear Mr. Griffin: The results of our geotechnical study for the proposed road and bridge improvements are presented in the following engineering report. Recommendations for foundations and earthwork are provided in this report. Field and laboratory test data, developed for this study, are also included. The study was authorized by your signature and return of the contract dated April 12, 1995, and received on April 14, 1995. Since this report is being submitted during the design phase, some changes in the project could occur after our report is submitted. Therefore, we request the opportunity to review this report with respect to final design. We appreciate the opportunity to provide geotechnical engineering services on your project. Should you have any questions, or find we can be of further service, please let us Distribution: (2) Above (2) Mr. Ulys Lane, III, P.E. - Weir & Associates, Inc. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 !' CONTENTS 1 INTRODUCTION 1.1 Project Description 1.2 Purpose and Scope 2 FlELD EXPLORATION AND LABORATORY TESTING 2.1 Field Exploration 2.2 Laboratory Testing 3 SUBSURFACE CONDITIONS 3.1 General 3.2 Stratigraphy 3.2.1 Soil Conditions 3.2.2 Primary Unweathered Woodbine Formation 3.2.3 Hard Rocks 3.3 Groundwater Observations 3.4 Site Geology 4 FOUNDATIONS 4.1 Foundation Type, Depth, and Allowable Loading 4.2 Drilled Shaf~ Construction 5 BELOW-GRADE STRUCTURES 5.1 Lateral Earth Pressures 5.2 Wall Drainage 5.3 Backfill Placement and Compaction 5.4 Retaining Wall Footings 6 SLOPE STABILITY ANALYSIS 6.1 General 6.2 Sections Selected for Analysis 6.3 Input Parameters 6.4 Results of Stability Analysis 7 CONSTRUCTION SLOPES AND TEMPORARY SHORING 7.1 General 7.2 Excavations and Slopes 7.3 Responsible Person 7.4 Permanent Slopes 2 2 3 4 4 4 4 4 5 5 5 6 6 7 9 9 9 10 11 13 13 13 13 13 15 15 15 16 16 ii ~ FW/I/2958/DENTAPRD. DOC/512-95/bg: 4 Rev. 0, 05/18/95 62958-001-001 CONTENTS (CONT'D) 7.5 Groundwater/Dewatering 8 EARTHWORK 8.1 Subgrade Preparation 8.2 Placing of Material 8.3 Moisture and Density Control 8.4 Imported Borrow Material 8.5 Trench/Wall Backfill 8.6 Contamination Testing and Certification 9 PAVEMENT SUBGRADE 9.1 General 9.2 Subgrade Treatment 9.3 Construction Procedures 9.3.1 Application 9.3.2 Mixing 9.3.3 Compaction 10 REPORT CLOSURE 11 LIlVlITATIONS 16 17 17 18 18 20 20 21 22 22 22 22 22 23 23 24 26 iii Rev. 0,05/18/95 FW/F2958/DENTAPRD.DOC/512-95~g:4 62958-001-001 TABLES AND ILLUSTRATIONS Table 5-1 Table 6-1 Table 6-2 12 14 14 FW/F2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 Rev. 0, 05/18/95 1 INTRODUCTION 1.1 Project Description This report presents the results of a geotechnical study for the proposed road and bridge improvements along Denton Tap Road from just south of the existing Denton Creek bridge to near Highland Drive in Coppell, Texas. The existing two lane road will be widened to six lanes and a new bridge will be constructed over Denton Creek. 1.2 Purpose and Scope The purpose of this geotechnical study has been to determine the general subsurface conditions, evaluate the engineering characteristics of the subsurface materials encountered, and develop recommendations for the type or types of foundations suitable for the project. Geotechnical parameters for retaining walls and earthwork are also provided. To accomplish its intended purposes, the study has been conducted in the following phases: (1) drilling sample bofings to determine the general subsurface conditions and to obtain samples for testing; (2) performing laboratory tests on appropriate samples to determine pertinent engineering properties of the subsurface materials; and, (3) performing engineering analyses, using the field and laboratory data to develop geotechnical recommendations for the proposed construction. FW/I/2958/DENTAPRD,DOC/512-95/bg:4 62958-001-001 ] Rev. 0, 05/18/95 2 FIELD EXPLORATION AND LABORATORY TESTING 2.1 Field Exploration Sub surface conditions were explored by 2 borings drilled to a depth of 65 to 71 feet in the proposed bridge area, and 3 borings drilled to a depth of 10 feet along the proposed road. The borings were drilled April 28, May 1 and 2, 1995, at the approximate locations shown on the Plan of Borings in Appendix A, Figure A. 1. The boring logs are also included in Appendix A, on Figures A. 3 through A. 9, and a key to terms and descriptions on the logs is provided on Figure A.2. Borings were located in the field by taped measurement from existing features along the roadway. Elevations of the borings were interpolated from topographic contour maps of the area provided to us by Weir & Associates, Inc. (Weir). The location and elevation of the borings should be considered accurate only to the degree implied by the methods used in their determination. The boring logs shown in this report contain information related to the types of materials encountered at specific locations and times and show lines delineating the interface between these materials. The stratification lines represent the approximate boundary between soil types and the transition can be gradual. Soil and rock descriptions on the borings logs are a compilation of field data, as well as from laboratory testing of samples. The logs also contain our field representative's interpretation of conditions that are believed to exist in those depth intervals between the actual samples taken. Therefore, these boring logs contain both factual and interpretative information. Relatively undisturbed samples of cohesive soils encountered in the borings were taken by rapidly pushing a 3-inch OD thin-walled tube sampler (ASTM D 1587) a distance of approximately 1 to 2 feet into the soil with hydraulic cylinders from the drill rig. Depths at which these samples were taken are designated "U" are indicated in the "Sample" column of the boring logs. After a tube was recovered from a boring, the sample was carefully extruded in the field, observed visually, and logged. A representative portion was selected, wrapped, and sealed to prevent loss of moisture and to protect the sample during transportation. Estimates of the consistency of the cohesive soil samples were obtained in the field using a hand penetrometer, which is factory calibrated in units of tons per square foot (tsf). The result of a hand penetrometer reading is recorded at a corresponding depth in the "Penetrometer, TSF" column of the boring logs. When the capacity of the hand penetrometer is exceeded, the value of 4.5+ is recorded. The Texas Department of Transportation (TxDOT) cone penetrometer test was used to evaluate the sandy shale and sandstone. Either the number of blows required to produce FW/I/2958/DENTAPRD.DO C/512-95/bg:4 62958-001-001 Rev. 0, 05/18/95 12 inches of penetration, or the inches of penetration due to 100 blows of the hammer are noted on the boring logs designated "T" in the "Penetration Resistance" column. Disturbed samples were taken by driving a standard ASTM 2-inch OD split-spoon sampler (ASTM D 1586) a distance of 18 inches into the soil with a 140-1b hammer falling freely a distance of 30 inches. Where resistance was high, the number of inches of penetration for 50 blows of the hammer was recorded. Depths at which the split-spoon samples were taken in these borings are designated "S" in the "Sample" column of the boring logs. The number of blows required to drive the sampler the final 12 inches of penetration or the inches of penetration for 50 blows is recorded at a corresponding depth in the "Blows Per Ft" column of the boring logs. Representative portions of each split-spoon sample were selected and sealed in plastic bags to prevent loss of moisture. The sandy shales were also sampled with an NX size double-tube core barrel fitted with a carbide bit. The amount of core recovered is recorded on the boring logs in the "Recovery, %" column and is designated "C." All samples were extruded in the field, visually classified, sealed and packaged for transportation. Groundwater observations made during the course of the field exploration are included on the boring logs. Groundwater level measurements refer only to those observed at the times and places indicated, and can vary with time, geologic condition, construction activity, rainfall, and other factors. 2.2 Laboratory Testing Representative samples of the soils were tested in the laboratory. Liquid limit and plastic limit tests (Atterberg limits) (ASTM D 4318) and grain size tests (ASTM D 1140) were performed on soil samples from the borings in order to classify them according to the Unified Soil Classification System (USCS) (ASTM D 2487). Strength properties of the cohesive soil and shale were evaluated by performing uncon~ned compression tests (ASTM D 2166). The results of these tests are reported as Qu values (in tons per square foot). Moisture and density determinations were also made on samples to determine the in situ conditions. Results of Atterberg Limits, percent passing no. 200 sieve, moisture content, unit dry weight, and unconfined compression tests are provided in the right-hand portion of the respective boring logs and a summary is included in Appendix B. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-0014301 3 Rex,. O, 05/18/95 3 SUBSURFACE CONDITIONS 3.1 General Soil deposits consist of alluvial soils deposited by Demon creek and residual Woodbine soils. The primary unweathered Woodbine formation is a complex interbedded system of shale, sand, and sandstone. The sands vary from uncemented soils to cemented "rock- like" materials. The shales typically grade from sandy and silty to clayey and carbonaceous. 3.2 Stratigraphy 3.2.1 Soil Conditions The alluvial and residual soils vary widely in character from fine silty sands to highly plastic clays. Typically, these soils were encountered within the upper 46 to 47 feet explored by B-1 and B-2. Liquid limits of 29 to 60 and plasticity index (PI) values of 16 to 38 were obtained on samples of these soils. The unconfined compressive strengths of the cohesive soils generally varied from less that 1 tsf to over 4 tsf. The sands are often nonplastic to slightly plastic. N-values for the sand and gravel, determined from the standard penetration tests, ranged from about 2 for 12 inches to over 50 indicating a wide range in relative density of very loose to very dense. Typically, the sand and gravel varies with respect to density. 3.2.2 Primary Unweathered Woodbine Formation The primary unweathered Woodbine Formation materials consisted of sandy shale, clay shale, shaly sand, sand, sandstone, siltstone, and limey sandstone. These materials are generally light gray, gray and dark gray in color, and within some depths are brownish- gray to black. The shaly materials are typically very stiff to moderately hard in consistency and the sand/sandstone materials are dense to very dense. Uncon~ned compressive strength tests performed on the primary unweathered materials revealed values ranging from approximately 4 to 50 tsf. The wide range in values is typical of the Woodbine Formation, and reflects the variable nature of materials themselves, particularly the degree of cementation of the sandy zones, the clay-like texture of the shale, slickensided fractures, and clay layers. Disturbance during sampling can also affect the sample test results. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 4 Rev. 0, 05/18/95 The cone penetrometer test generally provides a more realistic indication of the bearing capacity of the Woodbine materials, as compared to the uncon~ned compression test. Cone penetrometer values ranging from approximately 1.5 inch to 12 inches of penetration per 100 blows were recorded. Most values were in the 1.5-inch to 4-inch range. 3.2.3 Hard Rocks Rock materials were also encountered in the borings for the new bridge. The rocks are described as limy sandstone, grading to sandy limestone, and are very hard and highly cemented. Experience with these very hard materials has revealed them to be in the form of irregular-shaped boulders and/or layers varying in thickness from less than 1 foot to over 10 feet. Construction of foundations often requires rock-tooth augers, drop chisels, core barrels, or other rock excavation equipment where the hard rocks are encountered. 3.3 Groundwater Observations Groundwater, in the form of a perched condition, exists within the limits of the area explored. Indications are that the groundwater is perched within the permeable sand and gravel which lie above the sandy shale and sandstone as well as within sand layers present in the shale. Water-level measurements are recorded at the bottom of the log. Fluctuations in the water table are anticipated and are often dependent upon climatic conditions (rainfall, drought, etc.), the permeability of the sand, cross bedding of sands and clays, and adjacent grades. The water level at the time of construction could be higher or lower than the depths recorded to date. 3.4 Site Geology This site is underlain by the Woodbine geological formation and alluvial soils of the adjacent creek. Sand, gravel, clays, sandstone, and shales generally compose this formation. Iron oxides, lignite, gypsum, and py~te are also found throughout the formation. Dense and irregular shaped masses or hard sandstone occur at random throughout the formation and are commonly referred to as "boulders." Structurally, the Woodbine is quite complex in that it contains numerous small faults, lenticular masses, and consequent divergent dips. It is often difficult, if not impossible, to trace a particular bed for any distance. Water is found at various levels in the formation, some as perched tables in sand lenses. The outcrop of the Woodbine Formation is generally marked by sandy surface soils which support a dense growth of oak trees. FW/I/2958/DENTAPRD.DO C/512-95/bg:4 62958-001-001 5 Rev. 0, 05/18/95 4 FOUNDATIONS 4.1 Foundation Type, Depth, and Allowable Loading The bearing materials suitable for support of moderate to heavy column loads include gray sandy shales, shaly sands, and sandstones encountered approximately 46 to 46.5 feet below existing grade. Auger-excavated, reinforced concrete, straight-sided drilled shafts will provide a desirable means of transmitting structural loads to the beating material. An allowable end-bearing value of 20,000 pounds per square foot can be used to design the shaft. A skin friction value of 3,200 pounds per square foot can be used for that portion of the shaft perimeter in direct contact with the beating material after 1 foot of penetration and below the temporary steel casing. For pier resistance to pullout, a friction value of 1,600 pounds per square foot can be used. Regardless of loads, all shafts should penetrate into the bearing material a minimum of 5 feet. Beating values should be selected to include a factor of safety of 3 with regard to shear failure, dead load only. Foundations proportioned in accordance with these values will experience negligible settlement after construction. The weight of the footings below final grade may be neglected in determining the design loads. It is anticipated that temporary steel casing will be required to properly construct the shafts. The following is a summary of the foundation recommendations: Foundation type: Straight sided, drilled shafts Beating stratum: Gray sandy and clayey shale, shaly sand, and sandstone Bearing stratum encountered approximately: 46 to 47 feet below existing grade Minimum penetration into bearing stratum: 5 feet Allowable bearing pressure: 20,000 pounds per square foot (psi) Allowable skin friction: 3,200 psf (for compression loads) Resistance to pier pullout: 1,600 psf Minimum penetration into beating stratum prior to using skin friction: 1.0 foot FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 6 Rev. 0, 05/18/95 Temporary steel casing: Casing is anticipated to be required on all of the shafts. Reinforcing steel should be placed within the drilled shafts to resist tensile forces caused by expansion within the surrounding clays. Uplift forces and resulting tension forces will be exerted on shafts during volume changes in the expansive soils. Uplift pressures are estimated to be approximately 1,000 pounds per square foot acting over the perimeter of the drilled shaft for a depth of 12 feet. 4.2 Drilled Shaft Construction Drilled shaft construction should be monitored by a representative of the project geotechnical engineer to observe, among other things, the following items: Identification of bearing material. Adequate penetration of the shaft excavation into the bearing layer. The base and sides of the shaft excavation are clean of loose cuttings. That a sufficient head of plastic concrete is maintained within the casings at all times during their extraction to prevent the inflow of water. Precautions should be taken during the placement of reinforcing steel and concrete to prevent loose, excavated soil from falling into the excavation. Concrete should be placed as soon as practical after completion of the drilling, cleaning and inspection. Excavation for a drilled shaft should be filled with concrete before the end of the workday, thus preventing excessive deterioration of the bearing material. Prolonged exposure or inundation of the bearing surface with water will result in changes in strength and compressibility characteristics. If delays occur, the drilled shaft excavation should be slightly deepened and cleaned, in order to provide a fresh bearing surface. As previously discussed, dense to very dense sands and shaly sands are present within the primary Woodbine Formation. These predominantly granular layers are suitable beating materials for drilled shaft foundations. Depending on groundwater conditions, however, it may be necessary to extend the temporary casing through any sand layers that overlie shale in order to satisfactorily reduce seepage into the shaft during construction. The concrete should be placed in a manner to prevent the concrete from striking the reinforcing cage or the sides of the excavation, which could not only affect the positioning of the cage but may also result in segregation of the concrete mixture. A bottom discharge hopper is recommended for this purpose. A drilling rig of sufficient size and weight will be necessary, since the possibility of encountering hard rock layers exists. The rig must be capable of drilling and/or coring 7 Rev. O, 05/18/95 FW/F2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 through the hard layers to reach the desired bearing stratum and achieve the required penetration. Caution should be exercised during construction to prevent the bearing of a shaft on soft material within the founding stratum. Should any shaft excavation terminate on a soft seam or layer within the shale, after the required penetration has been achieved, the shat~ should be deepened until the next layer of firm shale or dense sand has been encountered. The drilling work could require rock-tooth augers, core barrels, and drop chisels to achieve the proper depth. See Boring logs and Section 3, Item 3.2.3. As noted above, it is expected that temporary casing will be required for construction. Water seepage into the pier shafts may occur even if the shafts are cased. Therefore, provisions should be made in the project specifications for underwater concrete placement if more than 4 inches of water is present in the bottom of the pier hole. A closed tremie should be used for underwater concrete placement and the end should be kept below the top of the concrete in the pier hole. A nominal shaft diameter of at least 24 inches is recommended to facilitate concrete placement with a tremie. 8 Rev. 0, 05/18/95 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 5 BELOW-GRADE STRUCTURES 5.1 Lateral Earth Pressures To reduce lateral earth pressures and to provide a porous drainage media, it is recommended that the walls be backfilled with granular material. On-site clays have relatively high plasticity index (PI) values and are expected to undergo seasonal volume changes and are therefore not recommended for backfill. Recommended lateral earth pressures for rigid walls with top restraint and flexible walls, such as retaining walls, are given in Table 5-1, Lateral Earth Pressures, for various types of backfill. The values given assume a horizontal backfill surface at the top of the wall. Construction of foundations or on-grade slab loads near below-grade walls will apply an additional horizontal load to the walls. A uniform horizontal pressure due to surcharge loads from construction and normal loadings, equal to the applicable earth pressure coefficient multiplied by the surcharge load, should be included in the wall design. Surcharge loads farther than the height of the wall back from the top of the below-grade wall do not need to be considered. For wails constructed below the design water levels, the higher equivalent fluid pressures, which account for pressures from water, should be used if a wall drainage system is not used. If a drainage system is incorporated, the design of walls can use the equivalent fluid pressures given for drained conditions. 5.2 Wall Drainage A wall drainage system is recommended to reduce pressure on below-grade walls. The drainage system should include a vertical granular drain and a perimeter collection system. The vertical drain should be at least 24 inches wide and extend to within three feet of the surface. The top three feet of backfill should consist of cohesive fill to limit surface water infiltration into the wall drain. The granular drainage material should have a gradation similar to ASTM C 33 Fine Concrete Aggregate. A prefabricated wall drainage mat can be substituted for the 2 foot of sand wall drain material. If the entire wall backfill consists of granular backfill, a separate wall drain is not necessary. The perimeter drain collection system for the vertical drain should consist of slotted or perforated pipe surrounded with a washed aggregate which is in turn surrounded by suitable nonwoven geotextile fabric similar to Treyira Sl125 or Quline QS0 or an equivalent. The pipe should have sufficient strength to support the backfill weight without FWaI2958/DENT APRD. DOC/512 -95/bg: 4 62958-001-001 9 Rev. O, 05/18/95 crushing. The aggregate should be at least six inches thick over the top and around the sides of the pipe, and have a gradation similar to ASTM C 33, Size No. 57. The collection system should be connected to a sump or some other discharge method. Flood water or other water should not be allowed to backflow into the underdrainage system. 5.3 Backfill Placement and Compaction Fill behind below-grade walls should be compacted, preferably by hand-operated tampers or light compaction equipment immediately adjacent to the wall. Heavy rollers should not be allowed closer than about six feet from the wall since high compactive effort will increase the lateral earth pressures. Where light compaction equipment and hand- operated compactors are used, the maximum lift thickness should be 4 inches. The fill should be compacted in maximum of 4-inch loose lifts to 70 percent relative density (ASTM D 4253 and D 4254). The nonexpansive, select fill material should be placed in maximum of 8-inch lifts and compacted to a density ranging between 92 and 98 percent of maximum standard Proctor (ASTM D 698) dry density at a moisture content ranging from 2 percentage points below optimum to 5 percentage points above (-2 to +5) for the backfill materials. The contractor may have to maintain a more narrow range (within the maximum allowable) in order to consistently achieve the specified density for some soils or under some conditions. The moisture content and density of all fill material should be maintained at the specified range of moisture and density. Backfill should be placed and compacted in a carefully controlled manner to reduce the magnitude of potential settlement. Experience has indicated that some settlement of the well-compacted fill should be anticipated for fills greater than approximately 5 feet thick. This settlement will result in movement of supported sidewalks or floor slabs placed on fill, and shear loads on pipes passing through the fill into the structure. Select fill should consist of a clayey sand or sandy clay and sand mixture with less than fifty percent passing the No. 200 sieve, a liquid limit less than 35, a PI between 4 and 15, with at least 85 percent passing the No. 4 sieve. It is recommended that a relatively impervious soil be placed in the upper layer of the backfill around the exterior of the structure for the purpose of minimizing the amount of infiltration of the outside surface water. It is recommended that the uppermost 2 feet of backfill material consist of a sandy clay or clay with a liquid limit in the range of 35 to 45, a PI in the range of 20 to 25, and the mount passing the No. 200 sieve greater than fifty percent. The ground surface should slope away from the structure on a gradient of 11/2 to 3 percent, such that surface water does not pond adjacent to the structure within the backfill zone. Topsoil and seeding should be accomplished to help prevent drying and cracking this uppermost layer of soil. The slope should be maintained on a 11/2 to 3 percent gradient after topsoil is placed. The 2-foot layer of cover soil should be compacted in maximum of 8-inch lifts to a density ranging between 95 and 100 percent of FW/I/2958/DENTAPRD.DOC/5 12-95/bg:4 62958-001-001 10 Rev. 0, 05/18/95 standard Proctor at a moisture content ranging from optimum to 4 percentage points above optimum (0 to +4). If concrete flatwork is placed at final grade, the use of a relatively impervious soil within the upper 2 feet is not necessary. The flatwork should extend at least 2 feet beyond the backfill zone. All joints should be filled with a flexible joint sealer. If the flatwork extends only into a portion of the backfill zone, use of the 2 feet of cover soil should be required within the remainder of the area. 5.4 Retaining Wall Footings It is anticipated that continuous footings will be used for the proposed retaining walls along Denton Tap Road. The footing should be placed a minimum of 3 feet below the lowest adjacent grade. An allowable bearing pressure of 2,500 pounds per square foot (PSF) or less (F. S .=3) can be used to design the footing. The footing should be placed on undisturbed soils or compacted and tested fill. FW/F2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 11 Rev. 0, 05/18/95 6 SLOPE STABILITY ANALYSIS 6.1 General UTEXAS3, a slope stability program developed to measure slope stability by the Spencer, Bishop, Corps of Engineers' modified Swedish, or Lowe and Karafiath's method of slices, was utilized for the stability analyses of the 2(H): I(V) slope adjacent to the bike/walking path and the 3(H): 1 (V) slope adjacent to the arterial roadway. Circular failure surfaces using the Spencer method of slices were used for both computer stability analyses. 6.2 Sections Selected for Analysis Slope stability analyses using circular failure surfaces were performed on typical cross sections for 2(H):I(V) slopes adjacent to the bike/walking path and 3(H):I(V) slopes adjacent to the arterial roadway. Figures 1 and 2 in Appendix C illustrate the cross sections selected and the critical failure surface calculated by the stability program. 6.3 Input Parameters The geometry of the cross sections was determined from the drawings associated with the construction of the arterial roadway. The subgrade characteristics for both sections were selected based on review of the boring logs from bofings in the vicinity of the sections. A sandy clay material was modeled in both sections as the subgrade material. Properties of the subgrade were selected based on review of the boring logs and based on engineering experience and judgment. The traffic loading on the arterial roadway section was modeled using a uniform surface pressure of 42 psf and with a seismic coefficient of 0.01. Table 6- 1 summarizes the unit weight and strength parameters utilized for the stability analyses. 6.4 Results of Stability Analysis The results of the stability analyses indicate that the proposed slopes are stable under the conditions analyzed. Table 6-2 summarizes the results of the stability analyses and compares the calculated factor of safety to the recommended minimum factor of safety. The recommended minimum factors of safety for the conditions analyzed were determined using recommendations from the Corps of Engineers "Design and Construction of Levees" manual (EM 1110-2-1913 ). The figures illustrating the sections analyzed and the computer stability analysis output is attached in Appendix C. FW/I/2958/DENTAPRD. DOC/5 12-95Pog:4 ] 3 Rev. 0, 05/18/95 62958-001-001 Table 6-1 Summary of Material Weight and Strength Properties Moist Unit Cohesion Internal Material Type Weight (psf) Friction (degrees) (lb/ft3) Sandy Clay Subgrade 125 [ 200 [ 16 Condition Analyzed Slope Adjacent to Bike/Walking Path Slope Adjacent to Arterial Roadway Table 6-2 Summary of Slope Stability Analysis Miramum Factor of Recommended Acceptable Factor of Safety Generated Miramum Factor of Safety Safety 2.3 1.5 Yes 2.3 1.5 Yes FW/I/2958/DENTAPRD.DOC/512-95/bg:4 ]4 Rev. 0, 05/18/95 62958-001-001 7 CONSTRUCTION SLOPES AND TEMPORARY SHORING 7.1 General The Owner and the Contractor should make themselves aware of and become familiar with applicable local, state and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards. Construction site safety generally is the sole responsibility of the Contractor, who shall also be solely responsible for the means, methods and sequencing of construction operations. We are providing this information solely as a service to our client. Under no circumstances should the information provided below be interpreted to mean that EMCON is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred. 7.2 Excavations and Slopes The Contractor should be aware that slope height, slope inclination, or excavation depths (including utility trench excavations) should in no case exceed those specified in local, state, or federal safety regulations, e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or successor regulations, such regulations are strictly enforced and, if they are not followed, the Owner, Contractor and/or earthwork and utility subcontractors could be liable for substantial penalties. The soils to be penetrated by the proposed excavation may vary significantly across the site. Our soil classifications are based solely on the materials encountered in widely spaced exploratory bofings. The Contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, we recommend that we be contacted immediately to evaluate the conditions encountered. If any excavation, including a utility trench, is extended to a depth of more than 20 feet, it will be necessary to have the side slopes designed by a professional engineer registered in Texas. As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to no less than equal the slope height. The exposed slope face should be protected against the elements. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 15 Rev. 0, 05/18/95 7.3 Responsible Person The Contractor's "responsible person, as defined in 29 CFR Part 1926," should evaluate the soil exposed in the excavations as part of the Contractor's safety procedures. The Contractor's "responsible person" should establish a minimum lateral distance from the crest of the slope for all vehicles and spoil piles. Likewise, the Contractor's "responsible person" should establish protective measures for exposed slope faces. Monitoring of temporary slopes, trenches and dewatering during construction should be undertaken by the contractor to detect early warnings of movement within slopes, structures, pavements, etc. 7.4 GroundwaterlDewatering Groundwater could be encountered within the excavations, depending on the depth of excavation and ground-water level. The decision as to the method for handling ground water, depends upon such factors as the soil characteristics within the excavation depth, site hydrogeology, the size and depth of the excavation, method of excavation and side slopes, the proximity of existing structures, their depth and foundation type and the design and function of the proposed structure. Choice of a particular method or a combination of methods for dewatering any given excavation will require an analysis of the subsurface soil and ground-water conditions, the requirements of the work and the contractor's experience with dewatering excavations. Once these facts are known, consideration can be given to the various methods available for handling ground water and a selection can be made as to a suitable method. A certain amount of flexibility is important in the dewatering process. Although a geotechnical study has been made, some unanticipated subsurface conditions could exist. 16 Rev. 0, 05/18/95 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 8 EARTHWORK 8.1 Subgrade Preparation Stripping should consist of the removal of all topsoil, roots, vegetation, and rubbish not removed by the clearing and grubbing operation. The actual stripping depth should be based on field observations with particular attention given to old drainage areas, uneven topography, and excessively wet soils. The stripped areas should be observed to determine if additional excavation is required to remove weak or otherwise objectionable materials that would adversely affect the fill placement. The subgrade should be firm and able to support the construction equipment without displacement. Sof~ or yielding subgrade should be corrected and made stable before construction proceeds. The subgrade should be proof rolled to detect soR spots, which if they exist, should be reworked. Proof rolling should be performed using a heavy pneumatic-tired roller, loaded dump truck, or similar equipment weighing approximately 25 tons. The proof rolling operations should be observed by the project geotechnical engineer or his representative. Existing slopes which will receive fill should be loosened by scarifying or plowing to a depth of not less than 6 inches. The fill material should be benched into the existing slope in such a manner as to provide adequate bonding between the fill and slope, as well as to allow the fill to be placed in horizontal lit~s. Prior to placement of compacted fill in any section of the embankment, at~er depressions and holes have been filled, the foundation of such sections should be compacted to the same density and moisture requirement as the embankment. In areas of the subgrade which, in the opinion of the project geotechnical engineer, are too sot~, wet or otherwise unstable to allow fill construction to begin, the use of plating and/or plating in combination with a geogrid may be required. Providing detailed recommendations for plating and/or use of geogrids for this project is beyond the scope of our work for this project. The traffic of heavy equipment, including heavy compaction equipment, may create pumping and general deterioration of the soil. Occasionally, some soils have to be excavated, mixed and dried, and replaced. At times, excavating and replacing with selected soils and/or chemically treating in-place materials is required before an adequate subgrade can be achieved. Therefore, it should be anticipated that some construction difficulties will be encountered during periods when these soils are saturated. 17 Rev. 0, 05/18/95 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 8.2 Placing of Material Fill materials should be placed on a properly prepared subgrade as specified. The combined excavation, placing, and spreading operation should be done in such a manner to obtain blending of material, and to provide that the materials, when compacted in the embankment, will have the most practicable degree of compaction and stability. Materials excavated from cut sections and/or borrow sources and hauled to construct fills must be mixed and not segregated, except where such segregated soil zones are required. All fill should be placed in horizontal lifts. Filling along (parallel to) slopes should not be permitted. In areas where slopes will be constructed using fill, the fill should extend beyond finished contours and cut back to grade. If the surface of the fill is too smooth and hard to bond properly with a succeeding layer, the surface should be roughened and loosened by discing before the succeeding layer is placed. Where fill is to be placed next to existing fill, that fill should be removed to unweathered, dense material. Each layer should be benched and disced as adjoining lifts are placed. Material hauling equipment should be so routed over the embankment surface to distribute the added compaction afforded by the rolling equipment, and to prevent the formation of ruts on the embankment surface. The surface of the fill should be graded to drain freely and maintained throughout construction. During the dumping and spreading process, the contractor should maintain at all times a force of men adequate to remove all roots and debris and all rocks greater than 4 inches in maximum dimension from the fill materials. No rocks should be allowed within the final 8 inches of subgrade. 8.3 Moisture and Density Control Following the spreading and mixing of the soil on the embankment, it should be processed by discing throughout its thickness to break up and provide additional blending of materials. Discing should consist of at least two passes of the disc plow. Additional passes of the disc plow should be made necessary to accomplish breaking up and blending the fill. The recommended loose lift thickness is 8 inches. The moisture content of the soil should be adjusted, if necessary, by either aeration or the addition of water to bring the moisture content within the specified range. Water required for sprinkling to bring the fill material to the proper moisture content should be applied evenly through each layer. Any layers which become damaged by weather conditions should be reprocessed to meet specification requirements. The compacted surface of a layer of fill should be lightly loosened by discing before the succeeding layer is placed. When the moisture content and the condition of the fill layer are satisfactory, compaction should be made with a tamping-foot roller (sheepsfoot with cleaner teeth) either towed by a FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-.001 1 R Rev. 0, 05/18/95 crawler-type tractor or the self-propelled type. The tamping-foot length should be a minimum of 8 inches. Vibratory tamping rollers may be required for compacting some types of fill material. The fill material should be compacted to a minimum of ninety-five (95) percent of the maximum dry density as determined by the moisture-density relations test method ASTM Designation D 698. The moisture content should range between 2 percentage points below optimum to 5 percentage points above optimum (-2 to +5) for soils with a plasticity index (PI) of less than 20. For soils with a PI of 20 or greater, the moisture content should range between optimum and 5 percentage points above optimum (0 to +5). The moisture content ranges specified are to be considered as maximum allowable ranges. The contractor may have to maintain a more narrow range (within the maximum allowable) in order to consistently achieve the specified density for some soils or under some conditions. The moisture content and density of all fill material should be maintained at the specified range of moisture and density. Fill behind below-grade walls should be compacted with hand-operated tampers or light compaction equipment immediately adjacent to the wall. A loose lift thickness of four to six inches is typically required for hand-operated tampers. Backfill on structures receiving fill on both sides should be kept within two feet of the opposite side. Refer to Section 5.3 for further discussion. Field density tests should be taken as each lift of fill material is placed. One field density test per lift for each 5,000 square feet of compacted area is recommended. A minimum of 2 tests per lift should be required. The earthwork operations should be observed and tested on a continuing basis by an experienced geotechnician working in conjunction with the project geotechnical engineer. The contractor should assist the geotechnician in taking tests to the extent of furnishing labor and equipment to prepare the areas for testing and curtailing operations in the vicinity of the test area during testing. Each lift should be compacted, tested, and approved before another lift is added. The purpose of the field density tests is to provide some indication that uniform and adequate compaction is being obtained. The actual quality of the fill, as compacted, should be the sole responsibility of the contractor and satisfactory results from the tests should not be considered as a guarantee of the quality of the contractor's filling operations. All slopes, whether temporary construction slopes or permanent embankment should be designed to allow drainage at planned areas where erosion protection can be provided, instead of allowing surface water to flow down unprotected slopes. Vegatative ground cover should be provided as soon as practical to completed slopes. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 ]9 Rev. O, 05/18/95 8.4 Imported Borrow Material Imported fill materials, used along the roadway, should consist of soil with a liquid limit (LL) less than 45 and a plasticity index (PI) less than 25. The fill should be free of vegetation, roots, debris, rocks, or other objectionable material. Prior to delivery of off- site soils, the owner or engineer should be notified. The requirements provided in Item 8.6 should be followed. 8.5 Trench/Wall Backfill Trench backfill for utilities should be properly placed and compacted. Dense or dry backfill can swell and create a mound along the ditch line. Loose or wet backfill can settle and form a depression along the ditch line. Distress to overlying structures, pavements, side walks, etc. can occur if heaving or settling happens. A granular bedding material is recommended for pipe bedding. Clean coarse sand, well- rounded pea gravel, or well graded crushed rock make good bedding materials. Care should be taken to prevent the backfilled trench from becoming a french drain and piping surface or subsurface water beneath structures or pavements. The use of concrete cut-off collars or clay plugs may be required to prevent this from occurring. The following minimum test frequency will be used; however, the test frequency should comply with project specifications if more frequent tests are specified. Vertical Interval: 12-inch lifts or alternate 6-inch lifts, depending on construction equipment and soil Horizontal Spacing: Wall Backfill - 100 feet Utility Trench Backfill under Pavement and Embankments - 250 feet Minimum - 3 tests per section per 12-inch interval Test locations should be staggered horizontally 20 to 50 feet (depending on trench length) for succeeding intervals so that tests do not fall over previous tests. Additionally, for trench widths greater than 2 feet, stagger the tests for each interval off center line. Moisture/Density Requirements: Trench Types Compaction (% of Standard Proctor) Moisture Content (% Points from Optimum) Wall 92 - 98 -2 to +5 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 20 Rgv. 0, 05/18/95 62958-O01-001 Utility (Under Pavements and Embankments) Plasticity Index 0 - 20 Plasticity Index >20 95 -2 to +5 95 0 to 4 8.6 Contamination Testing and Certification The Contractor should be required to arrange and pay for the services of a laboratory preapproved by the Owner to collect samples and perform a toxic contaminant scan of composite soil samples representative of each separate off-site borrow source in accordance with the U.S. Environmental Protection Agency (EPA) protocol for Total Metals (eight metals, EPA Method 3010/6010), pH (EPA Method 150.1), Chlorides (EPA Method 330.4), Volatile Organics (EPA Method 8240), and Total Petroleum Hydrocarbons (EPA Method 418.1 ). Copies of the results of the laboratory tests should be submitted with chains-of-custody to the Owner by the Contractor prior to proceeding to furnish soil materials to the site. Any potential off-site soil borrow on which scan test results indicate the presence of contaminants above background levels will be rejected as an off-site soil borrow source. The laboratory performing the scan test for contaminants for the Contractor should provide a written certification along with the test which states that the laboratory is EPA approved, that the tests were performed according to EPA guidelines, and that the samples were collected using EPA protocol. The Contractor should obtain a written, notarized certification from the landowner of each proposed off-site soil borrow source stating that to the best of the landowner's knowledge and belief there has never been contamination of the borrow source site with hazardous or toxic materials. These certifications should be submitted to the Owner by the Contractor prior to proceeding to furnish soil materials to the site. The lack of such certification on a potential off-site soil borrow source will be cause for rejection of that source. Soil materials derived from the excavation of underground petroleum storage tanks shall not be used as fill on this project. 2 1 Rev. 0, 05/18/95 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 9 PAVEMENT SUBGRADE 9.1 General Based on the soil borings, the subgrade soils are anticipated to be clay along the roadway. These soils have poor subgrade characteristics and can become sof~ and pump with an increase in moisture content. A commonly used method to improve the strength properties of the soils is to treat them with hydrated lime. Laboratory testing of the anticipated future subgrade soils consisted of Atterberg limits tests and percent passing No. 200 sieve. In addition, a series of liquid and plastic limit tests were conducted on the natural subgrade soils in order to determine optimum lime additive contents for the purpose of soil treatment below paving. In these tests, soil plasticity index was evaluated as a function of the percentage of dry soil weight. The pH of soil/lime mixtures was also determined. These test results are included in Appendix B. 9.2 Subgrade Treatment ,~_ An application rate of 27 pounds of hydrated lime per square yard of surface area for the 6- inch subgrade thickness is recommended. This complies with the City's standard requirements. The plasticity index of the lime/soil mixture should be 3-.5'or less. The estimated application rate is based on a soil unit dry weight of 125 pcf and 6 percent lime. The lime treated subgrade should extend a minimum of 12 inches outside the curb line. This will improve the support for the edge of the pavement and also lessen the "edge effect" associated with shrinkage during dry periods. 9.3 Construction Procedures Construction of the lime treated subgrade should follow Item 260 of TxDOT's most current Standard Specifications. The recommended gradation requirement at~er final mixing includes 100 percent passing the 1-3/4" sieve and 60 percent passing the No. 4 sieve. 9.3.1 Application The hydrated lime should be applied only to the area where the mixing operations can be completed during the same working day. The hydrated lime should be placed by the slurry method and 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 FW /I/2958/DENTAPRD. DOC/512-95/bg: 4 22 R~v. O, 05/18/95 62958-001-001 which will keep the lime and water in a uniform mixture. The distribution of lime at the rates indicated shall be attained by successive passes over a measured section of roadway until the proper lime content has been secured. The amount of lime to be added per area of stabilization can be determined by calculating the square yardage to be stabilized and then multiplying by the prescribed application rate. Lime delivery tickets should be submitted to the engineer to verify the amount of lime applied. The interval of time between application and mixing that the hydrated lime is exposed to the atmosphere, should be a maximum of 6 hours. 9.3.2 Mixing 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 retained on the 3/4" sieve are removed, the remainder of the material shall meet the following requirements when tested dry by laboratory sieves: Minimum passing 1-3/4" sieve - 100% Minimum passing No. 4 sieve - 60% Gradation tests should be performed for each 500 linear feet of roadway, with a minimum of one test per section of lime placement. A check for correct depth of stabilization should also be made. 9.3.3 Compaction Compaction of the mixture shall begin immediately axler mixing. The material should be aerated or sprinkled as necessary to provide the optimum moisture. Compaction shall begin at the bottom and continue until the entire depth of 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 recompacting by sprinkling and rolling. The surface should be maintained in a smooth condition, flee from undulations and ruts. The subgrade should be compacted to a minimum of 95 percent of Standard Proctor (ASTM D 698) density, at a moisture content ranging from optimum to four percentage points above optimum (0 to +4). 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 hairline cracking. The compacted section should be moist-cured for approximately 7 days. Field density tests should be taken at the rate of one (1) test per each 500 linear feet of roadway with a minimum of two (2) per lime placement. 23 Rev. 0, 05/18/95 FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 10 REPORT CLOSURE The borings made for this report were located in the field by taped measurement from the existing roadway. Elevations of the bofings were interpolated from topographic contour maps of the area provided to us by Weir & Associates, Inc. The locations and elevations of the bofings should be considered accurate only to the degree implied by the methods used in their determination. The boring logs shown in this report contain information related to the types of soil encountered at specific locations and times and show lines delineating the interface between these materials. The logs also contain our field representative's interpretation of conditions that are believed to exist in those depth intervals between the actual samples taken. Therefore, these boring logs contain both factual and interpretive information. It is not warranted that these logs are representative of subsurface conditions at other locations and times. With regard to groundwater conditions, this report presents data on groundwater levels as they were observed during the course of the field work. In particular, water level readings have been made in the borings at the times and under conditions stated in the text of the report and on the boring logs. It should be noted that fluctuations in the level of the groundwater table can occur with passage of time due to variations in rainfall, temperature and other factors. Also, this report does not include quantitative information on rates of flow of groundwater into excavations, on pumping capacities necessary to dewater the excavations, or on methods of dewatering excavations. Unanticipated soil conditions at a construction site are commonly encountered and cannot be fully predicted by mere soil samples, test borings or test pits. Such unexpected conditions frequently require that additional expenditures be made by the owner to attain a prope~y designed and constructed project. Therefore, provision for some contingency fund is recommended to accommodate such potential extra cost. The analyses, conclusions and recommendations contained in this report are based on site conditions as they existed at the time of our field investigation and further on the assumption that the exploratory bofings are representative of the subsurface conditions throughout the site; that is, the subsurface conditions everywhere are not significantly different from those disclosed by the borings at the time they were completed. If, during construction, different sub surface conditions from those encountered in our bofings are observed, or appear to be present beneath excavations, we must be advised promptly so that we can review these conditions and reconsider our recommendations where necessary. If there is a substantial lapse of time between submission of this report and the start of the work at the site, if conditions have changed due either to natural causes or to construction operations at or adjacent to the site, or if building locations, structural loads or finish grades are changed, we urge that we be promptly informed and retained to review our FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 24 Rev. 0, 05/18/95 report to determine the applicability of the conclusions and recommendations, considering the changed conditions and/or time lapse. The scope of our services did not include any environmental assessment or investigation for the presence or absence of wetlands or hazardous or toxic materials in the soil, surface water, groundwater or air, on or below or around this site. Any statements in this report or on the soil boring logs regarding odors noted or unusual or suspicious items or conditions observed are strictly for the information of our client. This report has been prepared for use in developing an overall design concept. Paragraphs, statements, test results, boring logs, diagrams, etc., should not be taken out of context, nor utilized without a knowledge and awareness of their intent within the overall concept of this report. The reproduction of this report, or any part thereof, supplied to persons other than the owner, should indicate that this study was made for foundation design purposes only and that verification of the subsurface conditions for purposes of determining difficulty of excavation, trafficability, etc., are responsibilities of the contractor. This report has been prepared for the exclusive use of the City of Coppell and its designated consultants for specific application to design of this project. The only warranty made by us in connection with the services provided is that we have used that degree of care and skill ordinarily exercised under similar conditions by reputable members of our profession practicing in the same or similar locality. No other warranty, express or implied, is made or intended. 25 Rev. 0, 05/18/95 FWaJ2958/DENTAPRD.DOC/512-95/bg:4 62958-001-001 11 LIMITATIONS The services described in this report were performed consistent with generally accepted geotechnical engineering principles and practices. No other warranty, express or implied, is made. These services were performed consistent with our agreement with our client. This report is solely for the use and information of our client unless otherwise noted. Any reliance on this report by a third party is at such party's sole risk. Opinions and recommendations contained in this report apply to conditions existing when services were performed and are intended only for the client, purposes, locations, time frames, and project parameters indicated. We do not warrant the accuracy of information supplied by others, nor the use of segregated portions of this report. The conclusions and recommendations in this report are invalid if · The assumed design loads change · The structures are relocated · The report is used for adjacent or other property or buildings · Grades, groundwater levels, or both, change between the issuance of this construction · Any other change is implemented that materially alters the project from that hen this report was prepared The boring logs do not provide a warranty of the conditions that may exist at the entire site. The extent and nature of sub surface soil and groundwater variations may not become evident until construction begins. Variations in soil conditions between borings could possibly exist between or beyond the points of exploration or groundwater elevations may change, both of which may require additional studies, consultation, and possible design revisions. Any person associated with this project who observes conditions or features of the site or surrounding areas that are different from those described in this report should report them immediately to us for consideration and evaluation. This report was prepared solely for the use of our client and should be reviewed in its entirety. FW/I/2958/DENTAPRD.DOC/512-95/bg:4 62958-0014)01 26 aev. o, 05/18/95 APPENDIX A / I · ,:tk;~: \t~ 4'- . . /xs~ x 0 n,' o_ bJ n.- r,/") z 0 0 0 0 Z GENERAL NOTES 8OIL OR ROCK TYFE,3 fshown in symbols column) Clay Lean Sandy Silty Clayey Sand Gravelly Clayey Gravel Clay Clay Sand Sand Sand Gravel Sandy Conglom- Weathered Shale Sandstone Limestone Solid Waste Igneous Volcanic Gravel erar~ Shale or Debris * DRILLING AND SAMPLING SYMBOLS: U: Thin-walled Tube - 3" O.D., unless otherwise noted S : Split Barrel Sampler - 2" O.D., unless otherwise noted Example: 25 = 25 blows/12" after 6" seating interval; 50/7 = 50 blows/7" ai~er 6" seating interval; REF = 50 blows C : Double Tube Core Barrel T : THD Cone Penetrometer Example: T60 = 60 blows/12"; T4.5" = 100 blows/4.5" rosy be used in combine- '.ion ,,eit. h ~he. types A : Auger Sample W : Wash Sample P : Packer Te~ D : Denison Sample Rk'X-~,TIVE DENb"rI~ OF COARSEGRAINED SOlL~: CONSISTENCY OFFINE-GRAINEDSOILS: Penetration Resistance Relative Unconfined Compressire Blows/foot Density Stren2th, Qu, tsf Consistency 0 - 4 Very loose Loss than 0.25 Very soft 4 - 10 Loose 0.25 to 0.50 Soe~ 10 - 30 Medium dense 0.50 to 1.00 Firm 30 - 50 Dense 1.00 to 2.00 Stiff over 50 Very dense 2.00 to 4.00 Very stiff 4.00 and higher Hard Slickensided Fiseured Laminated Interbedded Calcareous Well graded Poorly graded Having inclined planes of weakness that are slick and glossy in appearance. Containing shrinkage cracks, frequently filled with fine sand or silt; usually more or less vertical. Composed of thin layers of varying color and texture. Composed of alternate layers of different soil types. Containing appreciable quantities of calcium carbonate. Having wide range in grain sizes and substantial mounts of all intermediate particle sizes. Predominantly of one grain size, or having a range of sizes with some intermediate size missing. DECtREE OF WEA~EIERING.- Unweathered Slightly weathered Weathered Severely weathered Reck in its natural state before being exposed to atmospheric agents. Noted predominantly by color change with no disintegrated zones· Complete color change with zones of slightly decomposed rock. Complete color change with consistency, texture, and general appearance approaching soil. CUBSURFACE CONDITIONS: Soil and rock descri~ions on the boring logs are a compilation of field data as well as from laboratory testing of samples on those strata for which laboratory classification test results are presented on the boring logs. These classifications are based only on the actual samples tested, and the clnssification is then assigned to the remainder of the stratum interval based on visual classification. If laboratory classification test resuJts are not presented on the boring log for a particular stratum, then that stratum was classified by visual-manual procedures only. The stratification lines represent the approximate boundary between materials and the transition can be gradual. Classification of soils based upon visual-manual procedures was performed in general accordance with ASTIVI Standard D 2488. Classification of soils based upon laboratory tes~ results was performed in general accordance with ASTM Standard D 2487. Water-level observations have been made in the borings at the times indicated. It must be noted that fluctuations in the ground- water level may occur due to variations in rainfall, hydraulic conductivity of soil strata, construction activity, and other factors. FIGURE A.2 LOG OF BORING NO. B- 1 Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive Coppell, Texas -20 · u-1 Surface El.' + 460.3' MSL MATERIAL DESCRIPTION SANDY CLAY, dark brown to brown, stiff w/calcareous nodules U-3 U4 U-7 3.0 3.0 3.5 SANDY CLAY (CL), light brown to brown, firm, moist w/calcareous nodules & small gravel 12.5 1.5 2.0 CLAYEY SAND (SC), light brown to tan, loose, wet w/occasional layers of gray calcareous clay & w/fine to medium rounded gravel 21.0 18.3 19.5 II1.1 42 15 27 79 4.1 17.0 0.5 18.3 17.2 102.5 0.4 39 U-8 -35 ' 7, /. s-9/, -40 Completion Depth: Date Boring Started: Date Boring Completed: Engineer/Geologist: t- Pro iect No.: EMCON 71.0 ft. 4128195 5/1/95 T. Baker 62958.4101-001 1 23.5 Remarks: Seepage encountered @ 20.5 ft. during drilling. Water level measured @ 14.5 ft. & hole caved @ 23.4 ft. on 5-2-95. The stratification lines reprcsent ,npproximatc strata boundaries. In situ, the transition may be gr uiil. Continued Next Page FIGURE A.3 LOG OF BORING NO. B- 1 Project Description: DENTON TAP ROAD ~ Denton Creek to Highland Drive Coppen, Texas Location: d Surface El.: + 460.3' MSL ~ MATERIAL DESCRIPTION :Z - dense below 43 ft. LIMY SANDSTONE to SANDY LIMESTONE, very hard, light gray SANDSTONE, poorly to moderately cemented, gray, dense w/shale seams SANDY SHALE, dark gray, moderately hard w/interbedded sandstone seams & layers SHALE, sandy & clayey, dark gray, moderately hard 49.5 56.5 46 50/1/4 T1.75 TI .25 100 100 13.1 13.7 149.1 52.3 -70- 71.0 T12 -80 Completion Depth: Date Boring Started: Date Boring Completed: Engineer/Geologist: t, Project No.: EMCON 71.0 ft. 4128195 5/1/95 T. Baker 62958-001-001 Remarks: Seepage encountered @ 20.5 ~. during drilling. Water level measured @ 14.5 ft. & hole caved @ 23.4 ft. on 5-2-95. The stratification lines represent .approximat~ strata boundaries. In situ, the transition may be gradi~l. HGURE A.4 LOG OF BORING NO. B- Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive Coppert, Texas Location: a Surface El.' 4- 461.3' MSL ~ ~ ~ ~ MATERIAL DES~ION ~ u-I u-2 u-3 -15 -~-7 -2s 3 5 Z~9 ~ CLAY (CL), brown, very stiff w/gravel 4.5+ ] 3.5 0.5 CLAYEY SAND (SC), light brown, loog ,,L' '. w/fine gravel CLAYEY SAND (SC), brown & gray, loOSe, Wet CLAYEY SAND/SAND (5P-SC), brown, tan & gray, wet, medium dense w/gravel layers CLAYEY SAND (SC), dark gray & brown, medium dents, wet w/sand & gravel seams GRAVEL (GP) w/sand, tan & brown, medium dense, wet w/tan sand layers 65.0 ft. 5/2195 5/2195 T. Baker 62958-001-001 -40 Completion Depth: Date Boring Started: Date Boring Completed: Engineer/Geologist: ~. Project No.: EMCON 13.0 16.5 14.3 23.8 7 20.4 32.0 10 29 36.0 13 Remarks: Seepage encountered @ 13 ft. during drilling. The stratification lines represent .approximate strata boundaries. In situ, the transition may be gradhid. 69 Continued Next Page HGURE A.5 LOG OF BORING NO. B- 2 Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive CoOpell, Texas Location: ,: Surface El.: :k 461.3' MSL ~ MATERIAL DESCRIPTION l~l ..... ...... _ _S-11 ..... ..... -45--::::: _ _~"f'~:',::: ..... -50 C-13 :;:; .... .... ..... ..... .... .... .... -55~iiii .... .... .... .... _ __ _ __ _ __ -60 c-15 _ __ _ __ _ __ _ __ GRAVEL (GP) w/sand, tan & brown, medium dense, wet w/tan sand layers SAND (SP), gray & tan, dense, wet w/some gravel 42.0 59/4-1/2' SANDSTONE, poorly to moderately cemented, gray, dense w/dark gray shale seams & layers & some limy sandstone LIMY SANDSTONE, well cemented, light gray, very hard SANDSTONE, moderately to well cemented, gray, dense, w/shale seams SHALE, dark gray to brownish gray, moderately hard to hard w/some silty sand partings 50.0 52.0 57.5 Ti .5 TI .75 82 15.5 131.6 95 65.0 TI .5 -65 17.3 116.7 16.7 110.2 0.9 3.8 7.0 -75- -80 Completion Depth: Date Boring Started: Dat~ Boring Completed: Engineer/Geologist: t, Proiect No.: EMCON 65.0 ft. 5/2/95 5/2/95 T. Baker 62958-001-001 Remarks: Sccpagc encountered @ 13 R. during drilling. The stratification lines represent .approximate strata boundaries. In situ, the transition may be gradual. FIGURE A.6 -5 -10 -15- -20- -25 - -30- -35 - LOG OF BORING NO. B- 3 Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive Coppell, Texas Location: c ~ Surface El.: · 459.0' MSL ~ ~= ~ ~ ~ MATERIAL DESCRIPTION SANDY CLAY w/lime (CL), brown (FILL) SANDY CLAY (CL), dark brown, firm to stiff w/scattered fine gravel 2.0 2.0 4.0 10.0 ~ · 29 12 17 8.5 1.5 17.0 111.3 45 13 32 59 23.2 105.6 1.7 -40 Completion Depth: 10.0 it. Date Boring Started: 4/28/95 Date Boring Completed: 4/28/95 Engineer/Geologist: T. Baker Proiect No.: 62958-001-001 EMCON Remarks: Dry @ completion. The stratification lines represent .approximate strata boundaries. In situ, the transition may be gr ukl. FIGURE A.7 'T .....................T ...........................r -5 - 10 -15- -20- -25 - -30- -35 - LOG OF BORING NO. B- 4 Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive Coppell, Texas Location: c ~ Surface El.: + 460.0' MSL ~ U-2 U-3 MATERIAL DESCRIPTION SANDY CLAY (CL), dark brown, stiff CLAY (CH), dark brown, firm to stiff 2.0 2.0 7.0 SANDY CLAY (CL), tan & brown, stiff '~ ~ , L ,.;/~ ! ~ 3.5 10.0 ,.7 o = r. z-~ 13.9 115.4 29 13 16 49 1.5 15.0 14.9 -40 Completion Depth: Date Boring Started: Date Boring Completed: Engine~r/Ge, ologist: Project No.: EMCON 10.0 ft. 4/28/95 4/28/95 T. Baker 62958-001-001 Remarks: Dry @ completion. The stratification lines r~pres~nt _approximate strata boundaries. In situ, the transition may be graduhl. HGURE A.8 LOG OF BORING NO. B- 5 Project Description: DENTON TAP ROAD - Denton Creek to Highland Drive Coppell, Texas Location: ~ Surface El.: ~- 474.0, MSL ~~ DES~ION O-I ~ C~Y (CL-CH), d~k brow, ~iff ~ . ,. ~ . .(. 3.5 -5 3.5 CLAY (CH), brown, stiff 7.5 2.0 10.0 20.7 112.2 47 18 29 68 4.5 26.1 60 22 38 20.8 -15- -20- -25 - -30- -35 - -40 Completion Depth: Date Boring Started: Date Boring Completed: Engineer/Geologist: Proiect No.: EMCON 10.0 ft. 4/28/95 4/28/95 T. Baker 62958-001-001 Remarks: Dry @ completion. The stratification lines represent .approximate strata boundaries. In situ, the transition may be gr ifil. HGURE A.9 APPENDIX B · · Boring/ Percent Finer Unconflned Exploration Sample Liquid Plastic Plasticity Moisture Unit Dry Percent Percent Compressive Point Depth Limit Limit Index Content Weight Passing Passing Strength No. (~) CLL) (PL) (PI) (%) (pcf) #200 #40 (tsf} B-I B-1 B-1 B-1 B-1 B-1 B-I B-I B-I B-2 B-2 B-2 B-2 B-2 B-2 B-2 B-3 B-3 3.0 8.0 42 13.0 18.0 23.0 28.0 38.0 43.0 62.0 0.5 8.0 18.0 28.0 50.0 61.7 63.0 0.5 29 3.0 45 15 12 13 27 17 32 B- 3 8.0 B- 4 0.5 29 13 16 B- 4 3.0 B-4 _. 8:0 B- 5 0.5 47 18 29 B- 5 3.0 60 22 38 B- 5 8.0 18 19 17 17 18 24 13 14 13 14 24 20 16 17 17 9 17 14 15 15 21 26 21 111.1 102.5 149. l 131.6 116.7 110.2 111.3 105.6 115.4 112.2 79 39 69 59 68 4.1 0.4 52.3 0.9 3.8 7.0 !.7 4.5 · EMCON · , Summary of Material Properties DENTON TAP ROAD - Denton Creek to Highland Drive Coppell, Texas May 16, 1995 Sheet 1 of 1 HGURE B.1 PROJECT NO. · ,62958-001-001, SUMMARY OF RESULTS pH Lime Series Liquid, Plastic Limit and pH Determinations Project: Project No.: Description: Date Tested: Denton Tap Road 62958-001-001 Clay, brown,sandy Sample: B-3 @ 3.5' 5/12/95 Hydrated Lime Liquid Plastic Plasticity pH Added, % Limit, % Limit, % Index Reading 0 1 2 3 4 5 6 7 8 45 13 32 7.29 40 34 6 42 38 4 12.04 12.31 12.47 30 - m 20 0 0 1 2 3 4 5 6 7 8 9 PERCENT LIME _._ Liquid Limit._ Plastic Index._ pH Reading 14 13 12 11 10 9 8 7 6 EMCON FIGURE B. 2 APPENDIX C 2:-,I o~ wIJJ _~o z"' ml-- zo ~Z r~ will 0 :;)'10 ~ ~ 60:1,1. :ewLL ~e//I./~ :rio(3 H~' I. :elDoS UTEXAS3 - VER. 1.204 - 10/22/93 - (C) 1985-1993 S. G. WRIGHT 1 Copy Licensed to EMCON Baker-Shiflett, Inc., Fort Worth, TX. Date: 5:12:1995 Time: 9:46:36 Input file: COPPELL1.DAT TABLE NO. 1 ******************~,~***************~***** * COMPUTER PROGRAM DESIGNATION - UTEXAS3 * * Originally Coded By Stephen G. Wright * * version No. 1.204 * * Last Revision Date 10/22/93 * * (C) Copyright 1985-1993 S. G. Wright * * All Rights Reserved * * RESULTS OF COMPUTATIONS PERFORMED USING THIS COMPUTER * * PROGRAM SHOULD NOT BE USED FOR DESIGN PURPOSES UNLESS THEY * * HAVE BEEN VERIFIED BY INDEPENDENT ANALYSES, EXPERIMENTAL * * DATA OR FIELD EXPERIENCE. THE USER SHOULD UNDERSTAND THE * * ALGORITHMS AND ANALYTICAL PROCEDURES USED IN THE COMPUTER * * PROGRAM AND MUST HAVE READ ALL DOCUMENTATION FOR THIS * * PROGRAM BEFORE ATTEMPTING ITS USE. * * NEITHER THE UNIVERSITY OF TEXAS NOR STEPHEN G. WRIGHT * * MAKE OR ASSUME LIABILITY FOR ANY W~RRANTIES, EXPRESSED OR * * IMPLIED, CONCERNING THE ACCURACY, RELIABILITY, USEFULNESS * * OR ADAPTABILITY OF THIS COMPUTER PROGRAM. * TABLE NO. 2 ***************~*****~*** * NEW PROFILE LINE DATA * ~****************~***~*** PROFILE LINE 1 - MATERIAL TYPE = 1 GROUND SURFACE Point X Y 1 .000 468.000 2 16.000 468.000 3 32.000 460.000 4 48.000 460.000 All new profile lines defined - No old lines retained TABLE NO. 3 ~*******~*****~**~*****************~************~**********~****~**** * NEW MATERIAL PROPERTY DATA - CONVENTIONAL/FIRST-STAGE COMPUTATIONS * ,~,~****************~,~,~,~************************~***************~*~ DATA FOR MATERIAL TYPE 1 SUBGRADE LAYER Unit weight of material = 125.000 CONVENTIONAL (ISOTROPIC) SHEAR STRENGTHS Cohesion 200.000 Friction angle 16.000 degrees No (or zero) pore water pressures All new material properties defined - No old data retained TABLE NO. 15 * NEW ANALYSIS/COMPUTATION DATA * Circular Shear Surface(s) Automatic Search Performed Starting Center Coordinate for Search at - X= y= Required accuracy for critical center (= minimum spacing between grid points) = 1.000 Critical shear surface not allowed to pass below Y = For the initial mode of search all circles pass through the point at - Short form of output will be used for search 50.000 480.000 X = 32.000 Y = 460.000 .000 THE FOLLOWING REPRESENT EITHER DEFAULT OR PREVIOUSLY DEFINED VALUES: Initial trial estimate for the factor of safety = 3.000 Initial trial estimate for side force inclination = 15.000 degrees (Applicable to Spencer's procedure only) Maximum number of iterations allowed for calculating the factor of safety = 40 Allowed force imbalance for convergence = 100.000 Allowed moment imbalance for convergence = 100.000 Initial trial values for factor of safety (and side force inclination for Spencer's procedure) will be kept constant during search Maximum subtended angle to be used for subdivision of the circle into slices = 3.00 degrees Depth of crack = .000 Search will be continued to locate a more critical shear surface (if one exists) after the initial mode is complete Depth of water in crack = .000 Unit weight of water in crack = 62.400 Seismic coefficient = .000 Conventional (single-stage) computations to be performed Procedure used to compute the factor of safety: SPENCER TABLE NO. 16 * NEW SLOPE GEOMETRY DATA * NOTE - NO DATA WERE INPUT, SLOPE GEOMETRY DATA WERE GENERATED BY THE PROGRAM Slope Coordinates - Point X Y 1 .000 468.000 2 16.000 468.000 3 32.000 460.000 4 48.000 460.000 TABLE NO. 21 ***** 1-STAGE FINAL CRITICAL CIRCLE INFORMATION X Coordinate of Center 26.000 Y Coordinate of Center 475.000 Radius 16.155 Factor of Safety 2.322 Side Force Inclination -13.58 Number of circles tried No. of circles F calc. for 76 46 TABLE NO. 38 * Final Results for Stresses Along the Shear Surface * * (Results for Critical Shear Surface in Case of a Search.) * *************************************************************** SPENCER'S PROCEDURE USED TO COMPUTE FACTOR OF SAFETY Factor of Safety = 2.322 Side Force Inclination = -13.58 Degrees VALUES AT CENTER OF BASE OF SLICE Total Effective Slice Normal Normal Shear No. X-center Y-center Stress Stress Stress 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 11.6 12.0 12.5 13.0 13.5 14.0 14.6 15.2 15.8 16.3 17.0 17.7 18.5 19.2 20.0 20.8 21.6 22.4 23.3 24.1 24.9 25 7 26 4 27 3 28 1 28 9 29 8 30.6 31.4 31.9 467.6 466.9 466.2 465.5 464.8 464.2 463.5 463.0 462.5 462.1 461.6 461.1 460.7 460.3 460.0 459.7 459.5 459.2 459.1 459.0 458.9 458.9 458.9 458.9 459.0 459.1 459.3 459.5 459.8 460.0 -59.4 7.8 77.7 149.5 222.4 295.8 369.1 441.9 503.0 545.6 578.8 606.9 629.9 647.4 659.2 665.1 664.8 658.3 645.3 625.6 599.1 570 5 535 8 489 6 435 8 374 2 304 6 226 5 139.5 80.2 -59.4 78.8 7.8 87.1 77.7 95.7 149.5 104.6 222.4 113.6 295.8 122.7 369.1 131.7 441.9 140.7 503.0 148.3 545.6 153.5 578.8 157.6 606.9 161.1 629.9 163.9 647.4 166.1 659.2 167.5 665.1 168.3 664.8 168.2 658.3 167.4 645.3 165.8 625.6 163.4 599.1 160.1 570.5 156.6 535.8 152.3 489.6 146.6 435.8 140.0 374.2 132.4 304.6 123.8 226.5 114.1 139.5 103.4 80.2 96.0 CHECK SUMS - (ALL SHOULD BE SMALL) SUM OF FORCES IN VERTICAL DIRECTION SHOULD NOT EXCEED .100E+03 SUM OF FORCES IN HORIZONTAL DIRECTION SHOULD NOT EXCEED .100E+03 SUM OF MOMENTS ABOUT COORDINATE ORIGIN SHOULD NOT EXCEED .100E+03 SHEAR STRENGTH/SHEAR FORCE CHECK-SUM SHOULD NOT EXCEED .100E+03 .00 (= .00 (= .92 (= .00 (= .247E-03) .403E-03) .916E+00) .116E-03) ***** CAUTION ***** EFFECTIVE OR TOTAL NORMAL STRESS ON SHEAR SURFACE IS NEGATIVE AT POINTS ALONG THE UPPER ONE-HALF OF THE SHEAR SURFACE - A TENSION CRACK MAY BE NEEDED. TABLE NO. 39 * Final Results for Side Forces and Stresses Between Slices. * * (Results for Critical Shear Surface in Case of a Search.) * SPENCER'S PROCEDURE USED TO COMPUTE FACTOR OF SAFETY Factor of Safety = 2.322 Side Force Inclination = -13.58 Degrees VALUES AT RIGHT SIDE OF SLICE Y-Coord. of Slice Side Side Force No. X-Right Force Location 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 11 8 12 3 12 7 13 2 13 7 14 3 14.9 15.5 16.0 16.7 17.4 18.1 18.9 19.6 20.4 21.2 22.0 22.9 23.7 24.5 25.4 26.0 26.8 27.7 28.5 29.4 30.2 31.0 31.8 32.0 -77. 467.6 -110. 467.3 -99. 467.3 -47. 469.1 40. 459.8 159. 463.0 304. 463 1 470. 462 9 593. 462 8 770. 462 4 935. 462 1 1085. 461 8 1214. 461 5 1318. 461.3 1395. 461.0 1442. 460.8 1459. 460.6 1443. 460.4 1396. 460.2 1318 460.1 1213 460.0 1119 459.9 974 459.9 813 459.8 643 459.8 471 459.8 304 459.9 153 459.9 28 460.0 0. 556.1 Fraction Sigma Sigma of at at Height Top Bottom .438 -62.7 .518 -79.6 .677 -90.2 ABOVE -100.2 BELOW -110.7 BELOW -121.9 BELOW -133.7 050 -146.2 078 -155.2 110 -171.1 135 -181.5 154 -187.5 171 -189.9 .185 -189.4 .197 -186.3 208 -181.0 218 -173.8 227 -164.8 236 -154.2 244 -142.1 252 -128.6 258 -117.6 267 -101.7 276 -84.6 286 -66.0 298 -45.9 313 -23.7 .335 2.0 .324 -7.8 ABOVE-10000000.0 -137.1 -64.0 2.7 68.2 132.9 196.4 258.2 317.9 357.7 426.6 485.9 536.5 579.2 614.2 642.0 662.6 676.0 682.3 681.4 673.1 657.5 641.0 612.1 575.3 530.3 476.9 414.0 340.2 293.5 10000000.0 CHECK SUMS - (ALL SHOULD BE SMALL) SUM OF FORCES IN VERTICAL DIRECTION = SHOULD NOT EXCEED .100E+03 SUM OF FORCES IN HORIZONTAL DIRECTION = SHOULD NOT EXCEED .100E+03 SUM OF MOMENTS ABOUT COORDINATE ORIGIN = SHOULD NOT EXCEED .100E+03 SHEAR STRENGTH/SHEAR FORCE CHECK-SUM = SHOULD NOT EXCEED .100E+03 .00 (= .247E-03) .00 (= .403E-03) .92 (= .916E+00) .00 (= .116E-03) ***** CAUTION ***** FORCES BETWEEN SLICES ARE NEGATIVE AT POINTS ALONG THE UPPER ONE-HALF OF THE SHEAR SURFACE - A TENSION CRACK MAY BE NEEDED. ***** CAUTION ***** SOME OF THE FORCES BETWEEN SLICES ACT AT POINTS ABOVE THE SURFACE OF THE SLOPE OR BELOW THE SHEAR SURFACE - EITHER A TENSION CRACK MAY BE NEEDED OR THE SOLUTION MAY NOT BE A VALID SOLUTION. Z H)R!V'IO UTEXAS3 - VER. 1.204 - 10/22/93 - (C) 1985-1993 S. G. WRIGHT 1 Copy Licensed to EMCON Baker-Shiflett, Inc., Fort Worth, TX. Date: 5:12:1995 Time: 10:12:31 Input file: COPPELL2.DAT TABLE NO. 1 * COMPUTER PROGRAM DESIGNATION - UTEXAS3 * * Originally Coded By Stephen G. Wright * * Version No. 1.204 * * Last Revision Date 10/22/93 * * (C) Copyright 1985-1993 S. G. Wright * * All Rights Reserved * * RESULTS OF COMPUTATIONS PERFORMED USING THIS COMPUTER * * PROGRAM SHOULD NOT BE USED FOR DESIGN PURPOSES UNLESS THEY * * HAVE BEEN VERIFIED BY INDEPENDENT ANALYSES, EXPERIMENTAL * * DATA OR FIELD EXPERIENCE. THE USER SHOULD UNDERSTAND THE * * ALGORITHMS AND ANALYTICAL PROCEDURES USED IN THE COMPUTER * * PROGRAM AND MUST HAVE READ ALL DOCUMENTATION FOR THIS * * PROGRAM BEFORE ATTEMPTING ITS USE. * * NEITHER THE UNIVERSITY OF TEXAS NOR STEPHEN G. WRIGHT * * MAKE OR ASSUME LIABILITY FOR ANY W~TIES, EXPRESSED OR * * IMPLIED, CONCERNING THE ACCURACY, RELIABILITY, USEFULNESS * * OR ADAPTABILITY OF THIS COMPUTER PROGRAM. * TABLE NO. 2 * NEW PROFILE LINE DATA * PROFILE LINE 1 - MATERIAL TYPE GROUND SURFACE Point X Y 1 .000 470.000 2 36.000 470.000 3 52.000 470.000 4 88.000 470.000 5 118.000 460.000 6 140.000 460.000 All new profile lines defined - No old lines retained TABLE NO. 3 * NEW MATERIAL PROPERTY DATA - CONVENTIONAL/FIRST-STAGE COMPUTATIONS * DATA FOR MATERIAL TYPE 1 SUBGRADE LAYER Unit weight of material = 125.000 CONVENTIONAL (ISOTROPIC) SHEAR STRENGTHS Cohesion 200.000 Friction angle 16.000 degrees No (or zero) pore water pressures TABLE NO. 10 * NEW SURFACE PRESSURE DATA - CONVENTIONAL/FIRST-STAGE COMPUTATIONS * ALL NEW DATA INPUT - NO OLD DATA RETAINED Surface Pressures - Normal Shear Point X Y Pressure Stress 1 .000 470.000 42.000 2 36.000 470.000 42.000 3 36.000 470.000 .000 4 52.000 470.000 .000 5 52.000 470.000 42.000 6 88.000 470.000 42.000 000 000 000 000 000 000 TABLE NO. 15 * NEW ANALYSIS/COMPUTATION DATA * Circular Shear Surface(s) Automatic Search Performed Starting Center Coordinate for Search at - Required accuracy for critical center (= minimum spacing between grid points) = 1.000 Critical shear surface not allowed to pass below Y = For the initial mode of search all circles pass through the point at - x = y = Seismic coefficient = .010 Short form of output will be used for search 90.000 480.000 118.000 460.000 .000 THE FOLLOWING REPRESENT EITHER DEFAULT OR PREVIOUSLY DEFINED VALUES: Initial trial estimate for the factor of safety = 3.000 Initial trial estimate for side force inclination = 15.000 degrees (Applicable to Sponcer's procedure only) Maximum number of iterations allowed for calculating the factor of safety = 40 Allowed force imbalance for convergence = 100.000 Allowed moment imbalance for convergence = 100.000 Initial trial values for factor of safety (and side force inclination for Spencer's procedure) will be kept constant during search Maximum subtended angle to be used for subdivision of the circle into slices = 3.00 degrees Depth of crack = .000 Search will be continued to locate a more critical shear surface (if one exists) after the initial mode is complete Depth of water in crack = .000 Unit weight of water in crack = 62.400 Conventional (single-stage) computations to be performed Procedure used to compute the factor of safety: SPENCER TABLE NO. 16 * NEW SLOPE GEOMETRY DATA * NOTE - NO DATA WERE INPUT, SLOPE GEOMETRY DATA WERE GENERATED BY THE PROGRAM Slope Coordinates - Point X 1 .000 470.000 2 36.000 470.000 3 52.000 470.000 4 88.000 470.000 5 118.000 460.000 6 140.000 460.000 TABLE NO. 20 * SHORT-FORM TABLE FOR SEARCH WITH CIRCULAR SHEAR SURFACES * Center Coordinates of Critical Circle Mode X Y 1 Fixed Point at 105.000 485.000 X = 118.0 Y = 460.0 2 Tangent Line 106.000 486.000 at Y = 456.8 3 Constant Radius 106.000 486.000 Of R = 29.2 1-Stage Factor Side of Force Radius Safety Inclin. 28.178 2.337 -11.98 29.178 2.329 -12.08 29.178 2.329 -12.08 TABLE NO. 21 ***** i-STAGE FINAL CRITICAL CIRCLE INFORMATION X Coordinate of Center 106.000 Y Coordinate of Center 486.000 Radius 29.178 Factor of Safety 2.329 Side Force Inclination -12.08 Number of circles tried No. Of circles F calc. for 178 149 TABLE NO. 38 * Final Results for Stresses Along the Shear Surface * , (Results for Critical Shear Surface in Case of a Search.) * SPENCER'S PROCEDURE USED TO COMPUTE FACTOR OF SAFETY Factor of Safety = 2.329 Side Force Inclination = -12.08 Degrees ........ VALUES AT CENTER OF BASE OF SLICE ......... Slice No. X-center i 82.0 2 82.9 3 83.9 4 84.9 5 86.0 6 87.2 7 87.9 8 88.6 9 89.9 10 91.2 11 92.5 12 93.9 13 95.3 14 96.7 15 98.2 16 99.6 17 101.1 18 102.7 19 104.2 20 105.5 21 106.8 22 108.3 23 109.8 24 111.3 25 112.8 26 114.3 27 115.7 28 117.2 29 117.9 30 118.6 Y-center 469.4 468.1 467.0 465.8 464.8 463.7 463.1 462.6 461.7 460.9 460.1 459.5 458.9 458.4 457.9 457.5 457.2 457.0 456.9 456.8 456.8 456.9 457.1 457 3 457 6 458 0 458 5 459 1 459 4 459 7 Total Normal Stress 10.2 128.7 249.2 370.4 491.2 610.7 683.3 698.2 767.2 829.1 883.2 929.0 966.0 993.8 1012.0 1020.2 1018.0 1005.0 981.0 952.3 913.9 858.3 790.3 709.5 615.5 507.8 385.6 248.2 167.4 119.2 Effective Normal Stress 10.2 128.7 249.2 370.4 491.2 610.7 683.3 698.2 767.2 829.1 883.2 929.0 966.0 993.8 1012.0 1020.2 1018 0 1005 0 981 0 952 3 913 9 858 3 790.3 709.5 615.5 507.8 385.6 248.2 167.4 119.2 Shear Stress 87 1 101 7 116 6 131 5 146 4 161 1 170 0 171 9 180 4 188 0 194 6 200.3 204.8 208.3 210.5 211.5 211.2 209.6 206.7 203.2 198.4 191.6 183.2 173.3 161.7 148.4 133.4 116.5 106.5 100.6 CHECK SUMS - (ALL SHOULD BE SMALL) SUM OF FORCES IN VERTICAL DIRECTION = SHOULD NOT EXCEED .100E+03 SUM OF FORCES IN HORIZONTAL DIRECTION = SHOULD NOT EXCEED .100E+03 SUM OF MOMENTS ABOUT COORDINATE ORIGIN = SHOULD NOT EXCEED .100E+03 SHEAR STRENGTH/SHEAR FORCE CHECK-SUM = SHOULD NOT EXCEED .100E+03 .00 .00 2.24 .00 (= .575E-03) (= .127E-02) (= .224E+01) (= .226E-03) TABLE NO. 39 * Final Results for Side Forces and Stresses Between Slices. * (Results for Critical Shear Surface in Case of a Search.) SPENCER'S PROCEDURE USED TO COMPUTE FACTOR OF SAFETY Factor of Safety = 2.329 Side Force Inclination = -12.08 Degrees ............... VALUES AT RIGHT SIDE OF SLICE ................ Y-Coord. of Fraction Sigma Sigma Slice Side Side Force of at at No. X-Right Force Location Height Top Bottom 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 82.5 83.4 84.4 85.5 86.6 87.7 88.0 89.2 90.5 91.8 93.2 94.6 96.0 97 4 98 9 100 4 101 9 103 4 104 9 106 0 107 5 109 0 110 6 112 1 113 6 115 0 116 5 117.9 118.0 119.2 -64. 469.3 0. -816.2 180. 466.5 461. 466.0 828. 465.3 1262. 464.6 1363. 464.4 1809. 463.7 2250. 463.1 2670. 462.5 3054. 462.0 3389. 461.5 3662. 461.0 3865. 460.6 3989. 460.2 4031. 459.9 3986. 459.6 3857. 459.4 3646. 459.2 3454. 459.1 3120. 459.0 2729. 459.0 2295. 459.0 1836. 459.1 1374. 459.2 932. 459.4 539. 459.6 224. 459.8 200. 459.8 0. 591.5 .423 BELOW .041 147 180 195 197 217 234 247 258 267 275 .282 289 295 301 307 313 318 325 333 343 356 375 406 .467 .664 .718 ABOVE -26.8 -72.7 -61.9 61.9 -85.2 182.4 -106.9 297.9 -129.0 409.6 -151.8 517.0 ~157.0 539.9 -164.9 638.9 -166.9 724.9 -164.8 799.6 -159.7 863.9 -152.3 918.0 -143.0 962.2 -132.1 996.2 -119.7 1019.9 -106.0 1033.0 -91.0 1035.2 -74.6 1026.3 -56.8 1005.8 -43.5 984.5 -23.0 943.4 -.3 889.4 25.3 821.9 55.1 739.6 92.2 640.4 144.5 519.7 240.3 360.1 621.9 5.6 757.7 -101.7 .0 .0 CHECK SUMS - (ALL SHOULD BE SMALL) SUM OF FORCES IN VERTICAL DIRECTION = .00 (= .575E-03) SHOULD NOT EXCEED .100E+03 SUM OF FORCES IN HORIZONTAL DIRECTION = .00 (= .127E-02) SHOULD NOT EXCEED .100E+03 SUM OF MOMENTS ABOUT COORDINATE ORIGIN = 2.24 (= .224E+01) SHOULD NOT EXCEED .100E+03 SHEAR STRENGTH/SHEAR FORCE CHECK-SUM = .00 (= .226E-03) SHOULD NOT EXCEED .100E+03 ***** CAUTION ***** FORCES BETWEEN SLICES ARE NEGATIVE AT POINTS ALONG THE UPPER ONE-HALF OF THE SHEAR SURFACE - A TENSION CRACK NAY BE NEEDED. ***** CAUTION ***** SOME OF THE FORCES BETWEEN SLICES ACT AT POINTS ABOVE THE SURFACE OF THE SLOPE OR BELOW THE SHEAR SURFACE - EITHER A TENSION CRACK MAY BE NEEDED OR THE SOLUTION MAY NOT BE A VALID SOLUTION.