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SS9701-PR 961223 .... 2CHNICAL SERVICES SLOPE STABILITY ANALYSIS GRAPEVINE CREEK AT BELTLINE ROAD COPPELL, TEXAS Gentlemen: Submitted here is our proposal for providing geotechnical engineering services for the referenced project. This proposal is based on our site visit of December 18, 1996. Project Description and Site Geology The project consists of evaluating the cause(s) and providing recommendations to stabilize an approximate 200-foot wide landslide along Grapevine Creek. The head of the landslide crosses three residential properties, one of which contains a swimming pool. Left unmitigated, the landslide could threaten the integrity of the swimming pool. Based on experience on the adjacent site, geologic conditions are anticipated to consist of clay and sandy clay fill overlying weathered and unweathered shale of the Eagle Ford Formation. Field Investigation Considering the dimensions of the landslide and anticipated site geology, it is recommended subsurface conditions be evaluated with five sample borings. Two borings will be drilled at the top of the slope with an ATV-mounted drilling rig. Boring depths of about 35 feet are anticipated. The remaining three borings will be drilled within the landslide mass using hand-operated equipment. The hand borings will be drilled to a maximum depth of 15 feet. All borings will be sampled continuously to a depth of six feet, and at maximum five- foot intervals thereafter. Samples of cohesive soils and weathered shale will be obtained using three-inch diameter pushed tubes. Cohesionless soils (sands and gravels) will be sampled and evaluated in-sim by use of the Standard Penetration test (SPT). Unweathered shale will be cored continuously using double-tube, NX-size core barrels. Borings will be bailed of drill fluids at the completion of field operations, and subsequent observations made in order to evaluate ground water conditions. 2424 STUTZ DR · SUITE 400 · DALLAS. TX 75235 · TEL [214] 350 5600 ' F^X [214] 350 0019 December 23, 1996 Proposal No. 12-49 City of Coppell Engineering Department 255 Parkway Boulevard Coppell, Texas 75019 ATTN: Mr. Garreth Campbell GEOTECHNICAL SERVICES SLOPE STABILITY ANALYSIS GRAPEVINE CREEK AT BELTLINE ROAD COPPELL, TEXAS Gentlemen: Submitted here is our proposal for providing geotechnical engineering services for the referenced project. This proposal is based on our site visit of December 18, 1996. Project Description and Site Geology The project consists of evaluating the cause(s) and providing recommendations to stabilize an approximate 200-foot wide landslide along Grapevine Creek. The head of the landslide crosses three residential properties, one of which contains a swimming pool. Left unmitigated, the landslide could threaten the integrity of the swimming pool. Based on experience on the adjacent site, geologic conditions are anticipated to consist of clay and sandy clay fill overlying weathered and unweathered shale of the Eagle Ford Formation. Field Investigation Considering the dimensions of the landslide and anticipated site geology, it is recommended subsurface conditions be evaluated with five sample borings. Two borings will be drilled at the top of the slope with an ATV-mounted drilling rig. Boring depths of about 35 feet are anticipated. The remaining three borings will be drilled within thc landslide mass using hand-operated equipment. The hand borings will be drilled to a maximum depth of 15 feet. All borings will be sampled continuously to a depth of six feet, and at maximum five- foot intervals thereafter. Samples of cohesive soils and weathered shale will be obtained using three-inch diameter pushed tubes. Cohesionless soils (sands and gravels) will be sampled and evaluated in-situ by use of the Standard Penetration test (SPT). Unweathered shale will be cored continuously using double-tube, NX-size core barrels. Borings will be bailed of drill fluids at the completion of field operations, and subsequent observations made in order to evaluate ground water conditions. 2424 STUTZ DR - SUIT/ 400 · DALLAS, TX 75235 · TEL [214] 350 5600 · F~X [214] 350 0019 City of Coppell Proposal No. 12-49 December 23, 1996 Page 2 of 4 Precautions will be taken during the field investigation to avoid damage to underground utilities and structures. However, Reed Engineering Group, Inc. will not be liable for damage to utilities or structures not identified on plans provided to us, or mislocated in the field by other parties. A detailed topographic survey of the landslide and adjacent areas will be necessary to adequately evaluate the landslide. These services, if provided by Reed Engineering Group, will be subcontracted. Alternatively, the survey could be performed by City of Coppell personnel. Laboratory Investigation Upon retum to the laboratory, all samples will be visually classified by the project engineering geologist in accordance with the Unified Soil Classification System (USCS). Each sample of cohesive soil will be evaluated for consistency by use of a pocket penetrometer test. Selected samples will be subjected to classification tests and tests to evaluate strength and deformation characteristics. Anticipated classification tests consist of Atterberg Limits, moisture content, unit dry weight, and partial grain-size determinations. Strength and deformation will be evaluated by use of unconfined compression, double-ring shear, and consolidated-drained direct shear tests. Engineering Services The results of the field and laboratory investigations will be evaluated and presented with our recommendations in a bound report. The report will address, but not necessarily be limited to, the following: 1. description of the soil and ground water conditions as they relate to the performance and construction of the project; 2. evaluation of the cause(s) of the landslide and potential near-future impact on existing improvements; 3. alternative measures for stabilization/remediation of the landslide including geotechnical design parameters associated with each alternative; and 4. general earthwork and testing recommendations. · City of Coppell Proposal No. 12-49 December 23, 1996 Page 3 of 4 Four copies of the report will be provided. Additional copies may be obtained for a nominal fee. Budget Costs associated with the proposed scope of services are itemized on the attached cost breakdown. Based on the breakdown, we anticipate the total cost of our services to be on the order of $5,500.00 to $6,000.00. The upper limit budget will not be exceeded without prior authorization. In addition to the costs above, out-of-scope services associated with performing the topographic survey are anticipated to be on the order of $1,800.00 to $1,900.00 if subcontracted through Reed Engineering Group. Unless prior arrangements are agreed to in writing, payment for our services is due within 30 calendar days of the invoice date. Payments not received within 40 calendar days of the invoice date will be charged interest at a rate of 1.0 % per month. Authorization We appreciate the opportunity to present this proposal and look forward to working with you on the project. Authorization to proceed may be indicated by signing and returning one copy of this proposal to our office. If any questions arise, do not hesitate to call. Sincerely, FWS/ysh 7 copies submitted: (2) P, INC. Date City of Coppell Proposal No. 12-49 December 23, 1996 Page 4 of 4 COST ESTIMATE GEOTECHNICAL SERVICES SLOPE STABILITY ANALYSIS GRAPEVINE CREEK AT BELTLINE ROAD COPPELL, TEXAS Field Services Mobilization of ATV Rig 70 Linear Feet of Core Drilling in Soil and Rock 6 Hours, Drilling w/Hand-Operated Equipment (3- Man Crew) 4 Hours, Field Reconnaissance and Supervision of Drilling Crews - Project Engineering Geologist Subtotal, Field Laboratory Services 20 Moisture Content tests 5 Atterberg Limit tests 20 Soil Suction determinations 2 Partial Gradation determinations 2 Double-Ring Shear tests 2 Unconfined Compression tests 20 Dry Unit Weight determinations 2 C-U Direct Shear tests (w/residual) Subtotal, Laboratory Engineering Services 2 Hours, ClassificationofSoil Samples 24 Hours, Analysis and Report Preparation 4 Hours, Analysis and Review 16 Hours, Typing and Drafting Support Subtotal, Engineering $ 200.00 700.00 840.00 $2,000.00 $ 80.00 175.00 80.00 50.00 50.00 50.00 160.00 320.00 $ 965.00 $130.00 1,560.00 360.00 560.00 $2,610.00 TOTAL ESTIMATED AMOUNT $5.575.00 Based on the above quantities, the total cost for our services is estimated to be $5,500.00 to $6,000.00. Reed Engineering Group, Inc. reserves the right to vary quantities and types of services as the project requires. The upper limit budget will not be exceeded without prior authorization.