Common use of Geotechnical Services Clause in Contracts

Geotechnical Services. a. GEOTECHNICAL INVESTIGATION (19 roadway borings assumed, spaced approximately 750 feet to a 10 foot depth): • Provide a Geotechnical Investigation for the project evaluated by a professional geotechnical engineer Licensed in the State of Texas. The following items will be included in the geotechnical report: soil boring locations, boring logs (TxDOT Wincore output graphs/format), and plan of borings, subsurface exploration procedures, encountered subsurface conditions, field and laboratory test results, description of surface and subsurface conditions, groundwater conditions, analysis and recommendations for settlement and slope stability of the earthen embankments; and culvert bedding, analysis and recommendations for wingwalls, headwalls, and retaining walls, general earthwork recommendations, Swell potential evaluations, Pavement thickness design alternatives with subgrade stabilization, Potential Vertical Rise (PVR) calculations. • The soil borings will be properly backfilled with bentonite chips and a single lift of cold patch asphalt where applicable. The soil samples will be obtained using Shelby tubes and/or split-spoon samplers. Field-testing of soil samples will include pocket penetrometer in the cohesive soils and Standard Penetration Test (SPT) in the cohesionless soils. Texas Cone Penetrations will be performed in the culvert borings at five foot intervals. • Perform appropriate laboratory tests on soil samples recovered from the borings. Laboratory testing will include but not limited to: moisture content, liquid limit, plastic limit, unconfined compression, Texas Triaxial, resilient modulus, and free swell, sulfate testing, and particle size analysis tests, visual classification, dry density, California Bearing Ratio (CBR) tests, sulfate content tests, lime series analyses. • Provide geotechnical analysis needed for pavement design, foundation design, and slope stability, as required. For retaining walls, Engineer will provide calculations including global stability, sliding, bearing capacity, and overturning and recommendations for minimum footing depth. Where retaining walls will be inundated due to water, a drawdown analysis is required. In addition, retaining wall backfill type shall be specified. • The pavement design will include consideration of traffic loads to be based on the County’s average daily traffic (ADT) projections. The traffic data required includes current and projected traffic counts and truck percentages. The Engineer will prepare three (3) flexible pavement design alternatives and one (1) rigid pavement design alternative. Flexible pavement design alternatives shall include: subgrade stabilization (utilizing lime or cement) and flexible base layer; full depth asphalt section; temporary full depth asphalt pavement section. Rigid design alternative shall include flexible base, HMAC Bond Breaker, and continuous reinforced concrete pavement. Geogrid reinforcement will also be considered in these designs. Pavement thickness options using TxDOT FPS-21.

Geotechnical Services. a. GEOTECHNICAL INVESTIGATION Soil Borings: • Perform ten (19 roadway 10) pavement borings assumed, spaced approximately 750 feet along the entire proposed alignment to a 10 foot depth): depth of fifteen (15) feet. • Perform eight (8) retaining wall borings at about 200 ft spacing located at the San Gabriel River drilled to a depth of up to 15 ft below the existing ground surface or at least 5 ft in the limestone rock, whichever occurs first. • Perform seven (7) bridge borings at four bridge locations. The borings will extend to a depth of 55 ft below the existing ground surface and samples. Texas Cone Penetrometer testing will be performed at all boring locations. • Complete one (1) intersection boring, designated as Boring B-5 from the adjacent LJA scope of work (The fee associated with completing this boring remain in LJA scope of work). • Collect 3 bulk samples at each bridge location for scour analyses testing. • Develop soil boring layout for approval from the County prior to mobilization. b. Geotech Report: • Provide a Geotechnical Investigation Report for the project evaluated by a professional geotechnical engineer Licensed in the State of Texas. The following items will be included in the geotechnical report: soil boring locations, boring logs (TxDOT Wincore output graphs/format), and plan of borings, subsurface exploration procedures, encountered subsurface conditions, field and laboratory test results, description of surface and subsurface conditions, groundwater conditions, analysis and recommendations for settlement and slope stability of the earthen embankments; analysis and recommendations for bridge foundations, including allowable bearing and skin friction resistance, L-pile parameters for lateral analysis of drilled shafts, and recommendations for addressing karst features if encountered; recommendations for culvert bedding, ; analysis and recommendations for wingwalls, headwalls, retaining wall recommendations and Global Stability Analysis (including retaining wallswall design calculations and recommendations for wall settlement estimations, global stability analyses, and external stability including overturning, sliding and bearing capacity);and bridges, general earthwork recommendations, ; Swell potential evaluations, ; Pavement thickness design alternatives with subgrade stabilization, Potential Vertical Rise (PVR) ; PVR calculations. • The soil borings will be properly backfilled with bentonite chips and a single lift of cold patch asphalt where applicableProvide Soil Core Hole Drilling required for pavement borings. The soil samples will be obtained using Shelby tubes and/or split-spoon samplers. Field-testing of soil samples will include pocket penetrometer Follow the procedures in the cohesive soils Williamson County Design Criteria Manual and Standard Penetration Test (SPT) contact the appropriate utility location services to have underground utilities located prior to drilling in the cohesionless soils. Texas Cone Penetrations will be performed in the culvert borings at five foot intervalsan area. • Perform appropriate laboratory tests on soil samples recovered from the borings. Laboratory testing will may include but not limited to: to moisture content, liquid limit, plastic limit, unconfined compression, Texas Cone Penetration Tests (per TEX 132-E), Texas Triaxial, resilient modulus, and free swell, sulfate testing, and particle size analysis tests, visual classification, dry density, California Bearing Ratio (CBR) tests, sulfate content tests, lime series analyses. • Provide geotechnical analysis needed for pavement design, foundation design, and slope stability, other tests as required. For retaining walls, Engineer will provide calculations including global stability, sliding, bearing capacity, and overturning and recommendations for minimum footing depth. Where retaining walls will be inundated due to water, a drawdown analysis is required. In addition, retaining wall backfill type shall be specifiedprescribed in the TxDOT Geotechnical Manual. • The Engineer will incorporate soil boring data sheets prepared, signed, sealed and dated by the Geotechnical Engineer and in accordance with TxDOT’s current WINCORE software. • Perform a pavement condition assessment consisting of field inspection on existing pavement conditions and all other pertinent features that could affect the pavement design will include consideration including observations of traffic loads to be subsurface water. • Create a Preliminary Pavement Report and Final Pavement Report based on field testing, subsequent laboratory testing, following the County’s average daily traffic (ADT) projectionsformat noted in the Williamson County Design Criteria Manual. The traffic data required includes current • Prepare and projected traffic counts and truck percentages. The Engineer will prepare analyze three (3) flexible pavement design alternatives and one (1) rigid pavement options. The options will consist of a full- depth hot mix design alternative. Flexible pavement design alternatives shall include: subgrade stabilization (utilizing lime to be used in small areas or cement) and for temporary pavement, asphalt overlaying flexible base layer; full depth and lime stabilized subgrade, and asphalt section; overlying flexible base with cement stabilize base. Provide a temporary full depth pavement section for traffic control design with asphalt pavement section. Rigid design alternative shall include overlaying flexible base, HMAC Bond Breakerif needed. All pavement design analyses should be performed with TxDOT software FPS-21, and continuous reinforced concrete pavement. Geogrid reinforcement will also be considered in these designs. Pavement thickness options using TxDOT FPS-21unless otherwise approved by the County.

Geotechnical Services. a. GEOTECHNICAL INVESTIGATION The Sub-Consultant will complete geotechnical exploration along the project corridor. These services will be in general accordance with the standard specifications for subsurface investigations and design. This task includes the necessary field and office services to provide a geotechnical report for the project. The task involves completing the following twelve (19 roadway 12) borings assumed, spaced approximately 750 feet to a 10 foot depth): depth of 10-15 feet below existing grade: • Provide Roadway borings (250-ft intervals alternating EB/WB lanes) = 8 borings • Roadway boring (NW Ash Drive) = 1 boring • Roadway boring (▇▇ ▇▇▇▇▇▇ Street) = 1 boring • Roadway borings (NW/SW School Street) = 2 borings The purposes of the borings include determination of existing pavement sections, roadway/utility design, moisture contents, groundwater levels (for 4 of above borings), pavement depths (cores), laboratory testing, and engineering analysis. The borings will include all City/State required traffic control measures including coordination, permits, and arranging a Geotechnical Investigation for utility locate through Iowa One Call. The backfilling of the project boreholes will be performed following the borings and meet City/State requirements. This subsurface exploration will include laboratory testing, engineering analysis, pavement design, and a written report. The results of our field and laboratory programs will be evaluated by a professional geotechnical engineer Licensed licensed in the State of TexasIowa. The following items Based on the results of our evaluation, an engineering report will be included in prepared and include the geotechnical reportfollowing information: soil boring locations, • Description of the project. • Computer generated boring logs (TxDOT Wincore output graphs/format), with soil stratification based on visual soil classification • Summarized laboratory data on the boring logs • Groundwater levels observed during and plan shortly after completion of borings, subsurface drilling • Boring location diagram • Subsurface exploration procedures, encountered subsurface conditions, field and laboratory test results, description of surface and subsurface conditions, groundwater conditions, analysis and recommendations for settlement and slope stability of the earthen embankments; and culvert bedding, analysis and recommendations for wingwalls, headwalls, and retaining walls, general earthwork recommendations, Swell potential evaluations, Pavement thickness design alternatives with subgrade stabilization, Potential Vertical Rise (PVR) calculations. procedures • The Subsurface soil borings will be properly backfilled with bentonite chips and a single lift of cold patch asphalt where applicable. The soil samples will be obtained using Shelby tubes and/or split-spoon samplers. Field-testing of soil samples will include pocket penetrometer in the cohesive soils and Standard Penetration Test (SPT) in the cohesionless soils. Texas Cone Penetrations will be performed in the culvert borings at five foot intervals. • Perform appropriate laboratory tests on soil samples recovered from the borings. Laboratory testing will include but not limited to: moisture content, liquid limit, plastic limit, unconfined compression, Texas Triaxial, resilient modulus, and free swell, sulfate testing, and particle size analysis tests, visual classification, dry density, California Bearing Ratio (CBR) tests, sulfate content tests, lime series analyses. • Provide geotechnical analysis needed for pavement design, foundation design, and slope stability, as required. For retaining walls, Engineer will provide calculations including global stability, sliding, bearing capacity, and overturning and recommendations for minimum footing depth. Where retaining walls will be inundated due to water, a drawdown analysis is required. conditions In addition, retaining wall backfill type shall be specified. • The pavement design geotechnical recommendations for the project will include consideration of traffic loads to be based on the County’s average daily traffic (ADT) projections. The traffic data required includes current and projected traffic counts and truck percentages. The Engineer will prepare three (3) flexible pavement design alternatives and one (1) rigid pavement design alternative. Flexible pavement design alternatives shall include: subgrade stabilization • Bearing soils for culverts • Settlement and global slope stability review (utilizing lime or cementas defined above) • Earthwork construction • Expansive soil design considerations, if applicable • Cut and flexible base layer; full depth asphalt section; temporary full depth asphalt pavement section. Rigid design alternative shall include flexible basefill construction • Excavation and backfill • Site preparation, HMAC Bond Breaker, and continuous reinforced concrete pavement. Geogrid reinforcement will also be considered in these designs. Pavement thickness options using TxDOT FPS-21.including the suitability of the existing on-site soils for use as structural fill • Subsurface drainage recommendations • Subgrade preparation recommendations for grade supported pavements