Res 2015-160/approving a professional engineering services agreement between the City and Unintech Consulting Engineers, inc. for the provision of professional services in connection with the Mill Street Improvements project in the not-to-exceed amount o

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VERTICAL DATUM: NAVD88 SURFACE ADJUSTMENT FACTOR: To Be provided by City III. UTILITY ADJUSTMENTS (provided by Unintech) 1. Include the existing utility information in the plans. A good faith etTort shall be made to accommodate existing utility locations. Utility conflicts shall be identified during the design process to allow for relocation. All utility coordination shall be done through the City. 2. All utility relocations to be designed shall require a supplemental to this scope and fee. IV. GEOTECHNICAL (subconsultant HVJAssociates) A. Geotechnical Investigation ► . HVJ proposes to drill a total of four (4) soil borings for pavement to depths of fifteen (15) feet below the existing ground surface. The borings will be spaced along the alignment at approximately 500 foot spacing's, and will include one bore along Uhland Road for Uhland pavement design. 2. 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. 3. All the field sampling and laboratory tests will be performed according to typical geotechnical standards, where applicable, or with other well established procedures. HVJ will perform appropriate laboratory tests on soil samples recovered from the borings. Laboratory testing will include moisture content, liquid limit, plastic limit, unconfined compression, and sieve analysis tests. In addition, HVJ will test for sulfate content of the subgrade samples. B. Pavement Design 1. HVJ will design one reconstruction pavement section to achieve a 20 -Year Design Life. The City will approve the paving materials to be considered, i.e. HMAC over Flexible base, or HMAC over recycled stabilized existing materials, etc. The pavement design will include consideration of traffic loads to be provided to HVJ, lab test results, borings and NDT analyses. The TxDOT pavement design procedure will be followed, using FPS21 analysis program. The traffic data required includes current and projected traffic counts and truck percentages. 2. Because the roads are existing and critical information needs to be obtained regarding any variations in subgrade support and in -place pavement strength, HVJ proposes to utilize nondestructive deflection testing (NDT) with the Falling Weight Deflectometer (FWD). The use of NDT is crucial for finding any variations of in -place strength of the existing pavement/subgrade. When considering recycling, the existing base thickness is critical for proper design and the deflection data will tend to identify weaker areas which may have thinner base. The data will be used to finalize boring locations to ensure geotechnical data is collected for any changes in subgrade conditions or pavement layer changes as identified in profiles of the NDT data. The design will be based on the weakest existing base section to minimize the likelihood of having inadequate base thickness for recycling during construction. C. Engineering Report 1. HVJ anticipates providing geotechnical and pavement design report in Work Product 2, 30% complete design documents. In general, the following items will be included in HVJ's geotechnical report: (a) Site Vicinity map, (b) Geology map, (c) Plan of borings, (d) Boring logs, (e) Laboratory test results summary, (f) Groundwater conditions, (g) Generalized subsurface conditions, (h) Pavement thickness design, and (i) General earthwork recommendation. V. ROADWAY DESIGN CONTROLS 3 of 8 Unintech Consulting Engineers, Inc. 11/4/2015