Common use of Geotechnical Investigations Clause in Contracts

Geotechnical Investigations. Engineer and its geotechnical drilling sub-consultant will perform a geotechnical investigation along the proposed alignment to observe subsurface conditions and support the design of the new gravity sewer. Engineer assumes the entire alignment will be constructed by open-cut, with the exception of the US-70 road crossing. All borings are assumed to be performed in unpaved areas. The scope of the subsurface investigation will consist of the following:  Perform Standard Penetration Test (SPT) borings at approximately 500-foot-intervals along the alignment. Up to 16 borings will be drilled. In general, drill depths will extend to 2 feet below the proposed pipe invert.  Observe and log soil and groundwater conditions in all borings. SPT split-spoon sampling will be performed in general accordance with ASTM D1586 and soil samples will be given a USCS classification. Where refusal is encountered above the planned depth of boring, rock coring will be performed to at least a depth of 2 feet below the proposed pipe invert. For trenchless borings (US-70), rock coring will be performed to extend borings to the shaft bottom.  Borings where the pipe is proposed to be installed via open-cut will be backfilled with cuttings. Borings at the proposed trenchless crossing will be backfilled with grout.  Conduct laboratory testing on selected soil samples to confirm soil classification, estimate engineering properties, and determine suitability for re-use as backfill materials. Upon completion of the geotechnical investigation, Engineer will prepare a geotechnical data report summarizing the subsurface conditions observed in the borings and containing all data (boring logs, laboratory testing, etc.) collected during the investigation. Horizontal location of the test hole shall be located using GPS services.