Field Exploration Program Clause Samples

Field Exploration Program. This task will includes the performance of up to seven (7) borings to evaluate the subsurface conditions along the project alignments. The borings will be advanced using a truck-mounted drill rig to a depth of approximately 5 feet below the invert depth of the proposed pipeline to the maximum depth of 20 feet below the existing ground surface (bgs). The borings will be advanced using conventional hollow-stem auger drilling method to the target depth. In the event of early refusal on granitic rock or strongly cemented cobbles and boulders above the proposed pipeline invert elevations, the driller will convert to air rotary drilling method or HQ rock coring method, and continues drilling to the target depths. The field investigation will be performed under the direction of an experienced field geologist or engineer from the Geotechnical subconsultant’s firm. The soil materials encountered in the borings will be visually classified and logged, and representative samples of the soils will be collected for laboratory testing and analysis. During drilling, Standard Penetration Tests (SPT) will be performed with a specially manufactured "split spoon" sampler at selected depths. Relatively undisturbed samples will be obtained by driving a 3-inch (OD) diameter standard California sampler with a special cutting tip and inside lining of thin brass rings into the soils at the bottom of the borehole. Soil cuttings retained in the samplers will be field screened for the possible presence of volatile organic compounds using a MiniRAE 3000 gas monitor. In addition, loose bulk samples will also be collected from each borehole. Upon completion of the field exploration activities, the borings will be backfilled with concrete grout. Borings that are located in the paved public right-of-way will be repaired in accordance with the City of San Diego Standard Drawings for Public Work Construction SDG 123. The work areas will be cleaned and excess soil and/or fluid will be removed for offsite disposal. The field exploration activities will comply with State of California prevailing wage requirements.