Project Site Geotechnical Investigation. A geotechnical subsurface investigation plan will be developed to obtain data on sediment and soil characteristics, bearing capacity, and settlement of soils necessary for design, permitting, environmental compliance, and construction at the project site. Geotechnical evaluation of borrow sites are addressed in the Borrow Site task. The geotechnical data collection will be performed in two field investigative phases. The first initial phase will consist of performing seven cone pentation test (CPT) soundings to refusal depth along the beach area using an amphibious CPT rig capable of working in areas of up to 3 feet of water. The primary objective of the CPTs is to obtain detailed, nearly continuous, information on the stratigraphy at the site. The results of the CPTs will be used to evaluate the presence of soft foundations soils that could potentially impact the short- and long-term performance of the proposed structures. If soft foundations soils are identified, a second phase geotechnical field investigation program will be conducted to further evaluate the strength and compressibility characteristics of the soft foundation soils. The second phase investigation will consist of advancing up to three geotechnical boreholes to a termination depth of 50 feet along the dry beach areas of the project site using an All-Terrain Vehicle mounted drill rig. At least 14 days prior to mobilizing to the site, Texas 811, a service managed by Underground Service Alert (USA), will be notified of the proposed exploration locations. USA will notify utility companies that may have underground lines at the locations where the proposed explorations will occur. Utility companies will then mark the locations of their underground lines or will contact the investigation subcontractor if their utilities conflict with the proposed exploration locations and the locations will be relocated if necessary. The exploration points will be located in the field using hand-held GPS unit with submeter accuracy to position the rig over the investigation location.
Project Site Geotechnical Investigation. A geotechnical subsurface investigation plan will be developed to obtain data on sediment and soil characteristics, bearing capacity, and settlement of soils necessary for design, permitting, environmental compliance, and construction at the project site. Subsurface conditions at the site will be explored by performing 15 off-shore (marine) test borings extending to depths of 10-ft, 20-ft, and 50-ft below the mud line or the adjacent shoreline. In addition, grab samples will be collected at six (6) cross shore locations each to a depth of 1-ft to 2-ft below existing grade. The test borings will be drilled and sampled using a pontoon drilling rig. The grab samples will also be collected from the pontoon rig.
