Thompson Engineering was hired to provide geotechnical and laboratory testing services for the U.S. Fish and Wildlife Service’s (USFW) North Breton Island Restoration Project. The project site is located in the Breton Sound 30 miles off the southeast coast of Louisiana. The $75 million project received funds for early restoration as part of the Natural Resource Damage Assessment (NRDA) process associated with the BP Deepwater Horizon Oil Spill. The project involves the restoration and/or creation of 450 acres of beach, dune and marsh habitats, and habitat creation using roughly 5.5 million cubic yards of dredged material.
As a sub-consultant, Thompson assisted O’Brien & Gere (OBG) in the development of a geotechnical investigation work plan that determined the location and quantity of borings and samples to be collected, laboratory testing procedures to be followed, and the number of specific laboratory tests to be performed. Following approval of the work plan, Thompson assisted OBG in conducting a detailed geotechnical investigation and analysis to determine design parameters within project fill (e.g. island restoration) areas.
The geotechnical investigation involved:
Thompson assisted OBG in the development of the draft and final geotechnical data reports, which included recommendations related to the design of earthen containment dikes, maximum construction elevation, constructible side slopes, crown width, shrinkage estimates, consolidation during construction, time vs. settlement curves, and slope stability analyses.