FRP Deep Foundation Piles

Frost Engineering & Consulting was engaged to provide structural engineering services for a series of transmission power line deep foundations located in the floodplain of the Wolf River bend, a region characterized by highly corrosive conditions and particularly soft soil.

The project involved the design of seven vacuum-infused vinyl ester fiber reinforced polymer (FRP) deep foundation installations. Each foundation was designed for unique subsurface conditions consisting of 4 to 18 feet of very soft silt and sandy clay, underlain by similarly soft soils extending to depths of approximately 40 feet below grade with a high water table. To address these challenging geotechnical conditions, Frost designed FRP deep foundation piles between 36-41 feet in length and 48-54 inches in diameter, with several piles varying in diameter along the length, capable of withstanding the aggressive environmental exposure conditions and low soil bearing capacities.

The project involved the design of seven vacuum-infused vinyl ester FRP deep foundation installations.

The design included bolted and adhesive connections between the multiple FRP sections of the pile, the integration of the structural fin structures, and the steel pile cap designs for bolted connections to interface with the overhead steel structures quickly in the field, keeping within the required deflection criteria required for proper functioning of the transmission towers. The use of the FRP piles for the project resulted in significant weight and cost reductions when compared with traditional steel piles that would have been used in these conditions and allowed for simplified installation in these challenging locations for construction access.