Publication Abstract

Proceedings of the 43rd Annual Conference on Deep Foundations, 2018, Anaheim, CA, USA, (DFI)

Axial Cyclic Degradation of Marine Piles: A Strain-Based Fatigue Limit
Aaron S. Bradshaw, Ph.D., P.E., Ryan M. Coulson and E.I.T.

The offshore wind industry in the United States is slowly emerging with the recent construction of the first offshore wind farm located off the coast of Rhode Island. The turbines at the Block Island wind farm are supported by piled jacket structures, which historically have been used for much heavier oil and gas platforms. Offshore wind turbines have unique design requirements and the axial behavior of the supporting piles under cyclic loading is important to design. Cyclic degradation along the pile shaft can affect the capacity, deformation, and stiffness performance of the foundation and of the structure as a whole. This paper proposes a strain-based approach to estimate the fatigue (or endurance) limit of a cyclically loaded pile that may be applicable to long-term service loading. The method is applied to an existing load test dataset and the analysis results appear consistent with the observed pile response.

 article #3127; publication #1045 (AM-2018)