Response of Suction Caissons in Clay under Monotonic and Cyclic Horizontal Loading: Fid-Bau Portal

Response of Suction Caissons in Clay under Monotonic and Cyclic Horizontal Loading

Wallace, Jeff F. / Rutherford, Cassandra J.

Tidal energy converters (TECs) provide a means to extract energy from the horizontal flow of water resulting from the rise and fall of tides. It is critical that the behavior of all aspects of the TEC, including the foundation, be understood to optimize not only its reliability but also its cost efficiency. Unlike the majority of offshore energy structures that attempt to minimize the interaction with flowing water, a TEC is designed to interact with this flow through a rotating turbine. The rotating turbine blades, fluctuations in the tidal current speed and direction, wave loading, turbulence, and vibrations all result in a combined cyclic loading of the foundation or anchoring system. A suction caisson is a suitable foundation type to secure tidal current turbines to the seabed. In soft marine clays, the suction caisson provides an ideal foundation for TECs that can be installed without the need of equipment for pile driving or mobilizing gravity base foundation while allowing for the removal of the foundation, contributing to the overall “green” nature of the device. When configured in the monopod configuration the TEC will apply significant horizontal loading on the suction caisson. Therefore, the response of a suction caisson in the monopod configuration in soft clay with an aspect ratio of 1 is investigated under monotonic and cyclic horizontal loading.