ABSTRACT
Evaluation of the foundation stability is a crucial for the design of marine infrastructures, which involves fluid-structure-seabed interactions process. The soil liquefaction, shear failure and scour around coastal structures could be the key causes of the seabed instability that further lead to the failure of marine infrastructures. In this chapter, the dynamic soil response and liquefaction under various wave and current condition around breakwaters are discussed in detailed. Therein, wave/current-induced liquefaction around breakwaters are presented in this chapter. Four types of breakwaters, including composite breakwaters, submerged breakwaters, breakwater heads at river mouth and offshore detached breakwaters are considered for both 2-D and 3-D cases. In addition, the results from poro-elastic and poro-elastoplastic seabed models are compared and reveal that the liquefaction zones developed in the poro-elastoplastic seabed are much more severe compared with that in the poro-elastic seabed under the same external wave loading. Parametric studies show that the wave characteristics and soil properties significantly affect the liquefaction potential of breakwater foundations and the presence of currents, such as river current and longshore currents, could increase the risk of liquefaction of seabed foundation.
