A three-dimensional numerical model for wave-induced transient pore pressure around the head of a breakwater

The wave-induced pore pressure in marine sediment around a coastal structure has been recognised as a dominant factor in analysing the seabed instability in the vicinity of a breakwater. Most previous investigations for wave-induced pore water pressure have been limited to two-dimensions, which are not able to simulate the phenomenon around the head of a breakwater. In this paper, a three-dimensional numerical model for the wave-induced pore pressure around the head of a breakwater is established. With the present model, a parametric study is performed to investigate the effects of wave and soil characteristics on the seabed response. Numerical results conclude: (1) diffracted wave components significantly affect the distribution of pore water pressure, vertical effective normal stresses and liquefaction potential; (2) a liquefied hole occurs near the head of a breakwater; (3) incident wave angles do not only affect the pattern of liquefied regions, but also the maximum liquefaction depth; and (4) the soil type significantly affects the distribution of soil response and liquefaction, and liquefaction only occurs in fine sand, not coarse sand.