Large-Scale Experiments on Pore Pressure Generation underneath a Caisson Breakwater

Abstract

Results of large-scale model experiments in a wave flume are discussed. These experiments are concerned with the study of the generation of transient or instantaneous and residual pore pressure in a seabed beneath a caisson breakwater subjected to both pulsating and breaking wave loads. The simulated seabed and drainage conditions correspond to those encountered in a loose sand bed with thin clay or silt layers. Even under such unfavorable conditions total liquefaction due to residual pore pressures could not occur during the experiments. It is shown that the residual pore pressure is essentially generated by the caisson motions due to breaking wave loads and that they are closely related to residual soil deformations, which may lead to the failure of the breakwater.