Model Tests and Parametric Analysis on Pore Pressure Response in Silty Clay Seabed under Vertical Caisson Breakwater

Model tests aimed at investigating the wave-induced pore pressure responses of a silty clay seabed around a vertical caisson breakwater were conducted with a large-scale bespoke wave-breakwater-seabed system. The effects of water depth, wave parameters, and seabed consolidation conditions on oscillatory pore pressure were investigated. The residual pore pressure development against the number of cycles was also examined. The test results indicated that the oscillatory pore pressure was generally greater in the upper part of the seabed around the caisson at a large water depth and peaked at the front of the caisson at a small water depth. The oscillatory pore pressure increased with wave height and generally remained stable with an increasing number of cycles. In addition, the oscillatory pore pressure showed varying degrees of declination in the silty clay underneath the rubble after a pause period. The residual pore pressure observed in most areas of the seabed was concentrated in the silty clay underneath the caisson and increased with the number of cycles. These experimental observations will contribute to a better understanding of pore pressure responses in silty clay seabeds under vertical caissons and may have practical implications.