Cyclic Pore Pressure Generation in Silty Soils under the Action of Combined Waves and Current

Abstract

Ocean waves and current always coexist in the offshore shallow water environments, which may bring the corresponding seabed responses more complex than those under pure waves. The responses of a silty soil under the action of combined waves and current were physically modeled with a specially designed water flume. A series of tests for the progressive waves with a following-current or with an opposing-current have been conducted, respectively. Both the water-surface elevation and the pore pressure, including the transient and residual components, at various depths in the silty soil were measured simultaneously. The effects of both wave loading history and superimposing current upon waves on the pore pressure responses are examined. It is indicated that the amplitude of the transient pore-pressure component is enlarged for the following-current case and reduced for the opposing-current case. The maximum amplitude of the residual pore-pressure component decreases gradually during the subsequent series of wave loading under the same wave conditions.