Physical modeling of combined waves and current propagating around a partially embedded monopile in a porous seabed

Abstract

In this paper, a series of experimental data for wave (current)-induced pore-water pressure around a partially embedded monopile is presented. Unlike the previous studies, the combined action of waves and currents is studied. The partially embedded monopile is considered. The variations of pore-water pressures around the monopile in time and space are investigated by wave flume experiments. The experimental results indicate that the hydrodynamic response and the seabed response caused by the combined action of waves and currents are significantly different from those caused by wave load. When the following current is superimposed on the wave, the wave profile on the lateral side, rather than on the front, of the monopile fluctuates first, and the wave trough of the incident wave becomes small and gentle. Moreover, it was found that the amplitudes of pore-water pressures increase, while the attenuation of pore-water pressures slows down under the large wave energy with a large current. It was further found that the existence of a current has a significant effect on the pore-water pressure at z∕h = -0.3 on the front side and on the pore-water pressure at z∕h = -0.15 on the back side of the monopile. Additionally, the influence of the current on the vertical and horizontal distributions of pore-water pressures is related to the wave height.