Experimental investigations on the stability of clayey sloping seabed under wave actions

Abstract A series of wave flume tests have been performed in this paper to investigate the responses of clayey sloping seabed under wave actions, including the characteristics of wave shoaling, seabed topography and excess pore pressure. Different wave heights H, water depths D and two slope angles β (4° and 10°) were adopted and their effects were analyzed. It is found that obvious wave shoaling appears during the process of wave propagation along the sloping seabed. There are primarily two failure modes of the clayey sloping seabed under wave actions: for the bank sloping seabed, waves propagate and break on the slope and the seabed soil is scoured as pieces; for the submerged sloping seabed, a large area of shallow landslide occurs along the slope from top to bottom. It is also found that under plunging wave actions, the pore pressure response in clayey sloping seabed can be divided into three modes. The changes of three-dimensional seabed topography in the tests were captured and the quantity of clay scoured by waves was evaluated. Based on the experimental data, an advanced formula has been proposed to assess the critical failure condition and the quantity of the sloping clayey seabed scoured under wave actions.