Pore Pressure Response of Clayey Seabed under Ocean Wave

Abstract

In this study, a 2-D quasi-dynamic u-w-p model is developed to examine the wave-induced clayey seabed behavior. Further, this paper aims to provide a better understanding of the unstable condition of clayey seabed in the vicinity of coastal structure. In the proposed u-w-p model, acceleration, velocity, and displacement terms are considered different for both solid and fluid phases. The governing equations of u-w-p model are determined from constitutive law and conservation law under certain assumptions. The numerical solutions are developed by using Finite Difference Method (FDM) and three outputs (pore water pressure, effective vertical stress and shear stress) are analyzed. The result shows that both liquefaction and shear failure have low potential to occur in clayey seabed, this is due to by the soil structure and low permeability of clay. The pore water pressure vary linearly according to the depth, however, this variation is not significant in clayey seabed. In addition, there is no phase lag in clayey seabed. This paper presents the findings on wave induced stress variation in seabed with fine-grained soil, which differs to some of the published literature on sandy seabed.