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.