Wave (Current)-Induced Pore Pressure in Offshore Deposits: A Coupled Finite Element Model

Abstract

The interaction between wave and offshore deposits is of great importance for the foundation design of marine installations. However, most previous investigations have been limited to connecting separated wave and seabed sub-models with an individual interface program that transfers loads from the wave model to the seabed model. This research presents a two-dimensional coupled approach to study both wave and seabed processes simultaneously in the same FEM (finite element method) program (COMSOL Multiphysics). In the present model, the progressive wave is generated using a momentum source maker combined with a steady current, while the seabed response is applied with the poro-elastoplastic theory. The information between the flow domain and soil deposits is strongly shared, leading to a comprehensive investigation of wave-seabed interaction. Several cases have been simulated to test the wave generation capability and to validate the soil model. The numerical results present fairly good predictions of wave generation and pore pressure within the seabed, indicating that the present coupled model is a sufficient numerical tool for estimation of wave-induced pore pressure.

Effects of the Soil Property Distribution Gradient on the Wave-Induced Response of a Non-Homogeneous Seabed

“…From the above definitions, the governing equations can be derived. Substituting Equations (9)- (14) into Equations (1)-(3) and replacing the velocity of the pore pressure in Equation 3with Equation (20) yield the governing equations for the dynamic response of a non-homogeneous seabed in the scalar form:…”

“…Ülker and Rahman [13] used a similar approach to investigate the seabed response and clarified the application range of the QS, PD, and FD (fully dynamic) models. Liao et al [14] and Tong et al [15] considered the effect of currents on the wave-induced seabed response, and Chen et al [16] studied the nonlinear wave-induced response of an anisotropic seabed. Similar studies have been conducted to investigate the seabed response around marine structures, such as pipelines [17], composite breakwaters [18][19][20][21][22], and mono-piles [23,24].…”

Coastal Geohazard and Offshore Geotechnics

“…In this Special Issue, eighteen papers were published, covering three main themes: (1) mechanism of fluid-seabed interactions and its associate seabed instability under dynamic loading [1][2][3][4][5];…”

Effects of Principal Stress Rotation on the Fluid-Induced Soil Response in a Porous Seabed

“…Using the numerical model for wave-current interactions [30], Zhang et al [31] further investigated the wave (current)-induced oscillatory pore pressures in a porous seabed. Recently, Liao et al [32] proposed coupling models for residual seabed liquefaction subject to combined wave and current loading. Although numerous theoretical studies have been carried out since 2012, only two experimental studies for the wave (current)-induced oscillatory soil response are available in the literature [33,34].…”