Response of Poro-Elastic Seabed to a 3-D Wave System: A Finite Element Analysis

ABSTRACTMany marine structures have failed due to seabed instability and concomitant subsidence. Thus, the evaluation of the wave-induced soil response in a porous seabed has become an important factor for analyzing the stability of offshore facilities. However, most previous investigations for the wave-seabed interaction problem have only assumed a porous seabed as an uniform medium with constant permeability and shear modulus, in spite of strong evidences in the field. In this paper, a finite element model is proposed to investigate the wave-induced seabed response with variable permeability and shear modulus under the action of a three-dimensional wave system. The present finite element formulation is established by using a combination of semi-analytical techniques and the Galerkin procedure. The numerical results indicate that the influences of variable permeability and shear modulus on the wave-induced seabed response can not always be ignored.