Novel three-dimensional numerical model for residual seabed response to natural loadings near a single pile

The evaluation of seafloor stability is of vital importance for engineers involved in the protection of marine foundations. Hence, it has attracted considerable attention in the field of offshore geotechnical engineering. In this investigation, a novel three-dimensional (3D) numerical model of fluid-seabed-structure interactions (FSSI) is proposed within the framework of OpenFOAM to explore the residual soil dynamic response around a single pile. Different from previous studies, three new features are added in the present model. (i) The wave-current interactions are taken into consideration, (ii) the source term of pore pressure generations is redefined, and (iii) both the oscillatory pore pressure and residual pore pressure are considered while judging the soil liquefaction potential. After verified by previous laboratory experiments available in literature, the novel model is applied to investigate the residual soil response around the single pile induced by natural loadings. The numerical results confirm that the novel 3D model can provide sufficiently accurate predictions of fluid-seabed-structure interactions. Moreover, wave/current characteristics, soil properties, and pile diameter can significantly affect the fluid-induced residual pore pressures along the vicinity of the single pile.