Sediment transport and resulting topographic change can be affected by bottom flow velocity on the surface of the seabed and pore-water pressure on the surface layer of the seabed. In this study, a sediment transport model considering pore-water pressure on the surface layer of the seabed is proposed and incorporated into a three-dimensional coupled fluid-structure-sediment interaction model (FSSM). For validation, the FSSM is applied to tsunami-induced local scouring around an inland square cylinder. As a result, numerical results show that the topographic change including the evolution of the local scour around the seaward corner of the cylinder is predicted reasonably well using the FSSM, and suggest that it is essential to take into account pore-water pressure for tsunami-induced sediment transport phenomena.
