**2. Theoretical Models**

In this study, an integrated 2D numerical model is developed to simulate the fluid-structure seabed interaction, which is composed of two sub-models: the flow model and seabed model. The flow model is responsible for simulating the wave motion including the wave pressure and current velocity, while the seabed model evaluates the effective stress, displacement, and pore pressure in the seabed under the dynamic loading. The two sub-models adopt the one-way coupling algorithm which is connected by the continuous water pressure.
