Response of Finite Depth Seabed to Waves and Caisson Motion

Abstract

The response of a poroelastic seabed to waves and caisson motion is modeled using Biot consolidation theory. The caisson is founded on a rubble bedding layer overlying a seabed of finite depth. Two approximations are employed to solve the boundary‐value problem analytically: (1) A boundary layer approximation to decouple pore pressure and soil motion in the Biot equations; and (2) a contact solution approximation for a thin elastic layer to address the mixed‐type mud line condition. The analytical solution is verified by comparison with finite element model results and large‐scale experiments. The analytical and finite element model estimates of the soil stresses and surface displacements are in good agreement. Experimental and analytical comparisons for pore pressure are in agreement but the displacement comparisons are quite scattered.