Exact solution for dynamic response in poroelastic seabed under second-order Stokes wave

Based on the second-order Stokes wave theory, the dynamic response of a poroelastic seabed induced by nonlinear ocean wave is investigated. The controlling equations of the seabed are established in Cartesian coordinates using the Biot’s general consolidation theory and the Verruijt’s storage equation. The analytical solution of the dynamic response of the seabed is obtained by extending the ocean wave function and the field quantities in seabed to the complex domain using a rigorous mathematical derivation. The correctness and reliability of the analytical solution are verified by comparing with existing solutions. Finally, the effects of wave and seabed characteristic parameters on the vertical effective stress, horizontal effective stress, shear stress and pore pressure distribution of the seabed are analyzed. The results show that the wave and seabed characteristic parameters have a significant effect on the seabed dynamic response. The wave period and water depth have a significant impact on the second-order term of nonlinear wave, while the permeability and shear modulus respectively affect the rate of change and amplitude.