Analytical solutions for dynamic response in poroelastic seabed under second-order Stokes waves

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