A physical understanding of the wave-induced seabed response is essential for predicting the stability of foundations of marine structures. Most previous investigations for such a problem have been concerned with the case under linear wave loading, although most damage case occurs during storms, in which stiong wave non-linearity is observed. In this study, an analytical solution for the non-linear short-crested wave-induced pore pressure, effective stresses and shear stresses in a porous seabed is derived. Numerical results demonstrate the significant effects of wave non-linearity on the wave-induced soil response. Under certain combination of wave and soil conditions, the maximum difference of the wave-induced soil response between linear and nonlinear wave loading reach over 10% of the static water pressure.
Recently, considerable efforts have been devoted to the studies of wave-seabed interaction It has been well known that gravity water waves propagating over the ocean generate significant dynamic pressure on the seabed. These pressure fluctuations further induce effective stresses and pore water pressure within the soil matrix. Once the pore pressure becomes excessive with accompanying decreases in effective stresses, a sedimentary bed may become unstable, leading to seabed instability such as liquefaction and shear failure. Numerous offshore installations (such as pipelines, oil storage tanks, piers, breakwaters etc.) have been damaged by wave-induced seabed instability, rather than from construction cause (Lundgren et al., 1989; Silvester and Hsu, 1989) Based on the assumptions of compressible pore fluid and soil skeleton, leading to Biot's consolidation equation (Biot, 1941), numerous investigations have been carried out since 1970s (Madsen, 1978; Jeng, 1997). Some of them have considered the seabed as an infinite medium (Madsen, 1978; Jeng, 1997). Few have attempted to consider non-homogeneous soil characteristics and anisotropic soil behaviour (Jeng, 1997; Kitano and Mase, 1999).
