An analytical approximation for dynamic soil response of a porous seabed due to combined wave and current loading

Abstract

This paper presents a new analytical approximation for wave (current)–induced dynamic soil response. In this study, unlike in previous research projects, full dynamic soil behaviour was considered. The nonlinear waves propagating over an infinite seabed with uniform current were investigated, and the new analytical solution was validated with the previous field observations and laboratory experiments. The effects of currents and wave nonlinearity were examined based on the proposed analytical solution. Finally, a parametric study was carried out to examine the influence of the wave and seabed characteristics on the seabed response. As the numerical examples demonstrated, the effects of currents on the seabed response are significant only in the top region of the seabed (comprising approximately 10% of the wavelength). Based on parametric study, it is concluded that currents with third-order wave loading and full dynamic soil behaviour cannot always be ignored in the estimation of the wave-induced seabed responses, especially for almost-saturated soil, long-wave periods, and shallow water. A significant difference was also observed in the maximum liquefaction depth between the full dynamic and the consolidation models.