ABSTRACT
The problem of fluid-structure-seabed interactions has attracted great attention from scholars and engineers with rapid development of marine engineering industry such as offshore oil and gas industry. In addition to designing of the stability of structure itself, geotechnical design of marine structure foundation could also be vital, since numerous failure cases of marine infrastructures caused by the wave-induced seabed instability have been reported in the literature. In this chapter, the hydrodynamic models, including linear wave model and Reynolds-Averaged Navier-Stokes model, are introduced first, followed by the discussion of several porous seabed models for the wave-induced seabed response in marine environment. Both oscillatory and residual mechanisms of the wave-induced dynamic soil response are considered, as well as a two-way coupling model. The mistake of the scaling analysis in previous study is pointed out and re-analyzed. The Seed-Rahman model is extended to 2-D with a time-dependent function with the instant oscillatory shear stress that provides better prediction of the residual liquefaction. The newly developed two-way coupling model for the wave-induced oscillatory seabed response makes better physical sense and demonstrates significant differences comparing with previous one-way coupling model.
