Stress analysis of poroelastic seabed slopes under wave loading using the boundary element method

摘要

The effect of wave forces on the stability of a sloping seabed is investigated using linear wave theory and Biot's theory of poroelasticity. The wave forces on the slope, the wave-induced effective stresses and pore pressures are all computed by the boundary element method. Full derivations are presented for the boundary integral equations and fundamental solutions of the poroelastic theory for the case of sinusoidal loading conditions. The wave-induced stress field is combined with the in-situ stress field and the Mohr-Coulomb failure criterion is used to determine the zone of incipient failure. It is found that wave induced stresses must be analysed throughout an entire wave cycle in order to assess the likelihood of failure and also that the stability of a slope under waves is strongly dependent on the initial stress distribution.