PORE PRESSURES GENERATION IN A SEABED SUBJECTED TO WAVE LOADING

The effect of water waves on an underwater bed can be described by a p ressure wave propagating along its surface. In a granular seabed, the cyclic shear stresses thus induced cause a densification of the porous lattice which tends to raise the pressure of the pore fluid. The pres ent paper describes a quantitative study of the coupled phenomena of p ore pressure generation and diffussion in the medium. Using the yield design theory, a method for assessing the stability of the seabed unde r such a loading is derived from the computation of the pore pressure field.