NONLINEAR REGULAR WAVE, SUBMERGED BREAKWATER AND SEABED DYNAMIC INTERACTION

Numerical and physical models have been developed to study the nonline ar dynamic interaction between water waves and permeable submerged bre akwater over a finite thickness sand seabed. Modified Navier-Stokes eq uations have been used to solve the flow inside the porous media, and Blot's equations have been applied to solve the pore-elastic media. A combined BEM-FEM model has been modified to simulate the flow inside t he porous media and the wave deformation outside it. A pore-elastic fi nite element model has also been adapted and utilized under the effect of the nonlinear wave pressure, computed by the BEM-FEM model, along the surface boundary. A physical model has been made to record the wat er surface levels around the breakwater and the dynamic pore-water pre ssure inside the breakwater and foundation. The BEM-FEM model reproduc es the experimental results in the wave field fairly well. The pore-wa ter pressures computed by the pore-elastic and BEM-FEM models are comp ared with the experiment. The influence of the breakwater size on the wave deformation and the effect of the seabed thickness and stiffness on the breakwater stability are examined. (C) 1998 Elsevier Science B. V.