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.