MASS-TRANSPORT IN WATER-WAVES OVER AN ELASTIC BED

The mass transport velocity in water waves propagating over an elastic bed is investigated. Water is assumed to be incompressible and slight ly viscous. The elastic bed is also incompressible and satisfies the H ooke's law. For a small amplitude progressive wave perturbation soluti ons via a boundary-layer approach are obtained. Because the wave ampli tude is usually larger than the viscous boundary layer thickness and b ecause the free surface and the interface between water and the elasti c bed are moving, an orthogonal curvilinear coordinate system (Longuet -Higgins 1953) is used in the analysis of free surface and interfacial boundary layers so that boundary conditions can be applied on the act ual moving surfaces. Analytical solutions for the mass transport veloc ity inside the boundary layer adjacent to the elastic seabed and in th e core region of the water column are obtained. The mass transport vel ocity above a soft elastic bed could be twice of that over a rigid bed in the shallow water.