Wave forces on steeply-sloping sea walls: oblique incidence

Abstract

Previous work, [3], studying the forces exerted by non-breaking, normally-incident water waves of small amplitude on a sloping sea wall is here extended to the case of oblique incidence. The range of applicability of the Galerkin solutions is increased by means of the Shanks transform. Results are presented for a planar, outward-sloping sea wall. In shallow water, the total normal wave force per unit span is found to decrease as the wall slope increases, except for extremely obliquely incident waves. In deep water, it increases. Regarded as a function of the angle of incidence θ, the wave force in shallow water is virtually independent of θ, except for very oblique waves. In deep water, by contrast, the force first increases with θ and then decreases. In this case, the maximum wave force does not occur for normally incident waves.