Wave-Induced Pressures in Beds of Sand

Measurements of the variation of the fluctuating component of pressure have been made in two different beds of sand in a wave channel. The sand was laid from an overhead hopper, and it is shown that the stratification of the bed produced by this method causes the permeability to be different in the vertical and horizontal directions. It is suggested that a similar situation exists in the sea bed. Analytical relationships for the pressure and velocity distributions in such a situation are developed, and the agreement between theory and experiment is found to be quite good. As far as is known, this is the first time that the applicability of traditional porous-media analytical methods to wave-induced flow in beds of sand has been verified experimentally.