EVALUATION OF WAVE-INDUCED PORE PRESSURE IN SAND LAYER BY WAVE STEEPNESS.

The attenuation of wave-induced pore water pressures inside sand beds is investigated experimentally in a wave tank. It is found that the pore water pressure depends on the wave steepness. The attenuation equation of the pore pressure from the surface to the bottom of the sand layer is presented as a function of the wave steepness and includes two parameters determined experimentally. The parameters depend on the permeability of the bed. The empirical equation consists of both the characteristics of the water wave and the drainage conditions of the sand bed. The proposed empirical equation is examined with individual experimental results and various theories.