oa Experiments of P-wave propagation in imperfectly saturated sand - Effect of pore-water pressure

A series of P-wave propagation tests were conducted for imperfectly saturated sand specimens in a chamber under confining pressure in the range between 0 and 10 a.t.m. High - as well as low - frequency waves were observed to propagate with velocities and attenuations varying with the confining pressure. The natures of these waves are discussed by comparing the observed results with theories including those by Biot (1956). It is concluded that these waves are very likely various frequency components of Biot waves of the first kind.