Pore pressure coefficient for soil and rock and its relation to compressional wave velocity

In laboratory triaxial tests it has been common to check the specimen's degree of saturation by determining the pore pressure coefficient, B. The method is known as the B-value test and basically originated from Skempton's work on evaluation of the pore pressures in clays in the design of earth dams, in which he derived the well-known expression for B (Skempton, 1954):

Here Δσ is a small increase in all-round or confining pressure applied to an element of...