Finite Amplitude Effects in Marine Sediments

This study attempts to identify the possible sources for nonlinearity in marine sediments and to assess their relative importance.The medium is considered as composed of solid grains in a skeleton frame with fluid filled pores and all the components may have nonlinear stress-strain relations.It is shown that the acoustic parameter of nonlinearity (B/A) can be expressed as a weighted sum of contributions from the pore fluid, the solid, and the frame.Calculations of B/A for sand show that the most important contribution comes from the fluid but also with significant contributions from the bulk and shear moduli of the frame.