Reflection and transmission of plane waves at an interface of water/multilayered porous sediment overlying solid substrate

Researches in wave reflection and transmission at water-marine sediment interface have a long history and have received much attention during the past half-century in many scientific fields. A new stable reflectivity method is developed to solve the problem of wave propagation in coupling water-layered porous sediment-solid substrate system. The uniqueness of the method is that it not only has the advantage of traditional TRM method but also is able to accommodate numerous sediment layers with arbitrary thickness for wide range of wave frequency. The method proves to be able to well describe the wave propagation in the fluid-porous sediment-solid substrate system. The wave propagation is significantly influenced by the porous sediment layers, including thickness, layer number, arrangement and sediment properties. In the case of high wave frequency, even thin porous sediment leads to significant energy loss and the reflection coefficient mainly depends on the upper porous sediment layer. The influence of real shear modulus on reflection is substantial for low wave frequency, while the influence of permeability on reflection is significant for medium and high wave frequency. The reflection coefficient is extremely sensitive to the change in frequency within a certain frequency range.