Elastic waves propagation through a liquid-saturated poroelastic interlayer based on the fractional viscoelastic BISQ model

Abstract

The reflection and transmission problems of elastic waves, through a liquid-saturated poroelastic interlayer sandwiched between two elastic solid half-spaces, are investigated. The reflection and transmission coefficients are derived based on the Biot/squirt (BISQ) model, which incorporates both the Biot and squirt-flow mechanisms. Moreover, the viscoelasticity of the solid frame and the pore fluid are also considered. The fractional Zener model and the fractional dashpot model (Abel dashpot) are adopted for the solid frame and the pore fluid, respectively. The numerical results are provided and shown graphically. The dependences of the attenuation, the reflection and transmission coefficients upon the characteristic squirt flow length are numerically discussed. Comparing with that predicted by Biot theory without considering the squirt flow effects, it is observed that the reflection and transmission coefficients and the attenuation due to the sandwiched interlayer are affected noticeably by the effect of the squirt flow.