Rayleigh waves in a double porosity half-space

Based on the governing equations of double-porosity media extended from Biot's theory, the propagation characteristics of Rayleigh waves are discussed in this paper. Characteristic equations of Rayleigh waves in a double porosity half-space with the pervious boundary are derived by assuming that both the coupling mass coefficient ρ23 and coupling permeability term k(12) are equal to zeros. The dispersion and attenuation properties of Rayleigh waves in a double porosity medium are analyzed numerically. The effects of the porosity and fracture permeability on the behavior of the propagation of Rayleigh waves are investigated. It is found that Rayleigh waves in a double porosity half-space are dispersive and attenuated during propagation. The Rayleigh wave speed is always less than the phase velocity of P1 and shear waves, and always higher than the phase velocity of P3 wave.