Abstract: Based on Leclaire’s extension of the Biot model for saturated porous elastic medium, the propagation characteristics of the body waves in a three-phase porous elastic medium with two types of solid phase components are studied. Firstly, based on the Helmholtz decomposition of the displacement vector, the characteristic equations of the body waves in saturated frozen soil are established. Then the effects of the volume fraction of each phase, the shape of the particles and the contact between the particles on the inertial parameters, viscous parameters and elastic parameters are studied. The model of saturated frozen soil is degraded. The characteristic equations and propagation characteristics of body waves are analyzed assuming only liquid water or ice in pores. Finally, a numerical calculation is carried out to explore the relationship among phase velocity, attenuation coefficient of waves and parameters of soil consolidation, saturation, porosity, particle contact, wave frequency etc. The calculation results show that, different from saturated soil, there are 5 types of body waves in saturated frozen soil, i.e. 3 compressional waves and 2 shear waves. All body waves present dispersion and attenuation. The dispersion and attenuation of P1 wave and S1 wave are much smaller than those of P2, P3 and S2 waves. Body wave propagations are significantly affected by cementation parameters, saturation and porosity, but are slightly affected by contact parameters.

Key words: saturated frozen soil, three-phase porous medium, degradation, consolidation parameter, contact parameter, frequency, saturation, porosity