Linear elastic constitutive relation for multiphase porous media using microstructure superposition: Freeze-thaw soils

摘要

The constitutive relation derived in our previous work based on the microstructure superposition technique is implemented here for three-phase microstructure configuration to study the mechanical behavior of freeze-thaw soils. Three scenarios were considered for the frozen soils: frozen soil consisting of only two solids, soil skeleton and ice; frozen soil with soil skeleton, ice, and void; and frozen soil consisting soil skeleton, ice and pores saturated with fluid. The frozen soil studied is Alaska frozen soil mainly consisting of clay and silt particles at temperature about -10 ℃. The effective elastic constants were calculated for the media under each scenario using two sets of elastic constants of soil skeleton (clay mineral). The modeled results were compared with Hashin-Shtrikman's upper bound solution and the experimentally measured data. In addition to be able to model the mechanical behavior of freeze-thaw soils, the derived constitutive relation, as indicated in the results of this study, could also be used as a tool in determining the microstructure of freeze-thaw soils by measuring the elastic constants of soil skeleton, the elastic properties and unfrozen water content of the media.