The coupled heat-moisture-mechanic model of the frozen soil

Based on the equilibrium, continuity and energy principles of the multi-phase porous medium, the heat-moisture-deformation (HMD) coupling model is established for the frozen soil foundation in this paper, with the consideration of the force interaction between the soil skeleton and ice particle, and the energy jump behaviors during the phase-changing between ice and water. A numerical solution with FEM using the proposed model is developed on the plate of the Austrian software FINAL (Li and Chen, 1999) and a test calculation with the new developed model is also conducted for the thermal elastic consolidation of a one-dimensional sand column made previously by Aboustit. The practical analysis for the soil foundation demonstrated that the freezing and thawing have not only related to the temperature variation, but also related to the moisture migration. Reducing the permeability coefficient of the foundation soil, the freezing increases obviously due to the decreasing of the pore water drainage. The freezing differences between the sand-gravel pile and the silt-sand foundation due to the different heat conductivity also illustrate that the fine-gravel layer can be a better measure to resist the frozen heave in the road engineering in cold regions. (C) 2000 Elsevier Science B.V. All rights reserved.