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

Based on the equilibrium, continuity and energy principles of the multi-pha se porous medium, the heat-moisture-deformation (HMD) coupling model is est ablished for the frozen soil foundation in this paper, with the considerati on 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 calcul ation with the new developed model is also conducted for the thermal elasti c consolidation of a one-dimensional sand column made previously by Abousti t. The practical analysis for the soil foundation demonstrated that the fre ezing and thawing have not only related to the temperature variation, but a lso related to the moisture migration. Reducing the permeability coefficien t of the foundation soil, the freezing increases obviously due to the decre asing of the pore water drainage. The freezing differences between the sand -gravel pile and the silt-sand foundation due to the different heat conduct ivity 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.