Numerical Study on a Frost Heave Model Considering the Critical Separation Pressure

Abstract

To address the issues, such as the unclear physical meaning of the existing criteria for ice lens formation and the empirical values of the critical separation pressure, this paper modified the criterion by using the sum of the tensile strength and the overburden pressure of the soil as a critical separation pressure. Also, the soil compression coefficient was introduced into the governing equations coupled water and heat transfer. Then, a one-dimensional frost heave model was proposed considering the soil pore deformation and the critical separation pressure. A one-dimensional freezing test and numerical calculation were carried out on saturated frost-susceptible clay. The results showed that the frost heave model proposed in this paper accurately reflected the distribution of the soil temperature fields, the water contents, and the ice lenses. The calculated results of the freezing depth, the frost heave, and the frost shrinkage were consistent with the experimental results, validating the frost heave model. The revised criterion couples the critical separation pressure and the soil temperature field, providing a common basis for the analysis of the ice lens formation in different soils. Considering the influence of the pore deformation on frost heave, the frost heave model proposed in this paper was used to obtain the frost shrinkage at the early stage of soil freezing, which cannot be calculated by the rigid ice model.