A New Approach to Predict the Strength Criterion of Frozen Soils Based on Micromechanical Framework

Abstract

In the present study, a micromechanics-based strength criterion for frozen soils is proposed to estimate the macroscopic nonlinear strength properties of the matrix-inclusion systems. In the representative frozen soil element, the strength behaviors of soil particles and ice-crystals are assumed to be respectively characterized by two different elliptical strength criteria. With consideration of Mori-Tanaka scheme in continuum micromechanics, the interactions between soil particles and ice-crystals could well be taken into account by means of homogenization techniques, and moreover the φ-breakage function is introduced to describe the cracked effect of ice-crystals regardless of the influence of unfrozen water. In the framework of support function and plastic dissipative energy, the strength criterion is formulated with the equivalent principle from the microscopic and macroscopic viewpoint. The parameters of ice-crystals are decided in the reported literature with different temperatures, and meanwhile those of soil particles are determined by various soil types such as silty soils, loess and sands. In addition, the parameters in the proposed strength criterion have clear physical meanings by comparisons with macroscopic strength criterion. Compared with the existing experimental data, the predictions in the proposed strength criterion can qualitatively and quantitatively simulate the macroscopic strength responses of frozen soils.