Temperature damage and constitutive model of frozen soil under dynamic loading

Temperature damage of frozen soil, which is a unique type of dynamic damage, is caused by weakened bonds between ice and soil particles due to a rise in the temperature under dynamic loading. In this paper, on the basis of the physical and mechanical properties of frozen soil, relationships between temperature and strain under dynamic loading are deduced and simplified into a form corresponding to the dynamic behavior of frozen soil. An analysis of the relationship between temperature damage and the dynamic behavior of frozen soil reveals that the significant parameters influencing temperature damage are strain rate and effective ice content. Strain rate is obtained by direct measurement, and effective ice content is a major parameter in establishing the dynamic strength theory of frozen soil. The relationship between effective ice content and temperature rise is established by calculating the unfrozen water content. Using the inherent relationship between effective ice content and elastic modulus, a function of the equivalent modulus, which describes the effect of transient temperature rise on the dynamic behavior of frozen soil, is established. From dynamic loading experiments conducted using the split Hopkinson pressure bar method and the theoretical results, the stress-strain curves of frozen soil under different conditions of dynamic loading are obtained. The theoretical analysis is validated by the good agreement between the theoretical results and the experimental ones. (C) 2016 Elsevier Ltd. All rights reserved.