Dynamic Energy Evolution Mechanism and Viscoelastic Damage Constitutive Model of Frozen Soil under High Strain Rates

This study investigated the dynamic energy evolution mechanisms and failure behaviors of frozen soil subjected to impact loading. A split Hopkinson pressure bar was utilized to perform impact compression tests on frozen soil at varying temperatures (−5°C, −15°C, and −25°C). The experimental results reveal that frozen soil exhibits significant temperature and strain rate dependencies, with its strength increasing as the temperature decreases and the strain rate increases. The dissipated energy density was observed to increase exponentially with strain rate and linearly as the temperature decreased. Additionally, the nonlinear hardening and softening behaviors of frozen soil are predominantly influenced by temperature. To further describe the dynamic mechanical response, a viscoelastic damage constitutive model was developed. This model incorporates the effects of cryogenic suction and porosity on the tangent modulus and introduces a bivariate coupled damage mechanism. The model’s calculated results closely match the experimental data, confirming its validity.