Dynamic Deformation of Frozen Soil at a High Strain Rate: Experiments and Damage-Coupled Constitutive Model

The dynamic compressive deformation of frozen soil was investigated by conducting the split-Hopkinson pressure bar (SHPB) experiments at three temperatures and different high strain rates, and the dynamic stress–strain responses and failure modes of the frozen soil were analyzed. The experimental results demonstrate that the frozen soil exhibits evident dependence on the strain rate and temperature under the dynamic loading condition. The dynamic compressive stress–strain curve of the frozen soil was divided into three parts: the linear, nonlinear rising, and strain softening parts. The nonlinear rising and strain softening parts were both caused by the damage attributed to the debonding between the ice particles and soil matrix, from which a rate-dependent damage evolution equation was obtained. Moreover, a damage-coupled dynamic viscoelastic constitutive model of frozen soil at high strain rate was derived. A comparison between the theoretically predicted results and the experimental ones showed that the developed dynamic viscoelastic model could well describe the dynamic mechanical behavior of frozen soil at high strain rate.