A DEM-Based Approach for Modeling the Damage of Rock Under Freeze–Thaw Cycles

In this study, a new approach based on DEM was developed to simulate the damage of water-rich rock after freeze–thaw cycles. In this way, water-rich rock samples at low temperatures were simplified as rock particles, ice particles, rock–rock contacts, rock–ice contacts, and ice–ice contacts. The volume of the ice particles changed as the temperature changed. The change characteristics were determined by the relationship between the temperature and the unfrozen water content. The developed approach was proven to be effective by comparing the simulation results with the laboratory test results. The physico-mechanical behaviors of water-rich rock samples after freeze–thaw cycles were studied. The results showed that the volume and porosity significantly increased after the freeze–thaw cycles, especially after 15 freeze–thaw cycles, and the increase in the radius was significantly larger than the increase in height. The uniaxial compressive strength, elastic modulus, and peak strain had an exponential reduction as the number of cycles increased. In uniaxial compression tests, the tensile failure rate of the sample after freeze–thaw cycles increased compared with that of the sample without freeze–thaw cycle treatment. With the increase in the number of freeze–thaw cycles, the distribution of cracks in the rock sample was more homogeneous. However, overall, the cracks that formed due to the freeze–thaw cycles were more distributed near the surface of the sample.