A statistical model for predicting the triaxial compressive strength of transversely isotropic rocks subjected to freeze-thaw cycling

Freeze-thaw damage to rock masses is one of the most significant durability problems in many regions worldwide. This study conducts triaxial compression tests to experimentally investigate the strength properties of freeze-thawed core samples of Carboniferous slates with bedding angles of 30°, 45°, 60°, and 75° under different confining pressures. The triaxial compressive strength decreases as the number of freeze-thaw cycles increases, continuously increases with increasing confining pressure, and initially decreases and then increases as the bedding angle increases from 30° to 75°. Additionally, to satisfy the requirements of engineering projects in cold regions, a statistical model is proposed to predict the triaxial compressive strength of freeze-thawed transversely isotropic rocks based on the single discontinuity theory. In this model, the cohesive strength and angle of internal friction of the discontinuity are assumed to be functions of the number of freeze-thaw cycles. The validity and accuracy of this model are verified by comparing the results of the proposed model with those of the experiments. It is found that the model can correctly describe the influences of the number of freeze-thaw cycles, confining pressure, and bedding plane orientation on the triaxial compressive strength of freeze-thawed transversely isotropic rocks.