Study on cyclically dynamic behavior of tailing soil exposed to freeze-thaw cycles

摘要

Most of tailings impoundments in China expose to a risk of both earthquake and freeze-thaw effects. The seismic behavior of tailing soils in cold regions has drawn increasing attention in recent years. In this study, a range of 0 to 10 cycles of freeze-thaw treatment was carried out on zinc tailing soil under the close system. Subsequently, a series of undrained cyclic triaxial tests were performed on tailing soil samples after the above-mentioned treatment under various confining pressures and different cyclic stress ratios. Besides, the tailing soil samples were pulverized and remolded after triaxial test, identical cyclic triaxial experiments were performed on the newly generated samples for comparison purpose. The results show that the cyclically dynamic response of tailing soil was significantly affected by freeze-thaw cycles. With the increasing number of freeze-thaw cycles, the number of loading cycles and cyclic resistance at failure decreased, but the pore water pressure at failure increased. An empirical model was improved to predict the excessive pore water pressure of tailing soil, and the computed results agreed well with the tested ones. Overall, this study provides insights into the cyclically dynamic behavior of tailing soils exposed to freeze-thaw cycles.