Rockburst Behaviors of Beishan Granite Subjected to Instantaneous Unloading

Deep geological disposal is an internationally accepted way to deal with high-level radioactive waste. A better understanding of mechanical characteristics of host rock is very important for the stability of underground excavation and its long-term safety during operation. In the present study, tests have been performed using a true triaxial rock test system in combination with acoustic emission monitoring technique to investigate the rockburst process of the Beishan granite under the instantaneous unloading condition. When the rock specimen is loaded in three directions, the minimum principal stress in one direction is unloaded suddenly and the intermediate principal stress is kept constant and subsequently the maximum principal stress is increased. The rockburst phenomenon is successfully simulated in the laboratory. The experimental results show that occurrence of rockburst is attributed to the gradual energy accumulation and sudden energy release in the rock. This study provides an experimental basis for further investigating the influence of rock mechanics properties on underground construction and safe assessment in the Beishan area.