Physical and numerical study of the dynamic response of the surrounding rocks and supporting structures of deep caverns subjected to explosion plane waves

Abstract

With the continuous renewal of deep-drilling ground weapons, it is urgent to study the stability of caverns under the coupled loading of in-situ stress and stress waves produced by explosions. In this study, two model tests are conducted to explore the dynamic response and explosion resistance behaviors of caverns under high in-situ stress conditions. A large-scale three-dimensional model test bench is used to apply initial static pressure and a detonating cord is selected to apply the explosion plane wave through the plane charge. Then, the anti-explosion ability improvement is studied through numerical simulation. The results show that the lining and bolt support effectively reduce the deformation and vibration of the chamber. The peak displacement and acceleration of the vault decrease by 5% ~ 20% and 14% ~ 35%, respectively, after applying support. Due to the enhanced bearing capacity, the vault stress after applying support is approximately 1.3 times greater than that without support. The vault subsidence values after applying lengthening and densifying bolt supports are 62.7% and 70.8% smaller than the values of the lining-supported cavern, respectively; the peak acceleration values of the vault are 19.7% and 28.3% smaller than the values of the lining-supported cavern after applying lengthening and densifying bolt supports, respectively. Finally, the failure mechanism of the surrounding rock was revealed by analyzing the interaction between plane waves and the supporting structures.