Analysis of slab buckling rockburst of surrounding rock under dynamic and static combined disturbance

Slab buckling rockburst is a common form of rockburst under high ground stress conditions, posing a serious threat to engineering safety. Based on the catastrophe model of slab buckling rockburst of surrounding rock, the expressions of control variables of a single rock slab and combined rock slab under quasi-static effect in catastrophe theory are obtained. The tendency of rockburst in the deep-buried tunnel under quasi-static and dynamicstatic combined disturbances are studied by theoretical analysis and numerical simulation methods using the case study of Jinping II Hydropower Station. The failure depth of surrounding rock during rockburst is quantitatively calculated from both theoretical and numerical simulation. The theoretical calculation results show that the failure depth of slab buckling rockburst in the surrounding rock of the auxiliary tunnel of Jinping II Hydropower Station under quasi-static effect is 0.16 m. The rockburst may occur when the angular frequency of the dynamic load is less than 13.49 rad/s under the dynamic and static combined disturbance, and a minimal dynamic disturbance with an amplitude of 7000 Pa may lead to a rockburst in the surrounding rock. Numerical simulations reveal that the displacement of the surrounding rock is 9.3 cm and the failure depth of the surrounding rock is 0.2 m. The values are consistent with the theoretical calculation results, indicating that the numerical simulation results of RFPA2D are reliable.