According to the energy change of deep-buried marble in Jin-ping Ⅱ Hydropower Station under drilling blasting method and TBM excavation, a numerical model was proposed to discuss the relationship between the potential occurring range of rock burst and the mechanical characteristics of surrounding rock. The effects of the brittleness and strength of rock mass were studied. Besides, the results of numerical simulation were analysed and verified through the rock burst monitoring data of the diversion tunnel in Jin-ping Ⅱ Hydropower Station. The research shows that the disturbance of surrounding rock is small during TBM excavation and the stored energy near the excavation face is higher. As the thickness of the brittle rock is small, the rock burst grade may be rather lower. The burst depth is generally in the range of 0-1.0 m,and mostly less than 0.5 m. For blasting excavation, the strain energy of surrounding rock releases in a transient state, which reduces the energy source of rock burst, but owing that the thickness of the brittle rock is small, the burst depth is generally 2.0 m, and high-level rock bursts may more happen.
Journal of Vibration and Shock
energy storage limitation
tunnel boring machine(TBM) excavation
rock burst grade