Research on numerical simulation of rock damage zone under periodic blasting

摘要

The effect of cumulative damage on surrounding rock under periodic blasting, will inevitably lead to the weakening of rock mass mechanics parameters, resulting in the macro failure of engineering rock mass.Applying ANSYS/LS-DYNA to simulate the process of periodic blasting.Rock mass uses the HJC dynamic constitutive model and periodic blasting process by using segmented detonation approach to simulation.Through damage nephogram of the rock, analyzes the damage evolution behavior of rock under periodic blasting.The simulation results showed that: when blasting excavation, explosion shock loading can cause a range of damage disturbance zone L, within the scope, damage of rock mass will increase with the increase of number of blasting;outside damage disturbed zone L, initial residual rock inelastic deformation and damage accumulation unit superposition residual tensile stress can balance the stress wave generated by the explosion, making the value of rock damage is not increased;rock has a cumulative effect damage, but the damage is not a simple one-time blast damage accumulation, but nonlinear.