Characteristic Study Of Surrounding Rock Mass Deformation Considering Accumulative Damage Effect

The damage area is much larger than the blasting excavation area, so rock mass would be damaged several times and result in accumulative damage. The left bank diversion tunnel at Wudongde hydropower station is monitored and simulated for blasting vibration and rock mass deformation during excavation. Based on accumulative damage theory, the damage threshold and damage variable are adopted to consider the parameter weakening in different damage areas. The weakened rock mass parameter is adopted in each damaged element, and numerical simulations are conducted to simulate the accumulative damage induced by blasting excavation. By comparing monitored data and calculation results, the results considering accumulative damage is more close to the monitored values of both blasting vibration and rock mass deformation. Therefore, in numerical simulations of blasting excavation of tunnels, accumulative damage effect should be considered.