考虑累积损伤效应的围岩变形特性研究

隧道爆破开挖诱发的动力扰动作用范围往往远大于其开挖进尺，同一部位围岩受到循环爆破开挖的多次扰动普遍存在累积损伤。对乌东德水电站左岸导流洞爆破开挖过程中的爆破振动和围岩变形监测进行了监测和数值分析，基于累积损伤理论，通过引入损伤判据及损伤变量，考虑计算中产生的不同程度的损伤区域的岩体参数劣化，并将劣化后的参数引入相应损伤单元进行后续开挖爆破数值模拟计算，从而对岩体爆破开挖累积损伤效应进行模拟。通过比较乌东德水电站导流洞的实测数据以及数值模拟计算结果发现，考虑累积损伤的计算结果无论是爆破振动速度还是围岩变形均更接近于实测值。对爆破开挖的分析模拟中应考虑围岩的多次循环爆破累积损伤效应。

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.