深埋地下洞室断裂型岩爆机理的数值模拟

针对深部岩体中由断层、节理等不连续性结构面引发的岩爆地质灾害, 根据深埋地下隧洞中潜在发震断裂的分布特征和几何形态建立数值分析模型, 采用离散元单元法模拟存在刚性平直断裂的深部围岩的开挖响应, 并分别考察开挖接近并通过断裂附近时围岩应力状态的变化特征。通过探讨断裂的存在对围岩应力状态改变的作用机理, 揭示出断裂型岩爆是开挖面附近一定范围内存在的断裂构造在高应力作用下发生错动, 导致能量突然释放, 对围岩造成强烈冲击作用的结果, 基本与地震的断层“粘滑”机制相类似。

Numerical simulation on mechanism of fractured rock burst in deep underground tunnels

Aiming at rockburst geological disaster induced by discontinuity such as faults or joints in deep lay rock mass, numerical model is presented according to distributional characteristics and geometrical aspects of potential seismic faults in underground tunnel.Subsequently, excavation response of deep lay surrounding rock with rigid flat faults is simulated via distinct element codes, and varied features of stress state in surrounding rock are examined while excavation process approaches and then passes through fault zones.Finally, Mechanism of action is discussed on the base of stress state change induced by available faults.Energy releases sharply via rockburst under high stress, and it is revealed that faulted structure occur movement within a certain region of excavation section.Rockburst impacts on surrounding rock intensely, and the mechanism is similar to fault stick slip in earthquake process.