导流隧洞工程围岩突破现象与数值模拟

Sudden-crack Phenomenon and Simulation of Surrounding Rock-mass in Diversion Tunnel

根据工程岩体发生破坏时,总是从一处或少数几处开始破坏,通过应力场调整和岩体性质改变使破坏或者逐步扩展或者转入相对稳定的现象,提出用破坏追踪的方法对破坏过程进行数值模拟,在数值模拟的过程中,围岩的本构关系按全量型进行非线弹性分析,对不同的应力状态应用不同的强度准则,对不同的破坏状态应用不同的本构方程,对不同的破坏状态应用不同的弹性矩阵。通过一个导流隧洞的工程实例表明提出的方法可以模拟围岩破坏的过程,并且从破坏轨迹中可以分析出围岩的突破点和突破塌方的位置,为工程的支护设计和加固提供依据。

Based on the phenomenon that when a surrounding rock-mass cracks, failure will take place in a place or some places first, then the stress state is redistributed and property of rock-mass changes, then the failure changes for the worse or becomes stable, the method of finding crack trajectory is put forward to simulate the phenomenon. The constitutive of rock is nonlinear elasticity. Different failure criteria of rock are used according to different stress states. Different constitutive modules and different elastic matrices are used according to the modes of fracture. A case study of diversion tunnels shows that the method is right. The sudden-crack place and sudden-crack rock fall place can be found through crack trajectory. Suggestions have been made to design the supporting structure and grouting reinforcement.