岩体破坏的结构控制与应力控制转换机理及判据模型

首先，通过岩石受力破坏过程分析给出了岩块的强度参数与岩块破坏时形成的贯穿裂隙强度参数的关系．在此基础上，通过理论推导给出了结构面强度曲线和岩块强度曲线的位置关系，揭示了三轴压缩试验中，在低围压下岩体通常沿结构面破坏，而在高围压下岩体经常沿岩块剪切破坏的机理，并给出了由结构控制转换为应力控制的临界围压的解析解．其次，揭示了在岩体开挖中，岩体破坏的结构控制与应力控制的转换机理，给出了结构控制转化为应力控制的临界初始应力的解析解．算例表明，模型可以有效解释岩体力学行为的结构控制与应力控制的转换机理．

A model for switching mechanism and criteria of structure control and stress control on rock mass failure

First, the relationship of strength parameters for rock and penetrative crack formed when rock fails is obtained by analyzing the failure process of rock. On this basis, the paper obtains the location relationship of rock and structure plane＇s strength curves by theoretical derivation. The mechanism that rock mass fails along structure plane at low stress circumstances and fails through rock at high stress circumstances in triaxial experiment is proposed. The analytical solution of critical confining pressure for structure control turning to stress control is also given. Second, the switching mechanics of structure control and stress control in the excavation of rock mass is disclosed. The analytical solution of critical initial stress for structure control turning to stress control is given. The examples show that the proposed model can explain the switching mechanism of structure control and stress control on the mechanical behavior of rock mass.