基于动态莫尔圆的岩爆机制研究

Study on rock burst mechanisms based on dynamic Mohr's stress circle

通过将经典的莫尔圆应力分析扩展到岩爆发生过程的静态加载和动态卸载破坏过程的应力状态分析提出了动态莫尔圆的概念,并基于此建立岩爆破坏的动力学Mohr-Coulomb准则以及岩爆破裂角的预测模型。理论分析解释了岩爆等动力破坏中的黏聚力损失现象,并且表明根据静态加载应力可以预测其黏聚力损失值及岩石的破裂角。同时,通过开展花岗岩应变岩爆的物理模拟实验,验证了理论模型与实验值具有一致性。由于静态加载应力可以通过监测或已有的岩体力学知识来确定,因而,研究得到的理论成果具有实用性。

The concept of dynamic Mohr’s stress circle is proposed by extending the classical Mohr’s circular stress analysis to the static loading and dynamic unloading failure process during rock burst generation.Based on this,the dynamic Mohr-Coulomb criterion and theoretical model for predicting fracture angles of rock burst failure are established.These theoretical analyses well explain the cohesion loss phenomenon in dynamic failure such as rock burst,and show that the cohesion loss value and the rock fracture angles can be predicted according to the static loading stress.At the same time,rock burst experiment on granite was carried out and a good agreement between the analytical models and experimental results.Since the static loading stresses could be determined by means of instrumental measurement and prior knowledge in rock mechanics,the theoretical findings obtained in this research is of practical significance.