岩爆破坏过程能量释放的数值模拟

岩爆是地下岩石开挖中的一种工程灾害现象，是岩体结构发生破坏时，由于内部储存的弹性能释放并转换为动能而造成动力形式的破坏。岩爆破坏过程中的能量释放与岩体在应力峰值前后的应力-应变特性紧密相关。另外，施工中开挖速度引起的加载速率的变化也会对岩爆的产生有明显影响。以岩体全过程应力-应变曲线试验为基础分析岩爆破坏过程。分析中采用的模型考虑了岩石峰值后应力-应变特性及加载速率的影响。运用数值方法对岩石洞室的开挖过程进行了模拟，在模拟中对岩体破坏的发生及弹性能释放过程进行了分析。数值分析结果显示，岩体洞室开挖过程中岩石破坏由岩体表面向岩体内部发展，岩石的弹性能释放率也随着破坏的发展而不断增加。分析结果还显示，岩体破坏时的弹性能释放速率会随着开挖速率的提高而明显增加。

Numerical modeling of energy release in rockburst

Rockburst is one of the disasters can occurr in deep mining and rock excavation. It is a kind of dynamic fracture excited by the released elastic energy previously stored in the rock mass. The elastic energy releasing is correlated to the post peak behavior of the excavated rock mass. On the other hand, the rockburst phenomenon is also correlated with the excavation rate. A numerical modeling for rockburst is presented. The modeling is based on the complete stress-strain behavior of rocks obtained in laboratory. The post peak stress-strain behavior is specially considered in the analysis. Furthermore, the influences of loading rates are also included. The excavation process of a tunnel in rock mass is simulated in the study. The fracture development and the elastic energy releasing rates under different loading rates are computed in the simulation. The computed results indicate that the fracture is likely to initially occur near the rock surface and then propagate towards the internal zone of the rock mass. It is also demonstrated that rockburst is more likely to be occurred under a higher excavation rate than that under a lower excavation rate.