基于两体系统动态加卸载效应的冲击地压机理

从冲击地压事件的能量来源出发,提出了破裂体和释能体相互作用的冲击震源模型,分析了冲击地压过程中能量传递与释放的动态机制,指出冲击源两体之间存在动态加、卸载效应。破裂体中裂纹传播速度越快,对释能体的动态卸载效应越显著,释能体动态应力降越大,能量释放速率越高;释能体动能越大,作用于破裂体的动态加载速率越高,破裂体破坏速度越快,碎裂程度越高,冲击地压发生过程即为两体动态交互作用加速、稳定、减速过程,相关分析与室内两体试验现象吻合。据此理论推测了冲击源的尺度特征,华亭矿区典型冲击地压事件的同步钻孔应变观测结果表明冲击时在破裂区外围不同尺度范围内存在同步应力降,为上述理论提供了工程依据。

Rockburst mechanism analysis based on dynamic loading and unloading effect of two-body systems

With the consideration of the energy source of rockburst,the rockburst source model based on interaction between broken body and energy release body was proposed.The dynamic mechanism of energy transfer and release in the process of rockburst was analyzed.It was found that the dynamic loading and unloading effects exist between the two bodies in source body of rockburst.The faster the crack propagation rate of broken body is,the more significant the dynamic unloading effect of the energy release body is.The greater the dynamic stress drop is,and the higher the energy release rate is.The greater the kinetic energy of energy release body,the higher the dynamic loading rate of broken body.The faster the damage speed,and the higher the degree of fragmentation.The occurrence of rockburst is a process of acceleration,stabilization and reduction of dynamic interaction between two bodies.The correlation analysis is consistent with the two-body experimental phenomena.Based on the theory,the scale characteristics of the impact source were deduced.The results of borehole strain meter of typical rock burst events in Huating mining confirm that there is a synchronous stress drop in the different scales of the periphery of broken area,which provides an engineering basis for the above theory.