冲击矿压的静动叠加失稳机制和发生模式

基于静动叠加冲击矿压的黏弹脆性体突变模型和黏弹性介质中震动波的传播规律,研究了煤体静动叠加冲击失稳机制,结合实例分析了静动叠加冲击矿压的2种基本发生模式:高静载低动载模式和高静载高动载模式,讨论了震动波频率、结构弱面刚度等因素对震动波传递的影响。认为高静载低动载模式和高静载高动载模式能够揭示两类典型的冲击过程;震动动载形成的瞬时动应力增量与静载蠕变阶段的静应力叠加使煤体满足临界条件而发生冲击失稳;震动波传递不仅随弱面的力学性质劣化而弱化,且随震动波的物理特性变化如频率的增大和波幅的降低而弱化。研究结果能为冲击矿压监测和防治提供指导。

Rockburst mechanism and occurrence modes under superimposed static and dynamic loading

Using viscous-elastic-brittle rockburst model and tremor wave transmission rules in viscoelastic medium，the rockburst instability mechanism under superimposed static and dynamic loading was analyzed.With examples analysis，the effects of weak plane stiffness，tremor wave amplitude and frequency on tremor wave transmission and basic rockburst occurrence modes under superimposed static and dynamic loading were studied.These rockburst occurrence modes include two parts，one is high static loading and low dynamic loading mode，the other is high static loading and high dynamic loading mode.The results indicate that these modes can well reveal two typical rockburst instability processes.The superimposition of instantaneous dynamic stress increment and the static stress of creep phase make coal mass satisfy the critical conditions of rockburst occurrence.Tremor wave transmission weakens not only with the degradation of mechanical properties of weak plane but also with the changes of physical characteristics such as the frequency increase and the amplitude reduction of tremor wave.The research results provide guidance for rockburst monitoring and control.