围岩应力回迁诱发滞后性冲击与突出现象机制研究

Mechanism of hysteretic rockburst and outburst induced by surrounding rock stress returning

为探究卸压区域再次应力集中诱发异常冲击与突出事故的发生机制,以河南某矿25110工作面为例,结合河南2起典型事故,提出应力回迁概念。利用理论分析、数值模拟、现场实测等方法,研究应力回迁现象的发生过程、力学机制及防治对策。结果表明:围岩应力回迁现象存在,且具有滞后性、隐蔽性特征;深部煤体过度卸压弱化自身承载能力,并迫使支承压力向巷道方向回迁,是滞后性冲击与突出灾害发生的主要原因。结合该类灾害特点,提出近场强卸压与强支护、深部控卸压与强监测的防治对策,并被应用于河南某矿25110工作面,保证了该工作面的安全回采。

To investigate the occurrence mechanism of rockburst and outburst accidents induced by returned stress of surrounding rocks,a Stress Returning（ SR） concept was proposed on the basis of a case-study within a 25110 working face in a coal mine（ locates in Henan Province,China）,where two typical accidents had been occurred before. The process of occurrence,mechanical mechanism,and corresponding prevention countermeasures of the SR phenomenon were thoroughly studied using methods of theoretical analysis,numerical simulations and field measurements,etc. The results indicate that the SR is characterized by hysteresis and an eclipse period and that the excessive pressure relief of deep coal body reduces its load-bearing capacity and the abutment pressure is coerced back to the roadway,which is the main reason for occurrence hysteretic rockburst and outburst. Countermeasures adopted according to the results have been applied in the 25110 working face to guarantee the mining safety.