基于复合弱化结构的上覆煤柱区冲击地压防控研究

Study on prevention and control of rock burst in affected area of overlying coal pillar based on composite weak structure

为实现上覆煤柱影响区冲击地压的整体可控性,提出利用复合弱化结构进行冲击能量耗散,在阐述复合弱化结构定义、分类和弱化度及上覆煤柱导致冲击地压发生机理的基础上,分析了复合弱化结构的防冲力学机制。结果表明:弹性能指数、冲击能指数随复合弱化结构弱化度的增大而降低;复合弱化结构将冲击危险区域的弹性能分段耗散,能有效改变煤岩弹性能释放模式;对既定的残留煤柱采用顶板(煤)预破坏措施实现冲击能量的耗散。在唐山矿煤柱区域进行了现场试验,采取整体耗能措施后,冲击危险区域的钻孔应力值和钻屑量均小于发生冲击地压的临界值,保证了煤柱区的安全生产。

In order to realize the overall controllability of rock burst in the affected area of overlying coal pillar,the composite weak structure was proposed to dissipate the impact energy.On the basis of expounding the definition,classification and weakening degree of the composite weak structure and the mechanism of rock burst caused by overlying coal pillar,the anti-shock mechanical mechanism of the composite weak structure was analyzed.The results show that:the elastic energy index and the impact energy index decrease with the increase of the weakening degree of the composite weak structure;the composite weak structure dissipates the elasticity of the impact dangerous area by segments,which can effectively change the elastic energy release mode of coal rock;for the established residual coal pillar,the roof(coal)pre-failure measures are used to dissipate the impact energy.Field test was carried out in the coal pillar area of Tangshan Coal Mine.After the overall energy consumption measures were taken,the borehole stress value and drilling cuttings in the impact danger area were less than the critical value of rock burst,which ensured the safe production of coal pillar area.