区段煤柱聚能失稳关键因素及控制技术

Key factors and control technology of energy-gathered instability of coal pillar

针对综放工作面区段煤柱失稳问题,以蒋家河煤矿ZF211工作面25 m宽区段煤柱为工程背景,通过理论分析、数值模拟以及现场试验的方法分析了煤柱极限能量与侧向应力之间的函数关系,提出了煤柱弹性区失稳判据,研究了塑性区范围以及承载宽度对煤柱弹性区极限能量的影响。结果表明:区段煤柱弹性区极限能量与侧向应力呈二次正相关关系,侧向应力整体呈"上凸型"对称分布,能量大小随塑性区范围的增大而增大;极限弹性能密度随塑性区范围和煤柱承载宽度的增大而增大;煤柱弹性能呈"双峰型"分布,随着塑性区范围的增大而增大;提出了煤柱局部冲击和煤柱大范围连锁冲击2种聚能失稳形式;给出了相应的控制技术并在现场进行了应用,工程实践表明防治效果良好。

Coal pillars generally experience instability problems in the section of fully mechanized caving face. A case study was performed at the 25 m coal pillar in the ZF211 working face of Jiangjiahe Coal Mine. The function relationship between the ultimate energy and lateral stress of the coal pillar were analyzed through theoretical analysis,numerical simulation and field tests. The instability criterion of the elastic zone in the coal pillar was proposed,and the influence of the plastic zone range and the effective width on the ultimate energy of the elastic zone was studied. The results showed that the ultimate energy of the elastic zone had a quadratic positive correlation with the lateral stress,and the lateral stress was distributed symmetrically in an "upward convex" shape. The size of the "upward convex" shape increased with the extent of the plastic zone. The ultimate elastic energy density increased with the extent of the plastic zone and the effective width of the coal pillar. The elastic energy within the coal pillar was distributed in a "bimodal" pattern,which increased with the extent the plastic zone. Two forms of energy accumulation instability were proposed,local impact and large-scale chain impact. The corresponding control technology was put forward and applied in the field. The engineering practice showed that the control effect was good.