大空间采场远场关键层破断形式及其对矿压显现的影响

摘要

针对大同矿区特厚煤层综放大空间采场易出现大周期强矿压现象的特点,采用理论分析与现场实测方法,研究大空间采场上覆远场关键层破断形式及其对采场矿压显现的影响机制.首次提出大空间采场覆岩远场关键层“横O-X”破断的“三角板”结构力学模型,并初步分析了“三角板”结构的动态失稳过程,指明远场关键层“三角板”结构失稳是引发采场出现大周期强矿压显现的主要原因,这一结论也得到大同矿区特厚煤层开采实践的证实.此外,远场关键层破断影响采场矿压的现象在神东矿区亦有发生,且其“横O-X”破断特征也得到了地表采动裂缝形态的验证.研究结果可为大空间采场强矿压显现的科学控制提供指导.%In terms of the characteristic that the phenomenon of major cycle and strong strata behavior was prone to appear in the mining extremely thick coal seam of large space stope in Datong Coalfield,the theoretical analysis and field measurement were adopted to study the structural breakage of far field stratum in large space stope and its influential mechanism on strata behaviors.The "triangle plate" structural mechanics model for far field key stratum broken in the shape of "horizontal O-X" at large space stope was proposed initially,and analyzed its dynamic instability process.It was indicated that the instability of the "triangle plate" structure of far field key stratum was the primary reason for the phenomenon of major cycle and strong strata behavior,which was verified by the mining practice of extremely thick coal seam in Datong Coalfield.In addition,the phenomenon of the far field key stratum breakage induced strata behaviors also occurred in Shendong Coalfield,and its "horizontal O-X" breakage features were verified by the form of mining-induced fissures on ground.The research results can provide guidance to the scientific control of strong strata behaviors in large space stope.