深井厚煤层采空区迎采动隔离煤柱合理宽度研究

RESEARCH ON REASONABLE WIDTH OF PARTITION PILLAR CLOSE TO GOAF HEADING MINING IN THICK SEAM OF DEEP SHAFT

确定隔离煤柱合理宽度是确保深井厚煤层采空区迎工作面安全回采的关键。以田陈煤矿7108采空区迎采动隔离煤柱宽度的确定为工程背景,采用理论分析、数值模拟、现场监测等方法,对深井厚煤层采空区迎采动诱发冲击地压机制及隔离煤柱合理宽度进行研究。得到的主要结论为:(1)采空区迎7110工作面回采期间覆岩空间结构演变过程为"固定S型→移动S型→连体S型→C型→U型",隔离煤柱应力演化过程为"固定支承压力→移动支承压力→应力叠加→煤柱应力集中";(2)采空区迎采动诱发冲击地压的原因是应力集中造成煤体应力达到冲击应力条件;(3)在对隔离煤柱周围实施高强度卸压条件下,确定7108采空区迎采动隔离煤柱合理宽度为65 m,经实践,获得良好效果。研究结果对采矿工程诱发型冲击地压防治具有参考意义。

Setting reasonable partition pillar is a key to ensuring safe mining of working face heading the goaf in thick seam of deep shaft. Taking determining the width of partition pillar close to 7108 goaf heading mining of LW7110 in Tianchen Mine as the engineering background,the mechanism of the goaf heading mining inducing rock burst and the reasonable width of partition pillar were studied through theoretical analysis,numerical modeling and field monitoring. The following conclusions were obtained.(1) The evolution process of overlying strata spatial structure during LW7110 mining heading the goaf is described as 'the fixed S-shaped,the moving S-shaped,the connected S-shaped,the C-shaped and the U-shaped',and the evolution process of partition pillar stress is described as 'the fixed abutment pressure,the moving abutment pressure,the stress superposition and the stress concentration'.(2) The mechanism of rock burst induced by the goaf heading mining is described as the vertical stresses in the partition pillar reaches impact stress condition because of stress concentration.(3) Under the premise of implementing stress relief around the pillar,the reasonable width of partition pillar close to 7108 goaf heading mining is 65 m. Furthermore,the reasonableness of the partition pillar width was verified with a good result. The results can provide a reference for prevention of rock burst induced by mining engineering.