特厚煤层综放开采沿空掘巷合理煤柱宽度研究

Study on Reasonable Coal Pillar Width of Gob-side Entry Driving in Fully-mechanized Caving Mining of Extra-thick Coal Seam

针对坚硬特厚煤层综放开采沿空掘巷煤柱宽度的最佳选择及其围岩应力分布的问题,本文采用理论分析与数值模拟的研究方法。研究了工作面侧向及超前支承压力的分布规律,确立沿空巷道的科学布局。研究结果表明:在采空区处于不稳定状态时,煤层端部悬臂梁结构控制着侧方支承压力;而采空区处于稳定时,侧向支承压力会降低,但影响范围会随之扩大。通过应用FLAC^(3D)数值模拟软件,并通过比较煤柱垂直应力的变化特征,最终确定了11 m煤柱为最优留设宽度。在矿井特殊构造地段,采用注浆加固技术,不仅改变了岩体的原有破坏机制,而且显著提升了煤岩的整体强度。

Aiming at the problem of the best choice of coal pillar width and the stress distribution of surrounding rock in gob-side entry driving of fully mechanized caving mining in hard and extra-thick coal seam,this paper adopts the research methods of theoretical analysis and numerical simulation.The distribution law of lateral and advance abutment pressure of working face is studied to establish the scientific layout of gob-side entry.The results show that when the goaf is in an unstable state,the cantilever beam structure at the end of the coal seam controls the lateral abutment pressure;When the goaf is stable,the lateral abutment pressure will decrease,but the influence range will expand.By applying FLAC^(3D) numerical simulation software and comparing the variation characteristics of vertical stress of coal pillars,it is finally determined that the 11-meter coal pillar is the optimal width.In the special structural section of the mine,the grouting reinforcement technology not only changes the original failure mechanism of the rock mass,but also significantly improves the overall strength of the coal rock.