特厚煤层区段煤柱合理宽度研究及巷道支护优化

Research on reasonable width of section coal pillar in extra-thick coal seam and optimization of roadway support

合理宽度的留设是特厚煤层区段煤柱能否安全高效开采的关键。为了提高资源回采率,以韩家洼煤矿特厚煤层综放开采面为工程背景,对区段煤柱合理留设宽度进行了研究。通过现场观测调研,揭示了巷道在原支护方案下的变形特征和机理,运用稳定核区理论和极限平衡理论对特厚煤层综放面区段煤柱合理宽度进行了计算;并通过FLAC^(3D)软件分别构建了三种区段煤柱宽度方案,从应力演化与塑性区扩展的角度进行数值模拟综合对比分析,从而优化确定合理区段煤柱尺寸为12 m;根据22401工作面的地质和生产条件,以提高煤炭的资源回收率为首要经济需求,以控制围岩变形、位移和裂隙发展为主要工程内涵,以积极主动地保持围岩的整体性为主要技术目标,基于工程类比的方法,采用非对称"锚杆+钢带+钢筋带+锚索"的联合支护技术。该研究成果可为类似条件煤矿区段煤柱留设提供参考和借鉴。

The reasonable width is the key to the safe and efficient mining of coal pillar in extra thick coal seam.The reasonable reserve width of the section coal pillar is studied with the top-coal caving face of the extra-thick coal seam of the Hanjiawa coal mine as the object,in order to improve the resource recovery rate.Through field observation and investigation,the deformation characteristics and mechanism of the tunnel under the original support solution are revealed.The reasonable width of the section coal pillar is calculated using the stable central zone theory and the limit equilibrium theory.Three section coal pillar width solutions are designed using the FLAC^(3D) software.Comprehensive comparison analysis of the numerical simulation from the perspective of stress evolution and plastic zone expansion,and the optimized reasonable size of the section coal pillar is therefore determined to be 12 m.Considering the geological and production condition of the 22401 working face,through the engineering analogy method,the joint support technology of asymmetrical“anchor rod+steel belt+steel bar belt+anchor cable”is adopted to meet the primary economic requirement of improving the coal resource recovery rate,realize the engineering connotation of controlling surrounding rock deformation,displacement and crack development and reach the main technological target of proactively maintain the integrity of the surrounding rock.The study results can provide reference for section coal pillar settings of similar coal mines.