摘要
以同忻煤矿采矿地质条件为研究背景,采用理论分析、物理模拟和现场实测相结合的方法,建立了过煤柱特厚煤层开采“动-静”载荷组合作用力学模型,对比有煤柱和无煤柱条件下覆岩破断规律及煤柱对裂隙演化的影响,分析了不同宽度煤柱和高位关键层破断位置对裂隙演化的影响,揭示了过煤柱工作面开采水气下泄主通道形成机理。结果表明:高位关键层对覆岩破断和裂隙场演化有控制作用,其破断失稳后煤柱下方岩层受静载和动载双重载荷,易形成错动贯通型主破裂通道;高位关键层受煤柱集中应力影响发生提前破断,高位关键层破断后形成向上发育的主破裂通道,与煤柱底部两侧下方的破坏滑移面导通时,将发生采空区水气下泄;通过数值对比分析得到煤柱宽度越大,越不容易形成贯通的裂隙通道,高位关键层破断位置在煤柱左侧10 m时,底板滑移面与采动破裂面相交,更易形成贯通型裂隙通道;划分了不同推进阶段的水气下泄危险区域,提出了采用正压通风治理有害气体下泄的技术,保障了上覆煤柱下特厚煤层安全回采。研究成果可为大同矿区类似工作面过煤柱治理水气下泄提供参考。
Taking the geological conditions of Tongxin Coal Mine as the research background,the fol-lowing research work was completed by combining theoretical analysis,physical simulation,and field monitoring.First,a mechanical model of"dynamic-static"load interactions for extra-thick coal seam mining over a coal pillar was constructed.In addition,the overburden breakage patterns in the presence and absence of a coal pillar were compared to clarify the influence of a coal pillar on fracture evolution,and the influences of different widths of the coal pillar and different breakage positions of the high-level key stratum on fracture evolution were also analyzed.Finally,the formation mechanism of the main pathway for water and gas leakage during extra-thick coal seam mining over a coal pillar was unveiled.The results indicate that the high-level key stratum plays a controlling role in overburden breakage and fracture evolution.Once the overburden breaks and becomes unstable,the rock strata below the coal pillar are subjected to both static and dynamic loads,which conduces to forming a dislocation-connected main fracture channel.Affected by the concentrated stress of the coal pillar,the high-level key stratum experiences premature breakage,after which a main fracture channel that develops upward takes shape.When this channel connects with the damage slip surfaces below both sides of the bottom of the coal pillar,water and gas will leak from the goaf.Numerical comparative analysis shows that interconnected fracture channels are less likely to be formed in a wider coal pillar.When the breakage position of the high-level key stratum is 10 m away from the left side of the coal pillar,the slip surface of the floor intersects with the mining-induced fracture surface,facilitating the formation of interconnected fracture channels.Moreover,the areas with water and gas leakage hazards in different mining stages were divided,and the technique of positive pressure ventilation to control gas leakage was proposed in the hope of ensuring safe mining of the extra-thick coal seam beneath overlying coal pillars.The research findings are expected to provide a reference for the control of water and gas leakage over coal pillars in similar working faces of the Datong mining area.
作者
王文强
李振华
杜锋
曹正正
王伸
马鸣啸
WANG Wenqiang;LI Zhenhua;DU Feng;CAO Zhengzheng;WANG Shen;MA Mingxiao(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo,Henan 454003,China;Henan Mine Water Disaster Prevention and Control and Water Resources Utilization Engineering Technology Research Center,Henan Polytechnic University,Jiaozuo,Henan 454003,China;International Joint Research Laboratory of Henan Province for Underground Space Development and Disaster Prevention,Henan Polytechnic University,Jiaozuo,Henan 454003,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期856-867,共12页
Journal of Mining & Safety Engineering
基金
国家自然科学基金面上项目(52174073)
河南省杰出青年基金项目(222300420007)
河南省高校科技创新团队支持计划项目(23IRTSTHN005)。
关键词
特厚煤层
上覆煤柱
高位关键层
裂隙演化
extra-thick coal seam
overlying coal pillar
high-level key stratum
fracture evolution
