重复采动影响下柱式沿空留巷围岩稳定性研究

    Study on the surrounding rock stability of columnar gob-side entry retaining under the influence of repeated mining

    • 摘要: 本文以王庄煤矿柱式沿空留巷(C-GSER)技术为研究背景,结合两次采动期间覆岩破断特征构建巷道顶板力学模型,分析了顶板的传力机制和应力状态,利用FLAC3D数值模拟软件建立柱式沿空留巷计算模型,对矿山压力的动态演化规律和静态分布特征进行研究,从剪应力分布的角度对重复采动影响下围岩稳定性展开了讨论,研究结果表明:两次采动过程中覆岩分别呈现回转形式和整体式破断下沉形式,巷道顶板由“压-弯”组合变形向“压-弯-扭”组合变形转变,煤壁前方20 m为采动影响范围,应力变化率逐渐增大,煤壁后方30 m范围内为采场应力重分布的主要阶段,岩层变形差异产生层间剪切应力,应力集中区分布呈现阶段性转移和扩展特征。采用“超前加强支护+综合巷旁支护+空间隔离支护”的围岩控制技术方案后有效控制了围岩变形。

       

      Abstract: This study takes the columnar gob-side entry retaining (C-GSER) technology at Wangzhuang Coal Mine as research context. By integrating the fracturing characteristics of the overlying rock during two mining cycles, a mechanical model of the roadway roof is constructed to analyze the stress transfer mechanism and stress state of the roof. Using FLAC3D numerical simulation software, a computational model for columnar gob-side entry retaining is established to investigate the dynamic evolution and static distribution characteristics of mine pressure. The stability of the surrounding rock under repeated mining impacts is discussed from the perspective of shear stress distribution. Results indicate: overburden exhibited rotational and integral failure-subsidence patterns during the two mining cycles, with the roadway roof transitioning from “compression-bending” combined deformation to “compression-bending-torsion” combined deformation. The mining influence zone extends 20 m ahead of the coal face, where stress change rates progressively increase. Within the 30 m zone behind the coal face, the primary stage of stress redistribution occurs. Differential rock deformation generates inter-layer shear stresses, with stress concentration zones exhibiting phased migration and expansion characteristics. The rock mass control technology scheme employing “advance reinforcement support + integrated roadway side support + spatial isolation support” has effectively controlled rock mass deformation.

       

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