采空区积水对邻近巷道围岩稳定性分析研究

Stability of surrounding rock with water accumulation in goaf

  • 摘要: 以山西某煤矿采空区为背景,针对采空区积水对邻近巷道围岩稳定性的影响,采用现场测试、室内试验、数值模拟等方法进行了研究分析。首先基于三维激光扫描和声呐建立了含水采空区的三维几何模型;然后对不同损伤程度下煤岩开展渗透率试验,获得了渗透率的变化规律;最后在充分考虑渗透率的动态变化基础上,采用数值软件对邻近巷道围岩的稳定性进行了模拟分析。结果表明:孔隙水压力已经影响到邻近巷道围岩和上覆岩体;采空区赋水后,围岩极易出现渗水和透水情况;受开采扰动和积水渗透的双重影响,采空区与巷道的煤柱出现大范围塑性区,其稳定性较差。为了保证井下生产安全,建议增加井下临时性排水设施,及时将积水排出,避免透水事故的发生。

     

    Abstract: This study investigates the influence of water accumulation in goaf on the stability of surrounding rock in a coal mine in Shanxi Province via field test, laboratory experiment and numerical simulation. Specifically, we established 3D geometric models of water bodies and goaf in water-bearing goaf based on 3D laser scanning and sonar. We then conducted permeability test on coal rock under different degrees of damage, and obtained permeability variation patterns. We then analyzed the stability of surrounding rock near water-cut goaf using numerical software by considering the dynamic changes of permeability. Results show that: ① pore water pressure exerts significant impact on the surrounding rock and overlying rock mass. ② The surrounding rock is prone to water seepage and percolation after the old goaf is flooded. ③ A large range of plastic zone with low stability is observed in the coal pillar between the goaf and roadway due to mining disturbance and water seepage. Therefore to ensure the safety of underground production, it is suggested to increase temporary underground drainage facilities for in-time water discharge to avoid flooding accidents.

     

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