煤层群条件下回采巷道护巷煤柱宽度数值模拟研究

    Numerical simulation of pillar width of stoping roadway under coal seam group condition

    • 摘要: 在近距离煤层群协同开采条件下,上覆煤层回采所引发的采动扰动对下伏煤层回采巷道的围岩稳定性构成严重威胁。针对该问题,本文以惠安煤矿11、13号煤层为工程背景,结合弹塑性理论与离散元数值模拟,提出“围岩影响系数”指标,系统分析上覆采动扰动对下伏巷道的影响机制。通过FLAC3D与UDEC软件,模拟不同内错距布置下应力场与裂隙场的演化特征,明确围岩扰动边界(F=−0.4)与失稳临界(F =−0.6)判据。结果表明:当内错距小于20  m时,上下煤层巷道扰动区明显重叠,裂隙叠加严重,围岩稳定性显著下降;当内错距不小于20  m时,扰动区解耦,巷道裂隙区趋于独立,围岩结构完整性显著增强。研究明确了巷道安全布置的临界错距标准,揭示了采动-掘进扰动叠加机制,为下伏煤层巷道优化布置与支护设计提供理论依据与技术支撑。

       

      Abstract: Under the cooperative mining condition of close coal seam group, mining disturbance caused by mining of overlying coal seam poses a serious threat to the stability of surrounding rock of mining roadway of underlying coal seam. Aiming at this problem, this paper takes coal seams 11号 and 13号 of Hui 'an Coal Mine as the engineering background, combined with elastoplastic theory and discrete element numerical simulation, puts forward the index of "influence coefficient of surrounding rock", and systematically analyzes the influence mechanism of overlying mining disturbance on the underlying roadway. By using FLAC3D and UDEC software, the evolution characteristics of stress field and fracture field under different internal dislocation arrangement were simulated, and the disturbance boundary (F=−0.4) and instability critical (F=−0.6) criteria of surrounding rock were defined. The results show that when the internal fault distance is less than 20  m, the disturbance area of upper and lower coal seam roadway overlaps obviously, the fracture superposition is serious, and the stability of surrounding rock decreases significantly. When the internal fault distance is not less than 20  m, the disturbed area is decoupled, the roadway fissure area tends to be independent, and the structural integrity of surrounding rock is significantly enhanced. The critical deviation standard of roadway safety layout is studied, and the superposition mechanism of mining-excavation disturbance is revealed, which provides theoretical basis and technical support for optimal layout and support design of roadway in the underlying coal seam.

       

    /

    返回文章
    返回