倾斜煤层采空区岩体运移特征与沿空巷道围岩稳定性分析

    Influence of rock body transportation in inclined coal seam mining airspace on the stability of surrounding rock along the empty roadway

    • 摘要: 针对倾斜煤层开采过程中,采空区岩体运移特征对沿空巷道围岩稳定性的影响机制,以庄子河煤矿为研究对象,通过FLAC3D数值模拟技术,揭示了沿空巷道全服务周期内围岩应力场分布规律、塑性损伤演化机制以及巷旁支护结构的力学响应特征。研究结果表明,倾斜煤层条件下超前支承应力场与侧向残余应力场均随埋深增加呈梯度递增规律;二次采动影响显著增大超前支承应力峰值(增幅达43%)及其影响范围(扩展28%),引发侧向应力集中系数提高至1.75;采空区垮落岩体对顶板形成非对称支撑效应,导致巷道产生顺层剪切破坏并贯通采空区顶板塑性区;现有巷旁支护结构虽满足强度指标(强度安全储备系数K=4),但其抗侧向变形能力不足。

       

      Abstract: Aiming at the influence of rock transport characteristics in the tilted coal seam on the stability of the peripheral rock along the open roadway, we took Zhuangzihe Coal Mine as the research object, and revealed the distribution law of the peripheral rock stress field, the evolution mechanism of the plastic damage, and the mechanical response characteristics of the roadway support structure during the full service cycle of the open roadway through the numerical simulation technology of FLAC3D. The results show that the over-head bearing stress field and lateral residual stress field under inclined coal seam conditions show a gradient increasing law with the increase of burial depth; the influence of secondary mining significantly increases the peak value of over-head bearing stress (by 43%) and its influence range (by 28%), which triggers the increase of lateral stress concentration coefficient to 1.75; the collapsed rock body in the mining area forms an asymmetric support effect on the roof plate, which results in the downgrade and shear damage and penetrates the mine shaft; and the rock body collapses in the mining area to form an asymmetric support effect on the roof plate, which leads to the downgrade and shear damage and the penetration of the mine shaft. Shear damage and penetration through the plastic zone of the roof plate in the mining hollow zone; although the existing roadside support structure meets the strength index (strength safety reserve coefficient K=4), its resistance to lateral deformation is insufficient.

       

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