不同侧压系数下矩形巷道逐步开挖的稳定性分析

    Stability analysis of rectangular tunnel excavation under different lateral pressure coefficients

    • 摘要: 为了研究不同侧压系数下巷道逐步开挖对围岩稳定性的影响,在相似模拟试验的基础上,采用FLAC3D软件建模,通过对试验结果与数值模拟结果进行对比,确定数值模型的可行性,并基于数值模拟结果,对5组不同侧压系数下巷道逐步开挖的主应力差和塑性区的演化规律进行研究。结果表明:侧压系数一定时,随着巷道的开挖,顶板与底板主应力差呈先增加后减小并趋于稳定的变化趋势,帮部主应力差呈先缓慢增加、快速增加、缓慢增加至最高点并趋于稳定的变化趋势;随着侧压系数的增大,对巷道稳定性的影响程度依次为顶板、底板、两帮,围岩塑性区正在剪切破坏的分布范围呈缓慢增加、减小、增加的趋势,两帮围岩塑性区以正在剪切破坏为主。

       

      Abstract: In order to study the influence of gradual excavation of roadway on the stability of surrounding rock under different lateral pressure coefficients, FLAC3D software was used for modeling on the basis of similar simulation tests. The feasibility of the numerical model was determined by comparing the test results with the numerical simulation results. Based on the numerical simulation results, the evolution laws of principal stress difference and plastic zone of gradual excavation of roadway under five groups of different lateral pressure coefficients were studied. The results show that when the lateral pressure coefficient is constant, with the excavation of the roadway, the principal stress difference between the roof and the floor first increases and then decreases and tends to be stable, and the principal stress difference in the sidewall first slowly increases, rapidly increases, slowly increases to the highest point and tends to be stable. With the increase of lateral pressure coefficient, the influence degree of roadway stability is roof, floor and two sides. The distribution range of shear failure of surrounding rock plastic zone is slowly increasing, decreasing and increasing. The plastic zone of two sides is mainly shear failure.

       

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