深部厚煤层巷道失稳破裂演化过程离散元模拟研究

发布时间：2019-05-07 18:22

【摘要】：为研究深部厚煤层巷道围岩失稳破裂演化过程,以某煤矿厚煤层巷道为工程背景,采用离散元中随机分布三角形单元块体集合模型研究巷道开挖失稳。对深部厚煤层巷道围岩失稳破裂过程中位移、应力演化规律分析发现:两帮围岩水平应力释放相对于顶底板剧烈,竖向应力反之;围岩竖向应力释放的主要部位是巷道中部。结果表明,深部厚煤层巷道失稳破裂演化的2个主要特征为:1)顶板出现"尖顶型"垮冒,巷中是围岩失稳的关键部位;2)顶底板离层破坏严重。并对其相应机制进行分析:顶底煤岩松散破碎,自稳能力差,顶底板径向应力释放相对剧烈,巷道矩形断面顶、底板受力能力差等因素,导致围岩顶底板离层变形。基于深部厚煤层巷道失稳破裂的演化规律,给出锚索悬吊组合支护方式,结果表明该支护方式可有效地控制厚煤层巷道变形。
[Abstract]:In order to study the process of instability and fracture evolution of surrounding rock of deep thick seam roadway, a random distributed triangular element block set model in discrete element is used to study tunnel excavation instability based on the engineering background of a thick coal seam roadway in a coal mine. Based on the analysis of displacement and stress evolution in the process of instability and rupture of surrounding rock in deep thick coal seam, it is found that the horizontal stress release of the surrounding rock of both sides is intense relative to the roof and floor, and the vertical stress release of the surrounding rock is mainly located in the middle of the roadway. The results show that the two main characteristics of instability and fracture evolution of deep thick seam roadway are as follows: 1) the roof collapse occurs, which is the key part of the surrounding rock instability, and 2) the roof and floor break-up is serious. The corresponding mechanism is analyzed, such as loose fragmentation of top and bottom coal and rock, poor self-stabilization ability, relatively intense release of radial stress on top and bottom plate, poor bearing capacity of rectangular cross-section of roadway, and so on, which lead to deformation of roof and floor of surrounding rock. Based on the evolution law of instability and fracture of deep thick seam roadway, the combination support mode of anchor cable suspension is given. The results show that this support mode can effectively control the deformation of thick seam roadway.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室;
【基金】：江苏省杰出青年基金项目(BK20150005)
【分类号】：TD353

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