巷道掘进围岩纵向变形分析与支护技术

    Study on Longitudinal Deformation Analysis and Support Technology of Surrounding Rock in Roadway Excavation

    • 摘要: 为了研究开挖面空间效应对巷道掘进时的影响,利用Hoek拟合的位移释放系数方程来描述空间效应下的巷道围岩纵向变形规律,建立巷道径向位移与力学模型中虚拟支护力关系的数学模型,导出开挖面空间效应下虚拟支护力与距开挖面距离的关系式。基于Mohr-Coulomb强度准则,推导出巷道开挖时围岩应力、塑性区半径与开挖距离的数学表达式。根据巷道围岩纵向位移以及塑性区半径的变化规律,能够更好地对巷道进行支护设计。结果表明:以巷道开挖面为例,建立的模型计算与FLAC3D模拟分析进行对比,在开挖面处围岩位移释放约为31%,利用开挖面的空间效应及时地对巷道进行支护,能够有效控制巷道前期变形,减缓巷道围岩塑性区的发展。

       

      Abstract: To study the influence of excavation space effect on roadway excavation, Hoek’s displacement coefficient equation is used to describe the longitudinal deformation law of roadway surrounding rock under the spatial effect, and the relationship between the radial displacement of the roadway and the virtual support force in the mechanical model is established. The mathematical model derives the relationship between the virtual support force and the distance from the excavation face under the spatial effect of the excavation face. Based on the Mohr-Coulomb strength criterion, the mathematical expressions of surrounding rock stress, plastic zone radius and excavation distance during roadway excavation are derived. According to the variation of the longitudinal displacement of the surrounding rock of the roadway and the radius of the plastic zone, the support design of the roadway can be better. The results show that taking roadway excavation face as an example, compared with the FLAC3D simulation analysis, the displacement of the surrounding rock at the excavation face is about 31%, and the space effect of the excavation face is used to support the roadway in time. Protection can effectively control the deformation of the roadway in the early stage and slow down the development of the surrounding plastic zone of the roadway.

       

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