深部软岩巷道承受高地应力作用,导致围岩产生流变大变形是影响其安全稳定的重要因素。以阳煤一矿西大巷工程为例,分析软弱围岩变形破坏机制;建立能够反映工程地质状况及初始设计方案的有限元模型,以现场监测变形数据和钻孔窥视围岩变形破坏深度为基础,反演获取围岩力学参数和蠕变参数。提出适合软弱流变岩体的可缓冲渐变式双强壳体支护方法,即根据围岩破坏情况进行分层注浆加固,并在最外部架设可缩性U型钢支架,形成可变形缓冲层。建立新型支护方案的有限元模型,利用围岩反演参数预测围岩变形情况,并通过与现场监测数据对比分析,验证了所提支护方案的有效性。
The large rheological deformation of surrounding rock caused by the high ground stress is an important factor that affects the safety and stability of deep soft roadways. Deformation and failure mechanism of weak surrounding rock at the west roadway of Coal Mine of Yangquan Coal Mining Group No.1 are analysed. A finite element model is developed which can address the local geological conditions and the initial design scheme. Based on the field monitoring deformation data and rock borehole results, the mechanical parameters and creep parameters of the surrounding rock are obtained through a back analysis. A new support scheme,which consists of double cacheable and gradually variable supporting shells, is proposed for deep soft-rock tunnelling. The scheme is implemented through hierarchically grouting reinforcement according to the damage condition of the surrounding rock and setting up a U-steel support in the external area to form deformable buffer layer. Finite element method for simulating the new support scheme is developed. Using the parameters obtained from the back analysis, deformation of surrounding rock is predicted. By comparing the numerical results with the field monitoring data, the effectiveness of the new support scheme is verified.