富水裂隙岩体隧道裂隙形式对渗流场影响研究

Effect of fracture form on seepage field in water-rich fractured rock mass of tunnel

采用数值分析的方法,对不同裂隙形式的富水岩体隧道渗流场进行分析。根据隧道特点,用三维离散元软件3DEC建立模型,分析计算了存在竖直方向与存在竖直与水平方向的交叉裂隙岩体隧道渗流场特征,将计算数据进行比较,得到裂隙形式与富水隧道渗流场的关系。分析表明:裂隙岩体隧道开挖暴露面5m范围内,渗流场最容易受到隧道施工的影响,注浆圈外绝大部分区域水压力为静水压力;存在竖直方向交叉裂隙时比存在竖直与水平方向交叉裂隙时,渗入隧道中的水更多,导致衬砌背后水压力更大;当裂隙水向隧道中心流动时,不同方向的裂隙会导致水的分流。

In this paper,the seepage field of water-rich rock in different fracture forms is analyzed by means of numerical analysis. According to the characteristics of tunnel,the model is built with the three-dimensional discrete element software 3DEC. Then Seepage Field in vertical cross fractured rock mass tunnel and vertical horizontal direction cross fractured rock mass tunnel are analyzed and calculated. Based on the data obtained,the relationship between the fracture form and the seepage field of the water-rich tunnel is given. Analysis shows that the seepage field is most susceptible to the impact of tunnel construction in 5 meters of excavation exposed surface. Water pressure is hydrostatic pressure in those area which is outside the grouting ring. The amount of water flowing into the tunnel with vertical cross fissures is more than the amount of water flowing into the tunnel with vertical horizontal cross fissures. This makes the water pressure even bigger behind the lining. Different direction of the cracks will lead to water diversion when the water flow toward the center of the tunnel.