隧道开挖过程中复杂裂隙围岩的固流耦合分析

Analysis of Solid-Fluid Coupling for Tunnel Excavation in Complicated Fractured Rock Masses

隧道通过裂隙岩体的含水区段时,人为扰动了裂隙岩体、地下水等构成的复杂地质系统,是造成各种涌水、突水、突泥事故的重要原因。为了研究复杂地质条件下隧道开挖过程中岩体变形、流体运移相互作用过程,探讨其对隧道涌、突水的影响,在上述复杂过程进行理论分析的基础上,根据深埋隧道围岩裂隙发育规模与工程尺度的关系,建立可以同时考虑不同级别裂隙网络的复杂裂隙岩体水力学模型,采用有限元法对复杂裂隙岩体中开挖隧道的固流耦合过程进行了数值模拟,模拟结果体现了主干裂隙在渗流中的强导水作用和网络状裂隙的贮水功能与渗流滞后效应,开挖过程中复杂裂隙岩体渗流场与应力场的耦合作用显著的增加了隧道围岩屈服区。

When tunnels are through water-bearing section of fractured rock mass,a complex interaction process between rock mass deformation and fluid transportation is one of the most important reasons for water gushing,water bursting and mud bursting.To study the rock mass deformation and fluid transportation in tunnel excavation under complex geological conditions,a hydraulic model of complex crack rock mass was established from the relationship between the crack growth degree of surrounding rock in deep buried tunnel and the engineering scale,with which fracture network of different levels in rock mass could be considered simultaneously.Furthermore,a computer Fortran program was put forward to simulate the solid-fluid coupling of excavation process of a deep buried tunnel.And it was found that the principal fractures had strong flowing action and network fractures had storage function and lag effect in seepage area.And the yield area of surrounding rock was increased under the coupling of seepage field and stress field.