软弱破碎围岩隧道进洞新工法数值模拟及支护参数研究

Study on Numerical Simulation and Supporting Parameters of New Tunnel Entrance Excavation Method with Weak Surrounding Rock

我国西部山区地形陡峻、地质条件复杂,尤其是软弱围岩隧道洞口段施工十分困难,易出现洞口边坡滑动失稳或者强度不足等问题,因此,对软弱围岩隧道进洞施工新技术开展研究对我国西部山区建设具有重要意义。论文依托于昆明市某高速公路段隧道建设工程,基于软弱围岩变形控制技术提出采用全断面开挖配合玻璃纤维锚杆超前支护的隧道进洞新工法,并采用有限元软件MIDAS/GTS NX对该工法进行全过程模拟,研究玻璃纤维锚杆布设间距、锚杆长度、搭接长度对掌子面核心土加固效果的影响。

In the western mountainous area of China,the terrain is steep and the geological conditions are complex,especially the construction of the portal section of the tunnel with soft surrounding rock is very difficult,which is prone to slide instability or insufficient strength of the portal slope.Therefore,the research on the new construction technology of the tunnel with soft surrounding rock is of great significance to the construction of the western mountainous area of China.Based on a tunnel construction project of a expressway in Kunming City,a new tunnel entrance method is proposed based on the deformation control technology of soft surrounding rock,which adopts full section excavation and glass fiberbolt advance support.The whole process of the method is simulated by the finite element software MIDAS/GTS NX,and the effects ofthe spacing,length and lap length of the glass fiber anchor on the reinforcement effect of the core soil in the face are studied.