大断面软岩隧道开挖围岩卸荷及变形空间效应研究——以乌鲁木齐绕城高速(西线)工程西山隧道为例

Research on Unloading and Deformation Spatial Effect of Surrounding Rocks in Large-section Soft Rock Tunnel Excavation——Taking Xishan Tunnel of Urumqi Ring Expressway( West Line ) Project as an Example

我国修建的数量众多的大断面隧道工程,极大地提高了交通的便捷度。然而,在软弱岩层中修建大断面山岭隧道时,施工过程并不顺利,经常会遇到掌子面失稳、地表塌陷等工程问题。对此,文章以乌鲁木齐绕城高速(西线)工程西山隧道为工程背景,针对软岩及复杂地质大断面长大隧道的施工问题,立足隧道施工过程中不同部位的受力情况,结合现场的工程实例,进行理论分析研究,设计数值仿真试验,并用极差分析法分析试验数据,对大断面软岩隧道开挖过程中,开挖工法、断面大小及围岩等级对围岩卸荷和变形的影响程度进行深入研究,以期为同行提供一定的理论参考。

A large number of large-section tunnel projects built in China have greatly improved the convenience of transportation. However, when the large-section mountain tunnel is constructed in the soft rock stratum, the construction process is not smooth, and engineering problems such as tunnel face instability and surface collapse are often encountered. In this regard, the paper takes Xishan Tunnel of Urumqi Ring Expressway( West Line) project as the engineering background. Aiming at the construction problems of large and long tunnels with large section in soft rock and complex geology, based on the stress conditions of different parts during the tunnel construction process, combined with on-site engineering examples, theoretical analysis and research are carried out, numerical simulation tests are designed, and test data are analyzed by range analysis method. The influence of the excavation method, section size and surrounding rock grade in the process of excavation of large-section soft rock tunnels on the unloading and deformation of surrounding rocks during tunnel excavation is studied in depth, in order to provide a certain theoretical reference for peers.