基于围岩流变性的曾家坡软岩隧道稳定性分析

Stability Analysis of Zeng jiapo Soft Rock Tunnel Based on Surrounding Rock Rheology

软岩隧道建成后的长期稳定性受岩体流变性的影响。结合现场监测数据,采用有限差分软件FLAC 3D分析了曾家坡隧道的长期稳定性及其变形控制要点。分析结果表明:曾家坡隧道开挖施工过程中岩体流变范围约为隧道开挖半径的3倍;隧道拱顶、仰拱以及边墙的变形和受力均在隧道建成5年后逐渐趋于稳定;隧道建成后5年内应加强边墙处衬砌应力和变形的监测,5年以后应重点监测隧道拱顶和仰拱尤其是拱顶的应力和变形。

The long term stability of soft rock tunnel after completion is influenced by rock mass rheology. Based on the field monitoring data, the long term stability and deformation control key points of Zengjiapo tunnel was analyzed by using finite difference software FLAC 3D. Analysis results indicate that rheological range of rock mass is three times the tunnel excavation radius during Zengjiapo tunnel excavation construction process, the deformation and stress of the vault,invert and side wall in Zengjiapo tunnel generally tends to be stable beyond five years after the completion of the tunnel, the lining stress and deformation monitoring for the side wall should be strengthened within 5 years after the completion of the tunnel, the stress and deformation monitoring for tunnel vault and invert especially the vault should be monitored emphatically beyond 5 years.