Groundwater Seepage's Impacton Tunnel Stability

In the construction of road or railway projects,encounters with regions that are either extremely mountainous or with harsh climatic condition are quite often.In those cases,the construction of the tunnel is an effective way to not only reduce the mileage,save travel time,but also ensure the safety of travel.In the process of designing and constructing the tunnel,it is imperative to take account into the role of fissure water.If we chose to completely drain it,it would not only disrupt the order of the groundwater system,more severely,it will cause settlement on the foundation of the tunnel thus inflicting tremendous hazards.However,If we chose complete occlusion,it will over pressure the tunnel lining making it near improbable to maintain the tunnel's sustainability.Moreover,due to the the fracture interconnectivioy of rock mass,groundwater seepage is very complex,the original stable rock produces heavy stress distribution in the tunnel excavation,but also due to the coupling effect of stress field and seepage field,leading to changes in the groundwater flow as well.Therefore,when designing the tunnel,one of the key issues is to get a clear idea of groundwater movement,and also to ensure the safety of tunnel lining structure.Mainly based on the Chongqing City Shuangbei tunnel background support projects,this article will use the principles of groundwater flow field analysis,to research and discuss about following areas:(1)Exploit the similarity between the nature of seepage field and temperature field,carry out athermal analysis using ANSYS Workbench thermal conduction module to analyze the seepage problem.(2)Utilize ANSYS Workbench software to build a tunnel Shuangbei dimensional numerical model to analyze the role of osmotic pressure and water tunnel and also the surrounding rock structures permeate water pressure and groundwater seepage velocity distribution in the lining.(3)Working with the results of software models,compare and analyze the data stress and stress field coupling seepage field before and after,conclude the impacts of the seepage on surrounding rock stress and deformation.