Qingling Zhongnanshan Highway Tunnel Large Embedded Depath Monitoring Measurement And Numerical Analysis

With the development of traffic construction in china,especially the implement of western development strategy, highway tunnel option in the mountains and hills in expressway construction is in the growing attention and some embedded large depth, long-span tunnels appeared one after another.For seeking mechnical state and safety of surrounding rock and support lining structure under large embedded depth conditions during tunnel construction, taking Qingling Zhongnanshan highway tunnel as the background engineering which is the larggest scale and the second longgest highway tunnel in the world and considering tunnel's geological and engineering conditions, constrction monitoring measurement and numerical analysis was taken for the two large embedded depth test sections respectively in east and west line.First, field test was taken to tunnel structure mechnical state and stability. The content of monitoring measurement included surrounding rock pressure, interior displacement of surrounding rock, initial support and clearance convergence, steel arch stress, shotcrete stress, anchor axial force, contact pressure between primary support and secondary lining, secondary lining concrete stress and secondary lining clearance convergence and so on. Meanwhile,some problems coming across during arrangement and implementation of monitoring measurement was also taken for considering and discussion.Secondly, characteristics of deformation and lining's stress on primary support and secondary lining were analyzed by numerical simulation for construction process using finite elements analysis software (MIDAS/GTS).Finally, through the comparative analysis of field monitoring data and finite element numerical simulation results, the evaluation was taken on tunnel surrounding rock's stability and support lining structure's safety.Monitoring data and calculation results show that, on large embedded depth condition, steel arch and shotcrete are the main force structure, especially steel arch , significant role. Second lining of the security, good working conditions, there were enough safety reserves.