Stability Evaluation To Tunnels Of Zhong Nan-Shan Highway

Safety construction technology in extra-long tunnel and adapting to high quality and efficient management are important to be researched and improved.Zhongnanshan tunnel is a typical tunnel group project.There are many sections and geological structure,and new excavation tunnels will span the existing roads and rail tunnels several times,its spatial structure and mechanical characteristics are very complex.According to the methods and means,including to field geological investigation,experiment and field monitoring,etc.,the stability of tunnels were monitored and predict.The in-situ investigation showed that the Zhongnanshan tunnels spaned many engineering geology units.The character of engineering geological are very complex.And there had rockburst-prone and other engineering disasters. Based on laboratory tests,the physical and mechanical behavior of rock and parameters were achieved,which provides basis for the site construction decisions.In terms of FLAC3D numerical computation and analysis showed taht the displacement of across the tunnel in air duct and four-arch was large,the stress state was very complex in the construction of ventilation systems.Fourth-arch high arch foot section near is the stress concentration region,where had a prone of dynamic failure and rockburst.The over-less excavation of surrounding rock of tunnels was decreased based on hybrid monitoring. The blasting parameters and design are adjusted,the blasting effect and the disturbance of the main tunnel destruction were successfully controled.All of these achieved a rapid construction and improves efficiency of the tunnel.The research provides a reference for the safe construction and efficient construction to the others same conditions tunnels.