Tunnel Disease Treatment

With the quick development of the expressway construction, more and more tunnels were built in China and the length of tunnels increases one after another. While these achievements were gained, leakage and cracks of lining occurs in some of the tunnels due to long running time, geologic factors and aging of waterproof facilities. In some tunnels, the condition is so awful that obvious abutment shifting and lining damage have appeared. The structure these tunnels may be imbalanced and damaged in one day if no measure is taken. Therefore, the author brings out a study ranged from disease analysis to detect treatment based on settlement of Jingyang Expressway Tunnel section, to ensure the safety.To deal with the leakage and cracks of lining, the author firstly carried out a monitoring before, during and after the project in some typically section of the tunnel. Then a research is carried out on strengthening the tunnel crack lining by using the steel arching structure and shotcrete anchor. An analysis result of stress and deformation of steel arching structure supports the lining strengthening design. Further more, study show that the auto-placing hollow anchor bar should take the place of the traditional bar. The auto-placing hollow anchor bar can reinforce the surrounding rock, prevent leakage and decrease the cost as a result. The paper also includes a study of techniques of wet shotcrete for high intensity concrete (steel fiber concrete), reduce rebound, improving the effect of support and protection, reduce construction period.Through the research on those aspects, the perfect treatment shows that these measures are effective and economical.