Study On The Mechanism Of Crack Generation And Control Methods Of Tunnel Lining

As the comprehensive development of the implementation of economic strategy, the transportation infrastructure construction is widely developed. The tunnel is one important and essential structure in traffic. During the construction and use of tunnels, it's inevitable that Diseases of Tunnels will appear, because of the geological conditions, environment, design, construction, etc. Among them, the lining crack is one of the most common and serious disease. Therefore, research on the Cracking Mechanism and controlling methods of cracks become a hot issue.In this paper, firstly through the interaction between the surrounding and support, anlyze the cracking cause, and conclude the factors which affect the cracking of the lining. Then, numerical calculate on the mechanical characteristic of lining.Through the analysis, get conclusions as follows:1,Tunnel linings crack mainly because of the impact of the deformation pressure, the loosening pressure,the ground conditions, the unsymmetrical pressure, temperature and shrinkage stress, the expansion of the surrounding rock and frost heave pressure, corrosive effect,human factors in construction, cyclic load of the operating vehicles and so on.2,When the conditions of the surrounding rock are the same, the deeper the tunnels buried, the force is greater and the cracks are easier to develop.When the tunnels buried to some depth,because the arch function of the surrounding rock,the pressure of the surrounding rock becomes stable and the cracks stop to increasing.3,When the depths of tunnel are the same, the condition of the surrounding rock is poorer, the deformation pressure of tunnel linings is greater,the cracks are easier to develop.4,With bias voltage, the tunnel lining was asymmetrically forced,and lining structure was unstable,easy to crack. With invert, lining structure was more rationally forced and more stable, can effectively inhibit the lining crack.5,The main controlling methods of cracks are reinforcing the surrounding rock and the tunnel lining.