| In mountain area, there are a lot of railroad tunnels are built in slope. And some tunnel's diseases such as deformation and fracture occur frequently in these tunnels. The survey shows that deformation and fracture of tunnel is correlative with landslide intimately and endangers security of trains running seriously. Due to above causes, the tunnel deformation mechanism at landslide site, tunnel deformation and landslide forecasting and controlling are studied in the paper.1. Based on the investigation and research on nearly 30 building or built tunnels, the structure and cause of landslide, relative position between tunnel and sliding plane and the corresponding deformation features of tunnel are studied. The view that relative position between tunnel and sliding plane is the major cause to determine the deformation features of tunnel is put forward. And the mechanical patterns of tunnels situated different place in landslide are analyzed. Four typical geological mechanics models to analyze interrelation between landslide and tunnel deformation are given. On the basis of above, the interaction mechanism between landslide and tunnel deformation is discussed in detail by several methods such as analytic calculation, laboratory model test and numerical analysis method. The achievement of the research is helpful to set up integral theory of tunnel deformation at landslide site, and also can provide theoretical guide for designing effective engineering measures.2. The paper applies gray system theory to predicting study of tunnel deformation at landslide site, and the gray equal-dimensions and new-information model is presented. Combine with numerical analysis method, the connected predicting mode that first predicts tunnel deformation then landslide disaster is proposed. The predicting method not only can predict tunnel deformation independently, but also can forecast landslide disaster if necessary. In addition, the predicting method asks only a few original data, is convenient to build models and easy to handle and apply. Analysis of an example shows that the predicting method is reliable and effective.3. In the paper, the engineering measures to control tunnel deformation at landslide site are studied too. The viewpoint is set forth that engineering measures should be suitable to the deformation features of tunnels, and the specific choosingmethod is given. In view of some defects exist in the transfer coefficient method that is commonly applied to calculating landslide thrust at present, an improved method is drawn out. The improved transfer coefficient method has considered two unfavorable factors of sliding mass weight increasing and sliding plane strength decreasing, thus the problems are solved that the landslide thrust value calculated by transfer coefficient method-based on strength-reserve method is lower and the mechanics meaning of transfer coefficient method-based on overloading method is undefined. The results of a calculation example show that the improved transfer coefficient method is advantageous to safety design of landslide controlling. In view of the particularity of design of tunnel deformation controlling at landslide site, typical types of anti-slide pile and application conditions of various anti-slide pile types are put forward, and the methods to determine the reasonable site of anti-slide pile are pointed out. It has important directive significance for rational and effective design, of design of tunnel deformation controlling at landslide site. At the same time, the design and calculation methods of several major engineering measures such as common anti-slide pile, anti-slide pile with prestressed anchor cable and foundation beam with prestressed anchor cable, are discussed. It will be convenient for engineering department to reference at design.Along with the rapid development of national economy and the strategy of developing the western region implementing, there will be more and more railroad main lines to build in mountain area a...
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