Research on the Evolution Law of Tunnel Deformation Mode Based on Push Type Landslide

Research purposes: With the rapid development of land transportation in China, the problem of tunnel diseases caused by landslides has become increasingly prominent in mountainous areas. The most fundamental cause of tunnel deformation and destruction is the change of tunnel stress mode caused by landslides. At the same time, the different deformation stages of the slope have great influence on the mechanical deformation mode of the tunnel structure, and there is a lack of in - depth research in this area at present. Research conclusions: (1) Taking the tunnel - landslide parallel system as the research object, based on the deformation characteristics of the rock and soil mass of the sliding landslide, it is revealed that the essence of progressive failure process of tunnel is the process of landslide thrust and rock and soil resistance change. The movement characteristics of landslide in different evolution stages and the mechanical characteristics of tunnel are preliminarily discussed. Based on the stress mode of tunnel in different evolution stages, the models of semi - infinite long beam and semi -infinite long beam - cantilever beam are established. (2) Based on the theory of elastic foundation beam and structural mechanics, the deformation of tunnel structure in and out of the landslide is analyzed by coupling method. The theoretical calculation formulas of stress and deformation modes of tunnels in different stages are established, and the analytical expressions of corresponding control sections are put forward, which can realize the evaluation of stress and deformation of tunnels in different stages of landslide evolution. (3) A comparative analysis and verification are carried out through model tests. The results show that the theory can predict the development of the stress and deformation of the tunnel in landslide, and provide theoretical reference for the design and reinforcement of the tunnel in landslide area. © 2023 Editorial Department of Journal of Railway Engineering Society. All rights reserved.