Study On The Interaction Mechanism Between Nanping Tunnel And Landslide On The Dazhun Railway

When constructing roads in mountainous areas,it often crosses the slopes in the form of tunnels.When the slopes are landslides,the tunnels are affected by landslides and tend to have a certain degree of disease.Based on the Nanping tunnel-landslide,this paper studies the causes of the landslide formation in Nanping tunnel and the deformation mechanism of the tunnel under the landslide thrust,and simulates the whole process of the comprehensive treatment of the Nanping tunnel landslide.The feasibility of governance measures.(1)The geological model of the landslide body was established by using numerical simulation software.According to the geological section provided by the geological survey data,the model was divided into different stratum structures,and the development process of the soft zone was simulated.Some reasons for the formation of the landslide in Nanping tunnel were obtained :(1)The disintegration characteristics of mudstone in the landslide area of Nanping Tunnel;(2)The construction method of large excavation of slopes;(3)The characteristics of loess permeable and mudstone relative to water.(2)Using numerical simulation software to simplify the numerical model of landslide into three parts: sliding body,sliding zone and sliding bed.The numerical model of Nanping tunnel-landslide interaction is established.The interaction between landslide and tunnel and the deformation and failure of tunnel are studied.mechanism.The following conclusions are drawn:(1)The distribution of the sliding force of the slope is related to the friction angle of the sliding zone;(2)The deformation and failure mechanism of the tunnel under the landslide thrust is mainly studied;(3)The force mode of the tunnel is improved after the landslide is cut and the load is reduced.The landslide thrust effect is reduced,and the slope cutting has a certain effect on the tunnel disease remediation;(4)After applying the anti-slide pile,the tunnel stress mode has been completely improved,and the tunnel stress characteristics are basically consistent with the stress characteristics only when subjected to the vertical fill pressure.;(5)The tunnel is less biased during the excavation process around the tunnel;(6)The bending moment and shear force of the anti-slide pile during the excavation process have obvious regularity,and the maximum value is distributed near the slip surface.(3)Using the indoor model test,the following conclusions are drawn:(1)The stress change process of the Nanping tunnel under the condition of increasing landslide thrust is studied.The process of complete tunnel destruction is obtained: the left side wall is the first Destruction,then the deformation of the invert arch and the vault,and finally the destruction of the right side wall;(2)the tunneling disease after the anti-slide pile is effectively treated;(3)the shear force distribution of the anti-slide pile during the excavation of the soil beforethe pile and The numerical simulation is basically the same,and the distribution of earth pressure before and after the pile is analyzed.The research in this paper has investigated the interaction mechanism of the Nanping landslide-tunnel,and verified the feasibility of combining the anti-slide pile with the coat arch to control the landslide tunnel disease,and provided some theoretical basis and engineering experience for the prediction and prevention of similar tunnel diseases in the future.It has promoted the further improvement of disaster prevention and mitigation projects.