Experimental Study On Deformation Of Tunnel Surrounding Rock In Landslide Area

Under the background of "mending the shortcomings" of national infrastructure construction,a large number of rail transit facilities,such as high-speed railway,have been built in areas with complex geological conditions in the central and western regions of China.In order to ensure the safe and stable operation of various means of transportation,the requirement for the smoothness of the line is becoming higher and higher.Therefore,in the construction process,the line often has to cross the landslide in the form of a tunnel,thus forming a landslide tunnel.This paper relies on the scientific research project of China Railway Northwest Scientific Research Institute Limited-"Key Technologies of Long Tunnel Construction in Complex Environment-Deepening Research on Deformation Mechanism and Control Technology of Tunnel-Landslide System",taking Yangpoli Landslide Tunnel as the test prototype,a small scale indoor test model is generalized;An experimental device for simulating the graded sliding of traction landslide is designed.The displacement index of tunnel surrounding rock is defined as a measure index of series of test results;In the process of test,the influence of tunnel burial depth,location of tunnel in sliding body and location of slider on the displacement index of tunnel surrounding rock is studied by controlling single variable method.The test results are analyzed by GOM Correlate,a digital image correlation software,and the following conclusions are drawn:(1)When the location of the slider is the same as that of the tunnel layout area,the deeper the tunnel is buried in the landslide,the larger the displacement index of the surrounding rock of the tunnel calculated after the landslide occurs.(2)When the location of the slider is the same as the buried depth of the tunnel,the closer the location of the tunnel is to the front of the landslide body,the larger the displacement index of the surrounding rock of the tunnel calculated after the landslide occurs.(3)Under the same conditions of tunnel burial depth and tunnel location,when the crystal pad is placed on the sliding belt at the bottom of slide block 2,the larger the displacement index of tunnel surrounding rock calculated after landslide occurs.The test results can provide some reference for determining the reasonable downward position of the tunnel when it crosses the landslide.