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| Research on the Deformation Mechanism Model Test of Tunnel - Landslide Skew System |
| WU Hong - gang1, CHEN Xiao - yun2, AI Hui3 |
| (1. Northwest Research Institute Co. Ltd of CREC, Lanzhou, Gansu 730000, China. 2. China Academy of Railway Sciences, Beijing 100081, China. 3. Lanzhou Jiaotong University, Lanzhou，Gansu 730070，China) |
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Abstract Abstract: Research purposes: With the rapid development of the "Silk Road Economic Belt and the 21st - Century Maritime Silk Road"，the total length of the tunnel have accounted for a growing share of the railway line，leading to that lots of tunnel must pass through the landslide. In the tunnel - landslide skew system, the force conditions is the most complicated when there is a certain angle between tunnel trend and landslide main sliding direction, which is a serious threat for the construction and operation of the tunnel. At present, it did not form a unified understanding and standard for the design and construction of tunnel in our country, and also there is no complete calculation theory. This paper takes the tunnel - landslide skew system as the study object, sets up two different angles of tunnel model by model tests, simulates tunnel excavation process, and uses the rear load to prompt landslide occurrence slope downward peristalsis, around the tunnel arranges for strain gage to monitor and analyze tunnel strain respectively, and in the slope surface arranges dial indicator to monitor the displacement. Research conclusions:(1) Strain tests showed that tunnels in the vertical and horizontal directions were deformed, but the deformation vertical direction was significantly larger than the deformation in the horizontal direction. (2 ) Two - strain contrast tunnel showed that the angle of intersection between the tunnel and landslide main sliding direction was smaller, the deformation mode of the tunnel was closer to the cantilever structure. (3) Displacement tests showed the settlement of slope top at the contact surface point of bedrock and landslide was largest while the maximum point of horizontal displacement of slope top was in the middle portion of the tunnel entrance and bedrock. (4 ) Strain and displacement of tunnel slope variance analysis showed that disturbance difference of tunneling on landslide and bedrock was large, resulting in the landslide settlement larger, and the bedrock basically fixed. When tunneling in the slide body release level of surrounding rock stress was significantly greater than the excavation of the tunnel in the bedrock. (5 ) The research can provide references for the design and construction of railway tunnel which passes through the areas of landslide.
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Received: 30 December 2015
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2016, Vol. 33 
