Construction Technique Of Ganshao Liangcun Railway Tunnel With Shallow Overburden Built In Fractured Stratum

Abstract:This paper mainly Ganshao Liangcun railway tunnel engineering background, through the tunnel construction site monitoring and measuring techniques rock deformation data for a large cross-vi class bias Shallow tunnels are described and analyzed, and regression forecasting model and gray theory two theories of confining late deformed rocks were predicted to optimize the design and played a guiding role in the construction; combination of rock deformation and stress monitoring results, the CRD tunnel construction process in the construction process is more in-depth research work and got CRD construction method reasonable steps tunnel; deformation is too big for the tunnel surrounding lots, changing its arch treatment programs on a temporary swap vertical arch support for safety checking by MIDAS/GTS, and combined monitoring results after changing arch, arch indicate change reasonable solution. In this thesis, carried out research in the following aspects:(1) In the tunnel construction process, the tunnel structure deformation and internal force monitoring, test results indicate that the deformation of shallow bias Class VI rock tunnel excavation CRD method segments influenced each other:①Department vault deformation by measuring point②Ministry of excavation greater impact③Department. Rock stress test results show that relative to the outside of the tunnel, inside the tunnel early pressure on the big puzzle, inside the tunnel lining structure to reduce security and easier deformation due to excessive destruction of leaving the initial support, the impact of structural safety. Steel brace force test results show that the steel support axial force is mainly compressive stress, and arched back position is greater than the other parts of the axial force, the tunnel inside the steel support axial forces suffered generally greater than the outside, indicating a greater likelihood of buckling of the steel frame inside the tunnel. The monitoring results of deformation and internal force show a reasonable step should be the first construction outside of the mountain, and then construction inside(2) Application hyperbolic functions as a regression function of deformation and subsidence cave convergence dome fitting results show that the hyperbolic function fitting better, according to the curve of the final deformation and deformation values over a period of time predict the situation to guide the construction site and combine deformation rate applied to determine the best time for the second lining. Engineering applications show that GM (1,1) model than the GM (2,1) model is suitable for predicting the time series related to settlement prediction, indicating that the gray system GM (1,1) model can be used to predict the deformation of surrounding rock tunnel excavation. From the predicted trend control tunneling construction methods and rational processes.(3) For the tunnel rock deformation is too large lots, changing its arch treatment program for change through the arch MIDAS/GTS temporary vertical support for safety checking, combined with the monitoring results after changing arch, arch description reasonable exchange program.