Stablity Analysis Of The Subway Tunnel Test Section Below Through The Railway Bridges And Assessment Of Construction Risk

In recent years, with the rapid construction of city subway projects, the research onnew subway tunnel through the existing buildings and interaction between each otherhas become an important topic of the underground engineering. The article mainly studyobject were the Harbin subway tunnel below through the railway bridges, betweenHananzhan station and Nongkeyuan station, monitoring and numerical simulation thedeformation of surrounding rock of tunnel in construction process, and combined withthe actual situation of the construction site to assessment the tunnel construction risk.The research content of the article is as follow:(1) The3-D finite element model is used to simulate the excavation process of theHarbin Subway Tunnel Test Section below through the railway bridges, get thedisplacement and stress state of surrounding rock and support structure in the tunnelconstruction process. Study found that in the tunnel construction process, with theexcavation of the working face, fracture surface near the entrance of the hole tend tostability, the structure design of primary support meets the construction requirement.(2) Taking the SK0+710of fracture surface of the tunnel for example,comprehensive analysis the numerical simulation results and the site monitoring data,through the analysis of the monitoring data of the vault settlement of the tunnel andlevel of convergence found that the deformation of each section is larger in the initialexcavation of tunnel, and it is basically in a relatively stable state10days later.(3) GM(1,1) model of the Grey System Theory was used to forecast the vaultsettlement and level of convergence of the tunnel in the construction process, and thepredicted results and the measured results are more anastomosis. At the same time usesthe kent index method and the fuzzy mathematics method to assess the Harbin subwayconstruction risk levels, and the evaluation results are basically the same, finally verifies the risk of tunnel excavation in theory.