Safety Control Research On Subway Structure And Track With Multi-points Undercrossing Project

In the rail network continues to expand at the same time, urban rail transit lines must cross into the net, mutual transfer, and gradually form a network in order to meet people’s various travel requirements. Therefore, urban roads, bridges, railways and various pipelines and rail lines crossing project increased, a single point of risk has been gradually transformed into more risk points. Currently on rail safety and normal operations (limited speed) requirements continue to increase, leading to more risk points through the engineering of both the structure and the deformation and stress subway tracks redistribution, thereby affecting the safety of rail traffic. Multi risk point construction on the existing structure on the subway and rail analysis and safety control measures to carry out the subway construction project has important theoretical and practical value.Thesis project, the more risk points were studied through comprehensive system, including ANSYS simulation analysis, field monitoring data comparison and analysis of numerical simulation, and shield through engineering optimization and risk control measures. The main work and achievements are as follows:(1) A comprehensive summary of risk control through project-related information: Analysis of Shield Construction and mechanism of influence on the earth’s surface and the existing structure, and summarizes the major engineering method shield tunnel control surface subsidence. Surface subsidence control measures primarily from the holding face stability, reduce the formation of the disturbance, reasonable grouting caulking starting to consider other aspects.(2) The establishment of three-dimensional ANSYS finite element analysis model of relying on engineering calculation and analysis, analyze and summarize the existing subway and rail deformation of the structure under construction impacts. Multi-risk areas across the project, should be "the construction side, while recovery" that other risk points before construction of the track structure to best to include the impact of construction on the track previously eliminated.(3) The project measured data, analysis and forecasting and simulation results were compared to verify its accuracy, and summed up the law. Deform slightly larger than the actual station structure numerical simulation results, the track structural deformation as a whole showed "U" shaped form of the settling tank, the maximum position is consistent with the results of numerical simulation of deformation with respect to the simulation results, automation Found error of2.5%, manual monitoring error7.2%. ANSYS simulation results illustrate to some extent reflect the actual project enough deformation mechanism structure; the presence of numerical simulation results and measured a certain bias, manual monitoring is no automatic monitoring high degree of precision. Multi-point crossing project at risk, under the conditions permit, should be automatic monitoring(4) For the construction of the riskiest step sequence and analyze the situation without grouting construction, existing structures will not reach the critical strain. But does not meet the vertical track proposed metro subway operating company limited the safe operation of the deformation speed allowable maximum3.0mm, so the new Olympic Park in Beijing on the15th Line station adjacent to the existing crossing project Metro Line8Olympic Park construction project taken note Pulp strengthening measures to ensure the safe operation of limited-speed subway.