The Security Analysis Of Mined Metro Station Beneath The Existing Construction

Security control of urban underground projects is the the core technical problems of urban construction of rail transit and underground space development, not only the theoretical issues and key technologies that solve the stratigraphic and structural deformation control, but also forming a system control system is also very important. Risk assessment is the core of the risk management of tunnel and underground engineering, it’s primary task is to determine the safety risk evaluation criteria of the subway construction project, and then evaluate the project’s overall risk level. Risk analysis of tunnel construction is to given tunnel constructing’s risk probability of occurrence and its consequences, that on the basis of past loss of data analysis, using the probability theory and mathematical statistics to make qualitative and quantitative analysis on the occurrence of one or several specific risk of the accident probability and risk of accidents may result in loss.This article is mainly based on theoretical research and monitoring data, and combine with related engineering examples to analysis the safty problem of wearing the existing subway station. First is conducting study tunnel risk assessment theory, the basic content include of tunnel and the existing subway risk identification method, the probability model of risk estimates, risk decision theory, risk control technology, the theory of risk tracking and risk early warning and forecasting and so on. And then make the beijing subway ten line to wear one line Gongzhufen station as engineering background, the main task is monitor and analysis the influence to the existing station before the construction of new station and constructioning of the new station, including deformation and settlement of the existing station structure and orbit.This article using MIDAS/GTS establish the finite element model of pile-beam-arch method, and simulate its excavation process, analysis pile-beam-arch method caused the surface deformation、tunnel vault settlement、plastic zone、tunnel support structure stress and so on. Analysising the safety of the excavation process and taking the reasonable control measures.