Analysis Of Ground Subsidence Risk Management In Metro Shield Construction

The urban population is growing constantly which caused a certain degree of traffic jams. Metro construction in China has entered a rapid development period after years of development. Given the complexity of the subway project, accidents including ground collapse and damage to adjacent buildings which are all caused by ground subsidence happen easily during the construction process. Serious land subsidence has great danger. Therefore, it is necessary to launch ground subsidence risk management during metro construction to help prevent and avoid a serious land subsidence during construction process. What's more, it can reduce property damage and security risks, and has important real value.Firstly, this dissertation reviews articles at home and abroad related to subway shield construction ground subsidence; on the basis of understanding composition and risk mechanism of land subsidence in metro construction, the paper summed factors that cause ground subsidence and classify them. Then the dissertation divides ground subsidence into “safety” and “serious land subsidence” two states, and built DFT model to analyze ground subsidence risk, then the model was modularized into independent static subtrees and dynamic subtrees; Binary Decision Diagrams(BDD) and Markov method were applied to progress them respectively, the possibility of ground subsidence risk in metro tunneling is get after comprehensive analys is; on the basis, this paper gives global sensitivity analysis which is based on EFAST to find key influence factors. At last, it applys this two methods to project case, conclusion is consistent with the actual situation, proves the practicability of Dyna mic Fault Tree and global sensitivity analysis based EFAST in analyzing ground subsidence risk in metro tunneling.This dissertation makes use of DFT to the possibility of ground subsidence and EFAST to launch global sensitivity analysis risk in metro tunneling, which provides a new idea for the study of land subsidence risk management in metro shield construction. However, this research is still preliminary, there is still much research space in the field due to the influence of metro shield construction team construction on land subsidence is a complex process.