Study on Safety Assessment Index System for Subway Structure Based on Fuzzy Theory

With the operation of the subway tunnel, more and more safety problems will appeare. Considering the selection principles of the evaluation index and the causes of safety problems existed in the shield tunnel structure, the paper determinates the evaluation index and establishes the safety assessment index system for subway structure which can be applied in Shanghai soft-soil areas and reflects the stress characteristics of the shield tunnel structure comprehensively. Applying the fuzzy comprehensive evaluation, the analytical hierarchy process and the pattern recognition theory, the paper then establishes the evaluation model of the subway structure and conducts the quantitative synthetic analysis and evaluation through a typical example, Very important significance will be made to evaluate the safety situation of the subway structure,modify the deviation and improve the overall safety level of subway system.