Study On Safety Evaluation System Of The Existing Subway Shield Tunnel Lining Structure

The subway construction in china is developing very quickly, more and more metro lines are put into operation. During the safety inspection of metro tunnel, lacking of advanced method, mostly according to macroscopic observation and simple instrucments to judge the results of inspection, so it can only make qualitative analysis on factors that affect the working performance of the tunnel.The evaluation results are not reasonable. The analysis on mechanical performance of tunnel structure after diseases is mostly through the experiment and theory analysis, using numerical simulation analysis is very rare.Therefore, this paper does the preliminary studies on index system for safety evalution of subway tunnel lining structure and numerical model that considers the impact of disease.The thesis obeys the general produce and theory of security assessment, adopts the way fixed quality and fixed quantity, selects the assessment guidelines which can security. The essay constructs relatively reflect the status of tunnel structure assessment guideline system by adopting arrangement analytical method, as well as makes use of the authority of all items confirmed by scale method.This paper set up the second level fuzzy model, doning safety evaluation of existing lining structure. And the mumerical simulation of shield tunnel lining structure with crack and making comparison with design to determine the safety condition of the structure. Finally, making numerical analysis of structure without crack and comparing with that with crack.The results of the study show that:the evaluation system is reasonable, using railway standard of safety assessment to evaluate metro exist deviation; The crack has great influence on stress and deformation, so it should be fully taken into account. Meantime, the numerical analysis methods can effectively analysis mechanics of lining structure with disease.