Application Research On Evaluation System Of Grouting Leakage Stoppage Treatment In Metro Tunnel

The development of rail transit has greatly improved people's travel efficiency.At present,China is in the period of improving rail transit in modern cities and urban planning and construction of rail transit in developing cities.The leakage of tunnel structure appears in the operation of existing lines,which is more prominent in Metro tunnels.In order to ensure the safe and normal operation of the metro,it is necessary to reinforce the leakage of the Metro tunnel.Nowadays,the research on repair materials and reinforcement methods of leakage water in lining of metro tunnels is more in-depth,but the evaluation of reinforcement effect is slightly one-sided.At present,the evaluation of plugging and reinforcing effect is mainly based on post-grouting test and grouting detection,but the reliability of grouting system is less considered.If the two are combined,the evaluation system can be further improved.Influenced by the construction environment of Metro tunnels,the collected data are limited and uneven.In order to avoid data errors which have a great impact on the overall evaluation results,a fuzzy comprehensive evaluation method based on grey correlation analysis is used to evaluate the grouting system,which not only improves the calculation efficiency,but also avoids the problem of low data accuracy.This paper takes the actual case of a section of Guiyang Metro Line 1 tunnel grouting leak stoppage reinforcement as the object.Based on the existing grouting effect evaluation system,a new grouting effect evaluation system is established by fully combining the characteristics and reliability theory of the Metro tunnel.The evaluation system is applied to similar projects and the rationality of the grouting evaluation system is verified.The main research contents and achievements are as follows:(1)The reliability theory is used to establish the series-parallel relationship of grouting system,analyze the failure mode,establish the limit state equation,and obtain the reliability calculation method of grouting system in accordance with the engineering situation.(2)The parameters of practical engineering are brought into the limit state equation,and the reliability index of the project is obtained through calculation,which is regarded as one of the evaluation indexes of grouting effect.Combining with some existing grouting evaluation indexes,a new grouting evaluation system is formed.(3)Fuzzy evaluation method based on grey relational degree analysis is used to analyze the evaluation system,and the results of the fuzzy evaluation of grouting engineering are calculated.The calculation results are consistent with the results of field post-evaluation.(4)Applying the evaluation system to similar projects,the correctness and applicability of the evaluation system are verified.Using the evaluation system and the evaluation results,the improvement measures of the grouting system and the application scope of the evaluation system are deduced.