Assessment Approach For Healthy Condition Of Highway Tunnels Lining Structure Based On Variable Fuzzy Sets Theory

In view of the deficiency of index weight and evaluation theory in the current highway tunnel health assessment,the health evaluation index system,judging criteria for index and its dimensionless, the determination method of index weight and the health evaluation theory for tunnel lining structure were deeply studied. The main research contents are as follows:1.The distribution of lining crack, water leakage, lining thickness, cavity hehind lining are mastered based on the statistical analysis of field test data of Liu He and Yi He expressway tunnel, then analyze its causes.2.According to the selecting principle of evaluation index, tunnel structural breakage forms and its health impact factors are detailedly analyzed, and the lining structure health evaluation index are studied out,then the evaluation index system for health status of highway tunnel lining structure is founded.3.Analysing the existing division menthods of tunnel health grade at home and abroad, combined with the characteristics of tunnel engineering in China, the highway tunnel lining structure is divided into five health level. On the basis of the existing research results, judging criteria of indexes are gived and indicators dimensionless formula is established.4.To overcome the lack of hierarchical analysis method and reflect the true assessment level of experts, the fuzzy analytic hierarchy process(FAHP) and entropy value theory are used to determine the index weight, and improve the accuracy of the weight coefficient.5.Analysing the advantages and disadvantages of existing evaluation methods, a health status assessment method of tunnel lining structure based on variable fuzzy sets theory is proposed. Research results show that the variable fuzzy comprehensive evaluation model has better applicability in health evaluation of highway tunnel lining structure, using the variability of the variable fuzzy comprehensive evaluation model to analyze the stability of the level characteristic value, synthesizing evaluation results of different model to determine the health level of lining structure in final, improving the reliability of evaluation results.