Risk Analysis For Railway Tunnel Construction Based On Fuzzy Evidential Reasoning

Compared with other projects,the railway tunneling construction invests greatly and has complex geology conditions, many construction item and complex construction technique, lots of unpredictable risk factor, the great impact on the social environment and so on prominent characteristics. Then the construction can encounter many difficulties and the barrier, even significant engineering accidents emerge in endlessly. So, it has important practical significance to analyze the risk of the railway tunnel construction.This thesis carries out the study on fuzzy evidential reasoning method for risk analysis of the railway tunnel construction. First, the common risk analysis methods of railway tunnel construction are analyzed and the basic principle of fuzzy evidential reasoning theory is elaborated, then the applicability of fuzzy evidential reasoning method in the risk analysis of railway tunnel construction is introduced. Next, the domestic major accidents during railway tunnel construction in recent ten years are counted and analyzed, then main risk events in railway tunnel construction are obtained by consulting relevant literatures and engineering data, it mainly includes collapse, gushing water and burst mud, large deformation, gas formation, high geotemperature and rock burst, at the same time, all risk factors that may leading to the risk events are detailed analyzed, after that, the risk indicator system of railway tunnel construction is established. Afterwards, the risk evaluation model based on fuzzy evidential reasoning is established on the basis of fuzzy mathmatics theory and Dempster-Shafer theory of evidence, it mainly completes the risk assessment by establishing fuzzy belief structure model, data preprocessing, fuzzy evidential reasoning algorithm, fuzzy intersection reliability allocation and risk ranking. Finally, the risk assessment model based on fuzzy evidential reasoning is applied to Manghantu tunnel, and the risk assessment result is obtained, which illustrate the applicability of the method for the risk assessment of railway tunnel construction, then according to the risk assessment result, the corresponding risk control and management measures are put forword.