Research On Risk Assessment Of Operational Tunnel Structure Based On Bayesian Network

With the rapid development of China,s transportation infrastructure construction,The number of subway tunnels in use is increasing day by day.However,Due to operational tunnel subjected to the influence of various factors after a period of operation,tunnels appear different degree of damage of disease.These risks will reduce the service life of the tunnel and threaten the safety of the tunnel structure.If not found in time,it will seriously affect people's travel safety and bring serious economic losses to the society.In order to improve and solve this problem,this paper carries out the following research work on the safety condition of operational tunnel structure.1.The article has carried on the full analysis to the subway tunnel structure risk.According to relevant references and expert knowledge,the risk indicators in the safety assessment system of operating subway tunnel structures were determined,and four first-level indicators including external load,material deterioration,tunnel structure deformation and tunnel leakage were established,and the qualitative and quantitative criteria for 10 second-level indicators were determined.2.According to the criteria,this paper divides the risk factors affecting the safety of subway tunnel structure into five risk levels,establishes a bayesian network evaluation system,and predicts risk levels about the risk events and each risk factor based on the calculation results of GENIE software.3.In order to verify the accuracy and applicability of the bayesian network method,taking the structural safety of an operating subway tunnel as an example,this paper makes risk assessments of operating subway tunnel by using analytic hierarchy process(ahp)and cloud model method,and compares the results with the bayesian network method to prove the feasibility of the bayesian network method.4.According to the result of safety risk assessment of operational tunnel structure of a section,it is found that the main risk factors are peeling area,crack condition,reduction rate of lining thickness,deformation or movement speed,and wrong platform condition,and finally the relevant control measures are put forward.