Research On Safety Risk Assessment Of Metro Vehicle Systems

The subway operation in China has the characteristics of large passenger volume and fast operation speed,providing convenient services for short distance travel of urban residents in China.However,with the emergence of many new problems such as equipment updates and the increase of operating mileage,the development of China’s subway industry is facing various challenges.As a significant factor affecting the safety of subway vehicle operation,the vehicle system is the subsystem with the highest accident rate and the most direct impact on passengers during subway operation.Therefore,this article conducts a safety risk assessment of China’s subway vehicle system by constructing a comprehensive evaluation system for subway vehicle systems.The main research results are as follows:(1)By analyzing the statistical data of domestic and foreign subway vehicle operation accidents and on-site actual data,this article uses the grey statistical method to optimize and screen the 31 risk indicators selected in the initial selection.Based on the calculation results,the risk indicators with "high" importance are retained,and the risk indicators with "low" importance are eliminated.Finally,a risk evaluation index system including 9 primary indicators and 27 secondary indicators is established.This method reduces the intersection between risk assessment indicators and makes the evaluation indicator system more comprehensive.(2)In order to reduce the subjectivity of traditional methods for calculating weight values,this article adopts the relative entropy comprehensive weighting method,which combines order relationship analysis and entropy weighting method,to calculate the weight values of risk indicators at all levels.By combining expert opinions with actual data,the comprehensive weight values of risk indicators are calculated.(3)The traditional risk matrix method only considers the external uncertainty of possibility and severity of risk,ignoring the inherent vulnerability of risk caused by the coupling effect between two risk factors or systems.Therefore,this article establishes an improved risk matrix model of "possibility severity vulnerability",proposes a calculation method for vulnerability,and finally adds up the level scores of the three evaluation factors to obtain the risk magnitude of the secondary indicator.It improves the accuracy of risk level evaluation results for subway vehicle systems.(4)This article constructs a comprehensive evaluation system of "relative entropy comprehensive weighting method improved risk matrix method cloud model".By calculating the risk levels of the first level risk indicators and the target layer in order based on the indicator hierarchy using the cloud model.Compared with traditional risk assessment,the evaluation results are more comprehensive and accurate.Taking the vehicle system of Metro Line 1 in a certain city as an example,this article evaluates its risk level,based on the evaluation results,and divided the equipment under the vehicle system into four levels,and then targeted countermeasures were proposed.