Research On Differentiated Security Check Efficiency And Risk Assessment Of Urban Rail Transit

The passenger flow of urban rail transit is increasing recently,and the large passenger flow is normalized.The long security check time and low efficiency become the impetus for congestion,which seriously affects the efficiency of passengers entering the station.How to improve the security check efficiency on the premise of ensuring safety is a difficult problem in rail transit security check.This thesis analyzes and summarizes the temporal and spatial characteristics of rail transit passenger flow based on relevant researches.The differentiated security check mode is proposed to optimize the security check efficiency,and the safety risks of differentiated security check are evaluated based on the extension theory.First,this thesis studies the temporal and spatial characteristics and organization methods of urban rail transit passenger flow.By dissecting the passenger flow historical data,in terms of the time level,there exist morning and evening peaks during weekdays,and the peak period on weekends lasts for a long time,but the passenger flow is relatively small.As for the spatial level,the entry and egress passenger flow of different stations is distinct due to the diverse land use around the station.The influencing factors of passenger flow organization are analyzed from four aspects: land use along the line,station waiting space,traffic capacity,and passenger characteristics,combined with the temporal and spatial characteristics of passenger flow.The passenger flow organization measures of urban rail transit are expounded to support the research on security check optimization under the principle of ensuring passenger safety and convenience.Then,the differentiated security check mode of urban rail transit is proposed and the traffic efficiency is evaluated.Urban rail transit security check is a significant component of rail transit operation safety management and the efficiency of security check directly affects the passenger entry time.Based on the analysis of temporal and spatial characteristics of passenger flow and passenger flow organization measures,the existing security check mode is studied from three aspects: the strictness of security check,the configuration of security check equipment,and security check standards.This thesis recommends the establishment of a differentiated security check mode for urban rail transit.On the basis of passenger credit security,the differentiated security check of urban rail transit implements the standards in which small bags pass through and big bags with security check and implements diversion security check for entry passengers.The probability density functions of security check time under different security check standards are fitted and the thresholds are calculated.Then the traffic efficiency is evaluated to verify the traffic capacity of the differentiated security check according to the actual situation of the Nanjing Metro security check.At last,the differentiated security risk assessment is carried out based on extension theory.In the process of risk assessment,the differentiated security check evaluation index system of urban rail transit is constructed from four aspects: human factors,equipment factors,environmental factors,and management factors,and the combination weighting method is applied to determine the weight of each evaluation index.Then a differentiated security check safety risk assessment model is established based on extension theory combined with the multilevel comprehensive evaluation index system.A case study of differential security check in the station is analyzed to prove the effectiveness and operability of the model on the ground of the actual operation of Nanjing Metro.