The Research On The Vulnerability Of Urban Rail Transit Network

With the expanding of the scale of UMT network and the rising of its passenger flow, there have been many problems to be solved, such as the extension of passenger transfer time, imbalanced transfer, site congestion and the low efficiency of traffic flow。These problems have hindered the play of the operating performance and produced lots of security risks. Facts have proved that, the only way to solve the traffic problem is that studying the rules and characteristics of the showing problems with the increasingly complex of the network, exploring the network’s fragile lines or stations, mining the variation of these lines or stations under various conditions, and seeking reasonable operational security plan to guide practice. Vulnerability research of this paper on UMT network as follows:First, based on the summarize and refine to the existing literature, summed up the definition of the vulnerability of UMT network, which including two aspects, that is dynamic aspects (vulnerability from transport organization) and static aspects (vulnerability of static structure);Secondly, summarized several network types of the complex network and their corresponding basic characteristics, and proposed two main attack strategy, namely attacking each single site separately and attacking sites which meets the conditions one by one, both of which are used to analysis and establish the model of structural vulnerability. Through the analysis of vulnerability factors, selecting the factor of average connect efficiency as a measure of vulnerability, use its changes under the attack strategies to determine the vulnerability of the network.Thirdly, based on the analysis of the vulnerability factors, which affecting the transportation organization, considering the factors of the extending of the stop time which may caused by passengers’congestion at the station, and the delay on the station and the propagation of the delay in the network, considering the situation that, after the failure of the station, the measures will be took to limit passengers’entering the station by the manager, the paper established the congestion propagation model based on passenger flow’s real-time distribution. This model can reflect passengers’dynamic propagation process in the network, digging out the vulnerable sites.Finally, the optimization for the vulnerability of UMT network has been studied, which includes the optimization for the vulnerability of network’s structure and the vulnerability of network’s transportation organization. The first optimization based on the comparison of different network structure, the second is put forward on the basis of summarizing and refining the existing mature optimization results. The optimization could improve the vulnerability of UMT network, reduce vulnerability and improve reliability.