Research On State Vulnerability Of Urban Rail Network Based On Theory Of Complex Network

Urban rail network is an important carrier of urban public transport, assessing its vulnerability by the theory of complex network when the network faced with various emergencies has become a hot topic recently. The researches on the vulnerability of urban rail network are mostly concentrated in the network structure. But, those emergencies finally result in the re-distribution of the network volume, meaning the change in running state of the network. In this layer, there is few studies about.Therefore, it has theoretical value and practical significance to evaluate the state vulnerability of urban rail network and forecast the distribution of the network volume after the emergencies occurred based on the theory of complex network. So that people can locate the key unit, prevent the occurrence of various types of failures and accidents and guide the planning of urban rail network and the establishment of emergency measures.Based on the existing conceptions related to vulnerability, this paper firstly proposes that the state vulnerability of urban rail network means the sensitivity of urban rail network running state to the unit failure caused by attack or accident. Next, with the combination of typical statistical properties of complex networks, the assessment indicators of urban rail network state vulnerability are given. And futher, a method of classifying vulnerabilities is put forward based on the idea of ordered sample cluster analysis. On this basis, the urban rail network state vulnerability assessment model is built by the use of failure simulation strategies. Through the macro traffic analysis software and computer programming, this model can evaluate and classify the state vulnerability of urban rail network and achieve the network running state after the unit failure. Finally, in the instance analysis, it draws that the state vulnerability of each unit is related to the structure of the network, the volume and the burden on the shortest paths going through the unit. Once the failure of the high state vulnerability unit occurred, it would cause tremendous pressure to rest line by the transfer of the passenger, or even divide the entire network into a plurality of regions that can not communicate with each other, resulting in significant loss of network volume.