Research On Cascade Failure Of Urban Rail Transit Network Based On Disaster Spreading Theory

With the development of China’s modernization and urbanization,urban rail transit has developed rapidly in many cities,which has become an important part of urban transportation,and undertakes number of urban residents’ travel tasks every day.However,with the residents’ dependence on rail transit,the passenger flow is becoming larger and larger.To ensure the safe and effective operation of rail transit is an important issue that cannot be ignored.The failure of individual nodes in urban rail transit network may cause large-scale congestion of other nodes in the network,that is,there is cascading failure behavior in urban rail transit network,and the impact of failure will spread in the traffic network.Therefore,it is of great significance to study the cascaded failure dynamics model on urban rail transit network.Firstly,the research status of complex network theory and cascade failure behavior at home and abroad is summarized.According to characteristics of urban rail transit network,the weighted network based on geospatial information and travel cost is established,what’s more,the connotation and necessary conditions of cascading failure of urban rail network is put forward.Secondly,considering the impact of passenger congestion on travel,the calculation method of travel time cost is defined,and the calculation model of dynamic shortest path on urban rail transit network is constructed.Then,on the basis of the theory of disaster spreading,the cascaded failure dynamics model of urban rail transit network is constructed considering the comprehensive effect of self-healing ability and spread mechanism.And the time evolution process of node spread in the network after failure is described.Moreover,the relationship between the scale of intermediate joint failure and the type of initial failure node and the self-healing ability of node is analyzed.Finally,Chengdu Metro’s data is taken as an example to simulate the model.Results show that the cascaded failure scale of urban rail transit network is positively related to the degree of the initial failure node and negatively related to the self-repair ability of the node.It could be found that this model can effectively simulate the cascading failure behavior of urban rail transit network.