Research On Vulnerability Of Shenzhen Rail Transit Network

With the constant extension of high-speed railway and expressway in China,the regional pattern of the country has been changed greatly,However,during such progress,people shouldn’t neglect the unsolved problems of urban traffic congestion and air pollution generated by increasing number of vehicles.Due to such problems,the importance of urban rail traffic construction becomes prominent.Urban rail traffic nowadays is not only to the benefit for promotion of economy of peri-urban areas,but also meets the traffic demands of special sections.The scale of urban rail traffic keeps extending,but we can also see the problems that come along.Urban rail transit network is suffering from various kinds of accidents,endangering personal safety of passengers and bringing great pressures to the management of urban rail traffic.The paper is aiming at reducing the vulnerability of Urban rail transit network and providing scientific evidences to the management of urban rail traffic.The major research contents of the paper are as follows.Firstly,the author has consulted in existing relevant articles,sorting out relevant basic theoretical knowledge relating to complex network and the vulnerability of Urban rail transit network,summarizing the definition of the vulnerability of Urban rail transit network and dividing the vulnerability of Urban rail transit network into two aspects,which are the vulnerability of topological structure of Urban rail transit network and the vulnerability of transport service function of Urban rail transit network.Secondly,the author has modeled the topological structure of Urban rail transit network and computed the basic indexes of the structure using relevant software.The author has also adopted predetermined attack strategy and implemented attack stimulation experiment to find out the key stations and key sections in the network.In such experiment,the effect of network connectivity,as a comprehensive index,is selected as the evaluation index of the vulnerability of topological structure of the Urban rail transit network in ShenzhenThirdly,under the consideration of passenger-flow element,the paper has evaluated the vulnerability of transport service function of Urban rail transit network in Shenzhen.Due to the influences of unforeseeable accidents,delays of trains and massive crowd of passenger-flow may occur after the disruption of stations or sections,which would lead to the increase of passengers’ trip time for detouring or even being unable to reach the destination for some passengers.Based on the factors above,the paper has established the vulnerability evaluation model of the transport service function of Urban rail transit network and the passenger flow distribution model based on SUE(Stochastic User Equilibrium),implemented a computation with suitable algorithm(taking Shenzhen Subway as an example),and verified the feasibility of the models.Finally,through consulting in a number of relevant articles,the paper has improved the vulnerability of Urban rail transit network in two aspects of the structure and the transport service function.In the aspect of structure,the paper has divided it into two sub-aspects of"planning phase" and "reorganization and expansion" and proposed the optimization scheme taking Shenzhen Subway as an example.In the aspect of transport service function,the paper has proposed suggestions of making good precautionary measures before the occurrence of unforeseeable accidents and minimizing the loss after the occurrence of unforeseeable accidents by organizing effective measures.