Impact Assessment Study Of Urban Rail Transit Operation Accidents Dependent On Network

In China,urban rail transit is gradually entering the era of network operation. On the one hand,network operation has greatly improved operational efficiency,on the other hand,it has cased network amplification effect of operational accident.However,the exsiting accident impact assessment only involves casualties,economic loses,social impacts and so on,which lacks impact analysis of accidents from network-levl.LAt the same time,graph theory and complex network theory belonging to network science are mature and begin to be applied to the study of the complexity of the urban rail transit network.Therefore,dependenting on the complex network theory,this paper provides a network-level impact assessment method of urban rail accident,and select Shanghai as an example validated the assessment method,and analyzed the evaluation results.Train of the assessment idea is:establishment the urban rail transit network modelâ†'simulation various types of operation accidents in the modelâ†'calculate the assessment index of the network model after accidentsâ†'draw impact assessment conclusions of accident. Surrounding the assessment idea, this paper studied the accident type, complex network theory, assessment index, accident simulation algorithm and so on. The concrete research content and results are as follows:(1)Through counting and analyzing the type of metro operation accidents in recent years at home and abroad, and analyzing the influence of various operating accident types, this paper finds out that the effects of all kinds of accidents commonly has three types:station be close and cannot be opened to traffic,be close but will be open to traffic, the whole line shut down.(2)Researched the complex network theory, and established the Space L and Space P network analysis model of urban rail transit, respectively correspond to the physical structure and operational structure of the rail network. By analyzing the operating characteristics of urban rail transit network and the applicability of the network evaluation index,this paper chosed the connection efficiency E, transfer efficiency Et and subgraph relative size S three main evaluation index on the impact of the accident.Introduced the method to collect and preliminary process data of rail network, and writes the Matlab algorithm of various evaluation index and the simulation algorithm of different kinds of accidents. (3) Shanghai urban rail transit as an example,this paper assessed the accident impacts of several different situations:station be close but will be open to traffic,be close and cannot be opened to traffic, the whole line shut down and so on,finds out the latter two have large effects on network performance, the first one’s effect is relatively small;a few station has a great influence on the network, and most of the station to the network is only small impact;the transfer station of several routes and the station which connects radiation and the core usually have great influence on the network;the closing of the multiple terminal may cause disastrous effect to network,reduce connection efficiency and transfer efficiency and so on for more than50%.The proposed assessment method can calculate the effects of different types, different degree of operational accidents to the network’s connection efficiency and transfer performance.At the same time can predict the impact of possible operating accidents. It helps to understand accident influence from the network level, find out the important node or line within the network, has important practical significance.