Research On The Causation Mechanism Of Metro Accidents Based On Complex Network Theory

In recent years,with the rapid development of metro in China,new achievements have been made in the planning and operation of metro lines.At present,36 cities have put into operation in our country.With the continuous increase of metro operation lines and mileage,the number of metro operation accident has increased significantly with the growth of metro passenger flow.and safety issues become more and more important.The safety of metro operation is related to the travel demand of millions of people and the normal operation of the whole city.In this context,it is necessary to conduct in-depth research on the causation of metro operation safety accidents.We can find out the logic and rules behind the accidents through mining and sorting out the historical accident data.It can provide some suggestions to carry out prevention and early warning work for the relevant departments of metro operation safety management.The data of metro operation accidents at home and abroad is the basis of analysis.Based on the theory of complex network,the causation network model and the causation propagation model of metro operation accident are established.And then the causation mechanism is analyzed.The main research contents are listed as follows:Firstly,the accident causation chains are extracted according to the analysis of accident data.Based on the collected data of 730 metro operation accidents,the accidents are divided into different types according to their characteristics.The types,grades and probability of accidents are compared and analyzed from two aspects of single factor accidents and chain accidents.In addition,the set of accident causation factors are extracted by analyzing and sorting out the causes of accidents in the existing studies.Then the chains of accident causation are extracted from chain accidents,which as a foundation for follow-up analysis.Secondly,the causation network model of metro operation accident is established based on the theory of complex network.The structural characteristics of networks can be effectively analyzed with the help of complex network theory.The causation factors as nodes and the causation relationship between them as the edge in this paper,the metro operation accident causation model is established.The network structural characteristics is analyzed,including degree and degree distribution,betweenness,network density,clustering coefficient,etc.The results proved that the metro operation accident causation network has the characteristics of small-world network and scale-free network.It is show that the metro operation accident causation model has higher clustering coefficient and shorter causation propagation distance.Meanwhile,the network showed obvious vulnerability to target attack the important nodes.Thirdly,the causation propagation model of cascading failures is established.The structural analysis of accident causation model is just one aspect,not enough to explain the propagation property of chain accident.In order to further revealed the influence of causality among accident causation factors on the formation process of accidents.The cascading failures propagation model is established based on the load-capacity model of the theory of cascading failures,the foremost causation chains of accidents were found.The risk assessment of accident causation chain is carried out,and some high-importance branching chains are pointed out.