Research On Invulnerability Of Wuhan Rail Transit Network Under Cascading Failure

Urban rail transit plays an increasingly important role in the transportation of urban residents as an important part of public transport system.In recent years,many cities are entering the rapid development period of urban rail transit.The construction of rail transit network is becoming a trend.Wuhan is no exception.As of 2021 the third round of planning is completed,Wuhan will form a network of rail transit layout.However,the network operation of rail transit provides convenience for residents travel,but also brings some security risks.So how to improve the security of rail transit network operations and enhance the invulnerability of the rail transit network have important significance.Based on the theory of complex network,this paper takes the network of Wuhan rail transit plan in 2021 as the research object,and analyzes the invulnerability of Wuhan rail transit network under the effect of cascading failure.Firstly,through the analysis of Wuhan rail transit network status and planning,the scope of the study is determined.This paper uses PAJEK to generate Wuhan rail network topology map,abstracting each station into node and each track line into the edge.Meanwhile,this paper uses PAJEK and MATLAB to study the topological structure of Wuhan rail transit network and analyze the characteristics of Wuhan rail transit network.Secondly,the cascade failure model is established.The model defines the node load,capacity and load reassignment rules,and divides the node states into three categories: normal,overload and fail.Then,three kinds of attacks on Wuhan rail transit are designed: random attack,degree attack and betweenness attack.At the same time,we use two indexes to measure the invulnerability of Wuhan rail transit network including the ratio of Network fault node and average network efficiency.Later,this paper uses MATLAB to simulate the invulnerability of Wuhan rail transit network under the cascading failure.The following conclusions are drawn: the invulnerability of Wuhan rail transit network of random attack is superior to degree attack and betweenness attack and the invulnerability of degree attack is better than betweenness attack;The invulnerability of Wuhan rail transit network can be improved by adjusting the tolerance parameters appropriately.Finally,combining with simulation results,optimization strategies of the invulnerability of Wuhan rail transit network are proposed,which include protection of important nodes protection and some suggestions about optimization of subsequent network structure.In this paper,the research on the invulnerability of Wuhan rail transit network under cascading failure can help to identify the important sites in the Wuhan rail transit network and the weak parts of the ability to resist emergencies.The rail transit management departments can take protective measures by advance and prepare emergency plans for rail transit failure in order to control the range of cascading failure as much as possible,reduce harms and improve the invulnerability of Wuhan rail transit network when meeting the unexpected situations.The research also can provide recommendations for the follow-up planning design.