Node Importance Evaluation And Cascading Failure Invulnerability Analysis Of Urban Rail Transit Network

Compared with other transportation modes,urban rail transit has the advantages of low environmental pollution,low energy consumption,fast operation speed,high safety factor,large passenger flow,and can alleviate urban congestion and the pressure of the whole urban transportation system.Therefore,more and more people take urban rail transit as their daily travel choice.Nowadays,the rail transit operation network in some big cities has initially formed and is gradually moving towards the network operation stage,which leads to the failure of stations in the operation network due to external damage or equipment failure.This failure may spread rapidly in the urban rail transit network,resulting in serious consequences.Therefore,to study the cascading failure survivability of urban rail transit network,find out its weak stations and optimize them is very important to ensure the stability of urban rail transit operation and passenger safety.This paper mainly starts with analyzing the characteristics of urban rail transit network,excavating important network stations and studying the anti destruction performance of network,and carries out in-depth research on urban rail transit network.The main work is as follows:(1)This paper summarizes the relevant theories of complex network and the application status of complex network at home and abroad,compares and analyzes the application scope,advantages and disadvantages of the existing three network model construction methods,finally determines to use the space l method to construct the urban rail transit network topology model,and summarizes the common urban rail transit network characteristic indexes;(2)In order to accurately identify the important stations of urban rail transit network,Page Rank algorithm is introduced to calculate the PR value of each network node and determine the important nodes;Considering the network node centrality index and station passenger flow index,the comprehensive weight calculation method combining analytic hierarchy process and entropy weight method is used to calculate the weight of each evaluation index,and the comprehensive evaluation system model of the importance of urban rail transit network nodes is constructed based on TOPSIS algorithm.Based on the evaluation results,k-means algorithm is used to cluster the urban rail transit network nodes.(3)The cascading failure model of urban rail transit network is established,the cascading failure simulation algorithm is designed,and the invulnerability measurement indexes of urban rail transit network are selected,so as to quantitatively analyze the changes of network invulnerability under different attack modes and considering the cascading failure phenomenon of urban rail transit network.(4)This paper empirically analyzes the network characteristics of Shanghai rail transit network,evaluates the node importance of Shanghai rail transit network by using Page Rank algorithm and comprehensive evaluation model,and clusters the stations according to the importance.Finally,considering the cascading failure of the network,this paper analyzes the change of survivability of Shanghai rail transit network under different attack modes by simulation;(5)Taking Beijing,Shanghai and Shenzhen rail transit networks as examples,this paper compares and analyzes the survivability of the three urban rail transit networks,explores the impact of different network structures on the survivability of the network,and puts forward suggestions on the optimization and emergency management of the urban rail transit network;The results show that whether cascade failure is considered or not,urban rail transit network is more resistant to random attack than intentional attack;In case of cascade failure,the rail transit network considering station load redistribution is more vulnerable;At the initial stage of cascading failure propagation,increasing the station capacity can effectively reduce the impact range of cascading failure,but with the increase of the number of stations affected by cascading failure,the impact of station capacity on network survivability decreases;Cascading failures caused by failure of important stations have a wider impact on the network and greater damage to the whole network;Urban rail transit networks with high global connectivity show good survivability in the face of random faults,while networks with strong local aggregation have strong survivability in the face of deliberate attacks.