Research On Cascading Failure Of Urban Road Network Based On Node Importance

In the urban road traffic network,certain pivotal road sections or intersections will fail in a short time due to sudden natural disasters or traffic accidents.These failed intersections or road sections will quickly cause other related intersections or road sections to fail,forming a chain reaction,eventually leading to a large-scale paralysis of the road network,this phenomenon is called cascading failure in Complex Network.With the rapid development of urbanization and the rapid growth of traffic demand,the scale of urban road networks is getting larger and larger and the road network structure is becoming more and more complex.The risk of cascading failure of the road network is also increasing,and the extent of destroy is also increasing.Therefore,studying the cascading failure phenomenon of the urban road network is of great significance for preventing the large-scale paralysis and improving the stability and reliability of the road network.To this end,this paper combines Complex Network theory with the actual characteristics of urban road traffic networks,abstracts road intersections as network nodes,and abstracts road sections between intersections as network edges.By analyzing the road network topology and the significance of road network nodes,the cascade failure model of urban double-layer road network is constructed,and the evolution law of node failure is explored on this basis,and the control strategy of cascade failure is proposed.The main research work of this paper is summarized as follows:Firstly,the urban road network is abstracted into a complex network,the main method in the Complex Network theory is used to construct the geometric topology model of the urban road network,then the traffic characteristics,topological structure,and statistical characteristics of the Complex Network are studied.Secondly,construct an evaluation method for the significance of road network nodes,and evaluate the significance of road network nodes through node relevance,node-based shortest path and node contraction and other indicators.In order to verify the scientificity and effectiveness of the method,a case road network is used to evaluate the importance of the road network.The importance is evaluated and calculated and verified by co-simulation.At the same time,in order to verify the importance of the intersections of high importance in the actual traffic network,the traffic investigation and analysis of the high importance nodes are carried out.Then,based on the analysis of node importance,combined with the urban road network traffic characteristics,a two-layer road network cascade failure model based on the Coupled Map Lattice is constructed.The upper layer is the Coupled Map Lattice model for solving the road network failure influence process and law range,and the lower layer is the user balanced allocation model for allocating traffic.On the basis of the Coupled Map Lattice model algorithm,combined with the improved user equilibrium model algorithm,the two-layer road network cascading failure model is resolved and devised,and the solving steps of each algorithm are given in detail.At the same time,a virtual road network is designed to solve the cascade failure simulation and verify the effectiveness of the model and algorithm.Finally,in order to verify the reliability of the double-layer road network cascading failure model in the actual road network,the Suzhou Industrial Park example road network is used as the simulation object to construct the regional network topology structure diagram,and the example road network topology parameters and traffic The characteristic parameters are calculated,and the road network is simulated and analyzed based on the results of the importance analysis,and the failure process and influence range of the road network cascade under different attack modes are obtained.According to the results of the example simulation,combined with the characteristics of the actual road traffic network,a cascading failure control strategy is proposed,and simulation comparison analysis is carried out through the model,which proves that the strategy can effectively control the large-scale spread of the urban road network cascade failure.