Cascading Failure Resilience Assessment And Enhancement Strategies For Complex Passenger Transport Networks In Urban Agglomerations

A large-scale cascade failure of the transport system during an emergency disruption can severely affect the travelling public and cause incalculable economic damage.An efficient recovery strategy can effectively improve the safety of network operations.In order to enhance the resilience of urban complex passenger transport networks to unexpected disasters and reduce the hazards caused by cascading failures to improve the network resilience of transport systems,a study on the cascading failure behaviour of urban complex transport networks is conducted.(1)A cascade failure model for complex passenger traffic networks in urban agglomerations with recovery strategies is proposed.Firstly,a complex network model for urban agglomerations is constructed based on complex network theory,and a complex traffic network model is finally constructed by overlaying geographically close nodes based on the single-level traffic sub-network model of urban agglomerations.Secondly,an improved network cascade failure model with recovery strategy is proposed by coupling the topological characteristics of the traffic network and travelling characteristics.The recovery strategy is introduced into the load-capacity cascade failure model considering passenger flow characteristics and the load distribution function of the recovery nodes is constructed based on the load redistribution principle,and then the dynamic evolution of the composite network performance under the influence of cascade failure behaviour is sought.(2)A method for evaluating the resilience of transport networks in urban agglomerations and a strategy for improving it are proposed.The dynamic evolution of the system under the influence of cascading failure behaviour is considered,and the network resilience is measured and assessed from the perspective of network efficiency and connectivity performance based on the system function curve.Based on the theory of resilience enhancement strategy and the mechanism of emergency disturbance,three types of system resilience enhancement schemes are designed from the perspective of prevention,emergency response and recovery.(3)Using the Guanzhong Plain urban agglomeration as an example,the network topology and network accessibility characteristics are analysed by constructing a model of the public-rail composite passenger transport network,and then the network resilience is measured by using Python simulation to analyse the evolution of the cascade failure law of the urban agglomeration under three scenarios.The results of the study show that: in ex-ante prevention,the node resistance characteristics of the mesoscopic correlation are better than the degree correlation approach,and the urban cluster cascade network can focus on allocating more extra capacity to high mesoscopic nodes;in ex-ante control,the emergency resilience of heavily loaded nodes with larger nodes can significantly improve the system resilience,which is reflected in the reduction of the system performance loss value in the resistance phase and faster recovery rate in the recovery phase;in ex-ante recovery,the emergency resilience of heavily loaded nodes with larger nodes can significantly improve the system resilience;In terms of post-event recovery,the average values of the two types of resilience indicators,namely network efficiency and connectivity,are 0.822 and 0.959 respectively,which are better than those of 0.734 and 0.927 for the node-based priority recovery strategy and 0.756 and 0.916 for the meso-first recovery strategy,and the importance-based priority recovery strategy can achieve better recovery results in a short period of time.The study is a reference for the prevention and control of cascading failure behaviour of composite transport networks in urban agglomerations and the enhancement of the resilience of composite transport systems.