Abstract:

In order to investigate the impact differences of inter-layer and intra-layer passenger flow transfer proportions after stations failure on the invulnerability of the metro network, a multi-layer directed weighted metro network model was constructed, considering the train running time between stations, station dwell time, passenger transfer walking time, and waiting time. Station initial loads were determined by the actual passenger flow, and the station capacity was calculated using a nonlinear load-capacity model. Stations were sequentially targeted based on their relative importance. The maximum connected subgraph ratio and passenger travel efficiency ratio were selected as the metrics to measure the invulnerability of the metro network. An empirical analysis using the 2021 Xi'an metro network was conducted to study the effects of different inter-layer and intra-layer passenger flow transfer ratios and different capacity adjustment coefficients on the network's invulnerability. The results show that when the inter-layer passenger flow transfer ratio is 0.7, the impact on the invulnerability of the multi-layer metro network is minimal. When the capacity adjustment coefficients are set at b = 0.6 and c = 0.8, appropriately improving station service levels can enhance the network's invulnerability. As the number of attacked stations increases, the invulnerability of the metro network gradually decreases. Under the same attack conditions, the multi-layer directed weighted metro network demonstrates stronger invulnerability compared to the single-layer network, and the network's invulnerability is further reduced when cascading failures are considered.

Key words: cascading failure, multi-layer directed weighted metro network, invulnerability, attack strategy, load distribution, capacity adjustment coefficient