Risk-Based Importance Ranking of Urban Bridge Networks

The risk-based importance ranking method takes into account both the failure probability and the network-level consequences of urban bridges, having a significant advantage in guiding the allocation of maintenance funds under limitation conditions. This paper conducts a study on the importance ranking of urban bridges based on periodic inspection data from 445 highway bridges in a Chinese city. Urban transportation network data is extracted to construct an urban bridge network consisting of 186 nodes and 328 edges. A multi-dimensional importance indicator considering safety, social, functional, and environmental factors is established to comprehensively characterize the consequences of bridge failure. The edge on which a bridge is located is removed to simulate bridge failure for network calculation and to obtain the importance indicator. Results show that the consequences of failure in the functional and social dimensions constitute the primary and secondary components of the total consequences of bridge failure, respectively. The former accounts for 61.15%, while the latter accounts for 23.92%. In contrast, the safety indicator, representing structural repair, accounts for only 3.61%. The influence of bridge failure at the network level is significantly greater than that at the bridge level. The value of the present work lies in integrating these dimensions and demonstrating their combined effect on network-level ranking.