Life-cycle sustainability assessment of bridge networks based on cooperative game theory

Deteriorating bridge networks are vulnerable to extreme events, such as earthquakes and tsunamis, throughout their life-cycle, posing significant social, economic, and environmental risks. This paper presents a life-cycle sustainability assessment framework for bridge networks, distinguishing between the independent and cooperative impacts of bridge deterioration during seismic events. Independent impacts refer to the direct consequences of a single bridge’s condition, such as maintenance costs and safety risks, while cooperative impacts arise from bridge network interactions, such as traffic detour effects. These impacts are evaluated using a cooperative game theory approach, with the Shapley value employed to fairly distribute them among individual bridges. By integrating reliability and resilience within a probabilistic framework, the study establishes a direct connection between these concepts and sustainability assessment. Furthermore, the framework employs normalized Shapley values to integrate the sustainability impacts across the three dimensions of each bridge, weighted by their relative importance. The effectiveness of the proposed method is demonstrated through a case study that evaluates the sustainability of a bridge network over time, highlighting the critical role of each bridge. This framework provides valuable insights for defining the responsibility for sustainability losses of each bridge across the bridge network, contributing to effective life-cycle maintenance and post-disaster management strategies under resource constraints.