A resilience-based decision framework for post-earthquake restoration of bridge networks under uncertainty

As key components of the transportation infrastructure system, bridges are vulnerable to earthquake hazards during their service life. Restoration of damaged bridges is of great importance to resume the operation of the transportation networks in support of post-earthquake city reconstruction and rescue. This paper proposes a resilience-based framework to identify the near-optimal restoration scheduling of bridge networks after an earthquake. In the framework, an average travel time-based metric is introduced for the network performance analysis, and a probabilistic recovery model is adopted to describe the restoration characteristics of damaged bridge. Furthermore, the post-earthquake restoration scheduling problem is formulated as a mathematical model with the aim of maximizing network resilience, for which a modified GA-based optimization methodology is developed to obtain the near-optimal solution to this problem. Finally, the applicability of this framework in the scenario of bridge network recovery is demonstrated through two numerical examples. The results show that the proposed framework is effective in guiding the network restoration scheduling under resources and functionality constraints; the dynamic changes in traffic demand after an earthquake can significantly affect the optimal restoration sequence of damaged bridges, the evolution of network functionality and network resilience.