Life-cycle connectivity-based maintenance strategy for bridge networks subjected to corrosion considering correlation of bridge resistances

The safety of road networks is crucial for the well-being of the society. Corrosion is a common problem facing bridges. Traditionally, the reliability analysis is performed on individual bridges and maintenance strategies are laid out based on the reliability profiles resulting from this analysis. This paper aims to investigate how to allocate maintenance resources for a group of bridges in a transportation network. Performance indicators associated with connectivity between different nodes in the bridge network are selected as the objectives of the optimization associated with this allocation. Correlation profiles associated with resistances of bridges subjected to corrosion are taken into account in the optimization process. Two approaches to determine life-cycle maintenance strategies are considered: (a) ranking the importance of bridges in terms of their contribution to connectivity; (b) performing optimization to obtain optimal maintenance strategies associated with objectives related to connectivity and maintenance cost. For each approach, the strategies associated with different O (origin)-D (destination) pairs as well as a performance indicator illustrating the overall connectivity within the bridge network are investigated. The results show that different O-D pairs may have different optimal maintenance strategies under the same maintenance budget to maximize the probability of network connectivity. The correlation of bridge resistances has a significant influence on the probability of network connectivity, and as a result, needs to be accounted for.