Resource-constrained bridge maintenance optimization by harmonizing structural safety and maintenance duration

Bridges are progressively experiencing significant structural wear and challenges in their maintenance procedures. To address this issue, it's crucial to clarify the order of maintenance activities during the bridge maintenance process and the impact of maintenance resources on structural safety performance. This understanding allows for the precise establishment of a model that captures the changes in structural safety performance in relation to the bridge maintenance duration that are resource-constrained. This paper proposes a resource-constrained bridge maintenance optimization method where neither the structural safety performance loss nor the duration holds a dominant advantage. An Adjusted NSGA-II (Adj-NSGA-II) method is employed to determine the total structural safety performance loss and total duration throughout the bridge's operational cycle. The results show that the number of construction workers in the mathematical model proposed will have different degrees of influence on the change of the total construction duration under the similar total structural safety performance. The proposed method not only enhances the scientific management capabilities of decision-makers in bridge maintenance planning but also provides a framework that can be applied to maintain other structural forms.