Optimization of Bridge Management under Budget Constraints

Bridge management is a complex engineering issue with public safety and financial implications. It is a challenge to provide efficient bridge management systems, taking into account uncertainties in the structural degradation process, the loads and resistance of the structure, the decisions that are made concerning assessment strategies—such as inspections or structural health monitoring (SHM)—and maintenance and rehabilitation strategies. It is important to determine optimal management strategies that satisfy budget constraints, because efficient use of available financial funds is a primary objective of stakeholders. The purpose of this paper is to provide a probabilistic framework based on SHM results for optimization of management strategies under multiple criteria, including budget availability. To take into account uncertainties in the decision process, an event tree–based approach is used. This enables quantification of the expected inspection, SHM, maintenance and failure costs, and accuracy of the decision process according to the occurrence and duration of future SHM programs. To include budget constraints, the probability distribution of management cost—defined as the sum of inspection, SHM, and maintenance costs—is determined at each decision time and compared with an ideal budget distribution. The proposed approach is applied to an existing bridge.