A decision theoretic approach towards planning of proof load tests

Abstract

Accurate determination of the bearing capacity of bridges is of high importance for society. Concerns are raised about the actual bearing capacity of bridges due to aging related deterioration, ever increasing traffic loads and conservative design. Proof load testing is often used for evaluations of bridge capacity. However, extensive proof load tests tend to be costly. Further, the risks of damage to the bridge imply that a proof load test may not always be cost effective. The performance of proof load testing and its outcomes is further dependent on factors such as the chosen loading, the monitoring technology and methods, and the stop criteria. A decision theoretic approach is utilized to demonstrate the optimal strategy for proof load testing procedures and collection of information. The decision scenario constituting the planning and performance of the proof loading is considered along with prevention of damage to the bridge. The decision maker is the proof loading planner who chooses the loading, the monitoring technologies and methods as well as the stop criteria to minimize the expected costs of the test and to comply with acceptable risks. A case study is developed and the optimal strategy with respect to loading, monitoring technology and stop criteria is identified as those with the maximum utility to the decision maker.