ABSTRACT
ABSTRACT This paper is focused on the service life prediction of steel bridges subjected to a combination of corrosion and fatigue. Both deterioration mechanisms are dubious to handle in theoretical assessments due to large uncertainties, on the action effect side and the resistance side. A reliability-based assessment in combination with updating considering monitoring and inspections provide an approach to reduce the uncertainties. To evaluate what assessment actions to engage, this approach has been combined with Bayesian decision theory which provides a rational basis to evaluate the value of information (VoI). The Old Lidingö Bridge in Sweden is used as a case study to demonstrate the reliability-based approach. This bridge is subjected to severe corrosion and has been deemed unfit for service. However, it provides the only link to the island Lidingö for the local tram and pedestrians why the bridge owner has decided to keep it in service until a new bridge is in place. To secure the safety of the bridge, recurrent inspections are conducted and discovered defects are repaired immediately. A system for continuous monitoring of critical parts was installed during the spring 2017. The bridge, the approach for assessment, and the procedure for evaluating the VoI are presented in the paper.
