Prediction of reliability and cost profiles of deteriorating bridges under time- and performance-controlled maintenance

The reliability of civil infrastructure is time variant. This is due to strength deterioration and time-variant mechanical and environmental loadings. Demands for keeping civil infrastructure in functional and reliable states require maintenance interventions. Limited financial resources require optimal maintenance strategies. These strategies have to consider the effects of uncertainties not only on the structural reliability deterioration but also on the maintenance interventions. In this paper, a simulation-based method for predicting reliability index profiles of deteriorating bridges associated with both time- and performance-controlled maintenance interventions is introduced. The method provides a computational procedure which can handle various types of maintenance interventions in a consistent manner. This method also includes an advanced cost model which takes into account the interaction between costs of maintenance interventions and their effect on system reliability. Examples are presented demonstrating the application of computational procedure to a stock of existing deteriorating bridges under various maintenance scenarios.