Hazard-Based Optimum Lifetime Inspection and Repair Planning for Deteriorating Structures

Abstract

The hazard function is one of the most used lifetime distribution functions in reliability analysis of components and systems. Although it is extensively used in several scientific disciplines, few applications have been proposed in the field of civil infrastructure systems. In this paper, the hazard function is used to provide optimal inspection/repair lifetime planning for deteriorating structures through an iterative procedure. The proposed approach is based on the definition of a threshold value for the hazard function. Constraints are imposed based on both the maximum allowable expected total cost and minimum allowable effectiveness of each intervention. Uncertainties related to damage detection during inspections and attitudes towards repair are considered. An optimization procedure for determining the best threshold value for the hazard function, with target maximum expected failure time, is proposed. The method is applied to an existing deteriorating bridge deck under corrosion.