Probabilistic Optimum Bridge System Maintenance Management Considering Correlations of Deteriorating Components and Service Life Extensions

Abstract

Service life extensions of bridge components and systems due to maintenance can be correlated when the maintenance actions are applied to multiple bridge components. This paper deals with the probabilistic optimum bridge maintenance management of deteriorating bridge components and systems. The proposed maintenance management integrates two types of correlation: (1) the correlation among the safety margins of bridge components, and (2) the correlation among service life extensions due to maintenance actions. The effects of these two types of correlation on the extended service life, probability of failure, and optimum maintenance planning for bridge components and systems are investigated. This paper uses series-parallel models to represent a bridge system. The extended service life of a bridge system is estimated based on the extended service lives of its components considering (1) independent and perfectly correlated safety margins, and (2) independent, partially correlated, and perfectly correlated service life extensions. The optimum maintenance plannings for bridge components and systems are based on maximizing the time to reach their target probability of failure. The effects of the correlation associated with both the safety margins and the service life extensions on the optimum maintenance application times and the time to reach the target probability of failure are investigated. The proposed approach is illustrated on an existing reinforced concrete bridge under corrosion.