Maintenance Management of Multispan Masonry Arch Bridges by Reliability Concept

This paper presents a maintenance strategy of multispan masonry arch bridges by reliability concept. Based on axle load of the individual arches, a safety margin (limit state function) is introduced. Then, failure probabilities of each arch are estimated. Since failure of any arch makes the bridge failure, the bridge is treated as a series system with individual arches. Then, failure probabilities of arches are assembled to obtain failure probability of the bridge by Ditlevsen’s bounds. Acceptable reliability indices of masonry arch bridges are introduced using Nordic Committee of Building Regulation. From the reliability index variation with time, major maintenance of the bridge is predicted. The introduced maintenance strategy is illustrated with an old multispan brick masonry arch bridge from Sri Lanka