Performance Assessment and Maintenance of Masonry Arch Bridges

In order to maintain as many as 19600 masonry arch bridges on Indian railway network alone and innumerable of them on Indian Highways, it becomes de rigueur to assess the performance and devise a maintenance strategy for timely diagnosis of shortcoming / deficiencies in these existing ageing bridges. These techniques are essential to boost the confidence level of designers in masonry arch bridges and maintain the state of health of existing masonry arch bridges. At the same time, performance assessment and maintenance for newly constructed bridges, which are seldom is of prime importance due to the fact that freight hauliers are quick to see the advantage of heavier goods vehicles. The axle loads are on increase and limits do not seem likely to decrease in future.

The Performance assessment and maintenance can prevent the catastrophic failure and revolutionize the maintenance economics including the replacement of the distressed bridges in a phased manner. Available structural performance assessment techniques are reviewed here in the paper. The advantages, disadvantages and the applicability of these techniques for the masonry arch bridges are also discussed. Finally a strategy for the performance assessment of existing and newly constructed masonry arch bridges is proposed. At the end the maintenance strategy on the basis of diagnosis as an Indian experience on railway masonry arch bridges has also been included in the paper.