Assessment, Reliability and Maintenance of Masonry Arch Railway Bridges in Europe

The main purpose of this paper is to give an overview on the state of the art of inspection, assessment and maintenance of masonry arch railway bridges by the presentation of the results of an ongoing international research project run by the International Union of Railways (UIC) with the participation of 14 railway administrations. The survey has shown that the European railways partaking in the project possess more than 200,000 masonry arch bridges and culverts on their lines which is approximately 60%, a significant proportion, of their total bridge stock. It has been shown that several methods are used by the railway administrations for the assessment and structural analysis of masonry arch bridges. As the correlation between assessment results and measurements on arches is very limited, further research targeted towards a better understanding of their structural behaviour is considered essential. Several inspection methods have been used in recent years to investigate the condition or to determine the structure of masonry arch bridges. As well as the predominant use of visual inspections, and destructive investigation there is a tendency in recent years towards applying non-destructive testing techniques. As many masonry arches belong to the civil engineering heritage of the railways their substitution or refurbishment requires careful consideration. It was concluded that maintenance policies and repair measures for masonry bridges should rely more on existing structural capacity and give preference to stabilization rather than substitution or replacement.