Fatigue safety examination of a 150-year old riveted railway bridge

Built in 1859, the railway bridge over the Rhine between Koblenz (Switzerland) and Waldshut (Germany) consists of a three span continuous riveted steel truss girder and an approach viaduct in natural stone masonry. Due to ever increasing traffic demands the fatigue safety and service life of the bridge needed to be examined. Examination methods as defined in the new Swiss Codes on Existing Structures using updated load models and structural resistance are applied to investigate this structure that is for more than 150 years in service. Due to this rational approach, it could be shown that the bridge can remain in service for a long future service life. This paper describes the chosen approach and reports on the most significant results. In particular, the main principles and assumptions followed in this project are outlined. Also, scenarios for future maintenance and rehabilitation interventions are developed and compared on the basis of life cycle costing. The approach allows for more realistic examination of the fatigue life of the riveted steel structure and also includes an comprehensive approach including cultural and economic valuations.