Fatigue assessment of existing riveted truss bridges: case study

Many steel riveted bridges have been built in Poland since 1950 and they have not reached their design working lives yet. Nevertheless, a number of fatigue damages are found, especially with structural joints. Moreover, in the past 25 years the traffic on the Polish road network has increased significantly leading to the increasing number of heavy vehicles in the traffic flows. This may affect the safety, serviceability and durability of existing bridges. The road administration is therefore interested in reliable and agreed methods to assess the safety and durability of existing bridges. The special procedure has been prepared to provide technical insight on the way in which existing steel structures could be assessed and the remaining fatigue life could be estimated. This approach follows the principles and application rules in the Eurocodes and provides a scheme with various levels of analysis: a basic level with general methods and further levels, more complex and sophisticated and requiring specific experience and knowledge. This procedure has been used for the fatigue assessment of the 60-year-old riveted truss bridge. The applied procedure as well as the main results of the assessment have been presented in the paper.