Fatigue design aspects of orthotropic steel bridges

In the last decades, the traffic intensity and the wheel loads on bridges have increased considerably, resulting in fatigue cracks and repairs. Within the framework of ECSC funded research, several programmes have been carried out to investigate the traffic loads, the stresses they produce and the fatigue performance of various details. These programmes have been carried out by seven research institutes in six countries of the European Community. Especially in the programmes carried out recently, the experimental research was carried out in combination with numerical and analytical studies to obtain better insight in the stress distribution of the various connections. This paper highlights the results obtained up till now and the activities which still have to be carried out for an appropriate fatigue assessment of orthotropic steel bridges.