Recent advances in the fatigue design of steel bridges submitted to aleatory traffic loads

Abstract

This work presents recent developments in the fatigue design of bridges submitted to aleatory traffic loads. The purpose is to perform fatigue design according to Eurocode fatigue model 5 but replacing real-life measurements by Finite Element computations. Synthetic traffic loads are generated according to prescribed probability density functions representative of the real traffic. A Montecarlo approach is employed to estimate the damage induced on the structure. Lorries weight and inter-distances, as well as traffic composition are generated in an aleatory way. Different traffic regimes (free-flow vs jammed), depending on the time of the day, are also accounted for. A critical analysis of the traffic parameters is performed, based on simple influence lines and an extension of the approach to consider complex trucks geometry, transversal deviation with respect to the nominal traffic lane, as well as simultaneous multiple lanes, is discussed.