RETROFITTED METHODS RESEARCH OF FATIGUE CRACKS IN ORTHOTROPIC STEEL BRIDGE DECKS

In this paper, some retrofitted methods are introduced, and in these retrofitted methods the better one is using the concrete paving layer (CPL) on existed orthotropic steel deck. A local finite element model is established by ANSYS based on an orthotropic steel bridge deck sample, stress distribution of bridge deck are calculated under design vehicle load before and after strengthening, and the results are compared each other. The analysis results indicate that, under wheel pressure load, the orthotropic steel deck and the CPL all appear stress concentration, after the deck was strengthened by CPL, the stress peaks decrease obviously due to the lager stiffness of concrete overlay, which induce the increase of fatigue resistant of the orthotropic steel deck. Because the CPL is prone to crack when it bear lager tension stress, some high performance concrete with high tension strength such as steel fiber reinforced self-stressing concrete and Reactive Powder Concrete are suggested to be used in deck paving layer.