Research of Stress Concentration and Retrofitted Methods for Orthotropic Steel Bridge Decks

In this paper, the stress distribution of the orthotropic steel bridge deck in a suspend bridge under local wheel load is analyzed. Some retrofitted methods are introduced, two of which are studied. One is using the concrete paving layer (CPL), and the other is using the sandwich plate system (SPS) to strengthen the orthotropic steel bridge deck. Local finite element models are established by ANSYS; stress distribution of bridge deck is calculated under the designed vehicle load before and after the deck retrofitted by the CPL or the SPS, and the results are compared with each other. The analysis results indicate that, under wheel pressure load, the orthotropic steel deck appears stress concentration; after the deck was retrofitted no matter by the CPL or the SPS, all the stress peaks decrease obviously, and the fatigue resistance of the orthotropic steel deck increases, which indicate that the two methods are effective to retrofit the orthotropic steel bridge deck. Using the CPL method can lead to lower stress concentration than that of using the SPS method, but the concrete paving layer is easy to crack, so, high performance concrete with high tension strength is needed.