Research on Stress Spectrum of Steel Decks in Suspension Bridge Considering Measured Traffic Flow

This study investigated the traffic-induced stresses in the steel deck of a suspension bridge on the Yangtze River, taking into account the dependence of Young’s modulus of asphalt pavement on temperature. In particular, the stress spectra of local areas in the steel deck were studied. On the basis of the massive traffic data collected by a bridge toll system over one month, traffic composition and the vehicle load were statistically analyzed, and then a random traffic flow model that reflected the statistical characteristics of actual traffic flow, was generated. Through a bridge dynamic analysis of the random traffic flow model, a segment of the steel box girder which experiences the greatest stress was selected. The local stress variation and the stress spectrum under traffic flow were analyzed using a finite-element model (FEM). In the FEM analysis process, the impact of the temperature on mechanical properties of the asphalt pavement was considered. The results show that the middle segment of the main span has the largest moment amplitude. In addition, it was observed that the variation of Young’s modulus of asphalt pavement resulting from temperature change can significantly affect the stress of the steel box girder and the stress spectrum at different local areas in steel deck.