Bridge deck system reconstruction and mechanical behavior analysis of Nanjing Yangtze River Bridge

A reconstruction method for the top highway concrete deck system of the Nanjing Yangtze River Bridge was proposed based on the existing damages by using the steel orthotropic deck without stopping the train traffic. A finite element model was established to simulate the entire reconstruction stages. The accuracy of modeling was verified by the static loading test. First, the static and dynamic characteristics of the worst structural condition after removing the old concrete deck were investigated. Then, the mechanical behaviors of the concrete deck before reconstruction and the steel orthotropic deck after reconstruction, including the deformations of the main truss, the axial forces of the key components, and the reaction forces of bearings, were compared under the dead load and the train load. Finally, the spatial stress distribution of the steel orthotropic deck after reconstruction was analyzed. The results show that the bridge deck system of the Nanjing Yangtze River Bridge is fundamentally changed from the old concrete deck to the steel orthotropic deck without stopping the train traffic. This reconstruction not only eliminates the existing damages of old deck, but also reduces the self-weight and improve the loading of the key components. The integration of the bridge deck, the connection of the components, the structural stability, and whole stiffness are improved. The low density and the high strength of the steel orthotropic deck are fully developed. © 2018, Editorial Department of Journal of Southeast University. All right reserved.