Jing Liu: Degradation Model and Security Analysis of Hangers of Suspension Bridges

The hangers of a suspension bridge is one of the most important stressed members, the thorough research of the deterioration during operation period and the security analysis after the degeneration of hangers is essential. This is the basis of the strategy of preventive maintenance of suspension bridges. Firstly, the paper studies the four stages of degradation mechanisms of sling and calculation formula of degradation time, and establishes the theoretical relationship between the degree of degradation and resistance reduction coefficient, and then discusses the safety analysis method of sling with broken wire to consider the effect of dangle. Finally, taking an example of the 3rd sling of left Branch Bridge of Ma'anshan bridge, we conducted theoretical calculations of degradation time of sling and security calculations of sling after degradation. The method is purely analytical, and there was an error between the real data and analytical calculations. If we combine the real monitoring data and use it after parameter modification, we can improve greatly the analytical basis of the strategy of preventive maintenance. Keywords-Hanger;Degradation model;Safety analysis