Steel‐truss rigid‐tied arch bridges are among the most important structural forms of high‐speed railway bridges in China. Train‐flow monitoring data indicate that the train loads associated with multiline intersections account for 46.22% of the total train load. The fatigue performance of rigid shortest hangers under train loads at multiline intersections is important. Based on the engineering background of the Nanjing Dashengguan Yangtze River Bridge, which is the first six‐line railway bridge in the world, the fatigue performance of the shortest hangers under train loads at multiline intersections is first evaluated via long‐term dynamic strain monitoring. Furthermore, the effects of train loading parameters such as the number of train intersections and the driving direction on the axial‐bending effect and fatigue performance of the shortest hanger are analyzed. Then, the fatigue performance parameters of all the shortest hangers of the bridge in 5 cases involving multiline intersections are analyzed through numerical finite‐element simulations, and the annual cumulative fatigue damage of all 12 shortest hangers considering the axial‐bending effect is calculated according to the monitored train loads. Finally, the inspection periods of the shortest hangers are recommended on the basis of the degree of fatigue damage. The fatigue performance of the shortest hangers is significantly affected by multiline intersections. Moreover, the bending strain of the shortest hangers has a significant effect on the fatigue effect and is positively correlated with the number of train intersections. The maximum value of annual fatigue damage is calculated for the shortest hanger at the southern end of the first span of the middle truss. The results provide a basis for decision‐making involving the detection, maintenance, and management of the shortest hangers of steel‐truss rigid‐tied arch bridges.
Zhong et al. (Thu,) studied this question.