English：

Aiming at the fatigue safety problem of the flexible hangers of the key components of themiddle-bearing and below-bearing steel arch bridges, this paper takes a middle-bearing steel truss archbridge with a main span of 916m as the engineering background to study the fatigue performance of theear plate anchorage structure. The three-dimensional finite element model of the whole bridge isestablished. Combined with the dynamic analysis of vehicle load, the core rule that the stress of No. 1short hanger in the arch foot area is 2.5 to 3 times that of the mid-span hanger is revealed. By comparingthe equivalent fatigue vehicle and different national standard load models, the stress response of the keyparts of the anchorage structure is quantified. The maximum normal stress of the ear plate anchoragestructure plate is 51.0MPa, and the maximum shear stress of the weld is 21.3MPa,which meets therequirements of the multi-national standard limit. In practical engineering, the hole diameter tolerancebetween pin shaft and ear plate should be controlled equal or lesser than 0.1mm, and the hardnessgradient control should be implemented. The arc with radius greater than or equal to 50mm is set in thewelding transition zone between the anchor plate and the ear plate, and the welding toe is polished. Thehyperboloid spherical hinge is used to replace the ball crown block, and the fillet of the hole edge of thesplitter plate is greater than or equal to 2mm.