某提篮拱桥拱肋新颖,由钢桁拱外包混凝土形成的箱型截面,与仅有顶底板的钢混叠合结构对接而成,拱肋截面突变且构造复杂。本文采用有限元软件对该钢-混凝土结合拱肋混合接头进行施工过程模拟,分析了该部位在各施工阶段下的应力分布特点及变化规律。同时,根据模拟计算分析结果,对该部位进行结构优化。分析结果表明:混合接头结构在运营阶段主力组合作用下受力最为不利;该组合荷载作用下,接头箱形截面侧钢梁主压应力基本在-160~-245MPa之间,接头叠合结构侧钢梁主压应力-90~-215MPa之间,均超出《铁路钢桥设计规范》规定的容许应力值;混合接头叠合结构侧混凝土压应力储备相对不高;优化后的混合接头结构受力得到较大改善,符合相关规范要求。 The arch rib of a basket-lift arch bridge is novel. The box section formed by the concrete-encased concrete of the steel trussed arch is connected with the steel-concrete composite structure with only the top and bottom slabs. The cross section of the arch rib suddenly changes and the structure is complex. In this paper, the finite element software is used to simulate the construction process of the steel-concrete composite arch rib hybrid joint, and the stress distribution characteristics and variation regularity of the part under various construction stages are analyzed. At the same time, according to the result of simulation calculation and analysis, the structure is optimized. The results show that under the combined action of the main load, the main load of the hybrid joint structure is the most unfavorable. Under the combined load, the main compressive stress of the steel beam with joint box section is between -160 and -245MPa, The main compressive stress of the steel beam is between -90 and -215MPa, which are beyond the allowable stress values ​​stipulated in the Code for Design of Railway Steel Bridges. The compressive stress reserve of the concrete side of the hybrid joint structure is relatively not high. The optimized hybrid joint structure is stressed Get a big improvement, in line with the relevant regulatory requirements.