关键词: 钢混组合桁架桥, 温度荷载, 节点调控, 有限元分析

Abstract: The steel-concrete composite girder bridge truss has the advantages of good economic performance, high bearing capacity, large bending stiffness and so on, so it is widely used in our country. However, because the rods that make up the truss are long and thin, the overall heating and cooling of the structure will affect the closing of the truss and the positioning of the truss joints.In this paper, combining with engineering examples, MIDAS software is used to analyze the transverse displacements of trusses produced by different temperatures at the erection stage and the influence of vertical displacements of trusses on other joints after erection.Through the research results, it is concluded that the lateral displacement of the truss is linear under temperature load, and the vertical displacement of the nodes increases or decreases in the same way with other nodes.Therefore, in truss assembly, it is necessary to control the closing temperature within a reasonable range, and in elevation control, multiple nodes can be adjusted simultaneously, and the position and forced displacement of nodes can be determined by superposition principle.

Key words: steel-concrete composite truss bridge, temperature load, node control, finite element analysis