Abstract: Chao Tianmen Yangtze River Bridge is 932 m in total length,of which the main bridge is designed as a 3 span continuous steel truss single arch and girder with a long span arrangement (190 m+552 m+190 m).Based on the characteristics of main span closure,the thought,calculation and key operation procedure of main span closure are introduced. With MIDAS,three-dimensioned finite element simplified calculation model of Chao Tianmen bridge is established,and the construction monitoring process is also analyzed.Heavy pressure program design in construction monitoring of a bridge can be a reference to that of the similar bridge.

Key words: highway-railway bridge, truss bridge, heavy pressure, MIDAS/CIVIL

摘要： 朝天门长江大桥全长932 m,主桥为(190+552+190) m三跨连续单拱钢桁梁。结合主跨合龙特点介绍主跨合龙的思路、计算及操作要点,应用大型有限元分析程序MIDAS建立了朝天门长江大桥的三维有限元简化计算模型,并对其进行了施工过程控制分析。压重方案设计可以为同类桥梁的施工控制分析提供有益的思路。

关键词: 公铁两用桥, 桁架桥, 压重, MIDAS/CIVIL