Abstract: Taking the construction process of a large span continuous steel truss bridge as the background, the linear control method of the cantilever assembly process was studied. The finite element software MIDAS Civil was used to establish the steel truss beam bridge model in construction phase. Through the analysis on the effect of different pre-elevation on the linear control of assembly process, the formula for pre-elevation reasonable setting was derived, which determined the initial installation position of steel girder erection and the control alignment of the suspension process. Combined with the construction monitoring data, the analysis was carried out. The results show that the measured alignment is basically consistent with the predicted alignment, which indicates that the linear control method of setting pre-elevation is practical and effective.

Key words: bridge engineering, cantilever construction, steel truss girder, temporary pier, instability, control line shape

摘要： 以某在建大跨径连续钢 桁梁桥施工过程为背景，对半悬臂拼装过程的线形控制方法进行研究。采用有限元软件Midas Civil建立了钢桁梁主桥的施工阶段模型，通过分析不同预 抬高对拼装过程控制线形的影响，推导出预抬高的合理设置公式，确定了钢梁架设的起始安装位置及悬拼过程的控制线形，并结合施工监控数据进行分析 。结果表明：实测线形与预测线形基本吻合，说明设置预抬高的线形控制方法实用有效。

关键词: 桥梁工程, 悬臂施工, 钢桁梁, 临时墩, 失稳, 控制线形