Abstract Ji'nan Huanghe rail-cum-road bridge is a continuous steel truss girder bridge with rigid suspension stiffening chords. Considering the structural characteristics and construction conditions of the huge steel truss girder, a technique of incremental launching method with suspension cable stiffening chords was used for construction of the bridge. For the design of the support structures, assembling supports were used at the side spans and pier-side brackets were used at the central spans. During construction of the horizontal launchings, vertical jack-ups and transverse offsetting rectifying devices were arranged. The functions of the incremental launching devices and support system were qualified to realize the complicated construction work. An advanced synchronous control system was applied to implement the multi-point synchronous incremental launching. The strategy of using elastic support pads was proposed to decrease the harmful influences of the height differences of the three main trusses during construction. Using the finite element analysis, the controlling values of the height differences were determined between +15 and -25 mm to ensure the safety of the construction. The technique given in this paper could provide a reference for the construction of similar long-span bridges.

中文翻译：

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悬索加劲杆连续钢桁梁桥增量下桥施工技术

摘要 济南黄河铁路暨公路桥是一座连续钢桁梁桥，采用刚性悬索加劲肋。考虑到巨型钢桁梁的结构特点和施工条件，采用悬索加劲弦渐进下放法施工。对于支撑结构的设计，边跨采用装配式支撑，中间跨采用墩边支架。在水平发射器的建造过程中，布置了垂直自升式和横向偏移矫正装置。增量发射装置和支撑系统的功能足以实现复杂的施工工作。采用先进的同步控制系统实现多点同步增量发射。提出了使用弹性支撑垫的策略，以减少施工过程中三个主桁架高度差的有害影响。通过有限元分析，将高差控制值确定在+15~-25mm之间，以确保施工安全。本文给出的技术可为类似大跨度桥梁的施工提供参考。高度差的控制值确定在+15和-25mm之间，以确保施工安全。本文所提供的技术可为类似大跨度桥梁的施工提供参考。高度差的控制值确定在+15和-25mm之间，以确保施工安全。本文给出的技术可为类似大跨度桥梁的施工提供参考。