Key Techniques for Incremental Launching Construction Control of Steel Truss Girder of the Huanghe River Bridge on Zhengzhou-Jiaozuo Intercity Railway

The main bridge of the Hanghe River Bridge on the Zhengzhou-Jiaozuo intercity railway is a through steel truss girder bridge with eleven continuous units of(2×100)m,the total length of which is 2200 m.The steel truss girder is erected by the combined use of incremental launching and cantilever assembly.Construction control was carried out for the installation of the assembling scaffolds and the beams with sliding rails involved in the large-scale temporary structure ahead of the incremental launching construction.During the incremental launching,the height difference of the lifting(lowering)of the three-truss blocks,lateral offsetting and incremental launching distance were also controlled,realizing the precise control of the steel truss girder in three directions and ensuring that the assembling geometry reach the one it is intended to.