跨既有繁忙电气化铁路预应力混凝土连续箱梁单点顶推技术研究

由于本公路桥具有大悬臂、截面不对称、顶推就位后浇筑横向连接段、导梁与腹板连接受力复杂、纠偏难度大等特点,为使预应力混凝土连续箱梁能顺利跨越既有电气化铁路,在常规顶推施工经验的基础上对顶推方案进行改进与创新,采用大吨位单点顶推施工工艺,并提出一套"顶拉结合"的新型纠偏方式。实践证明,该顶推工艺操作简单、适用性强。通过对该技术的总结与研究,为类似跨线桥(跨铁路、公路等)工程提供借鉴和示范。

Research on Single-point Incremental Launching Technology of Prestressed Concrete Continuous Box Girder over Existing Busy Electrified Railway

This highway bridge is characterized by large cantilever,unsymmetrical section,the later casting of transverse connection segment after the beam is pushed in place,the completed stress distribution in joint regions between the launchingnose and the web,and the difficulties in rectification,and improvement and innovation of the incremental launching scheme are conducted on the basis of the experiences of the conventional incremental launching construction using large-tonnage single-point incremental launching method to allow the prestressed concrete continuous box girder smoothly across the existing electrified railway. A new method for rectification through pushing and pulling is initiated and proves to be simple and applicable. The research and summary of the process may provide reference and demonstration for other similar flyovers( crossing over railway or highway).