浅谈平曲线上立交桥连续箱梁顶推施工技术

Incremental Launching Construction Technology of Overpass Continuous Box Girder on the Plane Curve

唐山建华东道立交桥主桥因特殊的地理位置,其主桥位于直径700 m的曲线上,另受条件限制主桥需采用预应力混凝土连续箱梁顶推施工,由于主桥需上跨快速铁路,无法在铁路线上现浇施工,只能在铁路一侧现行预制,再进行顶推作业,这样可以保证施工安全作业。顶推时曲线段竖向水平偏差的控制、顶推时应力反复转换的安全施工、顶推时对既有线的安全保证是本工程的重难点。本文从以上几点出发,介绍主桥顶推施工技术难点,确保施工安全和施工进度要求。

The main bridge of Tangshan Jianhua East Road overpass,due to special geographical location,locates on a curve with a diameter of 700 m. Still due to the conditions,the prestressed concrete continuous box girder construction is used. Due to the rapid rail overhead,casting in place is not permissible. Instead,precast followed by incremental launching by the rail is adopted which can ensure the construction safety. Its technical difficulty lies in the control of vertical horizontal deflection,safety of repeated stress transformation at incremental launching,safety insurance of the existing lines.From these points,this paper introduces the difficulties of incremental launching and ways to ensure construction safety and construction schedule requirements.