芜湖长江公铁大桥南引桥40.7m简支梁施工关键技术

商合杭铁路芜湖长江公铁大桥南岸引桥下层铁路部分主梁采用双幅40.7m预应力混凝土简支箱梁结构,双幅40.7m简支梁区段采用"现浇+横移"的总体方案施工,其中,右幅箱梁在原位现浇;左幅箱梁在右幅梁位浇筑后再沿墩顶滑道横移至左幅设计位置。结合该项目桥跨布置、地质情况等,近长江侧4×40.7m区段简支梁采用斜腿支架施工,斜腿支架采用墩旁立柱、跨中斜柱和单层贝雷梁的结构体系,仅在单幅搭设;2处18×40.7m区段简支梁均采用移动模架施工,移动模架采用模板可纵向开合的上行式,其侧模和底模可纵向打开。

Key Techniques for Construction of 40.7m-Span SimplySupported Girders of South Approach Bridge of Wuhu Changjiang River Rail-cum-Road Bridge

The main girder for lower railway deck of the south approach bridge of Wuhu Changjiang River Rail-cum-Road Bridge on the newly built Shangqiu-Hefei-Hangzhou Railway is composed of 40.7 m-span railway twin simply-supported PC box girders,which is constructed with the general scheme of in-site casting+transverse sliding.The rightward girders are cast in situ,and the leftward girders are cast in the site of right girders and then transversely slid to the design site on the left along slide way at top of piers.Combined the arrangement of bridge spans with the geological conditions,an inclined-column formwork system that is composed of pier-side columns,inclined-column sat mid-span,and single-layer Bailey beam is adopted to construct the simply-supported girders at the 4×40.7 m segments near the Changjiang River side,which is set up on one side.The simply-supported girders at two 18×40.7 m segments are constructed by adopting movable shuttering form,in which deck-travelling with longitudinal opening and closing is adopted,and side formwork and bottom form work can be longitudinally opened.