大跨度钢箱梁斜拉桥顶推施工中的关键技术研究

Research on Key Technology in Incremental Launching Construction of Large-span Steel Box Girder Cable-stayed Bridge

大跨度钢箱梁斜拉桥在跨越河流、峡谷等地形复杂地区时具有独特的优势,是现代桥梁工程的重要类型。文章以大跨度钢箱梁斜拉桥顶推施工为研究对象,以四川某大跨度桥梁工程施工数据为背景,讨论了临时墩布置位置的优化分析、顶推过程中钢箱梁斜拉桥竖向位移及支承处横肋和纵肋板件厚度对梁体局部受力的影响。研究结果表明,在实际施工中梁体向下倾斜居多,最大的竖向位移达392.08 mm;当支承处横肋厚度为0.016 m时,横肋的应力减小到200 MPa以下,适当设置横肋可以有效减小横肋自身的应力,提高结构的稳定性和安全性。该研究成果对提升斜拉桥施工水平、推动交通建设具有一定的指导意义和实践价值。

Large-span steel box girder cable-stayed bridge has unique advantages when crossing rivers,canyons and other complex terrain areas,which is an important type of modern bridge engineering.Taking the incremental launching construction of large-span steel box girder cable-stayed bridge as the research object,and taking the construction data of a large-span bridge project in Sichuan as the background,this paper discusses the optimization analysis of the temporary pier layout position,the influence of the vertical displacement of the steel box girder cable-stayed bridge and the thickness of the transverse and longitudinal ribs at the support on the local stress of the beam during the incremental launching process.The results show that in the actual construction,the beam body is mostly inclined downward,and the maximum vertical displacement is 392.08 mm;when the thickness of the transverse rib at the support is 0.016 m,the stress of the transverse rib is reduced to below 200 MPa,and appropriate setting of the transverse rib can effectively reduce the stress of the transverse rib itself and improve the stability and safety of the structure.The research results have certain guiding signifi cance and practical value for improving the construction level of cable-stayed bridges and promoting traffi c construction.