桥梁深水长大桩基快速成桩施工技术

Construction Technology of Rapid Pile Formation for Bridge Deep-water Long Pile Foundation

随着大型桥梁的建设发展,跨江、跨河桥梁日趋大跨度发展,深水长大桩基在铁路和公路桥梁基础中得到了广泛应用。毛坪大渡河特大桥3个墩位采用桩基基础,桩径2.5m,桩长66m,孔深83m,通过对以往类似工程反复研究,结合本工程实际特点,多次组织专家进行论证、研究,提出并应用了“井字型钢结构导向架定位及插打钢护筒”、“气举反循环孔内排渣清孔”、“泥浆钻渣过滤分离及泥浆再循环利用”、“桩基钢筋笼安装定位装置”等施工技术,保证了桩基快速成桩质量,节约了成本,加快了施工进度,对同类工程有借鉴意义。

With the development of large-scale bridges,river-crossing bridges are becoming more and more long-span.Deep-water long pile foundations have been widely used in railway and highway bridge foundations.The three piers of the Dadu River Bridge in Maoping adopt pile foundations with a pile diameter of 2.5m,a pile length of 66m,and a hole depth of 83m.Through repeated studies on previous similar projects,combined with the actual characteristics of the project,experts have been organized for multiple demonstrations and studies.Construction technologies such as the"positioning of the well-shaped steel structure guide frame and inserting the steel protection tube","slag removal in the gas lift reverse circulation hole","filtration and separation of mud drilling slag and mud recycling utilization","installation and positioning device for pile foundation reinforcement cage"are proposed and applied,which ensured construction quality,saved costs,speed up the construction progress,and provides reference for similar projects.