安庆长江铁路大桥主墩大型深水基础施工方案与关键技术  

Construction Scheme and Key Construction Techniques for Large Deepwater Foundations of Main Piers of Anqing Changjiang River Railway Bridge

作　　者：农代培 季跃华[2] 徐炳法 

机构地区：[1]中铁大桥局安庆长江铁路大桥指挥部,安徽安庆246008 [2]中铁大桥局集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2012年第6期1-7,共7页Bridge Construction

摘　　要：宁安铁路安庆长江铁路大桥主桥为双塔多跨连续钢桁梁斜拉桥,该桥3号、4号墩均采用高桩承台基础。为解决桩基汛期施工风险大和3号墩深水无覆盖层斜岩面环境下桩基施工平台搭建难题,经方案比选,3号、4号墩基础采用先围堰(直径56m)后平台的双壁钢围堰施工方案。施工中采取了以下关键技术:3号墩围堰采用气囊法下河,4号墩围堰采用整体起吊下河;围堰采用无导向船重锚锚碇系统定位;采用活动插板法快速完成了斜岩面围堰底缺口封堵;围堰采取了分区封底施工。The main bridge of Anqing Changjiang River Railway Bridge on Nanjing-Anqing Railway is a double-pylon and multi-span continuous steel truss girder cable-stayed bridge and the main piers No. 3 and No. 4 of the bridge are supported on the elevated pile cap foundations. To cope with the problems that the construction risk of the pile foundations would be high in the flood period and the setting-up of the working platform would be difficult for the foundation of the Pier No. 3 on the inclined rock surface in deepwater and without overburden, it was deter- mined through comparison that the construction scheme of building the circular double-wall steel boxed cofferdams （each being 56 m in diameter） for the Piers No. 3 and No. 4 first and setting up the platforms late would be adopted. In the process of the construction, the following key tech- niques were applied, i.e. the cofferdam for the Pier No. 3 was launched to the river by the air bag method and the cofferdam for the Pier No. 4 was integrally lifted down to the river. Both the cof- ferdams were positioned at the pier sites by the heavy anchor anchorage systems without utilizing the guiding barges. The opening at the bottom of the cofferdam on the inclined rock surface was fast blockaded by the movable inserted steel plate method and the bases of the two cofferdams were sealed by tremie concrete in areas.

关 键 词：斜拉桥 基础 方案比选 钢围堰 桥梁施工 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.55[交通运输工程—道路与铁道工程]