安庆长江铁路大桥3号桥塔墩钢护筒群施工技术  

Construction Techniques for Steel Casing Groups of Pylon Pier No.3 of Anqing Changjiang River Railway Bridge

作　　者：黄旺明[1] 皮军云[1] 

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2011年第5期6-10,共5页Bridge Construction

摘　　要：安庆长江铁路大桥为双塔钢桁梁斜拉桥,其3号桥塔墩为大直径深水钻孔桩基础,采用钢围堰法施工。由于墩位处河床覆盖层厚不足1m,钢套箱围堰下沉着床后,河床基本冲刷为光板岩,为解决钻孔桩钢护筒的安装及定位问题,除中心钢护筒直接下沉安装外,其余36根钢护筒按区域分为A、B、C三类5组分批整体制造安装。护筒群A、B在码头上整体制造组拼后船运至墩位,利用浮吊整体下放后悬挂在围堰上,利用悬挂系统及导向槽结构调整并精确定位;护筒群C随围堰底节一同下沉着床。全部护筒安装定位后,在护筒内填砂堵漏、分层浇注水下封底混凝土以预埋固定钢护筒,最后进行钻孔桩施工。Anqing Changjiang River Railway Bridge is a steel truss girder cable-stayed bridge having double pylons.The Pylon Pier No.3 of the bridge rests on the deepwater large diameter bored pile foundation that was constructed by the steel boxed cofferdam method.Since the riverbed overburden at the location of the pier is not deeper than 1 m,the riverbed was scoured almost into bare slate shortly after the steel boxed cofferdam was sunk down and landed there.To resolve the problem of installing and positioning the steel casings for construction of the bored piles,with the exception that central steel casing was directly sunk down and installed,the rest of the 36 steel casings were classified into 3 kinds of A,B,C and 5 groups in accordance with the different areas of the foundation and were to be integrally fabricated and installed in batches.The steel casing groups A and B were firstly fabricated and assembled nearby the wharf,shipped to the pier site,integrally lowered down and suspended onto the cofferdam by floating crane and adjusted and precisely positioned,using the suspension system and guiding groove structure.The steel casing group C was then sunk down to the riverbed together with the bottom lift of the cofferdam.After all the steel casings were well installed and positioned in place,the casings were filled with sand to stop water from coming in,the base sealing tremie concrete was deposited in layers to fix the casings and finally the construction of the bored piles was to proceed.

关 键 词：安庆长江铁路大桥 斜拉桥 钻孔桩 摩擦桩 钢护筒群 桥梁施工 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.551[交通运输工程—道路与铁道工程]