摘要
新建京港高铁安九段鳊鱼洲长江大桥南汊航道桥为主跨672 m双塔双索面钢-混混合梁交叉索斜拉桥,主墩采用整体式承台、群桩基础;桥塔采用H形混凝土结构;主跨及辅助跨主梁采用钢箱梁、锚跨主梁采用预应力混凝土箱梁;斜拉索采用平行钢丝斜拉索,主跨跨中72 m范围设置7对交叉索。根据该桥结构特点及水文、地质条件,1号及6~9号墩采用旋挖钻机成孔、钢板桩围堰方案施工;2~5号墩均采用栈桥配合、先平台后矩形双壁钢套箱围堰方案施工;4号主墩钻孔桩采用“旋挖钻+回转钻”接力成孔方案施工,5号主墩钻孔桩在进行大堤防护加固处理后采用大功率旋挖钻机成孔方案施工。上部结构采用塔梁同步、钢梁与桥面附属结构同步方案施工,桥塔塔柱采用液压爬模方案施工,内倾的中塔柱施工时设3道临时对撑。锚跨主梁采用高位支架现浇方案施工;5号到6号墩辅助跨钢箱梁采取多点同步顶推方案施工,5号主墩主跨侧钢箱梁采用单悬臂方案架设;4号主墩中跨和辅助跨钢箱梁采用对称双悬臂方案架设;主梁设3个合龙口,按先辅助跨后中跨顺序合龙,九江侧辅助跨采用浇筑钢-混结合段混凝土合龙;黄梅侧辅助跨和中跨以钢箱梁节段为合龙段,并采取主动合龙。
The south branch navigation channel bridge of Bianyuzhou Changjiang River Bridge that carries part of the Anqing-Jiujiang Section of the newly-built Beijing-Hong Kong High Speed Railway is a two-pylon hybrid girder cable-stayed bridge with a main span of 672 m.The stay cables are fanned out in double cable planes,with pairs of crossing stay cables.The main piers stand on integral pile caps that are supported by group pile foundations.The pylons are H-shaped concrete structures.The superstructure of the central and auxiliary spans consists of steel box girders,while the superstructure in anchor spans is composed of prestressed concrete box girders.The stay cables contain parallel steel wires,and 7 pairs of the stay cables cross over each other within the 72 m range at the midspan of main span.To accommodate the structural characteristics of the bridge as well as hydrological and geological conditions,the boreholes of pier 1 and piers 6-9 were made by rotary drilling rigs,and piles were constructed with the protection of sheet-piled cofferdam.The construction of piers 2-5 was assisted with trestles,at the beginning,the construction was carried out with the assistance of a platform,and then rectangular double-walled steel suspension box cofferdam.The boreholes of pier 4 were made in a relay race manner by using excavators and rotary drilling rigs.After strengthening the embankment,the boreholes of pier 5 were made by high-power rotary drilling rigs.The erection of the superstructure was carried out in parallel with the construction of the pylons,and the steel girders and the deck appurtenances were also installed in a synchronized manner.The pylon columns were cast using hydraulic climbing formwork.To facilitate the casting of the inwardly-inclined central columns,three temporary diagonals were added.The concrete box girders in the anchor spans were cast on scaffolds.The steel box girders in central span over pier 4 and auxiliary spans were erected by balanced cantilever assembly method.Of the three closure gaps,the one in each auxiliary gap was closed ahead of that in the central span.The Jiujiang-side auxiliary span was closed by concreting the steel-concrete joint section,while the Huangmei-side auxiliary span and the central span were closed by installing the key steel box girder segments,being an active closure.
作者
朱秀涛
ZHU Xiu-tao(State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;Wuhan Bridge and Building Works Supervision Co.,Ltd.,Wuhan 430034,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2022年第2期1-10,共10页
Bridge Construction
基金
中国中铁股份有限公司科技研发计划项目(2018-重点-08)。
关键词
斜拉桥
高速铁路桥
钢-混混合梁
桩基础
基础施工
上部结构施工
合龙
施工方案
cable-stayed bridge
high-speed railway bridge
steel-concrete hybrid girder
pile foundation
foundation construction
superstructure construction
closure
construction scheme
