摘要
十淅高速丹江口水库特大桥为主跨760 m的双塔双索面部分地锚式混合梁斜拉桥。主墩采用群桩基础、八边形承台;桥塔采用H形混凝土结构;地锚式桥台采用箱形预应力混凝土结构;主梁采用混合梁,边跨为双边主肋预应力混凝土梁,主跨为钢-UHPC组合梁,主跨跨中设置中央无轴力连接装置+伸缩缝构造。针对该桥结构特点及水文条件,主墩桩基础和承台采用衡重式挡墙+单壁钢围堰方案,变水中施工为陆地施工,节约了工期和投资;塔柱采用液压爬模分节施工,中塔柱内倾塔肢间设2道水平横撑,保证了施工期塔柱受力和线形;地锚式桥台采用分块、分层并设后浇带的方案,有效改善了大体积混凝土的抗裂性能;边跨混凝土梁采用搭设钢管支架分段现浇施工;主跨钢主梁采取工厂化块件制造,库区陆地总拼并浇筑UHPC形成组合梁,再水运至桥位,采用桥面吊机悬臂吊装,现场施工湿接缝,解决了汉江上游航运能力不足的问题,同时创新提出并应用了钢-UHPC组合梁安装五步施工法,提高了主梁安装质量;中央无轴力连接装置采用逐缝合龙法高精度合龙方案,有效保证了结构功能的发挥。
The Danjiangkou Reservoir Bridge is a hybrid girder cable-stayed bridge with a main span of 760 m,The stay cables are arranged in double cable planes,with pairs of back stays anchored to the ground to form a partially earth-anchored cable-stayed system.The two pylons are H-shaped concrete structures supported by octagonal pile caps and bored piles.The anchorage-type abutments are prestressed concrete box structures.The superstructure in the main span consists of steel box girders that act compositely with the UHPC panels,featuring the axial-force-free connectors and expansion joints at the midspan,while the superstructures in the side spans are composed of double edge PCπ-girders,diaphragm beams and concrete panels.During the construction of pile foundations and pile caps of main piers,gravity retaining walls and single-wall steel cofferdams were employed in accordance with the structural characteristics of the bridge and the hydrological condition at the bridge site,to create a dry construction environment,and in turn to cut down the construction schedule and costs.The tower columns were cast in segments using climbing formwork,two horizontal bracings were installed between the inwardly-inclined central pylon columns to ensure the load bearing performance and geometrical shape of the pylon columns during construction.The anchorage-type abutment was cast in situ zone by zone and layer by layer,and stitched to be an integral whole,to improve the cracking resistance of the mass concrete structure.The concrete girders in the side spans were cast in situ on steel tubular scaffolds.The steel girders in the main span were prefabricated to be individual components in the factory,and assembled to take shape in the storage area,and subsequently overlaid with UHPC course to be composite girders.The composite girder segments were then shipped to the bridge site for cantilever installation with deck cranes,and finally stitched together.This prefabrication process did not challenge the transportation capacity of the upper re
作者
唐守峰
吴学伟
阳晏
沈峰
胡龙泳
TANG Shoufeng;WU Xuewei;YANG Yan;SHEN Feng;HU Longyong(Hubei Communications Investment Group Co.,Ltd.,Wuhan 430050,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2024年第2期8-15,共8页
Bridge Construction
基金
湖北省交通运输厅科技项目(2020-2-2-1)。
关键词
部分地锚式斜拉桥
钢-UHPC组合梁
衡重式挡墙+单壁钢围堰
地锚式桥台
中央无轴力连接装置
施工技术
partially-earth-anchored cable-stayed bridge
steel-UHPC composite girder
combined utilization of gravity retaining wall and single-wall steel cofferdam
axial-force-free connector at midspan
construction technique
