白沙洲长江大桥桥塔墩防撞关键技术  

Key Collision Protection Techniques for Pylon Piers of Baishazhou Changjiang River Bridge

作　　者：都恩伯 DU Enbo(Wuhan Bridge Special Technology Co.,Ltd.,China Railway Bridge Engineering Group,Wuhan 430205,China;State Key Laboratory of Bridge Intelligent and Green Construction,Wuhan 430034,China)

机构地区：[1]中铁大桥局武汉桥梁特种技术有限公司,湖北武汉430205 [2]桥梁智能与绿色建造全国重点实验室,湖北武汉430034

出　　处：《世界桥梁》2024年第6期114-120,共7页World Bridges

摘　　要：白沙洲长江大桥主桥为双塔双索面斜拉桥,桥塔均采用顺桥向单柱式、横桥向钻石形结构,基础为40根?1.55 m钻孔灌注桩,承台尺寸为32.4 m(横桥向)×20.4 m(顺桥向)×5 m(高),美国AASHTO规范模型计算显示桥塔墩年撞损频率较高,且原设计船舶撞击标准已无法满足当前通航标准及长江航运发展需求。为提升该桥桥塔墩的防撞能力,设计了组合型浮动式钢+复合材料防撞设施。该设施采用多级耗能体系及柔性防船撞结构,增强了大桥桥塔墩的防撞性能,并通过下塔柱增大截面补强使防撞设施在下塔柱范围内可随着水位自由升降,进一步增强了桥塔墩自身的防撞性能。下塔柱增大截面补强采用开口式单双壁组合型围堰,实现了补强的无水施工;组合型浮动式钢+复合材料防撞设施在工厂内分节段制造,并采用长效防腐技术延长了使用寿命。实施该防撞方案后,该桥桥塔墩能抵御3 000吨级满载船舶的水平撞击力,所受船舶撞击力明显低于桥塔墩自身的允许抗撞力,满足设防要求。The main bridge of Baishazhou Changjiang River Bridge is a cable-stayed bridge featuring the two diamond-shaped pylons from which two planes of stay cables are tensioned.Each pylon is mounted on a pile cap measuring 32.4 m(along bridge width)by 20.4 m(along bridge length)by 5 m(depth),which is in turn supported by 40 bored piles of 1.55 m diameter.In accordance with the theoretical-model calculations conducted referencing AASHTO,the annual collision frequency of the pylons is high,and the vessel collision standards at the design of the bridge could not suit the current navigation requirements and transportation needs of the Changjiang River.As a result,the pylon piers should be protected for vessel collision.A buoyant vessel collision resistant structure that consists of a steel box that is encased with fiber-reinforced polymer shell is developed for the bridge,with the former as the main collision resistant component due to its stiffness and the latter providing corrosion protection.The collision-facing sides are equipped with FRP fence,and the inner side contacting the pylon pier is equipped with flexible damping devices,creating a multi-stage energy dissipation system and a flexible collision protection structure.The composite collision protection structure was manufactured in the factory in segments,with a long term anti-corrosion coating to expand the service life.The cross-sections of lower pylon columns were enlarged to make sure that the vessel collision protection structure can rise and fall along the pylon body to provide better collision protection,during the cross-section enlarging construction,a single-wall and double-wall combined cofferdam was employed to allow the work carried out in a dry environment.After equipped with the collision protection structure,the pylon piers can resist the horizontal impact force of the fully-loaded 3000-t vessels,still with a safety margin,indicating the collision protection meets the requirements.

关 键 词：斜拉桥 桥墩防撞 浮动式柔性防船撞结构 塔柱补强 组合型围堰 多级耗能体系 长效防腐技术 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.26[交通运输工程—道路与铁道工程]