跨海大桥5万吨级防撞钢套箱兼作围堰的永临结合设计  

Permanent and Temporary Combined Design of 50,000⁃ton Anti⁃Collision Steel Caissons as Cofferdam for Sea⁃Crossing Bridge

作　　者：朵君泰 DUO Juntai(China Railway Fifth Survey and Design Institute Group Co.Ltd.,BeiJing 102600,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600

出　　处：《铁道建筑技术》2024年第9期50-54,共5页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2022-B05)。

摘　　要：为节省跨海大桥建造成本,节省工期,结合青龙门通航孔桥工程,针对其为目前世界最大跨度三塔钢箱梁斜拉桥,其主墩设置永久性大型防撞套箱,防撞标准为5万吨级海轮,主墩承台施工时的围堰,采取“永临结合”设计原则,即利用防撞套箱(永久结构)作为围堰侧壁结构,增加底部系统、吊挂系统、内支撑、导向、抗沉装置等临时结构,组成总重量2400 t的双壁钢吊箱围堰;并阐述了该围堰的设计条件、结构设计、结构计算,结果表明,整个施工过程中,围堰的结构受力、抗浮和抗沉均满足规范要求,设计方案可行。围堰现在已完成下放,正在进行承台浇筑施工,创下了目前世界最大宽度、最大壁厚、最大拼装尺寸、最大海上运输尺寸、最大海上整体吊装重量五项世界之最。本工程的成功应用,可为今后同类型基础施工提供借鉴。In order to save the construction cost and time of the sea⁃crossing bridge,combined with the Qinglongmen Navigation Hole Bridge Project,the main pier of the world′s largest span three tower steel box girder cable⁃stayed bridge is equipped with a permanent large anti⁃collision sleeve box,with a collision prevention standard of 50,000⁃ton of sea vessels.The cofferdam during the construction of the main pier cap adopts the′permanent and temporary combination′design principle,which uses the anti⁃collision sleeve box(permanent structure)as the side wall structure of the cofferdam,and adds temporary structures such as the bottom system,suspension system,internal support,guidance,and anti sinking device,to form a double wall steel suspension box cofferdam with a total weight of 2,400⁃ton.And the design conditions,structural design,and structural calculation of the cofferdam are elaborated.The results show that throughout the construction process,the structural stress,anti floating,and anti sinking of the cofferdam meet the requirements of the specifications,and the design scheme is feasible.The cofferdam has now been lowered and the construction of the pier cap is underway,setting five world records for the largest width,maximum wall thickness,maximum assembly size,maximum sea transportation size,and maximum overall lifting weight at sea.The successful application of this project can provide reference for future construction of similar foundations.

关 键 词：跨海大桥 承台 永临结合 防撞套箱 围堰 

分 类 号：U443.162[建筑科学—桥梁与隧道工程]