深中大桥东锚碇筑岛围堰基于淤泥强度动态增长的设计方法  

Design of Artificial Island Cofferdam for East Anchorage of Shenzhong Bridge Based on Dynamic Increase of Silt Strength

作　　者：张鸿[1,2,3] 李冕 刘建波 ZHANG Hong;LI Mian;LIU Jianbo(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan 430014,China;Key Laboratory of Large-Span Bridge Construction Technology,Wuhan 430014,China;CCCC Highway Bridge National Engineering Research Centre Co.,Ltd.,Beijing 100011,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430014 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430014 [3]中交公路长大桥建设国家工程研究中心有限公司,北京100011

出　　处：《桥梁建设》2024年第6期1-8,共8页Bridge Construction

基　　金：中交集团科技研发项目(2018-ZJKJ-03)。

摘　　要：深中通道深中大桥为主跨1 666 m的三跨钢箱梁悬索桥,其东锚碇为海中重力式锚碇,采用筑岛围堰方案施工。原筑岛围堰方案采用静态设计方法设计,采用“锁口钢管桩+工字型板桩+钢箱围箍”的组合式筑岛围堰方案。针对原方案存在的材料利用率低、结构设计尺寸偏大、结构之间受力不协调等缺点,在分析淤泥强度增长规律的基础上,提出基于淤泥强度动态增长的筑岛围堰设计方法(动态设计方法)。该方法首先确定不同施工阶段围堰支撑处土体弹簧刚度和平行钢丝索围箍等效弹性支撑刚度,然后利用响应面法建立各施工阶段自变量参数(钢管桩壁厚、钢管桩直径、围箍数量)与控制指标(钢管桩最大应力、桩顶最大位移、围箍最大应力)之间的映射关系;最后利用改进粒子群算法进行围堰结构设计参数优化。采用该动态设计方法进行设计,确定采用锁口钢管桩(直径2 000 mm、壁厚18 mm)+工字型板桩+平行钢丝索(7根,单根为184股?5 mm钢丝)柔性组合式筑岛围堰方案。采用有限元法计算静、动态设计方法下钢管桩最大应力,并与现场实测值比较。结果表明:动态设计方法下,围堰结构受力更合理,各构件应力水平更协调。The Shenzhong Bridge of Shenzhen-Zhongshan Link is a three-span steel box girder suspension bridge with a main span of 1666 m.The east offshore gravity anchorage of the bridge is constructed by an artificial island cofferdam method.The cofferdam was preliminarily designed by a static method,to be a composite structure formed of interlocking steel pipe piles,I-type steel sheet piles and steel box hoops.To improve the material utilization rate,reduce the size of the cofferdam,and address the inconsistent stress among different constituents,the silt strength growth process was analyzed,and an artificial island cofferdam design based on dynamic growth of silt strength was proposed.The first parameters determined include the soil spring stiffness at the supports of the cofferdam as well as the equivalent elastic supporting stiffness of the parallel-steel-wire cable hoops at different construction stages.Subsequently,the response surface method is applied to establish the mapping relationship between different variables at different construction stages(including wall thickness and diameter of steel pipe piles and number of hoops)and control indicators(including maximum stress of steel pipe pile,maximum pile-top displacement and maximum stress of hoops).At last,the design parameters of the cofferdam are modified by the improved particle swarm optimization algorithm.By using the proposed dynamic design,a flexible composite artificial island cofferdam is determined,which consists of interlocking steel pipe piles(with a diameter of 2000 mm and wall thickness of 18 mm)and I-type steel sheet piles and parallel-steel-wire cable hoops(seven cables,each consisting of 184,∅5 mm steel wires).The maximum stresses of the steel pipe piles in both the dynamic and static states were calculated by the finite element method and compared with the measured values.It is shown that the cofferdam designed by the dynamic method exhibits better load bearing capacity and more consistent stress among different constituents.

关 键 词：悬索桥 海中锚碇 筑岛围堰 淤泥强度动态增长 平行钢丝索 响应面法 改进粒子群算法 围堰设计 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.162[交通运输工程—道路与铁道工程]