宁波舟山港主通道北通航孔桥主墩承台封底关键技术  

Key Pile Cap Base Sealing Techniques for Main Piers of North Navigational Channel Bridge of Ningbo-Zhoushan Port Main Link

作　　者：潘立泉 陶盛强 PAN Li-quan;TAO Sheng-qiang(State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;Wuhan Bridge and Building Works Supervision Co.,Ltd.,Wuhan 430034,China;CCCC SHEC Fourth Engineering Co.,Ltd.,Wuhu 241000,China)

机构地区：[1]桥梁结构健康与安全国家重点实验室,湖北武汉430034 [2]武汉桥梁建筑工程监理有限公司,湖北武汉430034 [3]中交二航局第四工程有限公司,安徽芜湖241000

出　　处：《世界桥梁》2021年第1期14-19,共6页World Bridges

摘　　要：宁波舟山港主通道北通航孔桥为(125+260+125)m的钢-混凝土混合梁连续刚构桥。主墩承台下设13根∅3.5 m/3.0 m变径钻孔灌注桩,承台采用40 m×22.6 m×8 m的永久性防撞钢套箱施工,防撞钢套箱下放后进行封底混凝土施工。利用MIDAS Civil软件建立防撞钢套箱结构整体有限元模型,对承台施工阶段不同工况下封底混凝土受力进行计算分析,确定主墩承台封底采用厚度为2.21 m的C30混凝土。封底混凝土施工采用集料斗法,施工时,搭设封底浇筑平台、设置布料点,逐点首封,按照“由外向内、由中心向四周”的顺序灌注封底混凝土。在舟山外海恶劣施工条件下,承台施工期间封底结构安全且无渗水现象,取得了良好的施工效果。The north navigational channel bridge of Ningbo-Zhoushan Port Main Link is a steel-concrete hybrid girder continuous rigid-frame bridge with three spans of 125,260 and 125 m.The pile cap of the main pier is supported by 13 bored piles of 3.5 m diameter(varying 3.0 diameter locally).A permanent anti-collision steel box cofferdam with dimension of 40 m×22.6 m×8 m was utilized for the pile cap construction.When the anti-collision steel box cofferdam was lowere d into position,the base-sealing concreting work began.The global model of the anti collision steel box cofferdam was established by MIDAS Civil,to predict the loading condition of base sealing concrete under different forces in different construction stages of the pile cap.According to the calculation,the thickness of the C30 concrete base was determined at 2.21 m.The concrete was fed by hoppers.During the base-sealing concreting,a working platform was built,feeding points were arranged,and the concreting was carried out and moved from one feeding point to another,inwardly circling and extending from center towards edges.Though challenged by the harsh marine environment,the base-sealing concreting work was a success,with no water permeating and leaking phenomenon observed.

关 键 词：连续刚构桥 承台 防撞钢套箱 封底混凝土 施工技术 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]