援马尔代夫中马友谊大桥主桥V形墩施工关键技术  

Key Construction Techniques for V-Shaped Piers of Main Bridge of China-Maldives Friendship Bridge

作　　者：郑和晖[1,2,3] 李宁 陈少林[1] ZHENG He-hui;LI Ning;CHEN Shao-lin(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan 430040,China;Key Laboratory of Large-Span Bridge Construction Technology,Ministry of Transport,Wuhan 430040,China;R&D Center for Intelligent Infrastructure Manufacturing Technology,Ministry of Transport,Wuhan 430040,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430040 [3]交通运输行业交通基础设施智能制造技术研发中心,湖北武汉430040

出　　处：《世界桥梁》2020年第6期27-32,共6页World Bridges

基　　金：国家重点研发计划资助项目(2017YFC0703408)。

摘　　要：援马尔代夫中马友谊大桥主桥为(100+2×180+140+100+60)m混合梁连续刚构桥,其中19~21号墩为V形墩,最大倾角达70°。V形墩采用“斜拉扣挂现浇斜腿+内支架现浇0号块”的方案施工。斜拉扣挂支架系统由钢管支架、大刚度扣挂平台及长短扣索组成。为保证V形墩施工质量,采用有限元法进行施工过程精细化模拟,对施工控制技术进行研究。结果表明:在斜腿内布置预应力钢束以及在主梁悬浇过程中精确控制斜拉扣挂支架拆除时机,可有效化解斜腿根部以及三角区腋部开裂风险;在掌握扣索张拉变形规律基础上,基于扣索索力调整的V形墩斜腿线形控制方法能保证其毫米级精度。The main bridge of China-Maldives Friendship Bridge is a hybrid girder continuous rigid-frame bridge with span arrangement of 100,2×180,140,100 and 60 m.The piers 19-21 are V-shaped piers,with the maximum inclination angle reaching up to 70°.The inclined legs of the V-shaped piers were cast in-situ by the cable-stayed cantilever casting method,and the pier-top girder segment was cast on inner scaffoldings.The cable-stayed cantilever casting system comprises the steel tubular scaffoldings,fastening platform with great rigidity as well as long and short fastening stays.To ensure the construction quality of the V-shaped piers,the construction process was numerically simulated in a refined manner,and the construction techniques were studied.The results show that the potential risk of cracking in the roots of the inclined legs and the triangular regions were effectively avoided by installing prestr essing tendons in the inclined legs and accurately control the demolition timing of the cable-stayed casting system during the cantilever casting of the main girder.With the command of the law of deformation induced by fastening stays tensioning,the geometry control method for the V-shaped piers based on the force adjustment of fastening stays can achieve the millimeter-level accuracy.

关 键 词：跨海大桥 连续刚构桥 大倾角V形墩 斜拉扣挂 支架 裂缝控制 线形控制 施工技术 

分 类 号：U443.22[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]