武汉杨泗港长江大桥2号墩钢沉井施工关键技术.pdf

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1、桥梁建设２０１７年第４７卷第６期（总第２４７期）１０６BridgeConstruction，Vol．４７，No．６，２０１７（TotallyNo．２４７）文章编号：１００３－４７２２（２０１７）０６－０１０６－０５武汉杨泗港长江大桥2号墩钢沉井施工关键技术１２郑大超，朱斌（１．中铁大桥局武汉杨泗港长江大桥总承包项目经理部，湖北武汉４３００５０；２．武汉市城市建设投资开发集团有限公司，湖北武汉４３００５０）摘要：武汉杨泗港长江大桥主桥为主跨１７００m的双层钢桁梁悬索桥，该桥２号墩采用沉井基础，沉井高５０m，其中上部２２m为钢筋混凝土结构，下部２８m为钢壳混凝土结构（分为２节

2、，高度分别为２３m和５m，总重约４８５０t）。２３m高的底节钢沉井在工厂加工后，采用气囊法下水，下水时将下河托架和助浮结构进行一体化设计，利用气囊调整钢沉井角度，以实现钢沉井主动转向；采取在钢沉井底部设置纵、横梁及底托板，封闭１２个井孔的助浮措施，以减小沉井浮运吃水深度。底节钢沉井采用以顶推为主、帮拖为辅的方式浮运至墩位处抛锚，采用无导向船重锚定位系统定位；定位后接高余下５m高的钢沉井，接高后注水下沉钢沉井，并浇筑钢壳混凝土，将钢沉井下沉至设计高程，完成钢沉井施工。关键词：悬索桥；沉井基础；气囊法下水；助浮措施；定位；接高；施工技术；桥梁施工中图分类号：U４４８．２５；U

3、４４５．５５７文献标志码：AKeyTechniquesforConstructionofSteelOpenCaissonofPierNo．2ofYangsigangChangjiangRiverBridgeinWuhan１２ZHENGDachao，ZHUBin-（１．DivisionofGeneralContractProjectofYangsigangChangjiangRiverBridgeinWuhan，ChinaRailwayMajorBridgeEngineeringGroupCo．，Ltd．，Wuhan４３００５０，China；２．WuhanUrbanCons

4、tructionInvestmentandDevelopmentGroupCo．，Ltd．，Wuhan４３００５０，China）Abstract：ThemainbridgeoftheYangsigangChangjiangRiverBridgeinWuhanisadouble-decksteeltrussgirdersuspensionbridgewiththemainspanof１７００m．ThefoundationforthePierNo．２ofthebridgeistheopencaissonfoundation．Theheightofthecaissonis５０m

5、，ofwhichthe２２moftheupperpartofthecaissonisthereinforcedconcretestructurewhilethe２８mofthelowerpartisthesteelshellconcretestructure（dividedintothe２tierswiththeirheightrespective-lybeing２３m，５mandtotalweightbeingabout４８５０t）．Afterthefirsttiersteelopencaissonofthe２３mwaswellmanufacturedinthework

6、shop，itwaslaunchedtotheriver，usingtheairbagmethod．Forthelaunchingofthecaisson，thesupportbracketsandfloating-aidstructurewerede-signedintegrally．Theanglesofthecaissonwereadjusted，usingtheairbags，sothatthecaissoncouldsteeractively．Thefloating-aidmeasures，suchasthesettingofthelongitudinaland

7、trans-versebeamsandthesupportboardsatthebottomofthecaissonandtheclosingofthe１２wellholesinthecaisson，weretakensothatthedraughtofthecaissoncouldbereducedduringthefloating．Thecaissonwasfloatedtothepiersiteandwasanchoredtherebywayofpushingmainlyandtuggingasanaid．Thecais