多跨连续梁拱组合体系桥梁施工关键问题研究.pdf

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1、桥梁建设２０１７年第４７卷第４期（总第２４５期）４８BridgeConstruction，Vol．４７，No．４，２０１７（TotallyNo．２４５）文章编号：１００３－４７２２（２０１７）０４－００４８－０６多跨连续梁拱组合体系桥梁施工关键问题研究梅葵花，王贤良，赵育（长安大学公路学院，陕西西安７１００６４）摘要：安康市城东汉江大桥主桥为（７５＋２×１２５＋１６０＋２×１２５＋７５）m多跨连续梁拱组合体系桥梁，全桥采用先梁后拱法施工，系梁采用平衡悬臂浇筑法施工，中跨跨中３３m梁段采用支架现浇法施工。为选择合理的现浇

2、段支架拆除时机、边跨配重卸载时机、临时固结拆除顺序以及吊杆张拉顺序和次数等，采用MIDASCivil建立全桥有限元模型，针对各种方案下的结构进行模拟分析。结果表明：跨中现浇段的支架应在张拉完全部吊杆后再拆除；边跨配重应在中跨或次边跨合龙后再卸载；应待相邻孔合龙后再拆除前一合龙孔的临时固结；应对称交替地张拉吊杆，设计张拉力较小时可一次张拉到位，设计张拉力较大时应分批张拉到位。该桥采取以上方案施工后，结构受力状态良好。关键词：梁拱组合体系桥；悬臂浇筑法；有限元法；现浇支架；配重；临时固结；吊杆张拉顺序；桥梁施工中图分类号：

3、U４４８．２２；U４４５．４文献标志码：AStudyofCriticalIssuesonConstructionofaHybridSystemBridgeofMulti‐SpanContinuousGirderandArchesMEIKuihua，WANGXianliang，ZHAO‐Yu‐（SchoolofHighway，Chang′anUniversity，Xi′an７１００６４，China）Abstract：ThemainbridgeoftheChengdongHanjiangRiverBridgeinAnkan

4、gCityisahybridsystembridgeofmulti‐spancontinuousgirderandarcheswithspanarrangement（７５＋２×１２５＋１６０＋２×１２５＋７５）m．Thewholebridgeofthebridgeisconstructed，usingthemethodofcon‐structingthegirderbeforeconstructingthearches，ofwhichthetiegirderiscastinsitu，usingthefreecantil

5、evermethodandthe３３mlonggirdersegmentsatthemidspanofthecentralspanarecastinsitu，usingthescaffoldingmethod．Intheconstructionofthebridge，tochoosethereasona‐bletimeforremovalofthescaffoldingforthecast‐in‐situsegments，thetimeforunloadingofthecounterweightonthesidespa

6、ns，thesequencesforremovalofthetemporaryrigidfixityandthesequencesandtimesfortensioningofthehangers，theMIDASCivilwasusedtoestablishthefiniteelementmodelforthewholebridgeandthestructureunderthedifferentschemeswassimulatedandanalyzed．Theresultssuggestthatthescaffol

7、dingforthecast‐in‐situsegmentsatthemidspanofthecentralspanshouldberemovedafterthewholehangersarewelltensioned．Thecounter‐weightonthesidespansshouldbeunloadedafterthecentralspanorthesecondarysidespansareclosed．Thetemporaryrigidfixityforthepreviousclosedspanshould

8、beremovedaftertheadja‐centspansareclosed．Thehangersshouldbetensionedsymmetricallyandalternatively．Forthehangerswithlittledesignedtension，thehangersshouldbetensionedin