三塔斜拉桥主梁节段施工非线性稳定性分析

《三塔斜拉桥主梁节段施工非线性稳定性分析》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、桥梁建设2015年第45卷第2期(总第231期)BridgeConstruction，Vo1．45，No．2，2015(TotallyNo．231)文章编号：1003—4722(2015)02—0116—06三塔斜拉桥主梁节段施工非线性稳定性分析邓晓光，卢志芳，李倩(武汉理工大学道路桥梁与结构工程湖北省重点实验室，湖北武汉430070)摘要：针对传统的稳定性分析方法不能反映斜拉桥施工阶段各主梁节段的稳定性的问题，基于欧拉屈曲公式和斜拉桥几何非线性稳定分析理论，提出了一种考虑几何非线性的斜拉桥主粱节段稳定性分析方法，以武汉二七长江大桥为依托，对该三塔双

2、索面半飘浮结合梁斜拉桥施工阶段各主梁节段的稳定性进行研究。采用MIDAS软件建立了该桥施工阶段全桥有限元模型，通过给单元施加轴力增量，反复迭代计算出主梁节段的有效长度和长细比，代入主梁节段的稳定性控制方程。结果表明：在最大双悬臂阶段时，中塔处主梁节段稳定性控制方程值为0．05～0．55，均满足规范要求，中塔支座处主梁节段是悬臂施工稳定性的关键控制部位。关键词：斜拉桥；结合梁；几何非线性；有限元法；稳定性分析中图分类号：U441；U448．27文献标志码：ANonlinearityStabilityAnalysisofMainGirderSegment

3、sofThree--PylonCable--StayedBridgeatConstructionStageDENGXiao—guang，LUZhi-fang，LIQian(KeyLaboratoryofRoadwayBridge＆StructuralEngineeringofHubeiProvince，WuhanUniversityofTechnology，Wuhan430070，China)Abstract：InviewoftheproblemthattheconventionaIstabilityanalysismethodscannotre—f

4、lectthestabilityofthemaingirdersegmentsofcable-stayedbridgeatconstructionstageandbasedontheEulerSbucklingformulaandthegeometricnonlinearitystabilityanalysistheoryofthebridge，akindofthestabilityanalysismethodconsideringthegeometricnonlinearityforthemaingirdersegmentsofthebridgew

5、asproposed．TheWuhanErqiChangjiangRiverBridge，asemi—floatingsystemcompositegirdercable—stayedbridgewiththreepylonsanddoublecableplanes，wascitedasanexampleandthestabilityofthemaingirdersegmentsofthebridgeattheconstrue—tionstagewasstudied．ThesoftwareMIDASCivi1wasusedtocreatethefin

6、iteelementmodelforthewholebridgeofthebridge．Byapplyingtheaxialforceincrementtotheelementsanditerative—lycalculating，theeffectivelengthandslenderratiosofthemaingirdersegmentswereobtainedandweresubstitutedinthestabilitycontrolequationforthesegments．Theresultsofthestudyshowthatatt

7、hestageofthelongesttwo—sidecantileverofthebridge，thevaluesofthestabilitycontrolequationforthemaingirdersegmentsnearbytheintermediatepylonare0．O5～O．55andcansatisfytherelevantrequirementsinthecodes．Themaingirdersegmentsnearbythebearingoftheinter—mediatepylonarethecritica1partstha

8、tshouldbecontrolledinthestabilityatthecantilevercon—st