混凝土斜拉桥箱梁强受扭损伤试验研究.pdf

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1、桥梁建设２０１７年第４７卷第６期（总第２４７期）７８BridgeConstruction，Vol．４７，No．６，２０１７（TotallyNo．２４７）文章编号：１００３－４７２２（２０１７）０６－００７８－０６混凝土斜拉桥箱梁强受扭损伤试验研究刘国坤，颜东煌，陈常松，涂光亚（长沙理工大学土木与建筑学院，湖南长沙４１０１１４）摘要：某大跨斜拉桥主梁采用预应力混凝土箱梁，在施工过程中因火灾烧断主梁一侧９根斜拉索导致主梁强受扭损伤。为研究主梁强受扭损伤后的受力性能，设计制作相似比为１∶４的节段模型进行强受扭损伤模拟试验，并

2、采用有限元程序Abaqus对模型梁的受扭损伤过程进行模拟分析，研究断索后主梁的强受扭损伤状态，评估主梁损伤后的抗扭承载力及索力恢复后的弯曲性能。结果表明：模型梁强受扭损伤后的裂缝宽度、间距和角度与实桥高度相似，与有限元计算的损伤状态也一致；模型梁实测扭转变形与计算扭转变形及实桥控制截面扭转变形吻合较好；实桥断索时主梁所受最大扭矩荷载约为其抗扭承载力的７５％；索力恢复后，主梁的抗弯刚度有所下降，但对体系刚度影响有限，可加固修复。关键词：斜拉桥；预应力混凝土；箱形梁；强受扭损伤；抗扭承载力；弯曲性能；模型试验；有限元法中图

3、分类号：U４４８．２７；U４４１．４文献标志码：AExperimentalInvestigationofStrongTorsionDamagetoBoxGirderofaConcreteCable-StayedBridgeLIUGuokun，YANDonghuang，CHEN-Changsong，TU-Guangya-（SchoolofCivilEngineeringandArchitecture，ChangshaUniversityofScience&Technology，Changsha４１０１１４，China）A

4、bstract：Themaingirderofalongspancable-stayedbridgeistheprestressedconcreteboxgirder．Intheconstructionofthebridge，９staycablesontheonesideofthegirderwereburntandbrokeninafireandthebreakingofthecablescausedthegirdertosufferthestrongtorsiondam-age．Toinvestigatetheme

5、chanicalbehaviorofthegirderafterthetorsiondamage，thesectionalmodelbeamofasimilarityratioof１∶４wasdesignedandfabricatedandthesimulationtestsofthedamagewerecarriedout．Thetorsiondamageprocessofthebeamwasalsosimulatedandana-lyzed，usingthefiniteelementprogramABAQUS．Th

6、etorsiondamagestateofthegirderafterthebreakingofthecableswasstudiedandthetorsionbearingcapacityofthegirderafterthedamageandtheflexuralbehaviorofthestructureaftertherecoveryofthestaycableforceswasevaluated．Theresultsyieldthatthewidth，spacingandanglesofthecracksin

7、themodelbeamafterthestrongtorsiondamagearehighlysimilartothoseoftheactualbridgeandareingoodagreementwiththetorsiondamagestateofthefiniteelementcalculation．Themeasuredtorsiondeformationofthebeamisinagreementwiththecalculatedtorsiondeformationandwiththetorsiondefo

8、rma-tioninthecontrolsectionoftheactualbridge．Themaximumtorqueloadsubjectedbythemaingirderofthebridgeatthebreakingofthecablesaccountsforabout７５％ofthetorsionbearingca-收