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1、第29卷第3期2012年3月公路交通科技JournalofHighwayandTransportationResearchandDevelopmentV01.29No.3Mar.2012doi:10.3969/j.issn.1002—0268.2012.03.012大型混凝土箱梁水化熱溫度場(chǎng)的數(shù)值模擬陳志堅(jiān)1,(1.河海大學(xué)地球科學(xué)與工程學(xué)院,江蘇南京210098顧斌2;2.河海大學(xué)土木與交通學(xué)院,江蘇南京210098)摘要:針對(duì)大跨徑混凝土箱梁橋O號(hào)箱梁的特點(diǎn),詳細(xì)介紹分析了水化熱溫度場(chǎng)數(shù)值模
2、擬過程中混凝土參數(shù)的取值以及邊界條件的確定方法,以蘇通大橋輔助航道橋的O號(hào)箱梁為例,利用ANSYS對(duì)其混凝土澆注后的溫度場(chǎng)進(jìn)行了數(shù)值模擬,并與實(shí)測(cè)值進(jìn)行了對(duì)比。研究結(jié)果表明:混凝土硬化早期,溫度隨水泥水化的發(fā)展,經(jīng)歷了較快的溫升階段,到達(dá)最值后,進(jìn)入緩慢的溫降階段,最值出現(xiàn)的越早,溫降的速率越大;混凝土澆注后的最大內(nèi)外溫差與構(gòu)件厚度和表面邊界情況有關(guān),構(gòu)件厚度越大,表面散熱條件越好,可達(dá)到的最大內(nèi)外溫差也就越大;新舊混凝土結(jié)合面處存在溫度倒灌現(xiàn)象.混凝土養(yǎng)護(hù)期間,應(yīng)根據(jù)箱梁混凝土水化熱溫度場(chǎng)的特
3、點(diǎn),對(duì)重要部位進(jìn)行有針對(duì)性的養(yǎng)護(hù)。關(guān)鍵詞:橋梁工程;混凝土箱梁;水化熱;溫度場(chǎng);數(shù)值模擬中圖分類號(hào):U448.35文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1002—0268(2012)03—0064—06NumericalSimulationonHydrationHeatTemperatureFieldofLarge—sizeConcreteBoxGirderCHENZhijianl,GUBin2(1.SchoolofEarthSciencesandEngineering,HohaiUniversity,N,m
4、jingJinangsu210098,China;2.SchoolofCivilandTransportationEngineering,HohaiUniversity,NanjingJinangsu210098,China)Abstract:Accordingtothestartelementcharacteristicsoflong—spanconcreteboxgirderbridge,thedeterminationofconcreteparametersandboundarycondi
5、tionsinthenumericalsimulationprocessofthehydratedheattemperaturefieldwereintroducedandanalyzedindetail.TakenthestartelementofauxiliarychannelbridgeofSutongBridgeforexample,thesimulationanalysisofhydratedheattemperaturefieldofthedepositingperiodofstar
6、telementwasmadebyusingANSYS,andthecomparisonoftheresultsofFEAwiththemeasuredvalues.Theresultsindicatethat(1)duringtheearlyhardeningofconcrete,withthedevelopmentofcementhydration,itstemperatureexperiencedaphaseofrapidrise,andthenitdroppedslowlywhenitr
7、eachedtheextremevalue,thesoonertheextremevaluereached,thegreatertherateoftemperaturedroppingwas;(2)themaximumtemperaturedifferencebetweeninteriorandexteriorafterpouringwasconcernedwithcomponentthicknessandboundaryconditionofsurface,thethickerthecompo
8、nentwas,thegreatertheconditionoftheheatdissipationofsurfacewas,andthebiggerthetemperaturedifferencebetweeninsideandoutsidewas;(3)thephenomenonoftemperatureintrusioninthecombinedsurfaceofoldandnewconcreteexisted.Thus,duringthecuringconcrete,themainten