预应力混凝土连续梁桥外文文献

DeformationAnalysisofPrestressedContinuousSteel-ConcreteCompositeBeamsJianguoNie1;MuxuanTao2;C.S.Cai3;andShaojingLi4Abstract:Deformationcalculationofprestressedcontinuoussteel-concretecompositebeamsaccountingfortheslipeffectbetweenthesteelandconcreteinterfaceunderserviceloadsisanalyzed.Asimplifiedanalyticalmodelispresented.Basedonthismodel,formulasforpredictingthecrackingregionofconcreteslabneartheinteriorsupportsandtheincreaseoftheprestressingtendonforcearederived.Atableforcalculatingthemidspandeflectionoftwo-spanprestressedcontinuouscompositebeamsisalsoproposed.Itisfoundthattheinternalforceoftheprestressingtendonunderserviceloadscanbeaccuratelycalculatedusingtheproposedformulas.Byignoringtheincreaseofthetendonforce,thecalculateddeflectionareoverestimated,andconsideringtheincreaseofthetendonforcecansignificantlyimprovetheaccuracyofanalyticalpredictions.Asthecalculatedvaluesshowgoodagreementwiththetestresults,theproposedformulascanbereliablyappliedtothedeformationanalysisofprestressedcontinuouscompositebeams.Finally,basedontheformulasforcalculatingthedeformationoftwo-spanprestressedcontinuouscompositebeams,ageneralmethodfordeformationanalysisofpre-stressedcontinuouscompositebeamsisproposed.DOI:10.1061/
ASCEST.1943-541X.0000067CEDatabasesubjectheadings:Prestressedconcrete;Compositebeams;Deformation;Deflection;Cracking;Concreteslabs;Con-tinuousbeams.IntroductionContinuoussteel-concretecompositebeamsarewidelyusedinbuildingsandbridgesforhigherspan/depthratiosandlessdeflec-tionetc.,whichresultsinsuperioreconomicalperformancecom-paredwithsimplysupportedcompositebeams.Forcontinuouscompositebeams,negativebendingnearinteriorsupportswillresultinearlycrackingofconcreteslabandreductionofstiffness.Whenbeamsaredesignedforspanlengthsandloadsgreaterthanusual,therequirementofserviceabilitylimitstateduetounac-ceptabledeflectionandcrackwidthwouldrequireusingprestress-ingtechnique.Comparedwithconventionalsteel-concretecompositebeams,prestressedsteel-concretecompositebeamshaveafewmajorad-vantages:
1extendingtheelasticrangeofstructuralbehavior;
2increasingtheultimateloadingcapacity;
3decreasingthedeformationunderserviceloads;
4beingfavorableincrack-widthcontrol;
5fullyusingthematerialsandthusreducingthestructuralheightandoveralldeadload;and
6improvingthefatigueandfracturebehavior.SinceSzilard
1959suggestedamethodforthedesignandanalysisofprestressedsteel-concretecompositebeamsconsider-ingtheeffectsofconcreteshrinkageandcreep,manyresearchershavedevelopedmethodsforanalyzingthebehaviorofsimplysupportedprestressedcompositebeams
Hoadley1963;Klaiberetal.1982;Dunkeretal.1986;Saadatmanesh1986;Saadatmaneshetal.1989a,b,c;Albrechtetal.1995,Nieetal.2007.However,continuousprestressedcompositebeamshavenotbeenre-searcheduntilthelate1980s
TroitskyandRabbani1987;Troitsky1990;Dall’AstaandDezi1998,Ayyubetal.1990,1992a,b;Dall’AstaandZona2005.Asaresult,prestressedcon-tinuouscompositebeamshavenotwidelybeenusedpartlyduetothelackofdesigntheory.Infact,thebehaviorofprestressedcontinuouscompositebeamsdependsontheinteractionbetweenfourmaincomponents:thereinforcedconcreteslab,thesteelprofileofbeams,theshearconnections,andtheprestressingtendons,whichmakespre-stressedcontinuouscompositebeamsmorecomplexthanconven-tionalones.Dall’AstaandZona
2005proposedanonlinearfiniteelementmodelsimulatingthebehaviorofprestressedcon-tinuouscompositebeamsaccurately.Thisnumericalapproachisaverypowerfulresearchtoolforanalyzingtheexternallypre-stressedstructures,butitperhapsistoocomplicatedforaroutinedesignpractice.Asprestressingtechniqueisaneffectivewaytoreducedefor-mationandcrackwidthunderserviceloads,particularattentionhastobepaidtothedeformationcalculationofprestressingcon-tinuouscompositebeams.Themainobjectiveofthisresearchistodevelopcalculationmethodsforthedeformationofprestress-ingcontinuouscompositebeamsbasedonthereducedstiffness1Professor,Dept.ofCivilEngineering,KeyLaboratoryofStructuralEngineeringandVibrationofChinaEducationMinistry,TsinghuaUniv.,Beijing100084,China.2Ph.D.Candidate,Dept.ofCivilEngineering,KeyLaboratoryofStructuralEngineeringandVibrationofChinaEducationMinistry,TsinghuaUniv.,Beijing100084,China
correspondingauthor.E-mail:[e-mail]3AssociateProfessor,Dept.ofCivilandEnvironmentalEngineering,LouisianaStateUniv.,BatonRouge,LA,70803;presently,AdjunctPro-fessor,SchoolofCivilEngineeringandArchitecture,ChangshaUniv.ofScienceandTechnology,Changsha,China.4Formerly,GraduateStudent,Dept.ofCivilEngineering,KeyLabo-ratoryofStructuralEngineeringandVibrationofChinaEducationMin-istry,TsinghuaUniv.,Beijing100084,China.Note.ThismanuscriptwassubmittedonAugust10,2008;approvedonApril20,2009;publishedonlineonOctober15,2009.DiscussionperiodopenuntilApril1,2010;separatediscussionsmustbesubmittedforindividualpapers.ThispaperispartoftheJournalofStructuralEngineering,Vol.135,No.11,November1,2009.©ASCE,ISSN0733-9445/2009/11-1377–1389/$25.00.JOURNALOFSTRUCTURALENGINEERING©ASCE/NOVEMBER2009/1377Downloaded19Feb2012to218.197.119.130.RedistributionsubjecttoASCElicense