约束钢管混凝土柱的开发研究

第25卷第6期 2004年12月 建筑结构学报 JournalofBuildingStructures V01．25，No．6 Dec．，2004 文章编号：1000—6869(2004)06—0059一08 Developmentofconfinedconcretemledtubular(CCFT)columns XIA0Yanl·2HEWenhui2．MAOXiaoyon92·3 (1．UniversityofSouthCrnCalifornia，LosAngeles，CA90089—2531，USA； 2．CollegeofCivilEngineering，HunanUniversity，Changsha410082，China； 3．SuzhouTechnologyInstitute，Suzhou215000，China) Abstract：Thispaperintroducesaninnovativeconcretefilledsteeltubular(Cn’)colulnnsystem，namedasconfined CFTorCCFT．forimprovedseismicdesignofsteelandconcretecompositestructures．TheCCFrcolumnsystem combinestheadvantagesofconventionalCFYcolumnandtubedcolumnsystemsandovercomesthedefectsinearthquake resistantbehavioroftheconventionalconcretefilledsteeltubes．ThedesignconceptiSbasedonfundamentalmechanics． aimedatcontrollingthelocalbucklingofthesteeltubeandconfiningtheconcreteinthepotentialplastichingeregions ofaCFrcolumn．Toachievethis，severalefficientdetailsoftransverseconfinementwereproposed．Inthisstudy， carbonfiberreinforcedplastic(CFRP)andweldedsteelplatesasadditionalconfinementforCCrI'columnswere examinedexperimentally．Fromtheresultsofsimulatedseismicloadingtests．itisvalidatedthatthenewtypeofCFr columnsystemcanprovideexcellentseismicperformance． Keywords：CC订column；CFTcolumn；circular：squaresection；confinement；ductility；seismicbehavior 约束钢管混凝土柱的开发研究 肖 岩1,2，何文辉2，毛小勇2,3 (1．南加利福尼亚大学，美国洛杉矶，CA90089—2531； 2．湖南大学土木工程学院，湖南长沙410082；3．苏州科技学院，江苏苏州215000) 摘要：本文提出了一种更适合抗震 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 的新型钢管混凝土体系——约束钢管混凝土柱体系。它建立在清楚的力学概念基 础上，其设计着眼于在可能出现塑性铰的部位附加横向约束以控制钢管的局部屈曲和更有效地约束混凝土。这一新型钢 管混凝土柱体系兼具了钢管混凝土及套管混凝土柱两者的优点，克服了传统钢管混凝土柱的抗震缺陷，为抗震地区的高 层结构和桥梁设计提供了理想的选择。在本研究的第一阶段，作者们对FRP约束的圆钢管柱和钢板约束的方钢管柱进行 了模拟地震力的加载试验。其结果验证了约束钢管混凝土柱的良好抗震性能。 关键词：约束钢管混凝土柱；钢管混凝土柱；圆形截面；方形截面；约束；延性；抗震性能 中图分类号：TU528．59文献标识码：A 1 Introduction 基金项目：长江学者启动基金(531103012001)，国家自然科学基 (50278032)，湖南省科技厅(02JJY3046)共同资助。 作者简介：肖岩(1961一)，男，内蒙古呼和浩特人，教授。 收稿日期：2003年11月 Anewconcretefilledtubular(CFF)coluulnisconceived bythefirstauthorfromextensivepreviousresearchon CFTcolumnandthetubedcolumn[¨．Thetwodifferent butrelatedsystemsareconceptuallyshowninFig．1． InaconventionalCFTcolumnsystem，concreteisfilled insteeltubeswhichtypicallycontinuethroughoutseveral storiesorthefull-heightofabuilding【2，引．Thesteeltube is expectedtocarrystressesinlongitudinaldirection causedbyaxialloadingandmoments，aswellas 59 万方数据 transversestressescausedbyshearandtheinternal passivepressureduetoconcretedeformation，i．e．，the confiningstress．Duetotllefactthatasteeltubeisused aslongitudinalreinforcementtoresistaxialforceand moment，whensteeltubeyieldsunderexcessive longitudinalstressesduetomomentoraxialload．its transverseconfinement(particularlyintermsofstiffness) totheintemalconcreteisdrasticallyreduced．Besides． 10calbucklingofsteeltubeuponcyclicloadingalso hinderstheseismicbehaviorofaCFTcoluinnt4,5】． Theconceptofusingsteeltubeasprimarilytransverse reinforcementforreinforcedconcrete(RC)columnswas firststudiedbyaresearchgroupleadbyTomiif6-101．The terminologyof‘tubedcolumn’firstadoptedbyTomiiet a1．∞1。referstothefunctionofthetubeasthatofthe hoopsinahoopedRCcolumn．Thus，thecomposite actionbetweenthesteeltubeandconcreteisprimarily expectedintransversedirectiononlyforatubedcolumn， however，inbothlongitudinalandtransversedirectionsfor aconventionalCFTcolumn．Oneofthekeyfeaturesofa 60 Beam (a)cgrcolumn (a)钢管混凝土柱 Be咖 l I _ l Tub6d column (b)Tubedcolumn (b)套管混凝土柱 Fig．1Twodifferenttubularcolumnsystems 图1 两种不同的管式混凝土柱体系 tubedRCcolumnistoproperlydetailthetubetoavoidor reducedirecttransferofthelongitudinalstressesintothe tube，whichis designedprimarilyas transverse reinforcement．Thisis achievedbyprovidinga gap betweenthetubeandthebeamorfootingattheendsofa column，asshowninFig．1b．Thetubedcolumnsmay onlybeusedforthecriticalcolumnssuchastheshort columns，wallboundariesorcolumnsinlowerstoriesofa structure．Theconceptofthetubedcolumnwasvalidated throughtestingmodelcolumnsunderconstantaxialload andcvelicshearindouble—curvaturecondition[6q01． JacketingretrofitofexistingdeficientRCcolumnscan alsobeconsideredastheapplicationoftubedcolumn concept．Formostcases，thejacketisusedtoprovide additionaltransversereinforcementto increasetlle capacityandto improvetheductilityofanexisting column．Thisis achievedbyweldingsteelshellsor wrappingFRPstoencloseanexistingcolumntoforma tubedsystem【¨’1引． 2 ProposedCCFTcolumn AnewcFrcolumnsystemisconceivedbythefirstauthor followingextensivepreviousresearchstudiesoncgr columnsandsteelorFRPtubedcolumns．InthenewCFT column，additionaltransversereinforcementisdesigned forthepotentialplastichingeregions，asillustratedin Fig．2，toachieveimprovedseismicperformance．Based onfundamentalmechanics，thedesignconceptisaimedat controllingthelocalbucklingofthesteeltubeandmore efficientlyconfiningconcreteinthecriticalregionsofa CFTco／umn．Forthisreason．the columnsystemcanbenamedasconfinedCFTcolumn system，andisreferredtoasccgrhereafter．Though currentresearchprimarilyconcernswithbuilding structuredesign，itistheauthors’attentiontoapplythe conceptofCCFTinother andCFrarchbridgesin TheCCFTcolumnis structures，suchasbridgepiers thenearfuture． expectedto overcomemany disadvantagesoftheconventionalCFTcolumnandto providetheidealchoiceforstructuraldesignoftall 万方数据 CFT Fig．2PrDposedCCFFcolumnsystem 图2 建议的约束钢管混凝土柱体系 buildingsorbridges，particularlyinseismicregions． Ina CCFTcolumnthefunctionsofthethrough—tube (similartothetubeinaconventionalCFTcolumn)and theadditionaltransversereinforcementareseparated， withtheformermainlyresistslongitudinalstressescaused byaxialloadandmomentaswellasshearinthemidge portionofthecolumn，whereastheadditionaltransverse reinforcementmainlyenhancesthepotentialplastichinge regions． Theadditionaltransversereinforcementcaneffectively preventordelaythelocalbucklingofthethrough·tubein theplastichingeregionsofacFrcolumn，thusimproving itsseismicperformancewithstableloadcarryingcapacity andductility． Theconcreteinthecolumnplastichingeregionscanbe moreefficientlyconfinedbytheadditionaltransverse reinforcement，andasaconsequence，theductilityofthe columncanbeassured． Duetotheadditionaltransverseconfinement，the through—tubeinthecompressionzoneoftheplastichinge regionissubjectedtobiaxialcompressivestresses(strictly speaking，shouldbetriaxialcompression)．Thisisamore efficientworkingstateforsteeltubeascomparedwiththe combinationofaxialcompressionandtransversetension， whichistheworkingstressstateofthetubein compressionzonesofaconventionalCFTcolumn． InaconventionalC丌column．inordertopreventthe localbucklingofthesteeltubeintheplastichinge regions，relativelythickersteeltubeisrequired，and typicallysuchthicknessisprovidedthroughoutthelen群h ofthecolumn，particularlyforcolumnswitharectangular section．Ontheotherhand，ina CCFTcolumn，the through—tubeisdesignedmainlyaslongitudinal reinforcementtoresistaxialloadandmoment，andis enhancedtransverselybytheadditionaltransverse reinforcementinthepotentialplastichingeregions．The secondaryfunctionofthethrough—tubeistoresistshearin themiddleportionofthecolumn，andthiscantypically beachievedbyusingthesamethicknessofthe through—tube．Thus，itisexpectedthatevenwiththe additionofthetransversereinforcementforthepotential hingeregions，thetotalamountofsteelusageinaCCFT columnmaybelessthantheidenticalcvrcolumn． Apparently，sincetheadditionaltransversereinforcement isonlyprovidedforthepotentialplastichingeregionsof thecolumns，astructuralsystemusingCCFTcolumns remainsessentiallythesameasCFTstructure．Thus． designdetailssuchasconnectionsdevelopedfor conventionalcrystructuresarestillapplicabletothe proposedccvrsystem． Forthedesignoftheadditionaltransversereinfowement， thefollowingareconsideredbutnotlimitedaspotential optionsandareexaminedintheresearchprogram： (1)Additionalsteelshellsortubesal'eweldedtothe potentialplastichingeregionsofthethrough-tube， schematicallyshowninFig．2． (2)Angles，smalltubesorpipes,etc．，whichhavelarger transversestiffnessandresistancecanbeused,similaras thoseprovedtobeeffectivetoenhancetheretrofitting efficiencyofrectangularjacketingbythefirstauthor[16-17]． (3)Fiber-reinforcedplastics(FRP)canbeusedtocreate anewcompositesystem，asshowninthispaper． (4)ReinforcedconcreteshellsthatCallalSOsereasthe fire-proofforthesteeltube． Ajointresearchprogramdesignedtodevelopthedesign methodologyofstructureswithCCFTcolumnsiscurrently beingconductedattheHunanUniversityandthe UniversityofSouthernCalifornia．Thispaperdescribes theconceptofCCFTandtheexperimentalvalidation 万方数据 throughsimulatedseismicloadingtests．Priortothe seismicloadingtests，theauthorsalsoconductedaxial compressiveloadingtestonCCFTcylinderspecimensand validatedthebasicmechanicalbehaviorofCCFl’ columns【18·191． 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 1抗震试验试件参数 SpecimenSectionSteeltubeConfinementConcretestrength shape D／tratio 工’／MPa C1．CFTCircular 39．1 112 C2．CCFTD=336mm Cn口’ 39．1 C3一CFrCircular 28．O 54 C4．CCFTD=325mm CFRP+ 28．0 SQl·cFrSquare 40．0 58 SQ2一CCFTD=B= Steelplate 40．0 350ram Note：+nominalthickness，如=0．22ram／layer；rupturestrength， 矗=2500MPa；elasticmodulus，Ej=210GPa． 3 3．1 Six Simulatedseismictesting large—scalemodelCFrandCCFTcolumnswere designedtosimulatetypicalcolumnsinmulti-story buildingsinseismicregions．Thetestingmatrixisshown in7rable1 andthebasicdetailsofmeCFTcolumnsare illustratedinFig．3．Fourspecimenswerecircularwitha diameterof336mm(C1一cFr，c2一CCFl")or325mm (C3一CFT，C4-CCFT)，andtwospecimenswere350ramby 350mmsquarecross—section．Heightofthecolumnswas 1500ramfromthepointoflateralloadingtothetopofthe footing．ThicknessofsteeltubeWas3mmfortwocircular onesand6mmfortlleothers．Thespecimenswere designedandconstructedwitha stiffstubfootingof 2000ram×700mm×420mm．Thestubfootingswere heavilyreinforcedtoeliminateanyprematurefailure duringtesting． ThereWasnoanyspecialconfinementformodelcolumns C1一CFT，C3一cvrandSQ1-CFTforprovidingbenchmark dataofseismicbehaviorofconventionalC丌columns． FourlayersofCFRPwrappingwasusedtoprovide 62 additionalconfinementtothepotentialplastichinge regionsofcolumnsC2一CCF'randC4-CCFF．Thelengthof theconfinedzonewas300mm，closetothesection diameter．PriortoapplyingtheCFRPwrapping，alayerof lmmthickfoamtapeswereaffixedtothesurfaceofthe tubetoyieldacushioneffectbasedonthebasic mechanicaltestingstudies【16。17]showninFig．4．Model columnSQ2一CCFTwasconfinedinthepotentialplastic hingeregionbyweldedthickersteelplateswitha thicknessof18mm(Fig．4)． 鸬 F Fig．3CFFspecimendetails 图3 钢管混凝土柱试件详图 3mmor(maresmeltube CnLPWI'IIpswith Welded18mmthickplatm Immfoamtapetmtletlsy Fig．4CCFFcolumnsectiondetails 图4 约束混凝土柱截面详图 3．2 Specimenconstruction Materialpropertiesforallspecimensaresummarizedin Table1．Themixtureproportionspercubicmeterconcrete were190kgwater；425kgPortlandcement；1211kg coarseaggregates；and570kgfineaggregates．The concretecompressivestrengthvaluesshowninTable1 are basedoncompressiontestson150mmcubicspecimens， howeverconvertedintothecylinderstrength{。byafactor of0．8．TheChinesestandardQ235gradesterlwith averageyieldstrengthof235MPaWasusedforsteeltube inallthecolumns．Thetensilestrengthandthemodulus oftheunidirectionalCFRPsheetsusedforconfiningthetwo 万方数据 circularCCFTcolumnswere2500MPa,and210GPa, respectively,basedon0。22mm／layerthickflat．coupon tests． 3．3 Testingmethods Allthemodelcoluinnsweretestedusingthetestset—upshown inFig,5．’I’hetestset-up,designedbythefirsttwoauthors, canapplylateralloadingusingapseudocontrolledhydraulic actuatortolarge·scalemodelcolumninaconditionofvertical cantilever．Aconstantaxialloadof2000kNwasappliedto thecolumnthroughpost-tensioningtwo50ramdiameter high—strengthsteelrodsusingtwo1500kNcapacity hydraulichollowjacks．，I’lleforcesoftherodswere transferredtothecolumnbyacrossbeammountedontopof theloadstub．Inordertoeliminatethebendingofthe high—strengthrods,aspeciallydesignedpinwasconnected tothelowerendofeachrod． Fig．5Testset-up 图5试验加载装置 Theaxialloadappliedtothecolumnwasmeasuredbya setofstraingaugesaffixedonthehigh-strengthrods．The imposedlateraldisplacementwasmeasuredbyboththe displacementtransduceroftheactuatoranda separate linearpotentiometer．’111ecorrespondinglateralforcewas recordedbythebuilt—inloadcelloftheactuator． Electricalresistancestraingaugeswereaffixedonthe surfacesofthesteeltubeandtheadditionalconfinement CFRPnearcolumnend． Duringtesting，theaxialloadWasmaintainedconstantby thehydraulicsystem，whereasthelateralforcewascycled underlateraldisplacementcontrolcondition．Threesingle cycleswereinitiallyappliedcorrespondingtoan incrementof0．25％peakdriftratio，△／L，here△iSthe lateraldisplacementandListheclearlengthofthemodel columnmeasuredbetweentheapplicationpointofthe lateralforceandthetopoffooting．Then，threerepetitive loadingcycleswereappliedforeachofthepeakdrift ratios，△／L=1％，1．5％，2％，3％，4％，6％，8％ and10％．Suchstandardloadingprocedurewas attempteduntilthestagewherethemodelcolumnunder testingwasjudgedasunsuitableforfurtherloading． 3．4 Experimentalresults Circularcolumns：asshowllinFig．6a，circularCFI" roodelcolumnC】一CFTwitha D／tratioof112hada stablebehavioronlyuntilcyclescorrespondingtoapeak driftratioof2％inthepushdirectionwhereas1．5％in thepulldirection．Atthesestages，theSO—called ‘elephantfoot’typelocalbucklingofthesteeltubewas observedatthepositionabout20mmfromthebottomend ofthecolumn．Inthesubsequentloadingcycles，thelocal bucklingofthesteeltubesevered，formingseveral cripplesinthecolumnendregionwithalength cl-cFT 400fe-39 ．1MPa P=2000kN 3∞． 丑泞。112 200么绉k 100．!12)，◆／／—磊囊”j黝缓擎多r；8。l Driftratio，％ (a)CUFcolumu (a)钢管混凝土柱 C2-cc玎400[e'-39．1MPa P-20e0kN 300·黝A口。112 200—翔”㈤骖忾6。8。1 Driftratio，％ (b)CCFTcolumn俩tllCFRP (b)CFRP约束钢管混凝土柱 Fig．6Testresultsofcircularspecimenswith3mmthicksteeltube 图6 3mm圆形截面钢管混凝土柱试验结果 63 万方数据 approximatelyequaltothediameter．Duringtheloading cyclescorrespondingtoapeakdriftratioexceeding3％， thecolumnsectionswithintheendregionexpanded drasticallyindicatingtheinsufficientlateralconfinement providedonlybythethinsteeltube．Themomentcarrying capacitydegradedbelow80％ofthemaximumvalueat 4％peakdriftratiointhepullloadingdirection．The loadingWascontinueduntilthelossoftheaxialloading capacityduringthefirstcycleat8％． 2黑‰400。一_臻^酗瞳I —ff翻杉---，7新丑 。幽缪彩“ Driftratio，％ (a)CFrcolumn (a)钢管混凝土柱 燃．400^·-∞．帅僧● 励～么2乡Z：≯于衙铡髟h Drmratio，％ (b)CC兀1columrlwithCFRP (b)CFRP约束钢管混凝土柱 Fig．7Testmsultsofcircularspecimenswitll6mmthicksteeltube 图7 6mm圆形截面钢管混凝土柱试验结果 AsshowninFig．7a，withathickertube，CFTmodel C3一CFrbehavedsatisfactorilyuntila driftratioof8％． Localbucklingandlowcyclefatiguecausedruptureofthe steeltubealongthecircularsectionataheightofabout 50mm． DrasticallyimprovedbehaviorcanbeseenfromFig．6bfor CCFTmodelcolunlnC2．CC订．TheadditionalCFRP jacketwrappedinthepotentialplastichingeregion effectivelyrestrainedthelocalbucklingoftllesteeltube andprovidedbetterconfinementtothesection．Asa consequence．theCCFTcolumnwasabletodevelopa ductileandstablehystereticbehavioruntilapeakdrift ratioof8％．wherethetestwasterminatedduetorupture ofsteeltube．Comparingthehysteresisloopsshownin Fig．7aandFig，7b．itisclearthatCCFTmodelcolumn C4一CCVI"alsodemonstratedimprovedbehaviorcompared withitscounterpartC兀’modelC3一CFT． Thefinalconditionsofspecimenswith3mmthicksteel tubearecomparedinFig．8．Itisconcludedthatthe delayingoflocalbucklingofthesteeltubeandefficient confinementcontributedtotheimprovedseismicbehavior oftheCCnlcolumncomparedwiththecounterpartC：FY specimen． (a)CFT (b)CCFr (a)钢管混凝土柱 (b)CFRP约束钢管混凝土柱 Fig．8Finalfailurepatternsofcircularcolulnnswith3mmthick steeltubeorD／t=112 图8 3mm厚薄壁圆钢管混凝土柱试件(D／t=112)破坏形态 Squarecolumns：asshowninFig．9a．squareC兀 columnSQl．CFFexhibiteda prematurebehaviorwith significantcapacitydegradationafterdriftratiosexceeding 3％．Localout—of-planebucklingofthesquaretubewas observedforitscompressionfacenearcolumnendata loadingstageasearlyas1％peakdriftratio．’11lesevered localbucklingcausedthetubetorupturealongthewelded cornersduringtheloadingcyclescorrespondingtopeak driftratio4％．asexhibitedinFig．9a．Theuseofwelded additionalsteelplatestoconfinethepotentialplastic hingeregionofacFrcolumnwasdemonstrated successfullybythemodelcolumnSQ2-CCFT，asshown byitsexcellenthysteresisloopsinFig．9b．Asshownin Fig．10，localbucklingoftheconfinedspecimenwas completelypreventedwithintheconfinedregionandwas 万方数据 SQl-crr ，t·n,40．OMPII 600 ，以帅O州 物11／I-B／t：58 4002∞j厕 沁。k缫 绑jj i 1 Driftratio，％ (a)C盯column (a)钢管混凝土柱 SQ知OCFr N4．0MPa 600 P-20mI‘N 矶D／I-曰／t=58 4∞厂渤 0-S箴形∥j 6。i】 ／ 0 Driftratio，％ (b)ccvrcolumnwithsteelplate (b)焊接钢板约束钢管混凝土柱 Fig．9Testresultsofsquarespecimenswith6mmthicksteeltube 图9 6mm方形截面钢管混凝土柱试验结果 (a)CFT (bJCCFT (a)钢管混凝土柱 (b)焊接钢板约束钢管混凝土柱 Fig．10Finalfailurepatternsofsquarecolumns 图10方钢管混凝土柱试件破坏形态 forcedtoformabovetheconfinedregionatalargerlateral displacement．耶1issignificantlyenhancedthestiffness andincreasedtheloadcarryingcapacityasshownin Fig．9b．’nletestwasterminatedaftersuccessfully completingthefirstloadingcyclecorrespondingtopeak driftratio6％．fbrsalvagingthespecimenforthefollow upstudies． 3．5 Commentsonmomentcapacities InordertoapplytheCCFTconceptsinactualdesign practice，oneoftheurgentneedsistoassessthemoment carryingcapacityofaCCVFcoluum．Acomprehensive analyticalworkisstillunderway，therefore，thispaper onlydescribesanapproximateanalysisoftheultimate momentcapacityoftheCCFTcolumn．Thefollowing assumptionsareused： (1)TheultimatemomentofaCCvrcolumnsectioniS superposedbytheultimatemomentoftheconfined concreteandthesteeltube，asshowninFig．11． (2)Tensilestressisneglectedforconcrete，whereasthe compressionzoneoftheconcretedevelopsthefull concretestrength_7． (3)Asaconsequenceoftheadditionalconfinement．tlle fullultimatestrengthcanbedevelopedbythesteelbothin tensionandincompression． D／2．．t D／2—-t Concrete Steeltube Fig．11 Assumedultimateconditionsforconcreteandsteel 图11 混凝土及钢管截面的极限应力状态假设 Thecomparisonsoftheanalyticalmomentcapacitiesand thetestresultsfort11et11reeCCFTspecimensareshownin Table2．Notethatthetestresultsofthemomentcarrying capacitywastakenastheaverageofthemaximum capacitiesinthepushandthepullloadingdirections．As showninTable2，theapproximateanalysisprovidesa reasonablyconservativeestimationtothemomentcarrying capacityoftheccFrcolumn． 4 Conclusions Thepaperpresentedastudyonseismicbehaviorofanew CFFcolumnsystem，namedasCCFT，inwhichadditional confinementisprovidedtoimproveseismicperformance． TheccFrcolumnscombinetheadvantagesof conventionalcFrcolumnandtubedRCcolumnsystems． Simulatedseismicloadingtestsonlarge—scalespecimens describedinthispapersuccessfullyshowsuperiorseismic performanceoftheCCFTcolumns．Asimpleanalytical 65 j 万方数据 Table2 Assessmentofultimatemoment 表2抗弯强度计算 SpecimenTestcapacityAnalyticalcapacityMn，Mm 丝：!!型：巴2 些f!盟：垩2 【9] C2．CCFT 314 263 0．84 C4．CC丌402 397 0．98 SQ2．CCn 623 599 0．96 methodis alsosuggested，whichseemstobeableto providea reasonablepredictiontothemomentcarrying[101 capacityoftheCCFTcolumn． Acknowledgements Theauthorswouldliketothankthefollowinggentlemen fortheirhelpsatvariousstagesduringthestudy：Prof．YI Weijian，Prof．LIUYijiang，Prof．GUOYurong，Mr． SHANBo，Mr．ZHANGGuowei，Mr．MAOWeifeng．The researchwasalsoconductedasa collaborationbetween theHunanUniversityandtheUniversityofSoutlleITl California，USA． References 【1】XIAOY．FromsteeltubedcolumnstoFRPtubedcolu【mns fA】．ProceedingsofASCEStructuralConsressIC]． WashingtonDC，2001． 【2] 蔡绍怀．钢管混凝土结构的计算与应用【M】．北京：中国 建筑工业出版社，1989． 【3】钟善桐．钢管混凝土结构【M】．哈尔滨：黑龙江科学技术 出版社，1987． [4】 SAKINOK，TOMIIM．Hystereticbehaviorofconcretefilled squaresteeltubularbeam-columnsfailedinflexure[J】． TransactionsofJapanConcreteInstitute，1981，3：65—72． [5】Councilon例lBuildingsandUrbanHabimt．Castinplace concreteintallbuildingdesignandconstruction-7．3concrete timedsteeltubes[C]，McGrowHiU1992：202—222． [6】TOMII地SAKINOI('WATANABEKXIAOY．Lateral loadcapacityofreinforcedconcreteshortcolumnsconfinedby steeltube[A1．ProceedingsoftheInternationalSpeciality ConferenceoffConcreteFilledSteelTllbularStructures[C]． Har