解读我国钢筋混凝土抗震设计新规范Interpretationofnewcodesforseismicdesignofreinfor

解读我国钢筋混凝土抗震设计新规范(InterpretationofnewcodesforseismicdesignofreinforcedconcreteinChina)TheinterpretationofreinforcedconcreteaseismicdesignofChina'snewstandardKeywords:CodeforseismicdesignofbuildingsGB50011-2001,codefordesignofconcretestructuresGB50010-2002,technicalspecificationforconcretestructuresoftallbuildingJGJ3-2002.Todeterminethe1structuraldesignseismicforceThefeasibilityof1.1lowvalueofearthquakeforceBy1980s,allspecificationsforthedesignofarecognitionofthefactthatintheearthquake,thestructureinrealfailure,thereisalargeplasticdeformation(ductility),thestructuremayreachorclosetotheyieldingstateinasmallerearthquake;inalargeearthquake,somepartsofthestructurewillenterthenonelasticdeformationafteryielding,andwiththeincreaseoftheforceoftheearthquake,thestructureinelastic-plasticdeformationareaincreased,yieldintoadvancedpartsofelastic-plasticdeformationalsoincreases.Thestructureofthedeformationtodissipatemoreseismicenergy,convertingitintoheat.Forthedesignofearthquakeforceductilityjointrule,wecanunderstandtherelationshipbetweentheseismicforceandstructure:ontheonehandthelowseismicdesignstructure,seismicenergydissipatedbydeformationmoreinelasticmoreinelasticdeformation;ontheotherhand,thegreaterthestructure,reductionofstiffnessdampingmoreserious.Cycleratioincreased,structureseismicdesignforceincreasemore,thetotalseismicforceofthestructurehasalsobeenreducedmore.Thismakesusinthedesignprocess,withoutreducingthecomponentofverticalbearingcapacityoftheductilityofthestructureunderthepremise,cantakealessthantheseismicfortificationlevelasdesignforreactionofearthquake.Conversely,ifthedesignofearthquakeforcebasedonthelowerpartofthestructureyield,reducethebearingcapacityofhorizontalandverticalyieldunderthenonelasticdeformationtoachievegreater,alsoneedtohaveabetterductilityperformancestructure.So,weneedtosolvethefollowingtwoquestions:toestablishanappropriaterelationshipbetweenseismicfortificationintensityandtheseismicdesignvalue;howtodesignseismicforceandestablishedtherelationshipwiththeductilityofthestructurerequired.FortheproblemofA,manyscholarsrepresentedbyN.M.NewmarkthatwillreducethefortificationintensityearthquakeaccelerationcoefficientRbyseismicforce(intheUnitedStates)orstructuralperformancecoefficientQ(EC,NewZealand)reductionforstructuraldesignofacceleration,theequivalentyieldgivesasmallerstructurebearingcapacity,structureintheverticalthebearingcapacityisnotreducedcircumstances,towithstandearthquakebynonelasticyieldafterdeformation,realizetheearthquakeinvertedtarget.Therefore,thekeyoflowseismicdesignistoensurethestructureandcomponentstoachieveductilityrequiredintheearthquake.TheseismicforcereductionfactorRorstructuralperformancecoefficientQ,designspecificationofvariouscountrieshaveslightlydifferentapproach,butoverallRorqareusedtodesigntheearthquakefortificationratioandearthquakeintensityofthesectionstructure.Rorqislarger,theductilityofthestructureisrequiredtoreachQ,Rorsmaller,thestructureneedtoachievesmallerductility.Itcanachievetheearthquakedoesnotfall".FortheproblemofB,generallyhasthreekindsofdesignschemesareasfollows:(1)high-lowductilityseismicforcescheme;moderateearthquakeforce--secondaryductilityscheme;low-highductilityseismicforcescheme.Highforceschememainlyensurebearingcapacityofstructure,lowseismicductilityofthestructuremainguaranteescheme.Theactualearthquakedamageshowsthatthethreeschemes,fromtheseismiceffectandeconomicpointofview,toachievethegoaloffortification.Theseismicdesignofourcountryisthescheme(3)islow,theearthquakeforceductilityschemeusingsignificantlylessthanhigh,smallearthquakegroundmotionaccelerationseismicintensitytodeterminetheseismicdesignofstructure,anditwillbecombinedwithotherloads,sectiondesign,thereinforcedconcretestructureisformedintheearthquakethereactionprocessinthepostyieldmorefavorableenergydissipation,theenergypartsstructuremainlyhasgooddeformingcapacitytoachievetheearthquakeinvertedtarget.Ofcourse,wealsoseealittle,althoughthesethreeschemescanguarantee"theearthquakedoesnotfall,butinimprovingthestructureofstateinsmallearthquakesunderthescheme,(3)onlyimprovetheductilitylevelstructureandyieldlevelstructuredidnotsignificantlyimproveisobviouslynotasgoodasthescheme(1)and(2).Thatistosay,inordertoensurethe"minorearthquake,intheearthquakecanfix"scheme(1)and(2)isbetterthanthescheme(3).Vibrationpropagationinundergroundandsurfaceintheformofwave,duetothefactorsofsourcecharacteristics,faultmechanism,suchasthetransmissionofuncertaintyhasgreatrandomness.Ifyouwanttogetwhatgroundhasdifferentresponsestodifferentstructure,requiresvibrationcharacteristicsandstructuralresponsesinabridge.Becausetheshapefeaturespectrumofgroundmotionresponsecharacteristicsofdifferenttypesofdynamicstructureofmaximumresponse,sotheprojectcommonlyusedinseismicinfluencecoefficientspectrumcurveasthebasisofearthquakeactioncalculation.ThespectralcurveinChinaconsideringtheimpactintensity,epicentraldistance,siteclassification,structuralvibrationperiodanddampingratio.AccordingtothelatestrevisionofthezoningmapChinesegroundmotion,givenseismicintensity(earthquake)designbasicearthquakeaccelerationunderthe.Basedonthemagnitude,epicentraldistanceandsiteconditiononthestructureresponsespectrum,seismiccodetodynamicamplificationfactorof2.25.Accordingtostatistics,theearthquakeintensitythanthebasicintensityisreducedbyabout1.55degrees,equivalentto0.35timesthatreduceearthquake,earthquakereductioncoefficientis1/0.352.8.Inordertogetthedesignaccelerationstructureofsmallearthquakes,thevalueofthegravitationalaccelerationisthemaximumvalueofsmallearthquakeswhenthehorizontalearthquakeinfluencecoefficient.Comparedwithothercountries,toreducetheearthquakeforceinChinaandNewZealandcoefficientR2.7~2.8,thevalueof"limitedductilityofframe"(R=3);theEuropeancommunitybetweenthelowductilityofDC"L"(R=2.5)andductilityofDC"M"(R=3.75);thanintheUnitedStates"generalframework"(R=3.5)andsmaller.OnlyfromtheperspectiveofR,seemstoChinesespecificationductilitydemandintheearthquakeandcomparedtoothercountriesinthe"mediumlevelductilestructure.ButthepeakaccelerationcoefficientofhorizontalgroundmotionChineseunderseismicfortificationintensityvalues,thaninothercountriesofthelow(seetablebelow).Thestructureofthedynamicmagnificationfactorismostlyinthevicinityof2.25,andChina'splatformsegmentspectrumcurvecomparedwithothercountriesisverysmall,Somesteepdecline,causingtheresponsespectrumvaluethanothercountriesinthelow,essentiallyChinaR=2.8isequivalenttotheR=5,soinessence,China'suseof"low-highductilityseismicforce".Ductilitydemandneededinundertheearthquakecomparedwithothercountries,shouldbelongtothehighductilitydemand.AllthestandardTheUnitedStatesUBC1997NewZealandNZS3101TheEuropeanEC8ChineseGB50011-2001Accelerationcoefficient0.075~0.400.21~0.420.12~0.360.05~0.40Thecalculationof1.2earthquakeWiththeresponsespectrumtheorycontinuestomature,variouscountriesoftheseismicforceonthestructure,haveacceptedthebottomshearmethodandresponsespectrummethod.Chinesespecification:Thebottomshearmethodisapplicabletoaheightofnotmorethan40m,withsheardeformationandmassstiffnessalongtheheightofstructurewithuniformdistribution,andthestructureofthesingleparticleapproximation.Thestructureofthetotalseismicforcedeterminedby,andthenalongtheheightaccordingtotheinvertedtriangledistribution,andthetopmayincreasetheforceoftheearthquakeintheearthquakeforceadditionalvertex.Themodaldecompositionresponsespectrummethodissuitableforthemostoftheexistingbuildingstructuresystem.Throughthemodalcombinationconsideringparticipationmodeineachdifferentperiodintheseismicresponse.Tocalculatethestructuraltorsion,firstdetermineeachmodeinthehorizontalearthquakestandardforeachparticlevalueindeterminingthehorizontalearthquakeeffectaccordingtotheformulaofstructure;torsioncouplingcalculation,thefloorfromtwoorthogonalhorizontaldisplacementandangulardisplacementofthreedegreesoffreedom,todeterminetheearthquakestandardsofeachmodeateachfloorleveloftwodirectionandangledirectionaccordingtothevalue,ordeterminetheeffectofhorizontalseismicaction.Standardalsoprovides,inparticulartheirregularbuilding,abuilding,standard5.1.21listedintheheightrangeofthehigh-risebuilding,usingelastictimehistoryanalysisunderearthquakecalculation,theaveragevalueofthecalculationresultswhenapluralityofdesirablecurvesandthemodaldecompositionreactionlargervaluecalculationresultsspectrummethod.Inadditionthegeneralelastictimehistoryanalysismethodtojudgethelocationoftheweakstories.Forconsideringtheverticalearthquakeforceof9high-risebuildingarea,adoptthesimilarmethodbottomshearmethod,onlythevalueoftheverticalearthquakeforceisabout0.57timesthevalueofthehorizontalseismicforce.Foralongperiodstructure,groundmotionaccelerationanddisplacementoftheearthquakemayhaveagreaterimpactonthestructure,andthemodaldecompositionresponsespectrummethodtoestimatethenewspecificationbutalsoincreasethefloorhorizontalseismicforceminimumrequirements,seeseismiccodestructuralseismicdesignofbuildings.Threeseismicfortificationstandardisguaranteedthroughthetwostagesofdesign:frequentcheckingofbearingcapacityunderearthquake,themainstructureofthebuildingisnotdamaged,nodamagetononstructuralcomponentstoensurethenormalusefunctionofbuildingheavyrare;themainstructureofthebuildingundertheearthquakesuffereddamage,butnotcollapse.Theseismicdeformationisanimportantcontentoftwostagedesign.Thefirststagedesign,deformationcalculationonelasticlayerdisplacementanglerepresentation.Inordertoensurethestructuralandnonstructuralcomponentswithoutcrackingorcrackingisnotobvious,toensuretheseismicperformance.Thenewstandardincreasedtherangeofdeformation,Thebendingdeformationofhigh-risebuildingscandeductthebendingdeformationofthewholestructure,inpartbecauseitisharmlesstothedisplacementofthedisplacementofstructure,butdifferentpeoplefeelcomfortable,Thesecondstageofthedeformationunderrareearthquakeweaklayerelastic-plasticdeformationchecking,theelastic-plasticdisplacementsaid.Accordingtotheexperienceofearthquakedamage,experimentalresearchandanalysisofthecalculationresultspresentedthenodesandcomponentsreachedthelimitdeformationoftheinterlayerdisplacementanglelimit,topreventthestructureofweaklayerofelastoplasticdeformationcausedbyexcessivestructuralcollapse.Thescopeofspecificationforcheckingareclearlydefined,butconsideringtheelastoplasticdeformationcalculationcomplexityandthelackofpracticalsoftware,havedifferentrequirementsfordifferentbuildings.Inthefuturedevelopmentcanbeextendedtocheckmore,eventhedisplacementcontrolmethodbasedondesignstructure,meetsomespecialrequirementsonthetypeofbuildingstructuredisplacement,toensurethatthedisplacementofthestructureisintheacceptablerange.Thatis,thedisplacementcontrolstageandtheseismicdesignislimitedtothesinglestructureunderseismicresponse.Howtoeffectivelyconsiderthecumulativedamageeffectonstructuraldeformationandseismicperformanceintheearthquakeregionandearthquakes,toensurethatthestructureofthewholelifeperiodofsecurity,needfurtherresearch.Inthe3framestructureasanexampleonseismicconceptualdesignBecauseofthecomplexityofseismicdesignofbuildings,inpracticalengineeringseismicconceptualdesignisparticularlyimportant.Itmainlyincludesthefollowingcontents:architecturaldesignshouldpayattentiontorulesofstructure;thechoiceofbuildingareasonablestructure;ductilitydesignofantilateralforcestructureandcomponents.Inthispaper,theframeworkasanexampletohighlightthecapacitydesignmethodinseismicconceptualdesign(capacitydesign).Capacitydesignisthemaincontentofductilitydesignofstructure,includingtwoaspectsofinternalforceadjustmentandstructureofourcountrystandard.ItistwentiethCenturyinlate70s,methodofthereinforcedconcretestructureofNewZealandscholarsT.PaulayandParkproposedhasenoughductilityinlowseismicdesignvalueundertheconditionofthe.Thecoreideais:throughthe"strongcolumnandweakbeam"guidestructureformed"beamhingemechanism"or"beamhingemechanism";the"strongshearweakbending"avoidstructureintheexpectedductilitycapacitybeforetheshearfailure;throughthenecessarystructuralmeasurestothepossibleformationofaplastichingepartswithplasticrotationcapacityandtheenergydissipationcapacitynecessary.Fromtheabovethreeaspectstoensurethatthestructurehasthenecessaryductility.AsacommonframeworkFramestructureasthecommonstructureform,ofcourse,theductilitydesignismainlyfromthethreeaspectstoreflect.strongcolumnandweakbeamDynamicresponseanalysisshowsthatthedeformationcapacityandfailuremechanismofthestructure.Threekindsoftypicalcommonenergydissipationmechanism,"beamhingemechanism"and"columnhingemechanism,beamcolumnhingemechanism"."Beamhingemechanism"and"beamhingemechanism"beamtoyield,thewholeframeworkofalargerredistributionofinternalforceandenergyconsumptioncapacity,limitdisplacementbetweenlayers,plastichingenumber,notbecauseofindividualplastichingefailureandstructurefailure.Sotheseismicperformanceisgood,istheidealenergydissipationmechanismofreinforcedconcrete.Ourspecificationisusedtoallowcolumns,shearwallbeamcolumnhingehingeproject,takearelatively"strongcolumnweakbeammeasure,Thedelaytimeofhingepillar.Butcannotbecompletelyruledoutthepossibilityofcolumnhingemechanismweaklayer,sotheneedtolimittheaxialcompressionratio,whennecessarybythetimehistoryanalysismethodtodeterminethestructureoftheweaklayer,preventtheemergenceofcolumnhingemechanism.Theadjustmentmeasuresofourcommon"strongcolumnandweakbeam"istoartificiallyincreasingthecolumnflexuralcapacity,inducedintheLiangDuanfirstplastichinge.Thisistakingintoaccounttheactualmomentofcolumnintheearthquakemayincrease.Inthestructureofplastichinge,nonelasticpropertiesofconcretestructuresduetocrackingzoneandconcrete,thebondbetweenreinforcementandconcretedegradation,thestiffnessreduction.Beamstiffnesslowercompressioncolumnstructureisrelativelyserious,bytheinitialsheardeformationtransitiontoshearbendingdeformation,bendingmomentofcolumnwithbeamendmomentratioincreased;atthesametimethestructurecyclelengthened,affecttheparticipationfactorofeachmodeisthesizeofthestructure;seismicforcecoefficientoccurschanges,resultingintheincreaseofpartthecolumnmoment,duetohumanreasonandincreaseofsteelbarstructuredesign,makestheactualbeamincreasetheyieldstrength,sothatthebeamplastichingeincolumnmoment.Thestructureoftheplastichinge,hasthesamereasons,andtheinelasticprocessstructureafteryieldisfurtherincreasedduringtheearthquakeforce,increasetheforceoftheincreaseofcolumnmomentanywhere.Theearthquakeforcecausedbyoverturningmomentchangestheactualaxialforceinthecolumn.Weinthestandardlimitvalueofaxialcompressionratiogenerallycanguaranteeapillarinthelargerangeofbias,reducingtheaxialforcecandecreasepostyieldingcapacity.Criterion:inadditiontolessthan0.15andframebeamandframecolumnoutsidetheframetopandcolumn,columnendmomentdesignvalueshouldbeconsistentwiththelevelofrespectively1.4,two1.2,three1.1.9degreesandaframestructureshouldbeinaccordancewiththatvalueisdeterminedaccordingtothesolidreinforcedareaandmaterialstrengthstandard.Thebottomofthecolumnaxialforce,rotationcapacityofplastic,toavoidcrushingthecolumnhinge,oneortwo,threelevelframestructureofbottomcolumnsection,combinedmomentdesignvaluemultipliedbythecoefficient1.5,1.25and1.15.Combinedmomentadjustedcolumnshouldbemultipliedbythecoefficientofnotlessthan1.10.Thedesignofshearwallsectionbendingmomentofacombinationofseismicgradevalueswereadjusted,forcingtheplastichingetostrengthenthepositioninthebottomofthewalllimb,andalayerabovethebottomstrengthenedregionmomentdesignvaluefromthebottomofthewalllimbsectionofthecombinedmomentdesignvalue,otherpartsofthesystemincreasesthenumbermultipliedby1.2.Onthepartofframeshearwallstructure,oneortwoframeisthetopofthecolumnandcolumnbottom,thecombinedmomentdesignvalueshouldbemultipliedbythecoefficient1.5and1.25respectively.Theadjustmentmeasuresabove"strongcolumnandweakbeam",thenonlineardynamicresponseanalysisshowsthattheearthquakedoesnotmeetthebasicrequirementsoftheground.Inthe7zonebeamreinforcedbygravityloadcontrol,columnreinforcedbyminimumreinforcementratiocontrol.Fullyenhancestherelativeflexuralcapacityofbeamcolumn.Atthesametime,7degreeareaisdifficulttoappearpositivemomentplastichinge,resistancetoearthquakeplaysabeneficialrole.In9,thesolidreinforcedareaandmaterialstrengthstandardvaluecalculatedinthecolumnmoment,increasealsoleadstotheincreaseofbeamstructureofreinforcedmomentdesignvalueinthecolumn,inthemultiwaveinput,thebeamplastichingerotation,Thedevelopmentofafullcolumnplastichingedevelopmentisnotsufficient,turningasmall.Plasticdeformationismoreconcentratedandtheendofthebeam,meettheseismiccapacitydesignrequirements.The8degreeearthquakezone,thedisplacementreactionwithalmost9degrees,butattheendofcolumnplastichingewith9degreerotation,largebeamendplastichingerotationsmallbutfully,sothe"strongcolumnandweakbeam"effectisnotobvious,theexpertssuggest8degreeseismicgradetwo,moment.Thecoefficientshouldbe1.35,whichneedtobefurtherimproved.strongshearweakbending"Strongshearweakbending"istoensurethattheplastichingesectioninthedesiredshearingfailurebeforenonelasticdeformation.Thecommonstructure,mainlyinLiangDuan,attheendofcolumn,shearwall,shearwallholereinforcingareainthebottomendoftheconnectingbeam,LiangZhujointcorearea.Comparedwiththenonseismicstrengtheningmeasures,mainlytoimprovetheeffectofshear;adjusttheshearcapacityofthetwoaspects.shear2.5beamcrossheightratiogreaterthanoneortwo,threelevelofframebeamandshearwall,thesheardesignvalue,agrade1.3,twograde1.2,threegrade1.1,aframestructureand9degreeshallbeinaccordancewith.Oneortwo,threecolumnsandcolumns,thesheardesignvalue,agrade1.4,twograde1.2,threegrade1.1,aframestructureand9degreeshallbeinaccordancewith.Oneortwoandthreegradeshearwallreinforcedpartatthebottom,thesheardesignvalue,agrade1.6,twograde1.4,threegrade1.2,9degreesshallbeinaccordancewith.Beamcolumnjoints,seismicgradeoneortwoseismicjointcoreshearbearingcapacitycalculation,threeorfourlevelshouldbeconsistentwiththestructuralmeasures,thestructureofthe9degreeseismicandseismicgradelevel,takingintoaccountthebeamsidehasaplastichingenodecompletelybytheendofthebeamshearyieldmomentaccordingtotheactualdecisionbeamDuanshireinforcedareaandmaterialstrengthstandardvalue,atthesametimemultipliedbythecoefficient1.15.Calculationofotherstagebendingmomentinthebeamenddesign,shearincreasecoefficientis1.35,twois.2shearformulaThesteelconcreteundercyclicloadingofcontinuousbeamandcantileverbeamsubjectedtoshearexperimentsshowedthat,reducetheconcreteshearcompressionzoneshearstrengthreductionandobliquecrackbetweenaggregatebiteforceandlongitudinalreinforcementdowelstressisthemainreasonfortheshearcapacityisreduced.Specificationforconcreteshearstrengthreducednonseismicreinforcingbars60%,notreduced.Similarly,toshowthattheshearcapacityofcolumnssubjectedtoeccentriccompressiontest,cyclicloadingcolumnshearbearingcapacityof10%~30%decreased,mainlycausedbyconcretebeams,andtakethesameapproach.Accordingtotheexperimentalshearwall,thecyclicloadingthanthemonotonicloadingshearbearingcapacityof15%~20%decreased,theseismicshearstrengthreductioncoefficientmultipliedby0.8.Theshearcapacityofconcretestrutandhorizontalhooptwopartshearbearingcapacityofseismiccomponentsofbeamcolumnjoints,therelevantexpertsintherelevantformulaaregiven.Inordertopreventthebeamsandcolumns,beams,shearwall,nodebaroclinicdestruction,weontheshearsectionprovidestheshearbearingcapacitylimit,whichstipulatesthestirrupratiolimitvalue.Theinelasticdynamicresponseanalysisshowsthattheabovemeasuresbasicallymeettherequirementofstrongshearweakbending.Theseismicgradetwobeamcolumnintheearthquakeplasticrotationisstillgreat,Theexpertssuggestnotshearenlargedcoefficientthantheleveldifferenceistoolarge,thebeam1.25isbetter,thecolumnshouldbe1.3~1.35.Thevalueofrationalityneedstobefurtherimproved.Thatis,columnbeamjointsareverycomplex,inordertoensurethereliabilityofanchoringsteelbeamcolumninthenode,whileLiangZhuduanbendingoccurredbeforethefailure,nodeshearingfailure,itshouldbelongtothe"strongshearweakbending"category.Moreover,nodesonlyforseismicgradeoneortwoshearadjustmentcoefficientissmallerthantheincreaseofcolumnandstructuralmeasuresthantheweakcolumn.Therefore,"morenodes",notworthpromoting.3.3structuralmeasuresStructuralmeasuresbeams,columnsandshearwallsofplasticzonetoachievetheplasticrotationcapacityandenergydissipationcapacitytoensuretheactualneeds.Itiswiththe"strongshearweakbending"and"strongcolumnandweakbeam"arerelatedtoeachother,toensuretheductilityofthestructure."Strongshearweakbending"isthepremisetoensuretheplasticrotationcapacityandenergydissipationcapacity;thedegreeofstrongcolumnandweakbeam",affecttheconstructionmeasures,ifstrict"strongcolumnweakbeam",ensurethecolumnbottomdoesnotappearintheplastichinge,theratioofconstructionmeasurestoloosesomecorrespondingaxispressure.Ourcountryadoptstherelatively"strongcolumnweakbeam,columnhingedelaytime,soitisnecessarytotakestrictmeasurestoconstruct.Constructionmeasuresof3.3.1beamsTheductilityofbeamplastichingesectionisrelatedtomanyfactors,theductilitywithtensilereinforcementratioandyieldstrengthincreased;withtheminimumreinforcementratioandconcretestrengthincreasing,anddecreaseswiththeincreaseofthewidthofthecrosssectionincreases;plastichingestirrupscanpreventlongitudinalreinforcementbuckling,improveultimatecompressivestrainofconcreteandblockdiagonalcrackresistance,sheardeformationandenergydissipationcapacity,givefullplaytotheplastichinge;highbeamspanissmall,thesheardeformationratioisgreater,pronetoobliquecrackdamage,theductilitydecreases.Thebeamlongitudinalreinforcementstirrupratioistoolow,thereinforcedbeamaftercrackingmayyieldevenpulloff.Therefore,forthebeamlongitudinalreinforcementthemaximumreinforcementratioandminimumreinforcementratio,hoophaslength,maximumdiameter,minimumdistance,maximumsheardistance,stirrupratiostrictrules.Inordertoresistthepositivemomentcanguaranteetheductilityofthebeamendofthebeamendtensionsteelarearatiolimits.Atthesametime,alsotheminimumwidthofthebeam,thespandepthratioofheighttowidth,isprovided.Constructionmeasuresof3.3.2columnColumntypebendingforcecomponent,axialcompressionratioontheductilityandenergydissipationofgreatinfluence.Theaxialcompressionratioofcolumnh,largebiascomponentdestruction,largedeformation,goodductility,butenergyconsumptiondecreased;withtheincreaseofaxialcompressionratio,energyconsumptionincreases,buttheductilitydecreasedsharply,andtohelpreducetheductilityofstirrups.Weuseseismicdesignforlowlandpillars,mainlytoensuretheductility,energydissipationinsecond.Specificationlimitsofaxialcompressionratio,usuallycaninlargerangeofbiasin.Stirrupalsogreateffectontheductility,constraintoflongitudinalreinforcementandimprovethecompressivestrainofconcreteandblockdiagonalcrackdevelopment.Thecolumnisgenerallysymmetricalreinforcement,thereinforcementratioisgreater,thegreaterthedeformationpostyieldbetterductility.Thepillarsoftheminimumlongitudinalreinforcementratio,hoopreinforcementlength,maximumdiameter,minimumdistance,maximumsheardistance,stirrupratiotomakestrictrules.Atthesametimehighwidthonthecolumnratio,shearspanratio,heightandwidthoftheminimumsectiontomakeprovision,inordertoimprovetheseismicperformance.The3.3.3nodeconstructionmeasuresAsthenodeoftheanchoragezoneofsteelbeamsandcolumns,agreatinfluenceontheperformanceofstructure.Inordertoguaranteetheearthquakeandunderverticalload,thecorezoneofthejointshearpressuretoprovidethenecessaryconstraintsthanlownodecorearea,keepthenodeinadversecircumstancestheshearcapacityofthebeamcolu