考虑有侧移框架结构二阶效应的偏心距增大系数法的改进-刘毅

295Vol129,No15200810JournalofBuildingStructuresOct12008:100026869(2008)05201142061,2,1,1(1.,400045;2.,100013):,(GB500102002)P2(s2l0)P2P2,s2l0P2,:;;;:TU37514TU31811:AImprovementofmomentamplificationfactormethodconsideringsecond2ordereffectinlateralswayframeLIUYi1,ZHUAiping2,WEIWei1,BAIShaoliang1(1.FacultyofCivilEngineering,ChongqingUniversity,Chongqing400045,China;2.InstituteofBuildingStructures,ChinaAcademyofBuildingResearch,Beijing100013,China)Abstract:Basedontheregularityofsecond2ordereffectinlateralswayframe,theeccentricityormomentamplificationfactormethod(s2l0method)consideringP2effectinCodefordesignofconcretestructure(GB500102002)needsimprovement.DiscussingthedemonstratingtheregularityofP2effectandP2effectinswayframe,aconvenientnews2l0methodwasproposed,whichconsideredcharacteristicsofmagnifiednonlinearcurvaturecausedbytheswaymomentandthecharacteristicsofstory2effect.Aftercarefulcomparison,therationalruleofP2effectinswayframewasreflected,andtheaccuracyoftheproposedmethodwasassameasthecorrespondingmethodinACI,andfloormagnificationfactormethodalso.Keywords:reinforcedconcrete;framestructure;second2ordereffect;momentamplificationfactormethod:(59678035):(1971),,,,:200791,,(P2)(P2)1a1b(Mns)(Ms)()MnsMs,[1]P2,Mns,Ms(2bMsMs),i0rNij411,P2,P2Ms(),[223]P2MsMs,MsP2ACI318205[4]P2MsP2MnsMs,,Mns,Ms(a)Mns(b)Ms1Fig.1Momentinsymmetricalframecausedbyverticalandhorizontalloadrespectively,2aMns(,),Mns1Mns2(Mns1),P2(2aMns),,2aMns1Mns2,P2,Mns1Mns2,P2Mns1,,[5]P2Mns,,P2,Mns,2Fig.2SuperpositionrelationshipsofswaymomentsandnonswaymomentsinswayframeMnsP2[1],MsP2,MsMs(2b)P2Mns,P2P2MsMs(2b);,,2bP2MnsMsMnsMs2a2bMnsMs,MnsMs,2a2b,Me1Me1=Mns+Ms-Mns+Ms+Ms(1)Me12a2b,(),Me1/Me2110,2a2b,Cm2ns[5]ns(),;2a2b,511(1),;Cm[5]Cmns,Cm2ns(2)Mc=Cmns(Mns+Ms-Mns+Ms+Ms)(2),Cmns110,2a2bMe1Cmns110,,(1)Me1,(2),(2)Mns,Ms,(2)Mc=Cmns(Mns+sMs)(3)s=(Ms+Ms)/Ms(4)2a2b,,,(3)Cmns110Cmns=110,(3)Mc=Mns+sMs(5)(5)(2)P2MsMs2:(1)();(2);(3),,,((GB500102002)[6]014016),((JGJ32002)015)3,,1P2,(5);P2P2,(2);,Cmnss2P2,sisi=11-rNiji0ViHi(6),i0,ViHii(,),(6)(2)Ms,=11131115[728]()l0,sP2s((4)),l0P2,s2l0,s,sACI318205,ss=11-rN/rNcr(7)rNcr=(2EcI)/l20(8)(8)l0,,l0,(8)EcI,,,(7)(rN/rNcr)P2,(5)P2,(BS8110[9][10]),(5)P2ACI318205611(GB500102002),s:(1)uss=1+ul20e02(9)(2),s,M=s(Mns+Ms)(10)(3)(10)M(5),s(9)l0(4)Ms,(3),Ms/(Mns+Ms)0175,l0l0P2,:(1)(5)s,Ms,u(2)[6]Ms/(Mns+Ms)0175l0s,s,s(3)(10)(5)P2,(4)MnsMsl0,,(5),sMs,sjsj=1+sjl20je0j2(11)sjsj=Msj(EcI)3(12)(EcI)3(GB500102002)[6]016Ncr((8)),(12)(EcI)3=016EcIe0j=Msj/Nj(11),210,(11)sj=1+Msj016EcjIjNjMsjl20j10=1+Njl20j6EcjIj(13),P2,3P2Vij=Njsji/Hi(14),i,Hi,rVij=rNjsji/Hi(15)P2s,rVij=sirNj/Hi(16)(15)(16)s=rNjsj/rNj(17)3Fig.3Effectivelayerhorizontalforcemodelofasinglecolumninswayframe,(13)(17)P2,(5)P2,,(12)(EcI)3,P23P2P2((13)(17))711()((7))((6)),35311,4s(s)354,8012g,311,35,6700mm700mm600mm600mm4(::mm,kN)Fig.4Geometricalparameterandloadsituationinexampleframe,s014016;,(Ms+Ms+Ms)Ms,ss=Ms+Ms+MsMs(18)s56s,(6)i0,ACI318205,s(7),,(8)EcI,(8)l0,01350170564s:(1),,Mss,(2)11003s,s,4P2(3)1115ss,P2P2,,1110(4)444,02P2,s,P28115435sFig.5Comparisonofsinfourmethodofthree2spanfive2storyframe64311sFig.6Comparisonofsinfourmethodofthree2spaneleven2storyframe[1].[M].:,2003.(ChinaAcademyofBuildingResearch.Thedesignofconcretestructure[M].Beijing:ChinaArchitecture&BulidingPress,2003.(inChinese))[2]FordJS,ChangDC,BreenJE.Experimentalandanalyticalmodelingofunbrancedmultipanelconcreteframes[J].ACIJournalProceeding,1981,78(1):21235.[3]FordJS,ChangDC,BreenJE.Designindicationfromtestofunbrancedmultipanelconcreteframes[J].ACIJournalProceeding,1981,78(3):44246.[4]ACICommittee318.Buildingcoderequirementsforstructuralconcrete(ACI31822005)andcommentary(ACI318R22005)[S].AmericanConcreteInstitute,Detroit,2005.[5],,,.P2[J].,2006,27(5):64271.(WEIWei,ZHUAiping,LIUYi,BAIShaoliang.DesignmethodsofreinforcedconcreteframecolumnconsideringP2effect[J].JournalofBuildingStructures,2006,27(5):64271.(inChinese))[6]GB500102002[S].(GB500102002Codefordesignofconcretestructure[S].(inChinese))[7]RosenbluethE.Slendernesseffectsinbuilding[J].JournaloftheStructuralDivision,ASCE,1965,91(ST1):972102.[8]LaiShu2mingA,MacgregorJamesG.Geometricnonlinearitiesinunbracedmultistory2frames[J].JournalofStructuralEngineering,ASCE,1983,109(11):252822545.[9]BS811021StructuraluseofconcretePart1:Codeofpracticefordesignandconstruction[S].BritishStandardInstitution,1997.[10].[D].:,2004.(WEIWei.Strengthandstabilityofreinforcedconcreteframecolumnconsideringcharactersofnonlinearandsecond2ordereffect[D].Chongqing:ChongqingUniversity,2004.(inChinese))911