土木工程专业英语 课件 6.3 Earthquake resistance structure system

6.3EarthquakeResistantStructuralSystems

RigidFrameStructures框架

InfilledFrameStructures填充框架ShearWalls剪力墙

BracedFrames支撑框架Wall-frameStructures框架-剪力墙结构

Framed-TubeStructures框筒

Tube–in-tubeorHull-CoreStructuresBraced-TubeStructures桁架筒Bundled-TubeStructures束筒

RigidFrameStructures框架Rigidframestructurestypicallycomprisefloordiaphragms[5daIEfrAm]隔板

supportedonbeamswhichlinktocontinuouscolumns.HorizontaltrussingThejointsbetweenbeamandcolumnsareusuallyconsideredtobe‘rigid’.RigidFrameStructures框架RigidFrameStructurescarry

GravityloadsLateralloads

Theframesareexpectedtocarrythegravityloadsthroughtheflexuralactionofthebeamsandthepropping

[5prCpiN]支撑actionofthecolumns.flexuralactionNegativemomentsareinducedinthebeamadjacent

[E5dVeisEnt]tothecolumnscausingthemid-spanpositivemomenttobesignificantlylessthaninasimplysupportedspan.

mid-spanpositivemoment？lqLateralloads,imposedwithintheplaneoftheframe,areresistedthroughthedevelopmentofbendingmomentsinthebeamsandcolumns.Framedbuildingsoftenemploymomentresistantframesintwoorthogonal

[C:5WC^Enl]正交的

directions,inwhichcasethecolumnelementsarecommontobothframes.thecolumnelementiscommontobothframesRigidframestructuresarewellsuitedto

accommodate使适应highlevelsofinelastic[7ini5lAstik]

deformation.Whenacapacitydesignapproach承载力设计法isemployed,assigntheendzonesoftheflexuralbeamstoacceptthepost-elasticdeformationexpected(weakbeam)designthecolumnmemberssuchthattheirdependable可靠的strengthisinexcessof超过

theover-strengthcapacityofthebeamhingestherebyensuringtheyremainwithintheirelasticresponserange

regardlessoftheintensityofgroundshaking(Strongcolumn).

over-strengthcapacityofthebeamhingesRigidframestructuresare,however,oftenquiteflexible.Whentheyaredesignedtobefullyductile,specialprovisionsareoftenneededtopreventtheprematureonset

[5Cnset]ofdamagetonon-structuralcomponents.Rigidframeconstructionreinforcedconcretebuildings（ideallysuitedfor）steelframebuildings（costly）

Rigidframeconstructionisideally[aI5dIElI]

suitedforreinforcedconcretebuildingbecauseoftheinherent

[in5hiErEnt]

固有的rigidityofreinforcedconcretejointsTherigidframeformisalsousedforsteelframebuildings.Butmomentresistantconnectionsinsteeltendtobecostly.Thesizesofthecolumnsandgirdersatanylevelofarigidframearedirectlyinfluencedbythemagnitudeoftheexternalshearatthatlevel,andtheythereforeincreasetowardthebase.Consequently,thedesignofthefloorframingcannotberepetitive[ri5petitiv]asitisinsomebracedframes.Afurtherresultisthatsometimesitisnotpossibleintheloweststoreystoaccommodatetherequireddepthofgirderwithinthenormalceilingspace.InfilledFrameStructures填充框架Columnandgirderframingofreinforcedconcrete,orsometimessteel,isinfilledbypanelsofbrickwork,orcast-in-placeconcrete.InfilledFrameStructures填充框架Whenaninfilledframeissubjectedtolateralloading,theinfillbehaveseffectivelyasastrutalongitscompressiondiagonaltobracetheframe.InfilledFrameStructures填充框架Becausetheinfillsservealsoasexternalwallsorinternalpartitions,thesystemisaneconomicalwayofstiffeningandstrengtheningthestructure.ShearWalls剪力墙Ashearwall

isaverticalstructuralelementthatresistslateralforcesintheplaneofthewallthroughshearandbending.ShearWalls剪力墙ShearWallsconcretewalls

masonrywalls

highinplanstiffnesshighstrengthShearWalls剪力墙Ashearwallactsasabeamcantileveredoutofthegroundorfoundationpartofitsstrengthderivesfromitsdepth.shearwallsareorientedinonedirection,soonlylateralforcesinthisdirectioncanberesisted.symmetryhas

abearingon(关系到...,影响到...)whethertorsionaleffectswillbeproduced.shearwallssymmetricalintheplaneofloadingshearwallsattheinteriorofamultistoreybuildingwallsenclosingstairways,elevatorshafts,andmechanicalchases

（channel）

aremostlysolidandruntheentireheightofthebuilding,theyareoftenusedforshearwallshearwallsinbothdirectionsShearWalls剪力墙Shearwallsdonotneedtobesymmetricalinabuilding,butsymmetryispreferredtoavoidtorsionaleffects.DesignofShearWall

Shearwallsremainnominallyelasticunderlowormoderate

intensityloadings

post-elasticdeformationswilldevelopwithinthelowerportionofthewallunderhigh

intensityloadings

，(generallyconsideredtoextendoveraheightoftwicethewalllengthabovethefoundationsupportsystem).剪力墙设置底部加强部位Goodpost-elasticresponsecanbereadilyachievedwithinthisregionofreinforcedconcreteormasonryshearwallsthroughtheprovisionofadequateconfinementoftheprincipalreinforcingsteelandtheprohibitionoflapsplicesofreinforcingbars.Coupledshearwall联肢墙

Couplingbeams连梁coupleadjacentmoreslendershearwalls连梁剪切破坏Shearfailureofcouplingbeams连梁、墙肢破坏

ThecouplingbeamsthenbecomeshearlinksbetweenthetwowallsBracedFrames支撑框架Abracedframeisatrusssystemoftheconcentricoreccentrictypeinwhichthelateralforcesareresistedthroughaxialstressesinthemembers.杆件轴向拉伸或压缩BracedFrames支撑框架Atoneendofthebuildingtwobaysarebracedandattheotherendonlyonebayisbraced.buildingisonlybracedinonedirectionandthediagonalmembermaybeeitherintensionorcompression,dependingonwhichwaytheforceisappliedBracedFrames支撑框架Asinglediagonalcompressionmemberinonebaycanbeusedtobraceagainstlateralloadscomingfromeitherdirection.

Tensiondiagonalsmustberunbothwaystoaccountfortheloadcomingfromeitherdirection.Obviously,abracedframecanpresentdesignproblemsforwindowsanddoorways,butitisaveryefficientandrigidlateralforceresistingsystem.BracedFrames支撑框架Wall-frameStructures框架-剪力墙结构shearwallsarecombinedwithrigidframes剪力墙嵌入框架：带边框剪力墙（北京饭店）Wall-frameStructures框架-剪力墙结构WallstendtodeflectinaflexuralconfigurationframestendtodeflectinashearmodeWallsandframesareconstrainedtoadoptacommonshapebythehorizontalrigidityofthegirdersandslabs.Wallsandframesinteracthorizontally,especiallyatthetop,toproduceastifferandstrongerstructure.Althoughthewall-framestructureisusuallyperceivedasaconcretestructuralform,withshearwallsandconcreteframes,asteelcounterpartusingbracedframesandsteelrigidframesofferssimilarbenefitofhorizontalinteraction.Thebracedframesbehavewithanoverallflexuraltendencytointeractwiththeshearmodeoftherigidframes.Wall-frameStructures框架-剪力墙结构shearmodeflexuralmode在水平力作用下，框架和支撑框架侧移协调，结构的整体侧移曲线呈弯剪型Framed-TubeStructures框筒

Thelateralresistanceofframed–tube

structuresisprovidedbyverystiffmomentresistingframesthatforma“tube”aroundtheperimeterofthebuilding.Theframesconsistofcloselyspacedcolumn,2-4mbetweencenters,joinedbydeepspandrelgirders深梁Framed-TubeStructures框筒Whenlateralloadingacts,theperimeterframesalignedinthedirectionofloadingactasthe“web”ofthemassivetubecantilever,andthosenormaltothedirectionoftheloadingactasthe“flanges”.webflangeFramed-TubeStructures框筒TransferbeamTheclosespacingofthecolumnsthroughouttheheightofthestructuresisusuallyunacceptableattheentrancelevel.Thecolumnsarethereforemerged,orterminatedonatransferbeam,afewstoreysabovethebasesothatonlyafew,larger,morewidelyspacedcolumnscontinuetothebase.Framed-TubeStructures框筒剪力滞后(Shearlag)Thetubestructure’sstructuralefficiency,althoughhigh,stillleavesscopeforimprovementbecausethe“flange“framestendtosufferfrom“shearlag”受力特点:剪力滞后(Shearlag)

倾覆力矩产生的柱轴力分布Framed-TubeStructures框筒mid-face“flange”columnsarelessstressesthanthecornercolumnsandnotcontributingasfullyastheycouldtotheflangeaction.Tube–in-tubeorHull-CoreStructures

筒中筒Thisvariationoftheframedtubeconsistsofanouterframedtube,the“hull”,togetherwithaninternalelevatorandservicecore外筒（框筒)+内筒=筒中筒香港中环广场大厦（1995年）78层，309mTube–in-tubeorHull-CoreStructures

筒中筒Thehullandtheinnercoreactjointlyinresistingbothgravityandlateralloading.Innercore内筒bracedframes(steelstructure)钢结构：外筒为钢框筒，内筒为钢框筒或钢支撑框架concreteshearwalls(concretestructure)RC结构：外筒为混凝土框筒，内筒为剪力墙围成的井筒Tube–in-tubeorHull-CoreStructures

筒中筒Tosomeextent,theouterframedtubeandtheinnercoreinteracthorizontallyastheshearandflexuralcomponentsofawall-framestructure,withthebenefitofincreaselateralstiffness.However,thestructuraltubeusuallyadoptsahighlydominantrolebecauseofitsmuchgreaterstructuraldepth.Braced-TubeStructures桁架筒Anotherwayofimprovingtheefficiencyoftheframedtube,therebyincreasingitspotentialforgreaterheightsaswellasallowinggreaterspacingbetweenthecolumns,istoadddiagonalbracingtothefacesofthetube.thespacingofthecolumnscanbelargerandthedepthofthespandrelsless稀柱、浅梁和支