高层建筑与钢结构外文翻译.docx

高层建筑与钢结构外文翻译.docx

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高层建筑与钢结构外文翻译

毕业设计（论文）

外文翻译

2013年

5月

22日

High-riseBuildingandSteelConstruction

HUiWei-jun1，DONGHan1，WENGYu-ging2，CHENSi-lian1，WANGMao-giu1（1.Centraliron&SteelResearchinstitute，Beijing100081，China；

Althoughtherehavebeenmanyadvancementsinbuildingconstructiontechnologyingeneral.Spectaculararchievementshavebeenmadeinthedesignandconstructionofultrahigh-risebuildings.

Theearlydevelopmentofhigh-risebuildingsbeganwithstructuralsteelframing.Reinforcedconcreteandstressed-skintubesystemshavesincebeeneconomicallyandcompetitivelyusedinanumberofstructuresforbothresidentialandcommercialpurposes.Thehigh-risebuildingsrangingfrom50to110storiesthatarebeingbuiltallovertheUnitedStatesaretheresultofinnovationsanddevelopmentofnewstructualsystems.

Greaterheightentailsincreasedcolumnandbeamsizestomakebuildingsmorerigidsothatunderwindloadtheywillnotswaybeyondanacceptablelimit.Excessivelateralswaymaycauseseriousrecurringdamagetopartitionsceilings.andotherarchitecturaldetails.Inadditionexcessiveswaymaycausediscomforttotheoccupantsofthebuildingbecausetheirperceptionofsuchmotion.Structuralsystemsofreinforcedconcreteaswellassteeltakefulladvantageofinherentpotentialstiffnessofthetotalbuildingandthereforerequireadditionalstiffeningtolimitthesway.

Inasteelstructureforexampletheeconomycanbedefinedintermsofthetotalaveragequantityofsteelpersquarefootoffloorareaofthebuilding.CurveAinFig.1representstheaverageunitweightofaconventionalframewithincreasingnumbersofstories.CurveBrepresentstheaveragesteelweightiftheframeisprotectedfromalllateralloads.Thegapbetweentheupperboundaryandthelowerboundaryrepresentsthepremiumforheightforthetraditionalcolumn-and-beamframe.Structuralengineershavedevelopedstructuralsystemswithaviewtoeliminatingthispremium.

Systemsinsteel.Tallbuildingsinsteeldevelopedasaresultofseveraltypesofstructuralinnovations.Theinnovationshavebeenappliedtotheconstructionofbothofficeandapartmentbuildings.

Framewithrigidbelttrusses.Inordertotietheexteriorcolumnsofaframestructuretotheinteriorverticaltrussesasystemofrigidbelttrussesatmid-heightandatthetopofthebuildingmaybeused.AgoodexampleofthissystemistheFirstWisconsinBankBuilding1974inMilwaukee.

Framedtube.Themaximumefficiencyofthetotalstructureofatallbuildingforbothstrengthandstiffnesstoresistwindloadcanbeachievedonlyifallcolumnelementcanbeconnectedtoeachotherinsuchawaythattheentirebuildingactsasahollowtubeorrigidboxinprojectingoutoftheground.Thisparticularstructuralsystemwasprobablyusedforthefirsttimeinthe43-storyreinforcedconcreteDeWittChestnutApartmentBuildinginChicago.Themostsignificantuseofthissystemisinthetwinstructuralsteeltowersofthe110-storyWorldTradeCenterbuildinginNewYork

Column-diagonaltrusstube.Theexteriorcolumnsofabuildingcanbespacedreasonablyfarapartandyetbemadetoworktogetherasatubebyconnectingthemwithdiagonalmembersinterestingatthecentrelineofthecolumnsandbeams.ThissimpleyetextremelyefficientsystemwasusedforthefirsttimeontheJohnHancockCentreinChicagousingasmuchsteelasisnormallyneededforatraditional40-storybuilding.

Bundledtube.Withthecontinuingneedforlargerandtallerbuildingstheframedtubeorthecolumn-diagonaltrusstubemaybeusedinabundledformtocreatelargertubeenvelopeswhilemaintaininghighefficiency.The110-storySearsRoebuckHeadquartersBuildinginChicagohasninetubebundledatthebaseofthebuildinginthreerows.Someoftheseindividualtubesterminateatdifferentheightsofthebuildingdemonstratingtheunlimitedarchitecturalpossibilitiesofthislateststructuralconcept.TheSearstowerataheightof1450ft442mistheworld’stallestbuilding

Stressed-skintubesystem.Thetubestructuralsystemwasdevelopedforimproving.Theresistancetolateralforceswindandearthquakeandthecontrolofdriftlateralbuildingmovementinhigh-risebuilding.Thestressed-skintubetakesthetubesystemastepfurther.Thedevelopmentofthestressed-skintubeutilizesthefaadeofthebuildingasastructuralelementwhichactswiththeframedtubethusprovidinganefficientwayofresistinglateralloadsinhigh-risebuildingsandresultingincost-effectivecolumn-freeinteriorspacewithahighratioofnettogrossfloorarea.

Becauseofthecontributionofthestressed-skinfaadetheframedmembersofthetuberequirelessmassandarethuslighterandlessexpensive.Allthetypicalcolumnsandspandrelbeamsarestandardrolledshapesminimizingtheuseandcostofspecialbuilt-upmembers.Thedepthrequirementfortheperimeterspandrelbeamsisalsoreducedandtheneedforupsetbeamsabovefloorswhichwouldencroachonvaluablespaceisminimized.Thestructuralsystemhasbeenusedonthe54-storyOneMellonBankCenterinPittburgh.

Systemsinconcrete.Whiletallbuildingsconstructedofsteelhadanearlystartdevelopmentoftallbuildingsofreinforcedconcreteprogressedatafastenoughratetoprovideacompetitivechanllengetostructuralsteelsystemsforbothofficeandapartmentbuildings.

Framedtube.Asdiscussedabovethefirstframedtubeconceptfortallbuildingswasusedforthe43-storyDeWittChestnutApartmentBuilding.Inthisbuildingexteriorcolumnswerespacedat5.5ft1.68mcentersandinteriorcolumnswereusedasneededtosupportthe8-in.-thick20-mflat-plateconcreteslabs.

Tubeintube.Anothersysteminreinforcedconcreteforofficebuildingscombinesthetraditionalshearwallconstructionwithanexteriorframedtube.Thesystemconsistsofanouterframedtubeofverycloselyspacedcolumnsandaninteriorrigidshearwalltubeenclosingthecentralservicearea.ThesystemFig.2knownasthetube-in-tubesystemmadeitpossibletodesigntheworld’spresenttallest714ftor218mlightweightconcretebuildingthe52-storyOneShellPlazaBuildinginHoustonfortheunitpriceofatraditionalshearwallstructureofonly35stories.

SystemscombiningbothconcreteandsteelhavealsobeendevelopedanexampleofwhichisthecompositesystemdevelopedbyskidmoreOwingsampMerrilinwhichanexteri.

Anopticalmicrographandaphasemapoftheas-receivedbasematerialareshowninFig.4.Thebasematerialhasatypicalmicrostructureofwroughtduplexstainlesssteelscon-sistingofferritematrixwithausteniteislands.OIManalysisrevealedthattheausteniteislandscontainedahighernumberofgrainboundaries（mostlytwintypeboundaries）thantheferrite.

OIManalysisalsorevealedthattheferritecontentwasabout51%.Averagegrainsizesofausteniteandferritephasesinthebasematerialwereabout4.3and5.1_m,respectively.Opticalmicrostructuresofregions“A,”“B,”“C”and“D”showninFig.3areindicatedinFig.5.RegionBliesontheweldcentre,andregionDislocatedontheborderofthestirzoneandTMAZ.RegionsAandCarelocatedaround2mmawayfromtheweldcentreattheretreatingandadvancingsides,respectively.RegionBhasthemicrostructureconsist-ingofferritematrixwiththemoreelongatedausteniteislands.AusteniteislandsofregionBlookfinerthanthoseofthebasematerial.RegionAhasthesimilarmicrostructuretoregion

B,whileregionCseemstocontainfinerausteniteislandsthanregionB.Distributionoftheausteniteislandsisfinestinthestirzoneattheadvancingside,asshowninmicrographofregionD.Inthisregion,D,theausteniteinthestirzoneexhibitsanaveragegrainsizeoflyingimmediatelyadjacenttoelongatedausteniteislandsintheTMAZ.Phasemapsofregions,CENandintheweldareshowninAllregionsconsistofaferritematrixwiththeausteniteislandssimilartothatofthebasematerial.Dis-tributionoftheausteniteislandsinregionsandCENissimilartothatinthebasematerial,buttheausteniteislands

containmoregrainboundariesthanthebasematerial.Thegrainsizeprofile（Fig.8）showedthattheausteniteandferritegrainsinthestirzoneweresmallerthanthoseinthebasematerial.Additionally,thephasemapsshowedthatboththeausteniteandferritephasesinthestirzonedidnotexhibitaheavilydeformedmicrostructure,e.g.manylowanglegrainboundaries.BoththegrainsizeprofileandphasemapssuggestthatdynamicrecrystallisationoccurredbothintheausteniteandferritephasesduringFSW.Itisgener-allyknownthatdynamicrecrystallisationeasilyoccursintheausteniticstainlesssteels,whileferriticsteelshardlyexperi-encedynamicrecrystallisationbecausetheferritephasehasahighstackingfaultenergy.

Inthecaseoftheduplexstainlesssteels,however,de-formationislocalizedintheferritematrixathightemper-atures,becausetheferritephaseisrelativelyweakerthantheaustenite.Consequently,therecrystallisedgrainsareoftenformedinferritephasemoreeasilythaninaustenitephase.Someresearch]suggeststhattherecrystallisedgrainsintheferritephaseareformed

Bycontinuousdynamicrecrystallisation,whichischarac-terizedbystrain-inducedprogressiverotationofsubgrainswithlittleboundarymigration.Inthepresentstudy,thedu-plexstainlesssteelexperiencedplasticdeformationbytherotatingtoolatrelativelyhightemperaturesduringFSW.Assuch,itislikelythattheferritematrixinthestirzoneunder-goescontinuousdynamicrecrystallisationthroughthesamescenario.