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.