外文翻译建筑的组成部分.doc
河北科技师范学院毕业论文(设计)错误!未找到引用源。题目:ComponentsofABuildingandTallBuildings学生姓名:指导教师:系别:错误!未找到引用源。专业班级:河北科技师范学院教务处制1ComponentsofABuildingandTallBuildings1.AbstractMaterialsandstructuralformsarecombinedtomakeupthevariouspartsofabuilding,includingtheload-carryingframe,skin,floors,andpartitions.Thebuildingalsohasmechanicalandelectricalsystems,suchaselevators,heatingandcoolingsystems,andlightingsystems.Thesuperstructureisthatpartofabuildingaboveground,andthesubstructureandfoundationisthatpartofabuildingbelowground.Theskyscraperowesitsexistencetotwodevelopmentsofthe19thcentury:steelskeletonconstructionandthepassengerelevator.SteelasaconstructionmaterialdatesfromtheintroductionoftheBessemerconverterin1885.GustaveEiffel(1832-1932)introducedsteelconstructioninFrance.HisdesignsfortheGaleriedesMachinesandtheTowerfortheParisExpositionof1889expressedthelightnessofthesteelframework.TheEiffelTower,984feet(300meters)high,wasthetalleststructurebuiltbymanandwasnotsurpasseduntil40yearslaterbyaseriesofAmericanskyscrapers.ElishaOtisinstalledthefirstelevatorinadepartmentstoreinNewYorkin1857.In1889,EiffelinstalledthefirstelevatorsonagrandscaleintheEiffelTower,whosehydraulicelevatorscouldtransport2,350passengerstothesummiteveryhour.2.Load-CarryingFrameUntilthelate19thcentury,theexteriorwallsofabuildingwereusedasbearingwallstosupportthefloors.Thisconstructionisessentiallyapostandlinteltype,anditisstillusedinframeconstructionforhouses.Bearing-wallconstructionlimitedtheheightofbuildingbecauseoftheenormouswallthicknessrequired;forinstance,the16-storyMonadnockBuildingbuiltinthe1880sinChicagohadwalls5feet(1.5meters)thickatthelowerfloors.In1883,WilliamLeBaronJenney(1832-1907)supportedfloorsoncast-ironcolumnstoformacage-likeconstruction.Skeletonconstruction,consistingofsteelbeamsandcolumns,wasfirstusedin1889.Asaconsequenceofskeletonconstruction,theenclosingwallsbecomea“curtainwall”ratherthanservingasupportingfunction.Masonrywasthecurtainwallmaterialuntilthe1930s,whenlightmetalandglasscurtainwallswereused.Aftertheintroductionofbuildingscontinuedtoincreaserapidly.AlltallbuildingswerebuiltwithaskeletonofsteeluntilWorldWar.Afterthewar,theshortageofsteelandtheimprovedqualityofconcreteledtotallbuildingbeingbuiltofreinforcedconcrete.MarinaTower(1962)inChicagoisthetallestconcretebuildingintheUnitedStates;itsheight588feet(179meters)isexceededbythe650-foot(198-meter)PostOfficeTowerinLondonandbyothertowers.2Achangeinattitudeaboutskyscraperconstructionhasbroughtareturntotheuseofthebearingwall.InNewYorkCity,theColumbiaBroadcastingSystemBuilding,designedbyEeroSaarinenin1962,hasaperimeterwallconsistingof5-foot(1.5meter)wideconcretecolumnsspaced10feet(3meters)fromcolumncentertocenter.Thisperimeterwall,ineffect,constitutesabearingwall.Onereasonforthistrendisthatstiffnessagainsttheactionofwindcanbeeconomicallyobtainedbyusingthewallsofthebuildingasatube;theWorldTradeCenterbuildingisanotherexampleofthistubeapproach.Incontrast,rigidframesorverticaltrussesareusuallyprovidedtogivelateralstability.3.SkinTheskinofabuildingconsistsofbothtransparentelements(windows)andopaqueelements(walls).Windowsaretraditionallyglass,althoughplasticsarebeingused,especiallyinschoolswherebreakagecreatesamaintenanceproblem.Thewallelements,whichareusedtocoverthestructureandaresupportedbyit,arebuiltofavarietyofmaterials:brick,precastconcrete,stone,opaqueglass,plastics,steel,andaluminum.Woodisusedmainlyinhouseconstruction;itisnotgenerallyusedforcommercial,industrial,orpublicbuildingbecauseofthefirehazard.4.FloorsTheconstructionofthefloorsinabuildingdependsonthebasicstructuralframethatisused.Insteelskeletonconstruction,floorsareeitherslabsofconcreterestingonsteelbeamsoradeckconsistingofcorrugatedsteelwithaconcretetopping.Inconcreteconstruction,thefloorsareeitherslabsofconcreteonconcretebeamsoraseriesofcloselyspacedconcretebeams(ribs)intwodirectionstoppedwithathinconcreteslab,givingtheappearanceofawaffleonitsunderside.Thekindoffloorthatisuseddependsonthespanbetweensupportingcolumnsorwallsandthefunctionofthespace.Inanapartmentbuilding,forinstance,wherewallsandcolumnsarespacedat12to18feet(3.7to5.5meters),themostpopularconstructionisasolidconcreteslabwithnobeams.Theundersideoftheslabservesastheceilingforthespacebelowit.Corrugatedsteeldecksareoftenusedinofficebuildingsbecausethecorrugations,whenenclosedbyanothersheetofmetal,formductsfortelephoneandelectricallines.5.MechanicalandElectricalSystemsAmodernbuildingnotonlycontainsthespaceforwhichitisintended(office,classroom,apartment)butalsocontainsancillaryspaceformechanicalandelectricalsystemsthathelptoprovideacomfortableenvironment.Theseancillaryspacesinaskyscraperofficebuildingmayconstitute25%ofthetotalbuildingarea.Theimportanceofheating,ventilating,electrical,andplumbingsystemsinanofficebuildingisshownbythefactthat40%oftheconstructionbudgetisallocatedtothem.Becauseoftheincreaseduseofsealedbuildingwithwindowsthatcannotbeopened,elaboratemechanicalsystemsareprovidedforventilationandairconditioning.Ductsandpipescarryfreshairfromcentralfanroomsandairconditioningmachinery.Theceiling,whichis3suspendedbelowtheupperfloorconstruction,concealstheductworkandcontainsthelightingunits.Electricalwiringforpowerandfortelephonecommunicationmayalsobelocatedinthisceilingspaceormaybeburiedinthefloorconstructioninpipesorconduits.Therehavebeenattemptstoincorporatethemechanicalandelectricalsystemsintothearchitectureofbuildingbyfranklyexpressingthem;forexample,theAmericanRepublicInsuranceCompanyBuilding(1965)inDesMoines,Iowa,exposesboththeductsandthefloorstructureinanorganizedandelegantpatternanddispenseswiththesuspendedceiling.Thistypeofapproachmakesitpossibletoreducethecostofthebuildingandpermitsinnovations,suchasinthespanofthestructure.6.SoilsandFoundationsAllbuildingaresupportedontheground,andthereforethenatureofthesoilbecomesanextremelyimportantconsiderationinthedesignofanybuilding.Thedesignofafoundationdependsonmanysoilfactors,suchastypeofsoil,soilstratification,thicknessofsoillaversandtheircompaction,andgroundwaterconditions.Soilsrarelyhaveasinglecomposition;theygenerallyaremixturesinlayersofvaryingthickness.Forevaluation,soilsaregradedaccordingtoparticlesize,whichincreasesfromsilttoclaytosandtograveltorock.Ingeneral,thelargerparticlesoilswillsupportheavierloadsthanthesmallerones.Thehardestrockcansupportloadsupto100tonspersquarefoot(976.5metrictons/sqmeter),butthesoftestsiltcansupportaloadofonly0.25tonpersquarefoot(2.44metrictons/sqmeter).Allsoilsbeneaththesurfaceareinastateofcompaction;thatis,theyareunderapressurethatisequaltotheweightofthesoilcolumnaboveit.Manysoils(exceptformostsandsandgavels)exhibitelasticpropertiestheydeformwhencompressedunderloadandreboundwhentheloadisremoved.Theelasticityofsoilsisoftentime-dependent,thatis,deformationsofthesoiloccuroveralengthoftimewhichmayvaryfromminutestoyearsafteraloadisimposed.Overaperiodoftime,abuildingmaysettleifitimposesaloadonthesoilgreaterthanthenaturalcompactionweightofthesoil.Conversely,abuildingmayheaveifitimposesloadsonthesoilsmallerthanthenaturalcompactionweight.Thesoilmayalsoflowundertheweightofabuilding;thatis,ittendstobesqueezedout.Duetoboththecompactionandfloweffects,buildingstendsettle.Unevensettlements,exemplifiedbytheleaningtowersinPisaandBologna,canhavedamagingeffectsthebuildingmaylean,wallsandpartitionsmaycrack,windowsanddoorsmaybecomeinoperative,and,intheextreme,abuildingmaycollapse.Uniformsettlementsarenotsoserious,althoughextremeconditions,suchasthoseinMexicoCity,canhaveseriousconsequences.Overthepast100years,achangeinthegroundwaterleveltherehascausedsomebuildingstosettlemorethan10feet(3meters).Becausesuchmovementscanoccurduringandafterconstruction,carefulanalysisofthebehaviorofsoilsunderabuildingisvital.Thegreatvariabilityofsoilshasledtoavarietyofsolutionstothefoundationproblem.Where