土木外文翻译建筑物的组成及高层结构

ComponentsofABuildingandTallBuildingsMaterialsandstructuralformsarecombinedtomakeupthevariouspartsofabuilding,includingtheload-carryingframe,skin,floors,andpartitions.Thebuildingalsohasmechanicalandelectricalsystems,suchaselevators,heatingandcoolingsystems,andlightingsystems.Thesuperstructureisthatpartofabuildingaboveground,andthesubstructureandfoundationisthatpartofabuildingbelowground.Theskyscraperowesitsexistencetotwodevelopmentsofthe19thcentury:steelskeletonconstructionandthepassengerelevator.SteelasaconstructionmaterialdatesfromtheintroductionoftheBessemerconverterin1885.GustaveEiffel(1832-1932)introducedsteelconstructioninFrance.HisdesignsfortheGaleriedesMachinesandtheTowerfortheParisExpositionof1889expressedthelightnessofthesteelframework.TheEiffelTower,984feet(300meters)high,wasthetalleststructurebuiltbymanandwasnotsurpasseduntil40yearslaterbyaseriesofAmericanskyscrapers.ThefirstelevatorwasinstalledbyElishaOtisinstalledthefirstelevatorinadepartmentstoreinNewYorkin1857.In1889;EiffelinstalledthefirstelevatorsonagrandscaleintheEiffelTower,whosehydraulicelevatorscouldtransport2,350passengerstothesummiteveryhour.Load-CarryingFrame.Untilthelate19thcentury,theexteriorwallsofabuildingwereusedasbearingwallstosupportthefloors.Thisconstructionisessentiallyapostandlinteltype,anditisstillusedinframeconstructionforhouses.Bearing-wallconstructionlimitedtheheightofbuildingsbecauseoftheenormouswallthicknessrequired;Forinstance,the16-storyMonadnockBuildingbuiltinthe1880’sinChicagohadwalls5feet(1.5meters)thickatthelowerfloors.In1883,WilliamLeBaronJenney(1832-1907)supportedfloorsoncast-ironcolumnstoformacage-likeconstruction.Skeletonconstruction,consistingofsteelbeamsandcolumns,wasfirstusedin1889.Asaconsequenceofskeletonconstruction,theenclosingwallsbecomea“curtainwall”ratherthanservingasupportingfunction.Masonrywasthecurtainwallmaterialuntilthe1930’s,whenlightmetalandglasscurtainwallswereused.Aftertheintroductionofbuildingscontinuedtoincreaserapidly.AlltallbuildingswerebuiltwithaskeletonofsteeluntilWorldWarII.Afterthewar,theshortageofsteelandtheimprovedqualityofconcreteledtotallbuildingbeingbuiltofreinforcedconcrete.MarinaTower(1962)inChicagoisthetallestconcretebuildingintheUnitedStates;Itsheight—588feet(179meters)—isexceededbythe650-foot(198-meter)PostOfficeTowerinLondonandbyothertowers.Achangeinattitudeaboutskyscraperconstructionhasbroughtareturntotheuseofthebearingwall.InNewYorkCity,theColumbiaBroadcastingSystemBuilding,designedbyEeroSaarinenin1962,hasaperimeterwallconsistingof5-foot(1.5meter)wideconcretecolumnsspaced10feet(3meters)fromcolumncentertocenter.Thisperimeterwall,ineffect,constitutesabearingwall.Onereasonforthistrendisthatstiffnessagainsttheactionofwindcanbeeconomicallyobtainedbyusingthewallsofthebuildingasatube；theWorldTradeCenterbuildingisanotherexampleofthistubeapproach.Incontrast,rigidframesorverticaltrussesareusuallyprovidedtogivelateralstability.Skin.Theskinofabuildingconsistsofbothtransparentelements(windows)andopaqueelements(walls).Windowsaretraditionallyglass,althoughplasticsarebeingused,especiallyinschoolswherebreakagecreatesamaintenanceproblem.Thewallelements,whichareusedtocoverthestructureandaresupportedbyit,arebuiltofavarietyofmaterials:brick,precastconcrete,stone,opaqueglass,plastics,steel,andaluminum.Woodisusedmainlyinhouseconstruction；Itisnotgenerallyusedforcommercial,industrial,orpublicbuildingbecauseofthefirehazard.Floors.Theconstructionofthefloorsinabuildingdependsonthebasicstructuralframethatisused.Insteelskeletonconstruction,floorsareeitherslabsofconcreterestingonsteelbeamsoradeckconsistingofcorrugatedsteelwithaconcretetopping.Inconcreteconstruction,thefloorsareeitherslabsofconcreteonconcretebeamsoraseriesofcloselyspacedconcretebeams(ribs)intwodirectionstoppedwithathinconcreteslab,givingtheappearanceofawaffleonitsunderside.Thekindoffloorthatisuseddependsonthespanbetweensupportingcolumnsorwallsandthefunctionofthespace.Inanapartmentbuilding,forinstance,wherewallsandcolumnsarespacedat12to18feet(3.7to5.5meters),themostpopularconstructionisasolidconcreteslabwithnobeams.Theundersideoftheslabservesastheceilingforthespacebelowit.Corrugatedsteeldecksareoftenusedinofficebuildingsbecausethecorrugations,whenenclosedbyanothersheetofmetal,formductsfortelephoneandelectricallines.MechanicalandElectricalSystems.Amodernbuildingnotonlycontainsthespaceforwhichitisintended(office,classroom,apartment)butalsocontainsancillaryspaceformechanicalandelectricalsystemsthathelptoprovideacomfortableenvironment.Theseancillaryspacesinaskyscraperofficebuildingmayconstitute25%ofthetotalbuildingarea.Theimportanceofheating,ventilating,electrical,andplumbingsystemsinanofficebuildingisshownbythefactthat40%oftheconstructionbudgetisallocatedtothem.Becauseoftheincreaseduseofsealedbuildingwithwindowsthatcannotbeopened,elaboratemechanicalsystemsareprovidedforventilationandairconditioning.Ductsandpipescarryfreshairfromcentralfanroomsandairconditioningmachinery.Theceiling,whichissuspendedbelowtheupperfloorconstruction,concealstheductworkandcontainsthelightingunits.Electricalwiringforpowerandfortelephonecommunicationmayalsobelocatedinthisceilingspaceormaybeburiedinthefloorconstructioninpipesorconduits.Therehavebeenattemptstoincorporatethemechanicalandelectricalsystemsintothearchitectureofbuildingbyfranklyexpressingthem；Forexample,theAmericanRepublicInsuranceCompanyBuilding(1965)inDesMoines,Iowa,exposesboththeductsandthefloorstructureinanorganizedandelegantpatternanddispenseswiththesuspendedceiling.Thistypeofapproachmakesitpossibletoreducethecostofthebuildingandpermitsinnovations,suchasinthespanofthestructure.SoilsandFoundations.Allbuildingaresupportedontheground,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)exhibitelasticproperties—theydeformwhencompressedunderloadandreboundwhentheloadisremoved.Theelasticityofsoilsisoftentime-dependent,thatis,deformationsofthesoiloccuroveralengthoftimewhichmayvaryfromminutestoyearsafteraloadisimposed.Overaperiodoftime,abuildingmaysettleifitimposesaloadonthesoilgreaterthanthenaturalcompactionweightofthesoil.Conversely,abuildingmayheaveifitimposesloadsonthesoilsmallerthanthenaturalcompactionweight.Thesoilmayalsoflowundertheweightofabuilding;Thatis,ittendstobesqueezedout.Duetoboththecompactionandfloweffects,buildingstendsettle.Unevensettlements,exemplifiedbytheleaningtowersinPisaandBologna,canhavedamagingeffects—thebuildingmaylean,wallsandpartitionsmaycrack,windowsanddoorsmaybecomeinoperative,and,intheextreme,abuildingmaycollapse.Uniformsettlementsarenotsoserious,althoughextremeconditions,suchasthoseinMexicoCity,canhaveseriousconsequences.Overthepast100years,achangeinthegroundwaterleveltherehascausedsomebuildingstosettlemorethan10feet(3meters).Becausesuchmovementscanoccurduringandafterconstruction,carefulanalysisofthebehaviorofsoilsunderabuildingisvital.Thegreatvariabilityofsoilshasledtoavarietyofsolutionstothefoundationproblem.Wherefirmsoilexistsclosetothesurface,thesimplestsolutionistorestcolumnsonasmallslabofconcrete(spreadfooting).Wherethesoilissofter,itisnecessarytospreadthecolumnloadoveragreaterarea；inthiscase,acontinuousslabofconcrete(raftormat)underthewholebuildingisused.Incaseswherethesoilnearthesurfaceisunabletosupporttheweightofthebuilding,pilesofwood,steel,orconcretearedrivendowntofirmsoil.Theconstructionofabuildingproceedsnaturallyfromthefoundationuptothesuperstructure.Thedesignprocess,however,proceedsfromtheroofdowntothefoundation(inthedirectionofgravity).Inthepast,thefoundationwasnotsubjecttosystematicinvestigation.Ascientificapproachtothedesignoffoundationshasbeendevelopedinthe20thcentury.KarlTerzaghioftheUnitedStatespioneeredstudiesthatmadeitpossibletomakeaccuratepredictionsofthebehavioroffoundations,usingthescienceofsoilmechanicscoupledwithexplorationandtestingprocedures.Foundationfailuresofthepast,suchastheclassicalexampleoftheleaningtowerinPisa,havebecomealmostnonexistent.Foundationsstilhreahiddenbutcostlypartofmanybuildings.Althoughtherehavebeenmanyadvancementsinbuildingconstructiontechnologyingeneral,spectacularachievementshavebeenmadeinthedesignandconstructionofultrahigh-risebuildings.Theearlydevelopmentofhigh-risebuildingsbeganwithstructuralsteelframing.Reinforcedconcreteandstressed-skintubesystemshavesincebeeneconomicallyandcompetitivelyusedinanumberofstructuresforbothresidentialandcommercialpurposes.Thehigh-risebuildingsrangingfrom50to110storiesthatarebeingbuiltallovertheUnitedStatesaretheresultofinnovationsanddevelopmentofnewstructuralsystems.Greaterheightentailsincreasedcolumnandbeamsizestomakebuildingsmorerigidsothatunderwindloadtheywillnotswaybeyondanacceptablelimit.Excessivelateralswaymaycauseseriousrecurringdamagetopartitions,ceilings,andotherarchitecturaldetails.Inaddition,excessiveswaymaycausediscomforttotheoccupantsofthebuildingbecauseoftheirperceptionofsuchmotion.Structuralsystemsofreinforcedconcrete,aswellassteel,takefulladvantageoftheinherentpotentialstiffnessofthetotalbuildingandthereforedonotrequireadditionalstiffeningtolimitthesway.Inasteelstructure,forexample,theeconomycanbedefinedintermsofthetotalaveragequantityofsteelpersquarefootoffloorareaofthebuilding.Thegapbetweentheupperboundaryandthelowerboundaryrepresentsthepremiumforalllateralloads.Thegapbetweentheupperboundaryandthelowerboundaryrepresentsthepremiumforheightforthetraditionalcolumn-and-beamframe.Structuralengineershavedevelopedstructuralsystemswithaviewtoeliminatingthispremium.Systemsinsteel.Tallbuildingsinsteeldevelopedasaresultofseveraltypesofstructuralinnovations.Theinnovationshavebeenappliedtotheconstructionofbothofficeandapartmentbuildings.Frameswithrigidbelttrusses.Inordertotietheexteriorcolumnsofaframestructuretotheinteriorverticaltrusses,asystemofrigidbelttrussesatmid-heightandatthetopofthebuildingmaybeused.AgoodexampleofthissystemistheFirstWisconsinBankBuilding(1974)inMilwaukee.Framedtube.Themaximumefficiencyofthetotalstructureofatallbuilding,forbothstrengthandstiffness,toresistwindloadcanbeachievedonlyifallcolumnelementscanbeconnectedtoeachotherinsuchawaythattheentirebuildingactsasahollowtubeorrigidboxinprojectingoutoftheground.Thisparticularstructuralsystemwasprobablyusedforthefirsttimeinthe43-storyreinforcedconcreteDeWittChestnutApartmentBuildinginChicago.Themostsignificantuseofthissystemisinthetwinstructuralsteeltowersofthe110-storyWorldTradeCenterbuildinginNewYork.Column-diagonaltrusstube.Theexteriorcolumnsofabuildingcanbespacedreasonablyfarapartandyetbemadetoworktogetherasatubebyconnectingthemwithdiagonalmembersintersectingatthecenterlineofthecolumnsandbeams.ThissimpleyetextremelyefficientsystemwasusedforthefirsttimeontheJohnHancockCenterinChicago,usingasmuchsteelasisnormallyneededforatraditional40-storybuilding.Bundledtube.Withthecontinuingneedforlargerandtallerbuildings,theframedtubeorthecolumn-diagonaltrusstubemaybeusedinabundledformtocreatelargertubeenvelopeswhilemaintaininghighefficiency.The110-storySearsRoebuckHeadquartersBuildinginChicagohasninetubes,bundledatthebaseofthebuildinginthreerows.Someoftheseindividualtubesterminateatdifferentheightsofthebuilding,demonstratingtheunlimitedarchitecturalpossibilitiesofthislateststructuralconcept.TheSearstower,ataheightof1450ft(442m),istheworld'stallestbuilding.Stressed-skintubesystem.Thetubestructuralsystemwasdevelopedforimprovingtheresistancetolateralforces(windorearthquake)andthecontrolofdrift(lateralbuildingmovement)inhigh-risebuilding.Thestressed-skintubetakesthetubesystemastepfurther.Thedevelopmentofthestressed-skintubeutilizesthefacadeofthebuildingasastructuralelementwhichactswithactswiththeframedtube,thusprovidinganefficientwayofresistinglateralloadsinhigh-risebuildings,andresultingincost-effectivecolumn-freeinteriorspacewithahighratioofnettogrossfloorarea.Becauseofthecontributionofthestressed-skinfacade,theframedmembersofthetuberequirelessmass,andarethuslighterandlessexpansive.Allthetypicalcolumnsandspandrelbeamsarestandardrolledshapes,minimizingtheuseandcostofspecialbuilt-upmembers.Thedepthrequirementfortheperimeterspandrelbeamsisalsoreduced,andtheneedforupsetbeamsabovefloors,whichwouldencroachonvaluablespace,isminimized.Thestructuralsystemhasbeenusedonthe54-storyOneMellonBankCenterinPittsburgh.Systemsinconcrete.Whiletallbuildingsconstructedofsteelhadanearlystart,developmentoftallbuildingsofreinforcedconcreteprogressedatafastenoughratetoprovideacompetitivechallengetostructuralsteelsystemsforbothofficeandapartmentbuildings.Framedtube.Asdiscussedabove,thefirstframedtubeconceptfortallbuildingswasusedforthe43-storyDeWittChestnutApartmentBuilding.Inthisbuilding,exteriorcolumnswerespacedat5.5-ft(1.68-m)centers,andinteriorcolumnswereusedasneededtosupportthe8-in.-thick(20-cm)flat-plateconcreteslabs.Tubeintube.Anothersysteminreinforcedconcreteforofficebuildingscombinesthetraditionalshearwallconstructionwithanexteriorframedtube.Thesystemconsistsofanouterframedtubeofverycloselyspacedcolumnsandaninteriorrigidshearwalltubeenclosingthecentralservicearea.Thesystem(Fig.2),knownasthetube-in-tubesystem,madeitpossibletodesigntheworld'spresenttallest(714ftor218m)lightweightconcretebuilding(the52-storyOneShellPlazaBuildinginHouston)fortheunitpriceofatraditionalshearwallstructureofonly35stories.Systemscombiningbothconcreteandsteelhavealsobeendeveloped,anexampleofwhichisthecompositesystemdevelopedbySkidmore,Owings&Merrillinwhichanexteriorcloselyspacedframedtubeinconcreteenvelopsaninteriorsteelframing,therebycombiningtheadvantagesofbothreinforcedconcreteandstructuralsteelsystems.The52-storyOneShellSquareBuildinginNewOrleansisbasedonthissystem.出处：《土木工程专业英语》，段兵廷主编，武汉理工大学出版社建筑物的组成及高层结构材料和不同的结构形式组成建筑物各类不同部份，包括繁重框架、夕卜壳、楼板和隔墙。在建筑物内部还有机械和电气系统，例如电梯、供暖和冷却系统、照明系统等。地面以上的部份是建筑物的上部结构，地面以下部份为建筑物的基础和下部结构。摩天大楼的显现应归功于19世纪的两大进展：钢骨架结构和载人电梯。钢材作为一种建筑材料，是从1855年贝西默炼钢法被第一次介绍后开始应用的。古斯塔•艾菲尔(1832~1923)第一次将钢结构引入法国。1889年的巴黎国际展览会的塔和他为Galeriedes机械的设计表现了钢结构的灵活性。艾菲尔铁塔高300米，是那时人类建造的最高建筑物，直到40年后才由美国的摩天大楼超过其高度。第一部电梯是1857年ElishaOtis给纽约的一家百货公司所安装的。1889年，艾菲尔在艾菲尔铁塔上安装了第一部大型电梯，它每小时能够输送2350位乘客抵达塔顶。繁重框架。直到19世纪后期，建筑物的外墙被用做繁重墙来支撑楼层，这种结构是本质上是一种梁柱模型，它还被用在框架结构衡宇中。因为所需墙体的厚度专门大，繁重墙结构限制了建筑物的高度；例如，建于19世纪80年代的芝加哥16层高的MonadnockBuilding，在较低的楼层墙体厚度已达到1.5米。1883年，WillianLeBaronJenney(1832~1907)用铸铁柱来支撑楼层的方式以形成笼状结构。在1889年，框架结构第一次由钢梁和钢柱组成。由于骨架结构，围墙变成了一种〃幕墙”。砖石一直是〃幕墙”的要紧材料，直到20世纪30年代轻金属和玻璃幕墙的问世为止。自从钢框架第一次推出，建筑物的高度一直在迅速增加。在第二次世界大战前，所有的高层建筑都是钢结构。战争终止以后，钢材的缺乏和混凝土质量的改良，增进了钢筋混凝土高层建筑的进展。芝加哥的MarinaTowers(1962)是美国最高的混凝土建筑；它的高度是588英尺即179米，不久以后被伦敦的高达650英尺即198米的邮政大厦和其它的塔所超越。在关于摩天大楼构造观点的改变恢复了繁重墙的利用。在纽约，由EeroSaarinen于1962年设计的哥伦比亚广播公司大楼，由1.5米宽，柱与柱的中心间距为3米的混凝土柱组成的环形墙。这种围护墙有效地组成了建筑物的繁重墙。这种趋势进展的缘故是建筑物的墙作为一个筒体能够超级经济的取得抗风作用的足够强度；世贸大楼是另一个筒体法的例子。相较之下，刚性框架或垂直的桁架通经常使用于提供侧向稳固性。夕卜壳。一个建筑的外壳由透明元素（窗户）和不透明元素（墙）组成。窗户采纳传统上的玻璃作为材料，尽管塑料正在被利用，专门在学校，破损产生了一个保护问题。用来覆盖结构和起支撑作用墙，它是由各类的建筑材料组成：砖、预制构件、石头、不透明的玻璃、塑料、钢材和铝材。木头是过去建造衡宇的要紧材料；因为它易着火，因此不经常使用于商业的、工业的和公共建筑。楼板。一幢建筑的楼地面结构取决于它所利用的大体结构框架。在钢框架建筑中，楼地面或是钢梁上的混凝土楼板，或是由波纹钢配有混凝土骨料组成的凹板。在混凝土结构中，楼板或是混凝土梁上的混凝土楼板或是一系列紧密散布于混凝土梁在方向上端的薄混凝土楼板，在它的下面提供了一个多余的空寂间。这种类型的板取决于支撑柱之间的距离或墙间的跨度和空间的功能性。在一栋公寓大楼中，例如，墙和柱间距在3.7米到5.5米，最多见的结构是无梁实心混凝土楼盖。楼盖的下表面能够作为基层空间的天花板。办公大楼中常利用波纹钢地板，这是因为波纹钢地板的波纹当由另一块金属板盖上时，能够形成线和电线管道。机械和电力系统。一个现代建筑不仅包括必要利用空间（办公室，教室，公寓）而且也包括机械、电力系统等的辅助空间，以便营造一个舒适的生活环境。这些辅助空间可能占摩天大楼总建筑面积的25%。在一个办公大楼中，供暖、通风、电力和卫生设备系统的预算额占实际建筑总预算额的40%，显示了它们在建筑中的重要性。因为许多建筑是密封的，窗户不能被打开，因此由机械系统提供了通风设备和空气调剂设备。新鲜空气从中央换气室由空气调剂器用管道输入。通风管和操纵照明设备单元由悬挂在上面楼层结构下面的天花板遮住了。提供动力的电力线路和通信线路也可能在天花板里或也可能在楼地面结构层中的管道或导线管里。咱们曾尝试性地把机械、电力系统加入建筑物的建筑学中去。例如在爱荷华州首府的美国共和保险公司大楼，管道和楼地面的结构层有组织的、优美的悬挂在天花板上。这种型的方式使得建筑物的花费尽可能的减少了而且使结构有了创新，例如在结构间足昉面。土地和地基。所有的建筑物都是靠土层支撑在地面上的，因此土的特性成为建筑设计时极为重要的考虑因素。基础的设计取决于土的许多因素，例如土的类型，土分层的情形，土层的厚度和它的密实度，和地下水的情形等。土层很少有一个单一的成份；他们一般是厚度转变的混合状态土层。据评定，土层的品级是依照土分子的大小来划分，从小到大依次是淤泥、粘土、沙、石子、岩石。通常，较大分子的土支撑的荷载要大。最坚硬的岩石能够支撑的荷载大约是每平方米100吨，而最软的淤泥仅能够支撑的荷载大约是每平方米0.25吨。所有地表以下的土都处于受压状态，说得更精准些，这些土经受与作用在其上的土柱重量相等的压力。许多土显示出弹性的性质——在荷载作用下受压变形，当荷载解除后能够回弹。土的弹性常随时刻而改变，更精准地说，土层的变形在恒载作用下随着时刻的增加而不断地改变。过一段时刻后，若是加于土层上的荷载大于土自然压紧状态下的重量，那么建筑物会产生沉降。相反，那么会产生隆起，建筑物的重量可能会使本地货生流动；也确实是说，常常会发生土被挤出。由于土受压和流动的阻碍，使建筑物发生沉降。不均匀沉降例如比萨斜塔，损坏的结果是建筑物发生倾斜，墙和隔墙可能显现裂痕，窗户和门可能产生变形，或乃至建筑可能倒塌。均匀沉降可不能如此严峻，尽管可能显现危险状况，例如墨西哥城的一些建筑，显现各类各样的后果，在过去的一年里，地下水位发生了改变，致使一些建筑下沉了3米多。因为类似的状况可能发生在建造时也可能是建造后，因此警惕处置建筑物下的土层是极为重要的。土层庞大的转变使得解决地基问题的方法多样化。若是表面土层下的土为坚硬土层，最简单的方法是采纳混凝土基础。假设是软弱土层，加大柱的面积；假设如此的话，整个建筑就可采纳筏板基础。假设表面土层不能够支撑建筑物的重量，木结构建筑、钢结构建筑、或混凝土建筑应建造在坚硬土层上。建造一幢建筑物一样是从基础往上到上部结构。但是设计的进程是从屋顶开始到基础。在过去，地基处置不是一个系统的研究项目。在