高层建筑展望及建筑结构

专业英语翻译原文：ThefutureofthetallbuildingAndstructureofbuildingsZoningeffectsonthedensityoftallbuildingsandsolardesignmayraiseethicalchallenge.Acombinedprojectofoldandnewbuildingsmaybringbackhumanscaletoourcities.Ownersandconceptualdesignerswillbechallengedinthe1980stoproduceeconomicallysound,people-orientedbuildings.In1980theLevelHouse,designedbySkidmore,OwingsandMerril1(SOM)receivedthe25-yearawardfromtheAmericanInstituteofArchitects“inrecognitionofarchitecturaldesignofenduringsignificance”.Thisawardisgivenonceayearforabuildingbetween25and35yearsold.LewisMumforddescribedtheLeverHouseas“thefirstofficebuildinginwhichmodernmaterials,modernconstruction,modernfunctionshavebeencombinedwithamodernplan”.Atthetime,thisdaringconceptcouldonlybeachievedbyvisionarymenlikeGordonBunshaft,thedesigner,andCharlesLuckman,theownerandthen-presidentofLeverBrothers.Theprojectalsoincludedafew“first”:(1)itwasthefirstsealedglasstowereverbuilt;(2)itwasthefirstofficebuildingdesignedbySOM;and(3)itwasthefirstofficebuildingonParkAvenuetoomitretailspaceonthefirstfloor.Today,afterhundredsoflook-alikeandvariationsonthegriddesign,wehavereachedwhatmaybetheepitomeoftallbuildingdesign:thenondescriptbuilding.Exceptforafewrecentlycompletedbuildingsthatseemtobepeople-orientedintheirlowerfloors,mosttallbuildingsseemtobearepletionofthedull,graph-paper-likemonolithsinmanyofourcities.Canthisbetheendofthedesign-linefortallbuildings?Probablynot.Therearedefinitesignsthataremostencouraging.Architectsandownershaverecentlybeguntodiscussthedesignproblempublicly.Perhapsweareatthethresholdofanewera.The1980smaybringforthsomenewvisionarieslikeBunshaftandLuckman.Ifso,whatkindsofrestrictionsorchallengesdotheyface?ZoningIndicationsarestrongthatcitiesmayrestrictthedensityoftallbuildings,thatis,reducethenumberoftallbuildingspersquaremile.In1980thetermgrid-lockwasusedforthefirsttimepubliclyinNewYorkCity.Itcausedaterror-likesensationinthepitofone’sstomach.Thetermreferstoasituationinwhichtrafficcomestoastandstillformanycityblocksinalldirections.Thejam-upmayevenreachtothetunnelsandbridges.Strangelyenough,suchaseventhappenedinNewYorkinayearoffuelshortagesandhighgasolineprices.Ifwearetoavoidsimilaroccurrences,itisobviousthatthedensityofpeople,places,andvehiclesmustbedrasticallyreduced.Zoningmaybetheonlylong-termsolution.Solarzoningmaybecomemoreandmorepopularascityresidentsareblockedfromthesunbytallbuildings.Regardlessofhoweffectivelyatallbuildingisdesignedtoconserveenergy,itmayatthesametimedeprivearesidentorneighborofsolaraccess.Inthe1980stherighttoseethesunmaybecomeamostinterestingethicalquestionthatmayrevolutionizethearchitecturalfabricofthecity.Mixed-usezoningbecameafinanciallyviablealternativeduringthe1970s,maybecomecommonplaceduringthe1980s,especiallyifitiscombinedwithsolarzoningtoprovideaccesstothesunforalloccupants.RenovationEmeryRothandSonsdesignedthePalaceHotelinNewYorkasanadditiontoarenovatedhistoricVillardhouseonMadisonAvenue.Itisastrikingexampleofwhatcanbedonewithsalvageableandbeautifullydetailedoldbuildings.Recyclingbothlargeandsmallbuildingsmaybecomethewayinwhichhumanismandwarmthwillbereturnedtobuildingsduringthe80’s.Ifwemustcontinuetodesignwithglassandaluminuminstarkgridpatterns,forwhateverreason,wemayfindthatacombinationofnewandoldwillbecomethegreathumanedesigntrendofthefuture.ConceptualdesignIthasbeensuggestedinarchitecturalmagazinesthattheBankofAmericaofficebuildinginSanFranciscoistoolargeforthecity’sscale.IthasalsobeensuggestedthattheJohnHancockCenterinBostoninnotonlyoutofscalebutalsooutofcharacterwiththecity.Similarstatementsandopinionshavebeenmadeaboutothersignificanttallbuildingsincitiesthroughouttheworld.Thesecommentsraisesomebasicquestionsaboutthedesignprocessandwhoreallymakethedesigndecisionsonimportantstructures-andaboutwhowillmakethesedecisionsinthe1980s.Willtheforthcomingvisionaries-architectsandowners-returntomorehumanedesigns?Willthesociologistorpsychologistplayamoreimportantroleintheyearsaheadtohelpconvincethesevisionariesthatanew,radicallydifferent,human-scaledarchitectureislongoverdue?Ifthesearevalidquestions,coulditbethatour“best”architecturaldesignersofthe60’sand70’swillbecometheworstdesignersofthe80’sand90’s?Orwilltheylearnandrespondtoavaluablelessontheyshouldhavelearnedintheir“HistoryofArchitecture”courseincollegethat“architectureusuallyreflectsthesuccessorfailureorfailureofacivilizedsociety”?Onlytimewilltell.Abuildingiscloselyboundupwithpeople,foritprovidespeoplewiththenecessaryspacetoworkandlivein.Asclassifiedbytheiruse,buildingsaremainlyoftwotypes:industrialbuildingsandcivilbuildings.Industrialbuildingsareusedbyvariousfactoriesorindustrialproductionwhilecivilbuildingsarethosethatareusedbypeoplefordwelling,emplovment,educationandothersocialactivities.Theconstructionofindustrialbuildingsisthesameasthatofcivilbuildings.However,industrialandcivilbuildingsdifferinthematerialsused,andinthestructuralformsorsystemstheyareused.Consideringonlytheengineeringessentials,thestructureofabuildingcanbedefinedastheassemblageofthosepartswhichexistforthepurposeofmaintainingshapeandstability.Itsprimarypurposeistoresistanyloadsappliedtothebuildingandtotransmitthosetotheground.Intermsofarchitecture,thestructureofabuildingisanddoesmuchmorethanthat.Itisaninseparablepartofthebuildingformandtovaryingdegreesisageneratorofthatform.Usedskillfully,thebuildingstructurecanestablishorreinforceordersandrhythmsamongthearchitecturalvolumesandplanes.Itcanbevisuallydominantorrecessive.Itcandevelopharmoniesorconflicts.Itcanbebothconfiningandemancipating.And,unfortunatelyinsomecases,itcannotbeignored.Itisphysical.Thestructuremustalsobeengineeredtomaintainthearchitecturalform.Theprinciplesandtoolsofphysicsandmathematicsprovidethebasisfordifferentiatingbetweenrationalandirrationalformsintermsofconstruction.Artistscansometimesgenerateshapesthatobviateanyconsiderationofscience,butarchitectscannot.Thereareatleastthreeitemsthatmustbepresentinthestructureofabuilding:stability,strengthandstiffness,economy.Takingthefirstofthethreerequirements,itisobviousthatstabilityisneededtomaintainshape.Anunstablebuildingstructureimpliesunbalancedforcesoralackofequilibriumandaconsequentaccelerationofthestructureoritspieces.Therequirementofstrengthmeansthatthematerialsselectedtoresistthestressesgeneratedbytheloadsandshapesofthestructure(s)mustbeadequate.Indeed,a“factorofsafety”isusuallyprovidedsothatundertheanticipatedloads,agivenmaterialisnotstressedtoalevelevenclosetoitsrupturepoint.Thematerialpropertycalledstiffnessisconsideredwiththerequirementofstrength.Stiffnessisdifferentfromstrengthinthatitdirectlyinvolveshowmuchastructurestrainordeflectsunderload.Amaterialthatisverystrongbutlackinginstiffnesswilldeformtoomuchtobeofvalueinresistingtheforcesapplied.Economyofbuildingstructurereferstomorethanjustthecostofthematerialsused.Constructioneconomyisacomplicatedsubjectinvolvingrawmaterials,fabrication,erection,andmaintenance.Designandconstructionlaborcostsandthecostsofenergyconsumptionmustbeconsidered.Speedofconstructionandthecostofmoney(interest)arealsofactors.Inmostdesignsituations,morethanonestructuralmaterialrequiresconsideration.Completivealternativesalmostalwaysexist,andthechoiceisseldomobvious.Apartfromthesethreeprimaryrequirements,severalotherfactorsareworthyofemphasis.First,thestructureorstructuralsystemmustrelatetothebuilding’sfunction.Itshouldnotbeinconflictintermsofform.Forexample,alinearfunctiondemandsalinearstructure,andthereforeitwouldbeimpropertoroofabowlingalleywithadome.Similarly,atheatermusthavelarge,unobstructedspansbutafinerestaurantprobablyshouldnot.Statedsimply,thestructuremustbeappropriatetothefunctionitistoshelter.Second,thestructuremustbefire-resistant.Itisobviousthatthestructuralsystemmustbeabletomaintainitsintegrityatleastuntiltheoccupantsaresafelyout.Buildingcodesspecifythenumberofhoursforwhichcertainpartsofabuildingmustresisttheheatwithoutcollapse.Thestructuralmaterialsusedforthoseelementsmustbeinherentlyfire-resistantorbeadequatelyprotectedbyfireproofingmaterials.Thedegreeoffireresistancetobeprovidedwilldependuponanumberofitems,includingtheuseandoccupancyloadofthespace,itsdimensions,andthelocationofthebuilding.Third,thestructureshouldintegratewellwiththebuilding’scirculationsystems.Itshouldnotbeinconflictwiththepipingsystemsforwaterandwaste,theductingsystemsforair,or(mostimportant)themovementofpeople.Itisobviousbuildingsystemsmustbecoordinatedasthedesignprogresses.Onecandesigninasequentialstep-by-stepmannerwithinanyonesystem,butthedesignofallofthemshouldmoveinaparallelmannertowardcompletion.Spatially,allthevariouspartsofabuildingareinterdependent.Fourth,thestructuremustbepsychologicallysafeaswellasphysicallysafe.Ahigh-riseframethatswaysconsiderablyinthewindmightnotactuallybedangerousbutmaymakethebuildinguninhabitablejustthesame.Lightweightfloorsystemsthataretoo:”bouncy”canmaketheusersveryuncomfortable.Largeglasswindows,uninterruptedbydividingmotions,canbequitesafebutwillappearveryinsecuretotheoccupantstandingnexttoon40floorsabovethestreet.Sometimesthearchitectmustmakedeliberateattemptstoincreasetheapparentstrengthorsolidnessofthestructure.Thisapparentsafetymaybemoreimportantthanhonestlyexpressingthebuilding’sstructure,becausetheuntrainedviewercannotdistinguishbetweenrealandperceivedsafety.Thebuildingdesignerneedstounderstandthebehaviorlfphysicalstructuresunderload.Anabilitytointuitor“feel”structuralbehaviorispossessedbythosehavingmuchexperienceinvolvingstructuralanalysis,bothqualitativeandquantitative.Theconsequentknowledgeofhowforces,stresses,anddeformationsbuildupindifferentmaterialsandshapesisvitaltothedevelopmentofthis“sense”.Structuralanalysisistheprocessofdeterminingtheforcesanddeformationsinstructuresduetospecifiedloadssothatthestructurecanbedesignedrationally,andsothatthestateofsafetyofexistingstructurescanbechecked.Inthedesignofstructures,itisnecessarytostartwithaconceptleadingtoaconfigurationwhichcanthenbeanalyzed.Thisisdonesomemberscanbesizedandtheneededreinforcingdetermined,inorderto:a)carrythedesignloadswithoutdistressorexcessivedeformations(serviceabilityorworkingcondition);andb)topreventcollapsebeforeaspecifiedoverloadhasbeenplacedonthestructure(safetyorultimatecondition).Sincenormallyelasticconditionswillprevailundueworkingloads,astructuraltheorybasedontheassumptionsofelasticbehaviorisappropriatefordeterminingserviceabilityconditions.Collapseofastructurewillusuallyoccuronlylongaftertheelasticrangeofthematerialshasbeenexceededatcriticalpoints,sothatanultimatestrengththeorybasedontheinelasticbehaviorofthematerialsisnecessaryforarationaldeterminationofthesafetyofastructureagainstcollapse.Nevertheless,anelastictheorycanbeusedtodetermineasafeapproximationtothestrengthofductilestructures(thelowerboundapproachofplasticity),andthisapproachiscustomarilyfollowedinreinforcedconcretepractice.Forthisreasononlytheelastictheoryofstructuresispursuedinthischapter.Lookedatcritically,allstructuresareassembliesofthree-dimensionalelements,theexactanalysisofwhichisaforbiddingtaskevenunderidealconditionsandimpossibletocontemplateunderconditionsofprofessionalpractice.Forthisreason,animportantpartoftheanalyst’sworkisthesimplificationoftheactualstructureandloadingconditionstoamodelwhichissusceptibletorationalanalysis.Thus,astructuralframingsystemisdecomposedintoaslabandfloorbeamswhichinturnframeintogirderscarriedbycolumnswhichtransmittheloadstothefoundations.Sincetraditionalstructuralanalysishasbeenunabletocopewiththeactionoftheslab,thishasoftenbeenidealizedintoasystemofstripsactingasbeams.Aldo,long-handmethodhavebeenunabletocopewiththree-dimensionalframingsystems,sothattheentirestructurehasbeenmodeledbyasystemofplanarsubassemblies,tobeanalyzedoneatatime.Themodernmatrix-computermethodshaverevolutionizedstructuralanalysisbymakingitpossibletoanalyzeentiresystems,thusleadingtomorereliablepredictionsaboutthebehaviorofstructuresunderloads.Actualloadingconditionsarealsobothdifficulttodetermineandtoexpressrealistically,andmustbesimplifiedforpurposesofanalysis.Thus,trafficloadsonabridgestructure,whichareessentiallybothofdynamicandrandomnature,areusuallyidealizedintostaticallymovingstandardtrucks,ordistributedloads,intendedtosimulatethemostsevereloadingconditionsoccurringinpractice.Themostimportantuseofstructuralanalysisisasatoolinstructuraldesign.Assuch,itwillusuallybeapartofatrial-anderrorprocedure,inwhichanassumedconfigurationwithassumeddeadloadsisanalyzed,andthemembersdesignedinaccordancewiththeresultsoftheanalysis.Thisphaseiscalledthepreliminarydesigned;sincethisdesignisstillsubjecttochange,usuallyacrude,fastanalysismethodisadequate.Atthisstage,thecostofthestructureisestimated,loadsandmemberpropertiesarerevised,andthedesignischeckedforpossibleimprovements.Thechangesarenowincorporatedinthestructure,amorerefinedanalysisisperformed,andthememberdesignisrevised.Thisprojectiscarriedtoconvergence,therapidityofwhichwilldependonthecapabilityofthedesigner.Itisclearthatavarietyofanalysismethods,rangingfrom”quickanddirtytoexact”,isneededfordesignpurposes.Anefficientanalystmustthusbeincommandoftherigorousmethodsofanalysis,mustbeawareofavailabledesignandanalysisaids,aswellassimplificationspermittedbyapplicablebuildingcodes.Anup-to-dateanalystmustlikewisebeversedinthebasesofmatrixstructuralanalysisanditsuseindigitalcomputersaswellasintheuseofavailableanalysisprogramsorsoftware译文：高层建筑展望及建筑结构区域规划对高层建筑物的密度和对自然采光设计可能引起道德问题将产生影响。能源的有限性将继续成为建筑设计面临的独特挑战。新老建筑的结合将会给我们的城市带来人情味。要设计建造出经济实用，以人为本的建筑物，将会是业主和概念设计师在20世纪80年代面临的挑战。1980年欲斯柯摩尔、奥英斯和米瑞尔（SOM）设计的莱弗公寓获得了美国建筑师协会授予的25年奖“以奖励具有深远意义的优秀建筑设计”。这响奖每年授予一座房龄在25~35年之间的建筑物。用刘易斯.芒福德的话来说莱弗公寓是“第一座集现代材料、现代施工、现代功能与现代设计方案为一体的办公楼”。在当时，这样大胆的构思只有像设计师戈登.邦沙福特和业主—莱弗兄弟公司当时的总裁查尔斯.卢克曼那样富于幻想的人才能创造出来了。而且，这项工程包含了几个”第一”：（1）它是第一座全封闭的玻璃大厦；（2）它是SOM三人合作设计的第一栋办公楼；（3）它是公园大街第一座一层楼不设零售商场的办公楼。今天，经过众多外观相似而柱网变化的设计，我们已难以对建筑物进行归类，这也许是高层建筑设计的缩影。除了最近竣工的几栋低层楼房似乎比较怡人外，在我们的许多城市中，多数高层建筑物看上去就像图表上的柱标，好似一块块单调而又笨拙的巨石。难道这就是高层建筑设计行业的终点吗？也许不是。有迹象表明其发展是非常令人鼓舞的。建筑师和业主最近已开始公开讨论设计问题。也许我们正处在一个新时代的开端，20世纪80年代也许会产生一些像邦沙福特和卢克曼那样的幻想家。要是如此，他们会面临什么样的限制或挑战呢？区域规划很显然，城市可以限制高层建筑的密度，也就是减少每平方英里高层建筑的数量。1980年，“堵塞网”这个术语第一次在纽约市公开使用。它的出现在公众心中引起恐慌。这个词指的是城市中四面八方的街区同时出现的交通停滞不动的现象，堵塞甚至一直延伸到隧道里和高架桥上。奇怪的是，这种事情竟然发生在纽约燃料短缺、油价高涨的年份。很显然，要想避免类似情况的出现，就必须大幅度地降低人口、降低活动场所油价车辆的密度。区域规划也许是唯一长远的解决方法。城市居民由于收到高层建筑的遮挡而见不到阳光，因此，阳光规划将越来越受欢迎。无论高层建筑设计得如何节能，它同时有可能剥夺居住者和邻居享受阳光的权力。20世纪80年代享受阳光的权力会成为一个十分有趣的道德问题，这个问题会彻底改变城市的建筑布局。混合用途的分区规划在20世纪70年代还只是一种在经济上可行的抉择，在20世纪80年代将会得到普及，特别是将混合功能分区规划与阳光分区规划相结合，让所有的住户都享受到阳光。整修改造伊莫利.罗斯和桑斯两人合作设计的纽约王宫酒店是对麦迪逊大街上翻修后的古建筑维拉德公寓的补充和增色。这是一个如何对待可抢救的古建筑精品的突出实例。20世纪80年代对中西建筑物的重复利用将是人情味和温馨回到建筑物的途径。无论出于什么原因，如果我们必须继续使用玻璃和铝材进行那种呆板的方式设计的话，我们会发现新老建筑的结合将成为未来富有人情味建筑设计的大趋势。概念设计有些建筑杂志认为位于旧金山的美洲银行办公大楼对于该城市来说规模过大，位于波士顿的约翰.汉考克中心不仅与该城市的规模不成比例，而且与其特点不符，对于世界各地主要高层建筑物的类似评论还有不少。这类评论提出了有关设计程序，和谁是重点项目设计的决策者，以及上世纪80年代的建筑设计应由谁来决策等基本问题。未来的幻想家，即建筑师和业主会回到更富人情味的设计吗？在今后的几年里社会学家和心理学家会发挥他们的重要作用使这些幻想家相信一种截然不同的、合乎人体尺寸的新型建筑设计早该付诸实践吗？如果这些问题的突出解决有其合理性的话，那么六七十年代被我们视为“最杰出的”建筑设计师到了八九十年代就变成最差的吗？他们在大学“建筑史”这门课程中应该了解到“建筑常常反映了文明社会的成功与失败”，他们会学到这有益的一课并对此作出反应吗？也许只有时间才会作出回答。建筑物与人类有着密切的关系，它能为人们在其中工作和生活提供必要的空间。根据其功能不同，建筑物主要有两大类：工业建筑和民用建筑。工业建筑有各种工厂或制造厂，而民用建筑指的是那些人们用以居住、工作、教育或其他社会活动的场所。工业建筑的建造与民用建筑相同，但两者在所选用的材料、结构形式和体系方面是有差别的。就工程的实质而言，建筑结构可定义为：以保持形状和稳定为目的的各个基本构件的组合体。其基本目的是抵抗作用在建筑物上的各种荷载并把它传到地基上。从建筑学的角度来讲，建筑结构并非仅仅如此。它与建筑风格是不可分割的，在不同程度上是一种建筑风格的体现。如能巧妙地设计建筑结构，则可建立或加强建筑空间与建筑平面之间的格调与节奏。它在直观上可以是显性的或是隐性的。它能产生和谐体或对照体。他可能既局限又开放。不幸的是，在一些情况下，它不能被忽视。它是实际存在的。结构设计还必须与建筑风格相吻合。物理学和数学的原理及工具为区分在结构上的合理和不合理的形式提供了依据。艺术家有时可以不必考虑科学就能画出图形，但建筑师却不行。在建筑结构中至少应包括三项内容：稳定性，强度和刚度，经济性。在上述三项要求中，首先是稳定性。它在保持建筑物形状上是必不可少的。一座不稳定的建筑结构意味着有不平衡的力或失去平衡状态，并且由此导致结构整体或构件产生加速度。强度的要求意味着所选择的结构材料足以承受由荷载产生的应力并且结构形状必须适当。实际上，通常都提供一个安全系数以便在预计的荷载作用下，使所选用材料的应力不会接近破坏应力。被称为刚度的材料的特性，需与强度要求一起考虑。刚度不同于强度，因为它涉及荷载作用下结构应变的大小和变形的程度。它具有很高强度，但刚度较低的材料，在外力作用下会因变形过大而失去其使用价值。建筑结构的经济性指的不仅仅是所用材料的费用。建筑经济是一个复杂的问题，其中包括原材料、制作、安装和维修等。必须考虑设计和施工中人工费及能源消耗的费用。施工的速度和资金成本（利息）也是需要考虑的因素。对大多数设计情况，不能仅仅考虑一种建筑材料，经常存在一些有竞争性的其他选择，而具体应选择哪种并不明显。除了这三种最基本要求之外，其他几种因素也值得重视。首先，结构或结构体系必须和建筑物的功能相吻合而不应该与建筑形式相矛盾。例如，线形功能要求线形结构，所以若把保龄球场的顶部盖