中英高層建筑展望及建筑結構

專業(yè)英語翻譯原文：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譯文：高層建筑展望及建筑結構區(qū)域規(guī)劃對高層建筑物的密度和對自然采光設計可能引起道德問題將產生影響。能源的有限性將繼續(xù)成為建筑設計面臨的獨特挑戰(zhàn)。新老建筑的結合將會給我們的城市帶來人情味。要設計建造出經濟實用，以人為本的建筑物，將會是業(yè)主和概念設計師在20世紀80年代面臨的挑戰(zhàn)。1980年欲斯柯摩爾、奧英斯和米瑞爾（SOM）設計的萊弗公寓獲得了美國建筑師協會授予的25年獎“以獎勵具有深遠意義的優(yōu)秀建筑設計”。這響獎每年授予一座房齡在25~35年之間的建筑物。用劉易斯.芒福德的話來說萊弗公寓是“第一座集現代材料、現代施工、現代功能與現代設計方案為一體的辦公樓”。在當時，這樣大膽的構思只有像設計師戈登.邦沙福特和業(yè)主—萊弗兄弟公司當時的總裁查爾斯.盧克曼那樣富于幻想的人才能創(chuàng)造出來了。而且，這項工程包含了幾個”第一”：（1）它是第一座全封閉的玻璃大廈；（2）它是SOM三人合作設計的第一棟辦公樓；（3）它是公園大街第一座一層樓不設零售商場的辦公樓。今天，經過眾多外觀相似而柱網變化的設計，我們已難以對建筑物進行歸類，這也許是高層建筑設計的縮影。除了最近竣工的幾棟低層樓房似乎比較怡人外，在我們的許多城市中，多數高層建筑物看上去就像圖表上的柱標，好似一塊塊單調而又笨拙的巨石。難道這就是高層建筑設計行業(yè)的終點嗎？也許不是。有跡象表明其發(fā)展是非常令人鼓舞的。建筑師和業(yè)主最近已開始公開討論設計問題。也許我們正處在一個新時代的開端，20世紀80年代也許會產生一些像邦沙福特和盧克曼那樣的幻想家。要是如此，他們會面臨什么樣的限制或挑戰(zhàn)呢？區(qū)域規(guī)劃很顯然，城市可以限制高層建筑的密度，也就是減少每平方英里高層建筑的數量。1980年，“堵塞網”這個術語第一次在紐約市公開使用。它的出現在公眾心中引起恐慌。這個詞指的是城市中四面八方的街區(qū)同時出現的交通停滯不動的現象，堵塞甚至一直延伸到隧道里和高架橋上。奇怪的是，這種事情竟然發(fā)生在紐約燃料短缺、油價高漲的年份。很顯然，要想避免類似情況的出現，就必須大幅度地降低人口、降低活動場所油價車輛的密度。區(qū)域規(guī)劃也許是唯一長遠的解決方法。城市居民由于收到高層建筑的遮擋而見不到陽光，因此，陽光規(guī)劃將越來越受歡迎。無論高層建筑設計得如何節(jié)能，它同時有可能剝奪居住者和鄰居享受陽光的權力。20世紀80年代享受陽光的權力會成為一個十分有趣的道德問題，這個問題會徹底改變城市的建筑布局?；旌嫌猛镜姆謪^(qū)規(guī)劃在20世紀70年代還只是一種在經濟上可行的抉擇，在20世紀80年代將會得到普及，特別是將混合功能分區(qū)規(guī)劃與陽光分區(qū)規(guī)劃相結合，讓所有的住戶都享受到陽光。整修改造伊莫利.羅斯和桑斯兩人合作設計的紐約王宮酒店是對麥迪遜大街上翻修后的古建筑維拉德公寓的補充和增色。這是一個如何對待可搶救的古建筑精品的突出實例。20世紀80年代對中西建筑物的重復利用將是人情味和溫馨回到建筑物的途徑。無論出于什么原因，如果我們必須繼續(xù)使用玻璃和鋁材進行那種呆板的方式設計的話，我們會發(fā)現新老建筑的結合將成為未來富有人情味建筑設計的大趨勢。概念設計有些建筑雜志認為位于舊金山的美洲銀行辦公大樓對于該城市來說規(guī)模過大，位于波士頓的約翰.漢考克中心不僅與該城市的規(guī)模不成比例，而且與其特點不符，對于世界各地主要高層建筑物的類似評論還有不少。這類評論提出了有關設計程序，和誰是重點項目設計的決策者，以及上世紀80年代的建筑設計應由誰來決策等基本問題。未來的幻想家，即建筑師和業(yè)主會回到更富人情味的設計嗎？在今后的幾年里社會學家和心理學家會發(fā)揮他們的重要作用使這些幻想家相信一種截然不同的、合乎人體尺寸的新型建筑設計早該付諸實踐嗎？如果這些問題的突出解決有其合理性的話，那么六七十年代被我們視為“最杰出的”建筑設計師到了八九十年代就變成最差的嗎？他們在大學“建筑史”這門課程中應該了解到“建筑常常反映了文明社會的成功與失敗”，他們會學到這有益的一課并對此作出反應嗎？也許只有時間才會作出回答。建筑物與人類有著密切的關系，它能為人們在其中工作和生活提供必要的空間。根據其功能不同，建筑物主要有兩大類：工業(yè)建筑和民用建筑。工業(yè)建筑有各種工廠或制造廠，而民用建筑指的是那些人們用以居住、工作、教育或其他社會活動的場所。工業(yè)建筑的建造與民用建筑相同，但兩者在所選用的材料、結構形式和體系方面是有差別的。就工程的實質而言，建筑結構可定義為：以保持形狀和穩(wěn)定為目的的各個基本構件的組合體。其基本目的是抵抗作用在建筑物上的各種荷載并把它傳到地基上。從建筑學的角度來講，建筑結構并非僅僅如此。它與建筑風格是不可分割的，在不同程度上是一種建筑風格的體現。如能巧妙地設計建筑結構，則可建立或加強建筑空間與建筑平面之間的格調與節(jié)奏。它在直觀上可以是顯性的或是隱性的。它能產生和諧體或對照體。他可能既局限又開放。不幸的是，在一些情況下，它不能被忽視。它是實際存在的。結構設計還必須與建筑風格相吻合。物理學和數學的原理及工具為區(qū)分在結構上的合理和不合理的形式提供了依據。藝術家有時可以不必考慮科學就能畫出圖形，但建筑師卻不行。在建筑結構中至少應包括三項內容：穩(wěn)定性，強度和剛度，經濟性。在上述三項要求中，首先是穩(wěn)定性。它在保持建筑物形狀上是必不可少的。一座不穩(wěn)定的建筑結構意味著有不平衡的力或失去平衡狀態(tài)，并且由此導致結構整體或構件產生加速度。強度的要求意味著所選擇的結構材料足以承受由荷載產生的應力并且結構形狀必須適當。實際上，通常都提供一個安全系數以便在預計的荷載作用下，使所選用材料的應力不會接近破壞應力。被稱為剛度的材料的特性，需與強度要求一起考慮。剛度不同于強度，因為它涉及荷載作用下結構應變的大小和變形的程度。它具有很高強度，但剛度較低的材料，在外力作用下會因變形過大而失去其使用價值。建筑結構的經濟性指的不僅僅是所用材料的費用。建筑經濟是一個復雜的問題，其中包括原材料、制作、安裝和維修等。必須考慮設計和施工中人工費及能源消耗的費用。施工的速度和資金成本（利息）也是需要考慮的因素。對大多數設計情況，不能僅僅考慮一種建筑材料，經常存在一些有競爭性的其他選擇，而具體應選擇哪種并不明顯。除了這三種最基本要求之外，其他幾種因素也值得重視。首先，結構或結構體系必須和建筑物的功能相