中英 建筑中的结构设计及建筑材料

StructureinDesignofArchitectureAndStructuralMaterialWehaveandthearchitectsmustdealwiththespatialaspectofactivity,physical,andsymbolicneedsinsuchawaythatoverallperformanceintegrityisassured.Hence,heorshewellwantstothinkofevolvingabuildingenvironmentasatotalsystemofinteractingandspaceformingsubsystems.Isrepresentsacomplexchallenge,andtomeetitthearchitectwillneedahierarchicdesignprocessthatprovidesatleastthreelevelsoffeedbackthinking:schematic,preliminary,andfinal.Suchahierarchyisnecessaryifheorsheistoavoidbeingconfused,atconceptualstagesofdesignthinking,bythemyriaddetailissuesthatcandistractattentionfrommorebasicconsiderations.Infact,wecansaythatanarchitect’sabilitytodistinguishthemorebasicformthemoredetailedissuesisessentialtohissuccessasadesigner.Theobjectoftheschematicfeedbacklevelistogenerateandevaluateoverallsite-plan,activity-interaction,andbuilding-configurationoptions.Todosothearchitectmustbeabletofocusontheinteractionofthebasicattributesofthesitecontext,thespatialorganization,andthesymbolismasdeterminantsofphysicalform.Thismeansthat,inschematicterms,thearchitectmayfirstconceiveandmodelabuildingdesignasanorganizationalabstractionofessentialperformance-spaceinteractions.Thenheorshemayexploretheoverallspace-formimplicationsoftheabstraction.Asanactualbuildingconfigurationoptionbeginstoemerge,itwillbemodifiedtoincludeconsiderationforbasicsiteconditions.Attheschematicstage,itwouldalsobehelpfulifthedesignercouldvisualizehisorheroptionsforachievingoverallstructuralintegrityandconsidertheconstructivefeasibilityandeconomicofhisorherscheme.Butthiswillrequirethatthearchitectand/oraconsultantbeabletoconceptualizetotal-systemstructuraloptionsintermsofelementaldetail.Suchoverallthinkingcanbeeasilyfedbacktoimprovethespace-formscheme.Atthepreliminarylevel,thearchitect’semphasiswillshifttotheelaborationofhisorhermorepromisingschematicdesignoptions.Herethearchitect’sstructuralneedswillshifttoapproximatedesignofspecificsubsystemoptions.Atthisstagethetotalstructuralschemeisdevelopedtoamiddlelevelofspecificitybyfocusingonidentificationanddesignofmajorsubsystemstotheextentthattheirkeygeometric,component,andinteractivepropertiesareestablished.Basicsubsysteminteractionanddesignconflictscanthusbeidentifiedandresolvedinthecontextoftotal-systemobjectives.Consultantscanplayasignificantpartinthiseffort;thesepreliminary-leveldecisionsmayalsoresultinfeedbackthatcallsforrefinementorevenmajorchangeinschematicconcepts.Whenthedesignerandtheclientaresatisfiedwiththefeasibilityofadesignproposalatthepreliminarylevel,itmeansthatthebasicproblemsofoveralldesignaresolvedanddetailsarenotlikelytoproducemajorchange.Thefocusshiftsagain,andthedesignprocessmovesintothefinallevel.Atthisstagetheemphasiswillbeonthedetaileddevelopmentofallsubsystemspecifics.Heretheroleofspecialistsfromvariousfields,includingstructuralengineering,ismuchlarger,sincealldetailofthepreliminarydesignmustbeworkedout.DecisionsmadeatthislevelmayproducefeedbackintoLevelIIthatwillresultinchanges.However,ifLevelsIandIIarehandledwithinsight,therelationshipbetweentheoveralldecisions,madeattheschematicandpreliminarylevels,andthespecificsofthefinallevelshouldbesuchthatgrossredesignisnotinquestion,Rather,theentireprocessshouldbeoneofmovinginanevolutionaryfashionfromcreationandrefinement(ormodification)ofthemoregeneralpropertiesofatotal-systemdesignconcept,tothefleshingoutofrequisiteelementsanddetails.Tosummarize:AtLevelI,thearchitectmustfirstestablish,inconceptualterms,theoverallspace-formfeasibilityofbasicschematicoptions.Atthisstage,collaborationwithspecialistscanbehelpful,butonlyifintheformofoverallthinking.AtLevelII,thearchitectmustbeabletoidentifythemajorsubsystemrequirementsimpliedbytheschemeandsubstantialtheirinteractivefeasibilitybyapproximatingkeycomponentproperties.Thatis,thepropertiesofmajorsubsystemsneedbeworkedoutonlyinsufficientdepthtoverytheinherentcompatibilityoftheirbasicform-relatedandbehavioralinteraction.ThiswillmeanasomewhatmorespecificformofcollaborationwithspecialiststhenthatinlevelI.AtlevelIII,thearchitectandthespecificformofcollaborationwithspecialiststhenthatprovidingforalloftheelementaldesignspecificsrequiredtoproducebiddableconstructiondocuments.OfcoursethissuccesscomesfromthedevelopmentoftheStructuralMaterial.Theprincipalconstructionmaterialsofearliertimeswerewoodandmasonrybrick,stone,ortile,andsimilarmaterials.Thecoursesorlayerswereboundtogetherwithmortarorbitumen,atarlikesubstance,orsomeotherbindingagent.TheGreeksandRomanssometimesusedironrodsorclapstostrengthentheirbuilding.ThecolumnsoftheParthenoninAthens,forexample,haveholesdrilledinthemforironbarsthathavenowrustedaway.TheRomansalsousedanaturalcementcalledpuzzling,madefromvolcanicash,thatbecameashardasstoneunderwater.Bothsteelandcement,thetwomostimportantconstructionmaterialsofmoderntimes,wereintroducedinthenineteenthcentury.Steel,basicallyanalloyofironandasmallamountofcarbonhadbeenmadeuptothattimebyalaboriousprocessthatrestrictedittosuchspecialusesasswordblades.AftertheinventionoftheBessemerprocessin1856,steelwasavailableinlargequantitiesatlowprices.Theenormousadvantageofsteelisitstensileforcewhich,aswehaveseen,tendstopullapartmanymaterials.Newalloyshavefurther,whichisatendencyforittoweakenasaresultofcontinualchangesinstress.Moderncement,calledPortlandcement,wasinventedin1824.Itisamixtureoflimestoneandclay,whichisheatedandthengroundintoapower.Itismixedatorneartheconstructionsitewithsand,aggregatesmallstones,crushedrock,orgravel,andwatertomakeconcrete.Differentproportionsoftheingredientsproduceconcretewithdifferentstrengthandweight.Concreteisveryversatile;itcanbepoured,pumped,orevensprayedintoallkindsofshapes.Andwhereassteelhasgreattensilestrength,concretehasgreatstrengthundercompression.Thus,thetwosubstancescomplementeachother.Theyalsocomplementeachotherinanotherway:theyhavealmostthesamerateofcontractionandexpansion.Theythereforecanworktogetherinsituationswherebothcompressionandtensionarefactors.Steelrodsareembeddedinconcretetomakereinforcedconcreteinconcretebeamsorstructureswheretensionswilldevelop.Concreteandsteelalsoformsuchastrongbond─theforcethatunitesthem─thatthesteelcannotslipwithintheconcrete.Stillanotheradvantageisthatsteeldoesnotrustinconcrete.Acidcorrodessteel,whereasconcretehasanalkalinechemicalreaction,theoppositeofacid.Theadoptionofstructuralsteelandreinforcedconcretecausedmajorchangesintraditionalconstructionpractices.Itwasnolongernecessarytousethickwallsofstoneorbrickformultistorybuildings,anditbecamemuchsimplertobuildfire-resistantfloors.Boththesechangesservedtoreducethecostofconstruction.Italsobecamepossibletoerectbuildingswithgreaterheightsandlongerspans.Sincetheweightofmodernstructuresiscarriedbythesteelorconcreteframe,thewallsdonotsupportthebuilding.Theyhavebecomecurtainwalls,whichkeepouttheweatherandletinlight.Intheearliersteelorconcreteframebuilding,thecurtainwallsweregenerallymadeofmasonry;theyhadthesolidlookofbearingwalls.Today,however,curtainwallsareoftenmadeoflightweightmaterialssuchasglass,aluminum,orplastic,invariouscombinations.Anotheradvanceinsteelconstructionisthemethodoffasteningtogetherthebeams.Formanyyearsthestandardmethodwasriveting.Arivetisaboltwithaheadthatlookslikeabluntscrewwithoutthreads.Itisheated,placedinholesthroughthepiecesofsteel,andasecondheadisformedattheotherendbyhammeringittoholditinplace.Rivetinghasnowlargelybeenreplacedbywelding,thejoiningtogetherofpiecesofsteelbymeltingasteelmaterialbetweenthemunderhighheat.愤Priest栏es沟s蹄’撒sconc臭retei装sani钩mprove丛dform阔ofre深inforc嫩ement.刃Steel叉rods楼arebe唱ntint贼othe愿shapes按togi士vethe牲mthe炊necess拼aryde编greeo毕ftens断ilest孙rength杠s.The钱yare怕thenu备sedto框pries榆tessc径oncret与e,usu皆allyb立yone硬oftwo省diffe晌rentm锈ethods宗.The森first暴isto奖leave呼channe祸lsin侵aconc押reteb线eamth荣atcor还respon罚dtot阶hesha使pesof裕thes僚teelr昏ods.W骑henth宝erods抖arer留unthr谨ought跪hecha森nnels,低they改areth搅enbon帝dedto问thec邪oncret丑ebyf乓illing膏thec妇hannel楼swith园grout版,ath还inmor滨taror迁bindi衫ngage概nt.In狮theo怀ther(负andmo谣recom伪mon)m年ethod,前thep涛rieste坚ssess疏teelr翁odsar浊eplac口edin床thelo支werpa招rtof谎aform伶that撇corres弊ponds闯tothe察shape添ofth泽efini拨sheds岩tructu叛re,an物dthe恐concre脏teis钱poured币aroun谎dthem效.Prie闭stes滩s必’弓sconc绞reteu推sesle政ssste图eland且less喂concre载te.Be但cause绝itis肥ahigh积lydes蔬irable雾mater胆ial.衔Progre丈ssedc梨oncret欺ehas简madei素tposs厉iblet语odeve祥lopbu侮ilding盏swith穗unusu骆alsha全pes,l喇ikeso逝meof泄themo幼dern,抽sports艳arena溉s,wit蜻hlarg岸espac瞧esunb罢roken饲byany闭obstr眉ucting朱suppo链rts.T稳heuse爬sfor胞thisr祥elativ投elyne义wstru妨ctural禾metho猾dare长consta絮ntlyb塞eingd柜evelop翻ed.笛建筑中的结构拐设计及建筑材旦料如建筑师必须从畅一种全局的角犹度出发去处理粪建筑设计中应胞该考虑到的实借用活动，物质蚁及象征性的需特求。因此，他夹或他试图将有限相互有关的空筑间形式分体系音组成的总体系宁形成一个建筑六环境。这是一抢种复杂的挑战凑，为适应这一推挑战，建筑师晚需要有一个分停阶段的设计过闲程，其至少要功分三怪个狸“魂反摇馈粮”紫考虑阶段：方京案阶段，初步战设计阶段和施王工图设计阶段耗。疏这样的分阶段暂涉及是必需的贵，它可使设计帐者避免受很多雷细节的困惑，第而这些细节往厌往会干扰设计祥者的基本思路货。实际上，我单们可以说一个写成功的建筑设贫计师应该具备娇一种从很多细罢节中分辨出更里为基本的内容弹的能力。乐概念构思阶段胁的任务时提出封和斟酌全局场验地规划，活动牌相互作用及房般屋形式方案。灵为实现这些，刚建筑师必须注对意场地各部分升的基本使用，纸空间组织，并走应用象征手法迎确定其具体形耽式。这就要求五建筑师首先按胀照基本功能和多空间关系对一榴项建筑设计首幕先构思并模拟辞出一个抽象的列建筑物，然后誉再对这一抽象蛛的总体空间进赠行深入探究。谅在开始勾画具厦体的建筑形似避时，应考虑基他本的场所跳进交加以修改。写在方案阶段，这如果设计者能她够形象的预见钟所作方案的结吵构整体性，并鬼要考虑施工阶衫段可行性及经虚济性，那将是挑非常有帮助的森。这就要求建洒筑师或者过问起工程是能够从快主要分体系之旋间的关系而不其是从构建细节煮去构思总体结勒构方案。这种有能够易于反馈毁以改进空间形结式方案。演在初步设计阶潮段，建筑师的嫂重点工作应是毅详细化可能成墨为最终方案的忘设计，这是建伍筑师对结构的贵要求业转移到取做分体系具体迫方案的粗略设景计上。在这一廊阶段应该完成学对结构布置的顿中等程度的确烂定，重点论证授和设计主要分悬体系已确定它没们的主要几何沉尺寸，构件和尺相互关系。这炉样就可以依据花全局设计方案脚，确定并解决嚷各分体系的相耽互影响以及设锋计难题。顾问沸工程师在这一洲过程中作用重覆大，但各细部薪的考虑还留有易选择余地。当最然，这些初步区设计阶段所作猛的决定仍可以惨反馈回取使方似案概念进一步毛改善，或甚至烈可能有重大变成化。世当设计者和顾搬问工程师对初穷始阶段设计方韵案的可行性满亲意时，就意味络着全部设计的闷基本问题已经当解决，不会再穴因细节问题而昆发生大的变化欧。这是工作重随点将再次转移岭，进入细部设沈计。在这一阶婚段将重点完善岁各分体系的细积节设计。此时编包括结构工程朴在内的各个领征域的专家的作弯用将十分突出剖，应为所有施澡工的细节都必嚷须设计出来。评这一阶段的决责定，可能会反乔馈到第二阶段座并导致一些变果化。如果第一微阶段和第二阶瑞段的设计做的储深入，那么在壳最初两个阶段喊所得到的总体作结论和最后阶闻段的细节的重很新设计不再是富问题。当然，意整个实际过程少应该是逐步发呀展的过程，从举创造和细化（晓改进）总体设瘦计概念直到做骡出精确的结构局设计和细部构片造。悟综上所述：在洽第一阶段，建剪筑师必须首先读用概念的方式挺来确定基本方湾案的全部空间捉形式的可行性耳。在第一阶段悬，专业人员的郑合作是有意义喷的，但仅限于顿行程总的构思肾方面；在第二坛阶段，建筑师椒应该能够用图复形来确定各分哄体系的需求，殃并且通过估计驼关键构件的性颠能来证明其相替互作用的可行具性。也就是说芬，主要分体系父的性能只须做辟到一定深度，零需要验证他们艺的基本形式和墨相互关系是协醉调一致的。这撑需要与工程师小进行更加详细脚与明确的合作椅；在第三阶段苗，建筑师和专种业人员必须继旧续合作完成所必有构件的设计面细节，并制定歉良好的施工文域件。惊当然，这些设病计的成功来源食于建筑材料的妹发展与革新。构早期的建筑材副料主要是木材械和砌附块盯,孤如砖块讲、肢石材或瓦片及装其它类似的材盯料贼。敲砖和砖之间是忙由砂浆或者焦辩油状的沥青或冶其它粘合物粘补结在一起。希称腊人和罗马人蹦有时利用铁棒览或夹钳来加固邮他们的建筑。外例仙如漏,被在雅典的帕台昨农神庙的柱浸子定,刑就是由在水中吃也能变得如石炕材般坚硬的火育山灰建成的。乐钢材和水泥本─法现代最重要的灯两种建筑材莫料贼,谎在抛1夺9裕世纪得到了推间广。钢姜材维(岁从根本上叛说撑,伙是以铁为主要盟成分并含有少饺量碳元素的合模金捎)丘,同直到出现能够腥限制其特殊用顶途胡(庆如制造刀振刃荒)啊的费劳力的铸境造方雅法昨,睛才被铸造出来乘。吵在币185讲6家年贝塞麦炼钢闻法出现之磁后谎,茶钢材就以较低皱的价格大量供窑应。钢材最大呈的优点就是它嘴的抗拉强度非伞常怪高骤,膊这也就是绵说挨,伍当它在我们已吓知的能拉断许距多材料的一定担拉力作用挥下佩,来钢材不会丧失亚它的强度。新陵的合金嘴元素的加速入映,内大大增加了钢