《土木工程專業(yè)英語 第2版》 課件 Unit13 Design and Construction；Unit14 Design and Construction；Unit15 Scientific English Writing Skills

Unit13DesignandConstructionoftheJinMaoTower

EnglishforCivilEngineering——Teacher:Prof.ZhengLu（SchoolofCivilEngineering,TONGJIUNIVERSITY）Unit13DesignandConstructionoftheJinMaoTower

13.0Abstract13.1TheStructureSystem13.2Foundationengineering13.3Windengineering13.4Earthquakeengineering13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringLogic

結(jié)構(gòu)體系：結(jié)構(gòu)的主要材料、構(gòu)件、外形、主要承重體系的組成（核心筒、結(jié)構(gòu)伸臂桁架）基礎(chǔ)工程：樁、筏板、地下連續(xù)墻的結(jié)構(gòu)形式風(fēng)工程：風(fēng)洞試驗的初始條件、最終設(shè)計風(fēng)壓、風(fēng)洞試驗的結(jié)果地震工程：設(shè)計反應(yīng)譜、驗算構(gòu)件、鋼桁架特殊設(shè)計特殊結(jié)構(gòu)工程解決方案：抵御橫向荷載的結(jié)構(gòu)體系；核心筒和巨型復(fù)合柱之間相對位移的平衡解決方案現(xiàn)場結(jié)構(gòu)監(jiān)測：基礎(chǔ)監(jiān)測（筏板）+上部結(jié)構(gòu)（核心筒、巨型復(fù)合柱、剪力墻）Abstract

ThecompositestructuralsystemfortheJinMaoTowerlocatedinShanghai,Chinawasdesignedtoresisttyphoonwinds,earthquakeforces,andaccommodatepoorsoilconditionswhileprovidingaveryslendertowertobefullyoccupiedfortheofficeandhoteluses.ThestructurefortheJinMaoTowerwascompletedinAugust1997withoccupancyexpectedinAugust1998.TheToweristhetallestbuildinginChinaandthethirdtallestintheworld(asof1997).ThesuperstructureoftheTowerresistslateralloadswithacentralreinforcedconcreteshearwallcoreinterconnectedwithcompositemega-columns.Theoutriggertrussesatthree(3)two-storylevels.Gravityloadsareresistedbycompositefloormemberswhichframetostructuralsteelmega-columnsandtothecentralcoreandcompositemega-columns.ThefoundationsystemfortheTowerconsistsofopensteelpipepilescappedbyareinforcedconcretemat.Adeepslurrywallsystemformsthetemporaryretentionaswellasthepermanentfoundationsystemaroundthesite.介紹了金茂大廈的用途、結(jié)構(gòu)形式和地位。slender，細(xì)長；retention，阻擋；

mega-columns，巨型柱。opensteelpipepilescappedbyareinforcedconcretemat，鋼管樁筏基礎(chǔ)；

deepslurrywall，深地下連續(xù)墻。13.1The

Structure

SystemThesuperstructureforthe421meter-tall,88-storyJinMaoTowerconsistsofamixeduseofstructuralsteelandreinforcedconcretewithmajorstructuralmemberscomposedofbothstructuralsteelandreinforcedconcrete(composite).TheprimarycomponentsofthelateralsystemforthisslenderTower,withanoverallaspectratioof7:1tothetopoccupiedfloorandanoverallaspectratioof8:1tothetopspire,includeacentralreinforcedconcretecorewall

linkedtoexteriorcompositemega-columnsbystructuralsteeloutriggertrusses.Thecentralcorewallhousestheprimarybuildingservicefunctions,includingelevators,mechanicalfanroomsforHVACservices,andwashrooms.Theoctagon-shapedcoreisnominally27mdeepwithflangesvaryinginthicknessfrom850mmatthetopofthefoundationsto450mmatthelevel87withconcretestrengthvaryingfromC60toC40.spire,塔尖;outriggertrusses,伸臂桁架;octagon-shaped,八角形。mechanicalfanroomsforHVACservices，暖通空調(diào)電風(fēng)扇設(shè)備間。13.1Thestructuresystem

Four(4)–450mmthickinterconnectingcorewebwallsexistthroughouttheofficelevelswithnowebwallsonthehotellevels,creatinganatriumwithatotalheightof205mwhichleadsintothespire.Structuralsteeloutriggertrussesinterconnectthecentralcoreandthecompositemega-columnatthree2–storytalllevels.TheinterconnectionoccursbetweenLevel24&Level26,Level51&Level53,andLevel85&Level87.TheoutriggertrussesbetweenLevels85&87engagethe3-dimensionalstructuralsteelcaptrusssystem.ThecaptrusssystemwhichframesthetopofthebuildingbetweenLevel87andspireisusedtospanovertheopencore,supportthegravityloadofheavymechanicalspaces,engagethestructuralsteelspire,andresistlateralloadsabovethetopofthecentralcorewall/compositemega-columnsystem.介紹了金茂大廈的主要結(jié)構(gòu)形式和布置。web，腹板；atrium，中庭；spaces，控制室。captrusssystem，帽帶桁架。13.1Thestructuresystem

Inadditiontoresistinglateralloads,thecentralreinforcedconcretecorewallandthecompositemega-columnscarrygravityloads.Eight(8)built-upstructuralsteelmega-columnsalsocarrygravityloadsandcompositestructuralsteelwide-flangedbeamsandbuilt-uptrussesareusedtoframetypicalfloors.Thefloorframingelementsaretypicallyspacedat4.5mon-centerwithacompositemetaldeckslab(75mmmetaldecktoppedwith80mmofnormalweightconcrete)framingbetweenthesteelmembers.介紹巨型柱和樓板的設(shè)置情況。on-center，中心矩；compositemetaldeckslab，疊合金屬板。13.2Foundation

engineering

13.2Foundation

engineering

Areinforcedconcreteslurrysystemwasdesignedandconstructedaroundtheentireperimeterofthesite(0.75kilometer).Thethicknessoftheslurrywallis1mwithaconcretedesignstrengthofC40anddepthof33m.Theslurrywallbearsonmoderatelystiff,imperviousclay,alsoactingasatemporaryretentionsystemwall,apermanentwatercut-offsystem.Atiebackgroundanchorsystemwasdesignedandsuccessfullytestedtoprovidelateralsupportoftheslurrywallduringconstruction,however,thecontractor

chosetoconstructalocallyacceptedreinforcedconcretecross-lotbracingsystemforthethree(3)fullbasementlevelswhichextendedapproximately15mbelowgrade.Thepermanentgroundwatertableiswithin1mofexistinggrade.Basedonthesiteconditionsandtheslurrywalldepth,asub-soildrainingsystemwasdesignedtocarry18.5liter/secofwater.介紹地下連續(xù)墻的結(jié)構(gòu)布置情況bearson，承力在……；

impervious，不透水；clay，粘土層；contractor,承包商；sub-soil，（土壤的）底土，心土；tiebackgroundanchor，拉桿地錨體系；

cross-lotbracing,交叉支撐。13.3Wind

engineering

TyphoonwindsaswellasstrongextratropicalwindsexistinthelocalShanghaienvironment.MultipleanalyticalandphysicaltestingtechniqueswereusedtoevaluatethebehavioroftheTower.Sinceultra-tallstructureshadnotbeenpreviouslyconstructedinChina,theChinesewinddesigncodedidnotaddressstructurestallerthan160m.Therefore,coderequirementswereextrapolatedfortheTowerandwindtunnelstudieswereperformedtoconfirmCodeextrapolationsandtostudytheactual,“rational”localwindclimate.Windtunnelstudies,performedunderthedirectionofDr.NicholIsyumovatUniversityofWesternOntarioinconjunctionwiththeShanghaiClimateCenter,wereconductedforthebuildinglocatedintheexistingsiteconditionandconsideringthefuturemasterplandevelopmenttermedthe“developedPudong”condition.Theexistingsitecontextessentiallyconsistedoflow-risebuildings(3~5storiesinheight)withthefully“developedPudong”environmentconsistingof30~50storiesbuildingsandtwoultra-talltowerslocatedwithin300mofJinMao.Windtunnelinvestigationincludedalocalclimatestudy,constructionofproximitymodels,aforcebalancetest,anaeroelastictest,anexteriorpressuretest,andapedestrianlevelwindstudy.氣候的特殊性和因此開展的風(fēng)洞試驗相關(guān)數(shù)據(jù)。extratropical，溫風(fēng)帶；ultra-tall，超高；extrapolated，推算；

proximity，接近，近似；aeroelastic

test，氣彈實驗；pedestrianlevelwind，人行高度風(fēng)。13.3Wind

engineering

ThefinaldesignoftheTowerconsideredboththePeople’sRepublicofChinaBuildingCodeaswellasthe“rational”windtunnelstudies.Strengthdesignforalllateralload-resistingcomponentsisbasedontheCode-defined100-yearreturnwindwithabasicwindspeedof33m/sfora10minuteaveragetimeat10mabovegrade.ThebasicwindspeedcorrespondstoadesignwindpressurefortheTowerofapproximately0.7kPaatthebottomofthebuildingand3.5kPaatthetopofthebuilding.Resultsfromthewindtunnelstudies,consideringtheexistingsiteconditionandthe“developedPudong”conditionaswellasextratropicalandtyphoonwindsconfirmedthattheChineseCoderequirementsfordesignwereconservative.Serviceabilitydesign,includingtheevaluationofbuildingdriftandacceleration,wasbasedonthe“rational”windtunnelstudyresults.Windtunnelstudieswereperformedfor1-year,10-year,30-year,50-yearand100-yearreturnperiods.Thestudiesconsideredtheactualcharacteristicsofthestructure.Thefundamentaltranslationalperiodsofthestructureare5.7secondsineachprincipaldirectionandthefundamentaltorsionalperiodis2.5seconds.Theoverallbuildingdrift,withcomparableinter-storydrifts,forthe50-yearreturnwindwith2.5%structuraldampingisH/1142fortheexistingsiteconditionandH/857forthe“developedPudong”condition.強(qiáng)度和舒適度中的位移滿足情況。13.3Wind

engineering

Itwasdeterminedthatthetwo(2)ultra-tallstructuresproposedtobelocatedneartheJinMaoTower

wouldhaveasignificanteffectonthedynamicbehavior

resultinginsignificantlyhighereffectivestructuraldesignpressures.BuildingdriftsarewellwithintheinternationallyacceptedbuildingdriftofH/500.Considering1.5%structuraldampinganda10-yearreturnperiod,theexpectedbuildingaccelerationrangedfrom9–13milli-g’sforthetopflooroftheoccupiedhotelzone.Inaddition,expectedbuildingaccelerationrangedfrom3–5milli-g’sfora1-yearreturnperiodconsidering1.5%structuraldamping.Theinternationallyacceptableaccelerationsforahotelstructureare15–20milli-g’sfora10-yearreturnperiodand7–10milli-g’sfora1-yearreturnperiod.Becauseofthefavorableserviceabilitybehaviorofthebuilding,thepassivecharacteristicsalonecouldbeusedtocontroldynamicbehaviorwithnoadditionalmechanicaldamping

required.加速度的設(shè)計滿足情況mechanicaldamping

，機(jī)械阻尼。13.4Earthquake

engineering

TheapproachforevaluatingseismicloadingsfortheJinMaoTowerconsidersbothChineseCode-definedseismiccriteriaandactualsite-specificgeological,tectonic,seismologicalandsoilcharacteristics.Actualon-sitefieldsamplingofthesoilstrataandengineeringevaluationswereperformedbyWoodward-ClydeConsultants,theShanghaiInstituteofGeotechnicalInvestigationandSurveying,andtheShanghaiSeismologicalBureau.

Alllateralloadresistingsystems,includingallindividualmembers,weredesignedtoaccommodateforcesgeneratedfromtheChineseCode-definedresponsespectrumaswellassitespecificresponsespectrums.Extremeeventsite-specifictimehistoryaccelerationrecords(10%probabilityofoccurrenceina100-yearreturnperiod)wereusedintimehistoryanalysestostudythedynamicbehaviorofkeystructuralelementsincludingthecompositemega-columns,thecentralcore,andtheoutriggertrusses.地震分析涉及的方法、構(gòu)件等geological,tectonic,seismologica地理、板塊、地質(zhì)學(xué)。13.4Earthquake

engineering

ThesitespecificresponsespectrumsusedtodescribetheTower’sdynamicbehaviorincludedanalysesforamostprobableearthquakewitha63%probabilityofoccurrenceina50-yearreturnperiodandamostcredibleearthquakewitha10%probabilityofoccurrenceina100-yearreturnperiod）.Inaddition,theTowerwasevaluatedusinga3-dimensionaldynamictimehistoryanalysisforamostcredibleearthquakewitha10%probabilityofoccurrenceina100-yearreturnperiod.Inallcases,theChinese-definedcodewindrequirementsgovernedtheoverallbuildingbehaviorandstrengthdesign;however,specialconsiderationsweregiventotheoutriggertrussesandtheirconnections.Inalldesigncases,thesestructuralsteeltrussesweredesignedtoremainelastic.反應(yīng)譜的設(shè)置；伸臂桁架的特殊要求credible，可靠的，可信的。13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringThestructuraldesignfortheJinMaoTowercreatedanopportunitytodevelopuniquestructuralengineeringsolutions.Thesesolutionsincludedthepracticaldevelopmentofthetheoreticalconcepts,unusualdetailingoflargestructuralbuildingcomponents,andcomprehensive

monitoringofthein-placestructure.Theoverallstructuralsystemutilizesfundamentalphysicstoresistlateralloads.Theslendercantileveringreinforcedconcretecentralcoreisbracedbytheoutriggertrusseswhichactasleverstoengageperimetercompositemega-columns,maximizingtheoverallstructuraldepth.Theoverallstructuralredundancyislimitedbyengagingonlyforfour(4)compositemega-columnsineachprimarydirection.Structuralmaterialsarestrategicallyplacedtobalancetheappliedlateralloadswithforcesduetogravity.Verylittlestructuralmaterialpremiumswererealizedbecauseofthestructuralsystemused.Lateralsystempremiums

essentiallyrelatedtomaterialrequiredfortheoutriggertrussesonly

withoutmeasurablestructuralmaterialpremiums

requiredforcentralcorewallandcompositemega-columnselements.特殊結(jié)構(gòu)綜述；結(jié)構(gòu)體系的特殊性comprehensive,綜合;in-place,現(xiàn)場;

cantilevering

,懸臂;perimeter,周長，邊界;premiums

，額外費用。13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringEvenafterequalizingthestresslevelwithinthecentralcoreandcompositemega-columns,theexpectedrelativeshorteningbetweentheinterconnectedcentralcoreandcompositemega-columnswaslarge.Bycalculation,consideringlong-termcreep,shrinkage,andelasticshortening,theexpectedrelativemovementbetweentheseelementsatLevels24-26wasasmuchas50mm.Themagnitudeofrelativemovementwouldhaveinducedextremelyhighstressesintothestiffoutriggertrussmembersweighingasmuchas3280kg/m.Therefore,structuralsteelpinswithdiametersupto250mmweredetailedintotheoutriggertrusssystem(seeFig.13-3).核心筒與外框架相對位移interconnected，相互連接的creep

，蠕動；steelpins，鋼銷。13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringThesepinswereinstalledintocircularholesinhorizontalmembersandslotsindiagonalmemberstoallowtheoutriggertrussestoactasfreemovingmechanismsforalongperiodduringconstruction.Thisallowedamajorityoftherelativemovementtooccurfreeofrestrain,therefore,freeofstress.Afteralongperiodoftime,highstrengthboltswereinstalledintotheoutriggertrussconnectionsforthefinalserviceconditionofthelateralloadresistingsystem.Theexpectedrelativemovementafterthefinalboltingwasperformedwasamaximumof15mmatLevels24-26.Consideringtheflexibilityofthelongcompositemega-columns,thefinalforcesattractedtothetrussesdidnotappreciablyincreasethememberandconnectionsizes.為消除相對位移產(chǎn)生的應(yīng)力，而采用的鉸連接的方式slots，狹槽；

restrain，約束；diagonalmembers，角部構(gòu)件。13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringAcomprehensivestructuralsurveyandmonitoringprogramwasdesignedandimplementedintotheJinMaoTower.ThematfoundationsystemundertheTowerwasinitiallysurveyedjustafterpourcompletioninOctober1995andiscurrentlystillbeingsurveyed.Basedonasubstructure/soilanalysis,theexpectedmaximumlong-termTowermatsettlementis75mm.ThelatestTowermatsettlementisshowninFig.13-4.Inadditiontosurveyingthematforlong-termsettlement,thesuperstructurewasgaugedtomonitorbehavior.Extensometerswereplacedonthereinforcedconcretecentralcoreandonthereinforcedconcreteofthecompositemega-columns.對基礎(chǔ)和上部結(jié)構(gòu)的監(jiān)測內(nèi)容。comprehensive，綜合的全面的；pour，澆筑；

gauge，測量，檢測；

extensometers，應(yīng)變計；matfoundationsystem，筏板基礎(chǔ)。13.5Uniquestructuralengineeringsolutions/On-sitestructuremonitoringInaddition,straingaugeswereplacedonthebuilt-upstructuralsteelmega-columnsaswellasonthewideflangedstructuralsteelcolumnslocationwithintheconcreteencasementforthecompositemega-columns.SampleresultsofmeasuredstrainversuscalculatedstrainareshowninFig.13-5.Basedonthemeasureddata,correlationsweremadebetweentheoreticalandactuallong-termshorteningofverticalelementsduetocreep,shrinkage,andelasticshortening.SeeFig.13-6forresultsoftheshearwall.Lasersurveyingtechniqueswereusedforbothlateralandverticalbuildingalignment.Floorlevelsofthestructureweretypicallybuilttodrawingdesignelevation,compensatingforcreep,shrinkage,andelasticshorteningwhichoccurredduringconstruction.LateralpositionoftheTowerwasconstantlymonitoredfromoff-sitebenchmarksandwasfoundtobewellwithinacceptabletolerances.上層結(jié)構(gòu)的監(jiān)測內(nèi)容。

correlations

，糾正；draw，達(dá)到；benchmarks，基準(zhǔn)點。lasersurveying，激光監(jiān)測。13.6Conclusion

IncorporatingfundamentalstructuralengineeringconceptsintothefinaldesignoftheJinMaoTowerleadtoasolutionwhichnotonlyaddressedtheadversesiteconditionsbutalsoprovidedanefficientfinaldesign.Afinalevaluationofmonitoringandsurveydatawillbeperformed.Datafromtheas-builtstructuresubjectedtoactualimposedloadswillbecorrelatedwiththeoreticalresults.Thiscomparisonwillprovetobeinvaluableforthefuturedesignandconstructionofultra-talloccupiedstructures.將基礎(chǔ)結(jié)構(gòu)設(shè)計理念融入到金茂大廈的最終設(shè)計當(dāng)中，建成結(jié)構(gòu)實際檢測與理論的對比結(jié)果的價值。adverse，不利的；as-built，竣工，完成。Unit14DesignandConstructionoftheBurjKhalifaTowerEnglishforCivilEngineering——Teacher：Prof.ZhengLu（SchoolofCivilEngineering,TONGJIUNIVERSITY）Unit14DesignandConstructionoftheBurjKhalifaTower14.1Introduction14.2DesignandConstruction14.2.1TowerForm14.2.2TowerSuperstructure—TheButtressedCore14.2.3WindEngineering14.2.4TowerFoundations14.2.5ConstructionMethodsandConcreteTechnology14.3ImpactandReflections14.3.1Impact14.3.2Reflections14.3.3TheNextGenerationofSupertallBuildings-LessonsLearnedfromBurjKhalifa14.1Introduction

Whilemostoftenworld’spasttallestbuildingswerealmostexclusivelyofficetowers,BurjKhalifachangedtheparadigmbycreatinganintegratedverticalcity,combiningresidential,hotelandofficespace.Creatingthetowerrequiredcollaborationandinnovationbydozensofexpertsworkingtogethertowardcommongoals.Thefinishedtoweristheresultofseveralnewadvancesinmaterialtechnologies,structuralengineering,windengineering,seismicengineeringandcomputertechnology,aswellasconstructionmethods.哈利法塔介紹paradigm范例14.1Introduction

The163storyToweristhecenterpieceofaUSD20+billiondevelopmentlocatedjustoutsideofdowntownDubai.Itisamixed-usebuilding,consistingprimarilyofresidentialandofficeusage,aswellasanArmanihotelandretailoutlets.TheprojectincludedtheTower,anadjacentpodiumstructure,andlow-riseofficeandpoolannexbuildings.Thetotalareafortheprojectis465000m2,withtheTowerportionbeing280000m2.ConstructionforthepreliminaryworksandfoundationsbeganinJanuary2004.Afterahiatusinworkonthesite,theconstructionofthesuperstructurestartedinApril2005andwascompletedinJanuary2009.TheTowerwasopenedinJanuary2010.annex附屬建筑

；14.2DesignandConstruction

ThechallengeoftheBurjKhalifawasnotonlytocreatetheworld’stallestbuilding,butitwastodosoutilizingconventionalsystems,materials,andconstructionmethods,albeitmodifiedandutilizedinnewcapacities.Atowerofthisheighthadneverbeforebeenseen,whichrequiredmuchinnovation,bothintermsofnewideas,andindevelopingnewwaystouseandadvancecurrenttechnologies.Toachievethis,thedesignrequiredintensiveandconstantcollaborationbetweenarchitects,engineers,andspecialtyconsultantstodevelopabuildingformthataddressedstructuralefficiency,constructability,buildingaesthetics,andfunctionsimultaneously.哈利法塔設(shè)計和建造的挑戰(zhàn)conventional范例

；consultants顧問；constructability施工能力

14.2DesignandConstruction

14.2.1TowerFormAprimaryconcernintheengineeringoftallbuildingsistheeffectofwindonthebuildings’structure.TheformoftheBurjKhalifaistheresultofcollaborationbetweenthearchitectsandengineerstovarytheshapeofthebuildingalongitsheight,therebyminimizingwindforcesonthebuilding,whilealsokeepingthestructuresimpleandfosteringconstructability.ThefloorplanoftheTowerconsistsofatriaxial,Y-shapedplan,formedbyhavingthreeseparatewingsconnectedtoacentralcore.AstheTowerrisesinheight,onewingateachtier“setsback”inaspiralingpattern,furtheremphasizingitsheight.結(jié)構(gòu)形式triaxial三軸

；tier層14.2DesignandConstruction

Theresultis24differentprimaryfloorplates(plussomelessmajorvariations),creatingasteppinggeometrythatpresentsmultiplebuildingwidthsovertheheightofthebuilding,providinganenvironmentthat“confusesthewind”-thewindvorticesnevergetorganized,becauseateachnewtierthewindencountersadifferentbuildingshape.TheY-shapedplanisidealforresidentialandhotelusage,inthatitallowsmaximumviewsoutward,withoutoverlookinganeighboringunit.Thewingscontaintheresidentialunitsandhotelguestrooms,withthecentralcorehousingalloftheelevatorandmechanicalclosets.Additionally,theTowerisservicedbyfiveseparatemechanicalzones,locatedapproximately30floorsapartovertheheightofthebuilding.geometry幾何；residential住宅；elevator電梯

14.2DesignandConstruction

AbovetheoccupiedportionoftheTowerisalargelyopenspire,whichhousesmechanicalfunctionsandfuturecommunicationsusagesatitsbase.Theoverallshapeisanextremelyefficientsolutiontothepotentiallyconflictingstructuralrequirementsofasupertallresidentialtower.Startingfromaslendertop,thebuildingspreadsoutasthegravityandwindforcesaccumulate.Asaresult,eventhoughtheglobalforcesarelarge,theforcesintheindividualmembersarenot.conflicting相互沖突的14.2DesignandConstruction

14.2.2TowerSuperstructure—TheButtressedCoreThestructuralsystemfortheTowerhasbeentermeda“buttressedcore”system.Thebuttressedcorerepresentsanewtypeofsystem,aconceptualchangeinstructuraldesignwhoseevolutionarydevelopmentbeganwithanearlierdesignforTowerPalaceIIIinSeoul.Thesystemallowsforadramaticincreaseinheight,usingconventionalmaterialsandconstructiontechniques.Itsessenceisathree-wingedstructureinwhichastronghexagonalcentralcoreanchorsthreebuildingwings.Itisaninherentlystablesysteminthateachwingisbuttressedbytheothertwo.塔式上層建筑-支撐核心buttressed加支撐的

；hexagonal六邊形的14.2DesignandConstruction

Withinthewings,corridorwallsextendfromthecentralcoretoneartheendofthewing,terminatinginthickenedcrosswallsreferredtoas

hammerheadwalls.Thecentralcoreprovidesthetorsionalresistanceforthebuilding,whilethewingsprovidetheshearresistanceandincreasedmomentofinertia.Perimetercolumnsandflatplatefloorconstructioncompletethesystem.Atthemechanicalfloors,outriggerwallsareprovidedtotieallthewallsandcolumnstogetherallowingtheperimetercolumnstoparticipateinthelateralloadresistingsystem.Inthismanner,theBurjKhalifaactsasonegiantconcretebeamcantileveringoutofthegroundwiththesystemworkingtogetherasasingleunit.corridor走廊

；torsional扭轉(zhuǎn)；inertia慣性

；outrigger外伸

；cantilevering懸臂14.2DesignandConstruction

Everypieceofverticalconcrete(andtherebyeverygravitationalforce)ispartofthisgiantbeam,usedtoresistthewind.Thegravitationalloadthenhelpsstabilizethestructurebyutilizingtheweightofthebuildingtoresistthewind.Theresultisaveryefficienttower,whichisalsoextremelystifflaterallyandtorsionally.Infact,becauseoftheshapeofthebuildingandtheharmonicsofthestructure,theforcesandmotionsweregreatlyreduced,andthemotionandaccelerationcriteriacouldbesatisfiedwithouttheuseofsupplementaldampingdevices.抵抗風(fēng)載giant巨大的

14.2DesignandConstruction

14.2.3WindEngineeringThewindtunnelwasanessentialpartnerinthedesignprocessfromthebeginningoftheproject,asitwasimmediatelyapparentthatforabuildingofthisheightandslenderness,windforcesandtheresultingmotionsintheupperlevelswouldbecomedominantfactorsinthestructuraldesign.Anextensiveprogramofwindtunneltestsandotherstudieswasconductedutilizingboundarylayerwindtunnels.Thewindtunnelprogramincludedrigidmodelforcebalancetests,fullmulti-degreeoffreedomaeroelasticmodelstudies,measurementsoflocalizedpressures,pedestrianwindenvironmentstudies,andwindclimaticstudies(seeFig.14-1).UsingthewindtunneltounderstandandoptimizewindperformancewaskeytotheTower’sdesign.風(fēng)工程slenderness細(xì)長

；dominant占主導(dǎo)地位的；boundary邊界

；aeroelastic氣彈性的14.2DesignandConstruction

SeveralroundsofforcebalancetestswereundertakenasthegeometryoftheTowerevolvedandwasrefined.Aftereachroundoftests,thedatawasanalyzedandthebuildingwasreshapedtofurtherminimizethewindeffects.Asaresultofthiseffort,severalrevisionstothebuildingweremade.SomewererelatedtothegeometryoftheTower:thesizeandshapeofthewingsweremodified,andthenumberandspacingofthesetbackschangedthroughouttheprocess,asweretheirlocations:theoriginalmassinghadthesetbacksoccurringinaspiralingcounterclockwisepattern,whichwasrevisedtobeinaclockwisedirection.reshape改造

；counterclockwise逆時針方向；clockwise順時針方向

14.2DesignandConstruction

Takentogether,thesemeasureshadasignificantimpactinencouragingdisorganizedvortexsheddingovertheheightoftheTower.Anotherrevisionwasrelatedtotheorientationofthebuilding.TheTowerhassiximportantwinddirections,allparalleltothemajoraxesofthewings—threedirectionswherewindisblowingintothe“nose”ofeachwing,andthreedirectionswherewindisblowingintothe“tail”ofeachwingatthecenterofthebuilding.TheorientationoftheTowerwasthenselectedtobetteraccommodatethemostfrequentstrongwinddirectionsforDubai:northwest,south,andeast.vortex渦

；orientation朝向；parallel平行

14.2DesignandConstruction

14.2.4TowerFoundationsTheTowerisfoundedona3.7mthicksolidreinforcedconcreteraft,supportedby194boredcast-in-placepiles.Thepilesare1.5mindiameterandabout43mlong,withacapacityof3000t.Thediameterandlengthofthepilesrepresentedthelargestandlongestpilesconventionallyavailableintheregion.Apileloadtestingprogramwasconductedpriortoproductionpiling,wherebythe1.5mpilesweretestedtomorethantwicetheratedcapacity(over6000t).ThepilesutilizedC60self-consolidatingconcrete(SCC)andwerepl