土木工程外文翻译经典

Design,Construction&StructuralDetailsofBurjDubai
ThegoaloftheBurjDubaiTowerisnotsimplytobetheworld'shighestbuilding:it'stoembodytheworld'shighestaspirations.Thesuperstructureiscurrentlyunderconstructionandasoffall2007hasreachedover160stories.Thefinalheightofthebuildingis2,717feet(828meters).Theheightofthemulti-uskyscraperwill"comfortably"exceedthecurrentrecordholder,the509meter(1671ft)tallTaipei101.The280,000m2 (3,000,000ft2)reinforcedconcretemulti-uBurjDubaitowerisutilizedforretail,aGiorgioArmaniHotel,residentialandoffice.Aswithallsuper-tallprojects,difficultstructuralengineeringproblemsneededtobeaddresdandresolved。
StructuralSystemDescription
BurjKhalifahas"refugefloors"at25to30storyintervalsthataremorefireresistantandhaveparateairsuppliesincaofemergency.Itsreinforcedconcretestructuremakesitstrongerthansteel-frameskyscrapers
DesignerspurpolyshapedthestructuralconcreteBurjDubai-"Y"shapedinplan-toreducethewindforcesonthetower,aswellastokeepthestructuresimpleandfosterconstructibility.Thestructuralsystemcanbedescribedasa"buttresd"core(Figures1,2and3).Eachwing,withitsownhighperformanceconcretecorridorwallsandperimetercolumns,buttresstheothersviaasix-sidedcentralcore,orhexagonalhub.Theresultisatowerthatixtremelystifflaterallyandtorsionally.SOMappliedarigorousgeometrytothetowerthatalignedallthecommoncentralcore,wall,andcolumnelements。
Eachtierofthebuildingtsbackinaspiralsteppingpatternupthebuilding.ThetbacksareorganizedwiththeTower'sgrid,suchthatthebuildingsteppingisaccomplishedbyaligningcolumnsabovewithwallsbelowtoprovideasmoothloadpath.Thisallowstheconstructiontoproceedwithoutthenormaldifficultiesassociatedwithcolumntransfers
ThetbacksareorganizedsuchthattheTower'swidthchangesateachtback.Theadvantageofthesteppingandshapingisto"confuthewind'1.Thewindvorticesnevergetorganizedbecauateachnewtierthewindencountersadifferentbuildingshape.
TheTowerandPodiumstructuresarecurrentlyunderconstruction(Figure3)andtheprojectisscheduledfortoppingoutin2008。
ArchitecturalDesign
ThecontextoftheBurjDubaibeinglocatedinthecityofDubai,UAE,drovetheinspirationforthebuildingformtoincorporatecultural,historical,andorganicinfluencesparticulartotheregion。
Thecenterhexagonalreinforcedconcretecorewallsprovidethetorsionalresistanceofthestructuresimilartoaclodtubeoraxle.Thecenterhexagonalwallsarebuttresdbythewingwallsandhammerheadwallswhichbehaveasthewebsandflangesofabeamtoresistthewindshearsandmoments.
Outriggersatthemechanicalfloorsallowthecolumnstoparticipateinthelateralloadresistanceofthestructure;hence,alloftheverticalconcreteisutilizedtosupportbothgravityandlateralloads.ThewallconcretespecifiedstrengthsrangedfromC80toC60cubestrengthandutilizedPortlandcementandflyash
Localaggregateswereutilizedfortheconcretemixdesign.TheC80concreteforthelowerportionofthestructurehadaspecifiedYoung'sElasticModulusof43,800N/mm2(6,350ksi)at90days.Thewallandcolumnsizeswereoptimizedusingvirtualwork.'LaGrangemultipliermethodologywhichresultsinaveryefficientstructure(Bakeretah,2000).ThereinforcedconcretestructurewasdesignedinaccordancewiththerequirementsofACI318-02BuildingCodeRequirementsforStructuralConcrete
Thewallthicknessandcolumnsizeswerefine-tunedtoreducetheeffectsofcreepandshrinkageontheindividualelementswhichcompothestructure.Toreducetheeffectsofdifferentialcolumnshortening,duetocreep,betweentheperimetercolumnsandinteriorwalls,theperimetercolumnsweresizedsuchthatthelf-weightgravitystressontheperimetercolumnsmatchedthestressontheinteriorcorridorwalls.Thefive(5)tsofoutriggers,distributedupthebuilding,tiealltheverticalloadcarryingelementstogether,furtherensuringuniformgravitystress:hence,reducingdifferentialcreepmovements.Sincetheshrinkageinconcreteoccursmorequicklyinthinnerwallsorcolumns,theperimetercolumnthicknessof600mm(24")matchedthetypicalcorridorwallthickness(similarvolumetosurfaceratios)(Figure5)toensurethecolumnsandwallswillgenerallyshortenatthesamerateduetoconcreteshrinkage
ThetopctionoftheTowerconsistsofastructuralsteelspireutilizingadiagonallybracedlateralsystem.Thestructuralsteelspirewasdesignedforgravity,wind,ismicandfatigueinaccordancewiththerequirementsof
AISCLoadandResistanceFactorDesignSpecificationforStructuralSteelBuildings(1999).Theexteriorexpodsteelisprotectedwithaflameappliedaluminumfinish.
AnalysisforGravity
Thestructurewasanalyzedforgravity(includingP-Deltaanalysis),wind,andismicloadingsbyETABSversion8.4(Figure6).Thethree-dimensionalanalysismodelconsistedofthereinforcedconcretewalls,linkbeams,slabs,raft,piles,andthespirestructuralsteelsystem.Thefull3Danalysismodelconsistedofover73,500shellsand75,000nodes.Underlateralwindloading,thebuildingdeflectionsarewellbelowcommonlyudcriteria.Thedynamicanalysisindicatedthefirstmodeislateralsideswaywithaperiodof11.3conds(Figure7).Thecondmodeisaperpendicularlateralsideswaywithaperiodof10.2conds.Torsionisthefifthmodewithaperiodof4.3conds
SiteTestandAnalysis
TheDubaiMunicipality(DM)specifiesDubaiasaUBC97Zone2aismicregion(withaismiczonefaciorZ=0.15andsoilprofileSc).Theismicanalysisconsistedofasitespecificresponspectraanalysis.SeismicloadingtypicallydidnotgovernthedesignofthereinforcedconcreteTowerstructure.SeismicloadingdidgovernthedesignofthereinforcedconcretePodiumbuildingsandtheTowerstructuralsteelspire
Dr.MaxIrvine(withStructuralMechanics&DynamicsConsultingEngineerslocatedinSydneyAustralia)developedsitespecificismicreportsfortheprojectincludingaismichazardanalysis.Thepotentialforliquefactionwasinvestigatedbadonveralacceptedmethods;itwasdeterminedthatliquefactionisnotconsideredtohaveanystructuralimplicationsforthedeepatedTowerfoundations.
Inadditiontothestandardcubetests,theraftconcretewasfieldtestedpriortoplacementbyflowtable(Figure10).L-box,V-BoxandtemperatureTheTowerfoundationsconsistofapilesupportedraft.Thesolidreinforcedconcreteraftis3.7meters(12ft)thickandwaspouredutilizingC50(cubestrength)lfconsolidatingconcrete(SCC).Theraftwasconstructedinfour(4)paratepours(threewingsandthecentercore).Eachraftpouroccurredoveratleasta24hourperiod.Reinforcementwastypicallyat300mmspacingintheraft,andarrangedsuchthatevery10lhbarineachdirectionwasomitted,resultinginariesof"pourenhancementstrips"throughouttheraftatwhich600mmx600mmopeningsatregularintervalsfacilitatedaccessandconcreteplacement.
TheTowerraftissupportedby194boredcast-in-placepiles.Thepilesare1.5meterindiameterandapproximately43meterslongwithadesigncapacityof3,000tonneach.TheTowerpileloadtestsupportedover6,000tonnes(Figure12).TheC60(cubestrength)SCCconcretewasplacedbythetremiemethodutilizingpolymerslurry.Thefrictionpilesaresupportedinthenaturallycementedcalcisiltiteconglomeritic聚结calcisiltitefomiationsdevelopinganultimatepileskinfrictionof250to350kPa(2.6to3.6tons/ft).Whentherebarcagewasplacedinthepiles,specialattentionwaspaidtoorienttherebarcagesuchthattheraftbottomrebarcouldbethreadedthroughthenumerouspilerebarcageswithoutinterruption,whichgreatlysimplifiedtheraftconstruction.
ThesitegeotechnicalinvestigationconsistedofthefollowingPhas。PhaI;23Boreholes(threewithpressuremetertesting)withdepthsupto90m.
Pha2:3Boreholesdrilledwithcross-holegeophysics.。Pha3:6Boreholes(twowithpressuremetertesting)withdepthsupto60m。Pha4:1Boreholewithcross-holeanddown-holegophysics;depth=140m
3Dfoundationttlementanalysis
Adetailed3Dfoundationttlementanalysiswascarriedout(byHyderConsultingLtd.,UK)badontheresultsofthegeotechnicalinvestigationandthepileloadtestresults.Itwasdeterminedthemaximumlong-termttlementovertimewouldbeaboutamaximumof80mm(3.1").Thisttlementwouldbeagradualcurvatureofthetopofgradeovertheentirelargesite.WhentheconstructionwasatLevel135,theaveragefoundationttlementwas30mm(1.2").ThegeotechnicalstudieswerepeerreviewedbybothMr.ClydeBakerofSTSConsultants,Ltd.(Chicago,IL,USA)andbyDr.HarryPoulosofCoffeyGeosciences(Sydney,Australia).
ThegroundwaterinwhichtheBurjDubaisubstructureisconstructedisparticularlyvere,withchlorideconcentrationsofupto4.5%,andsulfatesofupto0.6%.Thechlorideandsulfateconcentrationsfoundinthegroundwaterareevenhigherthantheconcentrationsinawater.Accordingly,theprimaryconsiderationindesigningthepilesandraftfoundationwasdurability.Theconcretemixforthepileswasa60MPamixbadonatripleblendwith25%flyash,7%silicafume,andawatertocementratioof0.32.Theconcretewasalsodesignedasafullylfconsolidatingconcrete,incorporatingaviscositymodifyingadmixturewithaslumpflowof675+/-75mmtolimitthepossibilityofdefectsduringconstruction.
Duetotheaggressiveconditionsprentcaudbytheextremelycorrosivegroundwater,arigorousprogramofanti-corrosionmeasureswasrequiredtoensurethedurabilityofthefoundations.Measuresimplementedincludedspecializedwaterproofingsystems,increadconcretecover,theadditionofcorrosioninhibitorstotheconcretemix.stringentcrackcontroldesigncriteria,andcathodicprotectionsystemutilizingtitaniummesh(Figure13)withanimpresdcurrent.
WindEngineering
Forabuildingofthisheightandslenderness,windforcesandtheresultingmotionsintheupperlevelsbecomedominantfactorsinthestructuraldesign.AnextensiveprogramofwindtunneltestsandotherstudieswereundertakenunderthedirectionofDr.PeterIrwinofRowanWilliamsDaviesandIrwinInc.'s(RWD1)boundary*layerwindtunnelsinGuelph.Ontario(Figure14).Thewindtunnelprogramincludedrigid-modelforcebalancetests,afoilmultidegreeoffreedomaeroelasticmodelstudies,measurementsoflocalizedpressures,pedestrianwind
environmentstudiesandwindclimaticstudies.Windtunnelmodelsaccountforthecrosswindeffectsofwindinducedvortexsheddingonthebuilding.Theaeroelasticandforcebalancestudiesudmodelsmostlyat1:500scale.TheRWDIwindengineeringwaspeerreviewedbyDr.NickIsyumovoftheUniversityofWesternOntarioBoundaryLayerWindTunnelLaboratory.
迪拜的设计
迪拜塔的目的不仅仅只是成为世界上最高的建筑:而是象征着世界上最高的抱负。那个庞然大物目前正在建设当中,而到了2007年秋就已经超过了160多层。最后的高度将达到828米。这栋混合结构的摩天大厦将轻轻松松超过目前最高纪录的保持着台北101大厦。这栋拥有280000立方米混凝土的混合结构迪拜塔将投入商用,最为一个宾馆,商品房还有办公用所。和其他超高工程一样,复杂的工程意味着面临一大堆的工程问题要解决。
迪拜塔每隔25到30层便设置一个“避难层”,这些层跟普通楼层比起来更加能抗火而且备有独立的空气提供系统以防事故。钢筋混凝土结构使得它比全钢结构摩天大厦更坚实。
设计者有意的将混凝土结构的迪拜塔设计成“y”形状的来减少风荷载对它的影响,同时也简化结构提高施工的可行性。结构系统可以用“板根状”核心。每一翼上面的高性能混凝土走廊和周围的柱子通过位于核心的六边形集合板和其他的翼相连。这个特点使得迪拜塔具有十足的抗水平荷载和抗扭刚度。Som应用严格的几何来使得塔内的中心和墙柱得以均衡受力。建筑的每一层都设置了螺旋形的垫层。这种装置是通过塔的布置格式设定,这样那个垫层就能准确的被安置通过矫正柱子和相面的墙来提供一个联系顺滑的路线。这样就可以使得建设不用碰到柱子运输过程中所碰到的种种问题从而顺利进行。
迪拜塔的被设置成每一个单元的宽度都是不一样的。阶梯状和尖状的优势是可以削弱分散风力。因为每一层的形状都不一样所以漩涡风不会形成。整个塔当前还正在建设当中,而这个项目计划在2008年封顶。
建筑设计
迪拜塔坐落于迪拜的市中心,Uae,驱动着城市的文化历史,并且对局部区域产生了重大影响。
位于中心以六边形分布的核心墙为给结构所提供的抗扭力相当于一个套管或者车轴,在结构的外表提供一个坚实结构。正六边形的墙体是通过翼缘板来加固的,而这也是作为梁的用于抵抗剪力和偶然荷载的翼缘板和凸出部分。
在机动层的桁架使得柱子可以一起抵抗位于结构的侧向上的荷载。因此,所有的垂直的混凝土在水平和重力两个方向上都有得到了应用。特种水泥的强度能达到c80到c60立方体强度,原料包括用波兰水泥和火山灰。
而混凝土是用当地的搅拌器搅拌的。占少数比例的C80的混凝土在第90天的初期弹性模数有43,800N/mm2。墙体和柱子的最佳的尺寸都是用L综合方法算出来的,而这时使得整体结构被利用得很充分合理。混凝土结构的设计是根据aci318-02混凝土建筑标准规范的要求设计的。
墙的厚度和柱子的尺寸是互相协调的,较少了各个构件因为滑移和收缩而产生的不良影响。为了减少因为滑移所造成的不同柱子缩短的影响,周边的柱子的尺寸是这样制定的:结构自重在周边柱子产生的压力加上建筑在内走廊的墙所产生的压力。分布于建筑内的5榀桁架把所有的承受竖向荷载的构件联系了起来,进一步保证了整体的竖向承载力,因此。
塔的顶部是由运用一个斜向支撑侧向系统的钢塔尖。这个钢结构塔尖是根据《美国钢结构协会关于钢结构建筑的荷载规定和抵抗因素设计说明》的相关要求去设计的,用来抵抗重力,风力,地震和疲劳的破坏。暴露在外的钢构件是用焊接在外的铝箔来保护的
自身重力受力分析
结构的重力(非几何线性分析),风,地震荷载是通过8.4版本的结构软件来分析的。三维模型的组成包括:混凝土墙体,连系梁,板,筏板,桩,还有钢塔尖系统。全部的三维结构分析有共有73500个板件和75000个节点。在侧向风荷载作用下,建筑的偏斜程度被控制在正常规定下。结构的动态分析显示了第一振动周期为11.3秒。而第二振动模型的振动周期为10.2秒。涉及扭转的第十五个模型的振动周期为4.3。
选址评估分析。
迪拜当局政府制定迪拜为一个(美国97抗震规范)2a地震区()。地震分析包括指定的地点回应光谱分析。地震荷载一般不能主导整个钢筋混凝土塔结构的设计。但是地震荷载却能够左右钢筋混凝土台和塔式的钢结构的设计。
(澳大利亚悉尼的结构原理和动态结构资讯工程师顾问)撰写了该地址的包含一次地震所可能带来的灾难情况的地震预测分析报告。各种潜在的液化液体通过几种被广泛认可的方法调查研究。在这里这些液化的液体被认为是对塔深部基础在结构上的没有任何的影响的。
.除了标准立方体试块实验,筏板混凝土在被送至安装之前也在流动性试验台上通过了局部的强度测验。塔的基础由筏形桩台构成。这坚硬的钢筋混凝土筏板有3.7米厚,并且采用的是c50的加强混凝土。筏板分成独立的四块灌溉而成。每一块筏板都要花费24个小时才能完成灌溉。
整个塔的筏型基础是由194根转孔灌注桩支撑。桩的直径有1.5米长度有43米长,每根都能够承重3000吨的重力。而实际上通过测试可以达到6000吨的承载力。而添加聚合物(润滑剂的c60的混凝土时通过是混凝土导管来输送的。摩擦桩是通过混凝土表面和岩石表面的聚结作用来实现承载的,而在底部桩体和岩土的摩擦力能够达到250到3