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TheNewBadalonaRailwayBridge–AStructurefortheCitySum__ryThedesignofstructuresinmetropolitanhabitatsisalwaysachallengeduetotheimportantnumberofrequirementstofulfil.Designespeciallywhenitdealswithrailwaysorroadshastocombinetheneedsofthoseinfrastructureswiththehu__nenviro__entwhichisthecaseoftherailwaybridgeinthecityofBadalona.Nowadaysthecityareathatfa__stheseaisoccupiedbycontaminatingindustries.ThecouncilistryingtoopenthecitytotheMediterraneanSeademolishingunsightlyanduselessbuildingsandchangingtheuseoftheoneswitharchitecturalortechnicalvalue.Nowabeachandayachtingharbourarebeingbuilt.Arailwaylinerunsparalleltothecoastdividingthe__ntreofthecityfromtheshorearea.Therearenofundstoconstructatunnelfortherailwaylineconsequentlyabridgehastobebuilttoincreasetheconnectionbetweenthe__ntreofthecityandthenewcoastfacilities.Adesigncompetitionwascarriedoutforarailwaybridgewhichwillcrossanewpedestrianareaapartofthenewharbourandtwostreets.ThecontractforthebridgedesignwasawardedtoFHECORConsultingEngineersonthebasisofapreliminarydesign.Theideaoftheproposalwastocombinefunctionalitystructuralrationalityaestheticsandlowconstructionand__intenan__costs.Alsotheclienthastheintentiontoconstructthebridgeasaland__rkthatwillbethei__geofthenewurbandevelopment.Keywords:UrbanBridgeRailwayPrestressedStructuralshape.
1.IntroductionBadalonaisa__jorsa____itecityofBarcelonaontheMediterraneancoast.Thenucleusofthecityiscutofffromtheshorelinebytherailwaylinewhichconnectsthedifferentsuburban__ntresofBarcelonalocatedalongtheMediterraneancoast.TherailwaylineiscurrentlyoneoftheSpanishRailwayConsortium’sRENFEmostprofitablepassengerlines.Alongtherailwaylineindustrialbuildingsh__esprungupovertheyearsformingaon__importantindustrial__ntrebutatthesametimefurtheringthealienationofthepeopleofBadalonafromthesea.Inordertotrytoregeneratethecoastandimproveitsconnectionwiththeurban__ntretheCityofBadalonatogetherwiththeCo__rcalCouncilofBar__lonah__ecreated__rinadeBadalonaS.A.whose__inpurposeistoregeneratetheurbanlandscapebycarryingouta__jorurbandevelopmentprojectwhichincludesaportforsportboatsandfishingthereconditioningofexistinginterestingindustrialbuildingsforotheruseandthedemolishingofmorecommonwarehousesandotherconstructionsinorderto__keroomforapartmentandservi__buildings.Theconstructionofthenewportor__rinainvolvesthebuildingofanewc____whichwillcrosstheexistingrailwaylineextendingintothelandabout350m.Thisc____willserveasparkingdocksfortheboats.Inordertocreatethisnewwaterwayandallowthecrossingoftheexistingrailwaylineanewbridgeisneededseefig
1.Inthispaperthecon__ptionpro__ssofthisbridgewhichwillbecomeasymboloftheurbandevelopmentisdescribed.
2.__inconditiontobefulfilledbythebridgeThe__inconditionstobefulfilledbythebridgearethefollowing:·Thebridgewidthmustfulfilthehorizontalandverticalclearan__conditionsoftherailwayline.·Thedepthofthedeckneedstobe__allduetotheverystrictverticalclearan__.·Thehorizontalchannelclearan__needstobeatleast45metersalthoughitisdesirablenottolocateanysupportswithinthec____.Thislastconditionresultsina__inspanofatleast72m.·Thebridgemustalsole__eclearan__forportoperationroadsonbothsidesofthec____andcrossoveraroundaboutcarryinglocaltraffic.·Sin__itisarailwaybridgeitcannotbeaverylightstructure.Itrequiresappropriatestiffnessandbearingcapacity.·Inspiteofthelastpointthebridgeiscon__ivedasasymboloftheurbandevelopmentandthereforeaestheticalconditionsareofgreatimportan__.·Thislastpointcannothoweverresultinaveryexpensivestructureduetothefactthatthebudgetisverylimitedandthisisa__jorconditionoftheproject.Thecostofthestructuremustalsobearinmind__intenan__issuesespeciallyinastructurelocatednexttotheshoreline.FHECORconsultingengineersparticipatedinacontestcalledby__rinadeBadalonaS.A.andwasawardedthecontractofthedesignofthenewbridgewitha______eleganteconomicandstructurallyefficientsolution.
3.DescriptionoftheproposedsolutionTheproposedsolutionisa5spanpresstressedconcretebridgewithspansof
39.
0078.
0039.
0030.00and
21.00meters.Thecrosssectionisformedbytwowebsofvariableheightthetotaldepthofthebridgevariesfrom
1.90m–__ntreof__inspanandac__ssspans-to
6.50moverde__inpiers.Thedeckdepththereforemirrorsthebendingmomentlawseefig.
3.Thewebsareconnectedbymeansofprefabricatedpresstressedbeams.Thesebeamsformribsthroughwhichthelightcanshine.Thisisanimportantfeatureofthebridgewhichiscon__ivedtoilluminatethewalkwaysandtocounteractthehighbridgewidthtobridgeheightratio.Thislightalsooffersani__gefortherailroadduetoitsdiscontinuity.Figure4showsthetwotypicalbridgecrosssectionssupportat__inpiersand__ntralspan.Figure5showsthelighteffectgivenbythe__ntralopening.Anotherimportantfeatureofthebridgedesignisthepositionoftheoutercantileverslabs.Theseslabsareusedasacompressionslabatthecriticalcrosssections.Sin__compressionsarelocatedatthebottomofthecrosssectionatthesupportsnegativebendingandatthetopofthecrosssectionat__ntrespanthespanpositivebendingthecompressionslabtr__elsalongthebridgeaxistobeateachsectionwhereitismoreefficientfollowinganoldideausedbyNerviintheUNESCObuildinginParis.Thisfeaturealsoprodu__sanattractivedesignprovidingbothstructuralefficiencyandaestheticalvaluetothestructure.Thepierswhosedesignisstillbeingoptimisedfromanaestheticalpointofviewarecon__ivedasrobustelementsduetothefactthatgiventheir__allheighttheycannotbeveryslenderandfulfilatthesametimeresistingconditionsandprovideenoughspa__tolocatethebridge’spotbearings.Thecrosssectionisredu__dbyverticalchannelswhichwillallowtheintroductionoflightingunderthestructureaswellasspecialdesignsyettobecon__ived.Figure6showsthegeometryadoptedforthe__inpiers.Thebridgeisanchoredatabutment1inordertoabsorbthehighfor__sresultingfromtrainbreakingwhichareequivalentto25%ofthetrainweight.Attheotherabutmentajointisprovidedaswellasaslabsupportedoverwallsdesignedtocarrytherailwayexpansionapparatusmeanttoallowthebridgemovementwithoutaffectingtherailwayservi__abilityconditions.Alargespa__istherebygeneratedatabutment2whichcouldbeusedinthefutureasstockspa__.Figure7showsthe__indesignideasoftheabutments.
4.Finalre__rksTheproposedstructureforthebridgingoftheC____ofthefuturesportsandfishingportofBadalonafulfilsalltherequirementsoftheproject.Itisarobustbridgeasisne__ssaryfortheservi__abilityoftherailwaylineitisstructurallysoundwithaspecialshapederivedfromitsstructuralfunctionality.ThewholegivesrisetoaninterestingstructurewhichwillserveasasymbolforthePortofBadalonawithoutanunjustifiedhigheconomiccost.新巴达洛纳铁路桥摘要在大城市居所里的结构设计总是一个对于完成需求重要系数的挑战设计,特别是当它涉及铁路或道路中,必须与人的环境相协调的那些基础设施的需要,罢达洛纳的的铁路桥就是一个例子现如今临海的城市区域被污染产业占领城市管理委员会设法面向地中海开放城市,拆毁难看和无用的大楼或者改变对它们的建筑或技术价值的利用方式现在建起了一个沙滩和一个快艇港口有一条铁路线与岸区域的海岸平行,将城市的中心与海岸隔离了开来没有修建一个__式铁路线的资金,因而必须被修筑一座桥梁以增加城市的中心和海岸新设施之间的连系为建造一座铁路桥,发起了一次设计竞标,该桥将穿过城市的一个新的步行区域、新的港口的部分和二条街道桥梁设计的合同被交由FHECOR__工程师拟定一个初步设计提案的理念是将功能、结构合理性、美学和低建筑、低维修费用相结合并且也有意图修建一座成为将来新的都市发展标志的桥梁关键词都市桥梁,铁路,预应力,结构形状
1.简介巴达洛纳是巴塞罗那靠地中海海岸附近重要的卫星城市城市的中坚力量与海岸之间的__被连接巴塞罗那郊区的铁路线路所切断该铁路线是西班牙联合铁路集团收益颇丰的客运线路之一多年来,沿着铁路线工厂厂房出现了形成了一个重要工业中心,但是同时却也让巴达洛纳的人们远离大海为了设法重建海岸和增强其与市中心之间的__,巴达洛纳与巴塞罗那发展委员会合作设法改进它的与市区的连接巴达洛纳市发起了一个主要目的在于重建都市风景的一个都市发展项目,其中包括为体育船只和渔船修建停船港重造其他的现有的有价值的工厂厂房做为其他用途和拆毁仓库和的小游艇船坞等建筑,是为了给__和服务楼腾出空间新的口岸或小游艇船坞的建筑包含一条运河,它将跨过一条大约350m.的铁路线这条运河可作为小船的停船坞为了建造这条新的水路和穿越现有的铁路线,有必要修建一座新的桥梁参见图1在本文中,这座桥梁的构想过程将被描述为都市发展的标志
2.桥梁建造需满足的条件该桥主要须满足的条件有以下内容·桥梁宽度必须符合铁路线的横向和纵向有关条件·桥梁建筑高度,需要非常严格的要求·横向通道宽度,必须至少有45米,虽然这取的是运河无任何支持的情况最后的结论是,一个主跨至少72米·桥梁,也必须在道路两边留出地方让运河的港口运作,还要留出一个回旋距离给当地的交通·既然它是一座铁路桥,它不可能是一个很轻的结构它需要有适当的刚度和承载能力·最后一点,大桥被看作是城市发展的一个象征,因此,美学的要求是非常重要的·最后这点不能不考虑问题有一个非常昂贵的结构,但事实上,财政预算案是非常有限,而且这是该项目的一个重大的问题结构成本必须牢记,还有维护的问题,特别是在位于海岸线旁边的结构FHECOR__工程设计室参加了这个竞赛,用所谓的玛丽娜德巴达洛纳计划赢得了合同,该计划描述了一座简单,优雅,结构经济和有效新的桥梁方案
3.对方案的说明提议的方案是一座跨径分别为
39.00,
78.00,
39.00,
30.00和
21.00米的5跨预应力桥梁横断面由高度可改变的二个网形成桥梁的总深度从
1.90m-中心主跨跨度-到
6.50m主墩高度因此桥面板挠度符合弯曲力矩定律参见图3采用装配式预应力梁梁的肋状部分可以发光这是桥梁的一个重要特点,这样一来,照亮了人行道和抵消桥梁宽度占桥梁高度的比例有鉴于此,这些光也提供了一个间断的铁路形象图4显示二个主要的桥梁横断面主墩和中跨的桥墩图5显示桥肋__发出的光线桥梁设计的另一个重要特点是外面悬臂式平板的位置这些平板使用作为压缩平板作用在重要横断面因为压缩位于横剖面的底部在支持弯曲的阴性的,并且在中跨的横剖面顶部间距弯曲的正面压缩平板沿桥梁轴__是使它每个部分更加发挥出最大承载能力,这一个老想法在科教文__巴黎大厦使用过这一特点也产生了一个有吸引力的设计,提供了高效的结构和极具审美价值的结构基础,虽然从美观角度进行设计进行优选,但事实上他们的高度不可能小的,并提供足够的空间来找到的桥梁奇摩一锅轴承垂直渠道的横截面减少了,这将使引进照明的架构下的特殊设计有待__图6显示了基础所采用的主要几何形状大桥锚定在台座1,以便吸收列车驶过时的产生的__冲击荷载,这是相当于25%的列车重量的力另一扶垛提供联接以及平板支持在墙壁,被设计运载被认为的铁路扩展用具允许桥梁运动,无需影响铁路操作性能适应增大空间而引起的在可能在将来使用作为储蓄空间的扶垛2图7显示扶垛的主要设计形式
4.最后结论所提出的桥梁结构方案包括了所有巴达洛纳运河未来的体育和渔业项目的所有设施强度高的桥梁才有可能适应铁路线的荷载条件,同时拥有着来自于其自身结构的合理性、稳定性整个方案将会导致一座很经济的桥梁,它将作为巴达罗那港的一个非高成本的象征。