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外文翻译

山东交通学院

2016届毕业生毕业论文（设计）

中英文科技翻译

题目：

桥梁工程和桥梁美学

Title:

：

BRIDGEENGINEERINGANDAESTHETICS

专业：

土木工程

班级：

土木111班

学号：

110711132

姓名：

傅明涛

指导教师：

庞传琴

完成日期：

2016年6月11日

BRIDGEENGINEERINGANDAESTHETICS

EvolvementofbridgeEngineering,briefreview

AmongtheearlydocumentedreviewsofconstructionmaterialsandstructuretypesarethebooksofMarcusVitruviosPolliointhefirstcenturyB.C.ThebasicprinciplesofstaticsweredevelopedbytheGreeks,andwereexemplifiedinworksandapplicationsbyLeonardodaVinci,Cardeno,andGalileo.Inthefifteenthandsixteenthcentury,engineersseemedtobeunawareofthisrecord,andreliedsolelyonexperienceandtraditionforbuildingbridgesandaqueducts.ThestateoftheartchangedrapidlytowardtheendoftheseventeenthcenturywhenLeibnitz,Newton,andBernoulliintroducedmathematicalformulations.PublishedworksbyLahire（1695）andBelidor（1792）aboutthetheoreticalanalysisofstructuresprovidedthebasisinthefieldofmechanicsofmaterials.

Kuzmanovic（1977）focusesonstoneandwoodasthefirstbridge-buildingmaterials.Ironwasintroducedduringthetransitionalperiodfromwoodtosteel.Accordingtorecentrecords,concretewasusedinFranceasearlyas1840forabridge39feet（12m）longtospantheGaroyneCanalatGrisoles,butreinforcedconcretewasnotintroducedinbridgeconstructionuntilthebeginningofthiscentury.Prestressedconcretewasfirstusedin1927.

Stonebridgesofthearchtype（integratedsuperstructureandsubstructure）wereconstructedinRomeandotherEuropeancitiesinthemiddleages.Thesearcheswerehalf-circular,withflatarchesbeginningtodominatebridgeworkduringtheRenaissanceperiod.Thisconceptwasmarkedlyimprovedattheendoftheeighteenthcenturyandfoundstructurallyadequatetoaccommodatefuturerailroadloads.Intermsofanalysisanduseofmaterials,stonebridgeshavenotchangedmuch,butthetheoreticaltreatmentwasimprovedbyintroducingthepressure-lineconceptintheearly1670s（Lahire,1695）.Thearchtheorywasdocumentedinmodeltestswheretypicalfailuremodeswereconsidered（Frezier,1739）.Culmann（1851）introducedtheelasticcentermethodforfixed-endarches,andshowedthatthreeredundantparameterscanbefoundbytheuseofthreeequationsofcoMPatibility.

WoodentrusseswereusedinbridgesduringthesixteenthcenturywhenPalladiobuilttriangularframesforbridgespans10feetlong.Thiseffortalsofocusedonthethreebasicprinciplesogbridgedesign:

convenience（serviceability）,appearance,andendurance（strength）.severaltimbertrussbridgeswereconstructedinwesternEuropebeginninginthe1750swithspansupto200feet（61m）supportedonstonesubstructures.SignificantprogresswaspossibleintheUnitedStatesandRussiaduringthenineteenthcentury,promptedbytheneedtocrossmajorriversandbyanabundanceofsuitabletimber.Favorableeconomicconsiderationsincludedinitiallowcostandfastconstruction.

Thetransitionfromwoodenbridgestosteeltypesprobablydidnotbeginuntilabout1840,althoughthefirstdocumenteduseofironinbridgeswasthechainbridgebuiltin1734acrosstheOderRiverinPrussia.Thefirsttrusscompletelymadeofironwasin1840intheUnitedStates,followedbyEnglandin1845,Germanyin1853,andRussiain1857.In1840,thefirstironarchtrussbridgewasbuiltacrosstheErieCanalatUtica.

TheImpetusofAnalysis

Thetheoryofstructures,developedmainlyintheninetheenthcentury,focusedontrussanalysis,withthefirstbookonbridgeswrittenin1811.TheWarrentriangulartrusswasintroducedin1846,supplementedbyamethodforcalculatingthecorrecetforces.I-beamsfabricatedfromplatesbecamepopularinEnglandandwereusedinshort-spanbridges.

In1866,Culmannexplainedtheprinciplesofcantilevertrussbridges,andoneyearlaterthefirstcantileverbridgewasbuiltacrosstheMainRiverinHassfurt,Germany,withacenterspanof425feet（130m）.ThefirstcantileverbridgeintheUnitedStateswasbuiltin1875acrosstheKentuckyRiver.AmostimpressiverailwaycantileverbridgeinthenineteenthcenturywastheFirstofForthbridge,builtbetween1883and1893,withspanmagnitudesof1711feet（521.5m）.

Ataboutthesametime,structuralsteelwasintroducedasaprimematerialinbridgework,althoughitsqualitywasoftenpoor.SeveralearlyexamplesaretheEadsbridgeinSt.Louis;theBrooklynbridgeinNewYork;andtheGlasgowbridgeinMissouri,allcompletedbetween1874and1883.

AmongtheanalyticalanddesignprogresstobementionedarethecontributionsofMaxwell,particularlyforcertainstaticallyindeterminatetrusses;thebooksbyCremona（1872）ongraphicalstatics;theforcemethodredefinedbyMohr;andtheworksbyClapeyronwhointroducedthethree-momentequations.

TheImpetusofNewMaterials

Sincethebeginningofthetwentiethcentury,concretehastakenitsplaceasoneofthemostusefulandimportantstructuralmaterials.BecauseofthecoMParativeeasewithwhichitcanbemoldedintoanydesiredshape,itsstructuralusesarealmostunlimited.WhereverPortlandcementandsuitableaggregatesareavailable,itcanreplaceothermaterialsforcertaintypesofstructures,suchasbridgesubstructureandfoundationelements.

Inaddition,theintroductionofreinforcedconcreteinmultispanframesatthebeginningofthiscenturyimposednewanalyticalrequirements.Structuresofahighorderofredundancycouldnotbeanalyzedwiththeclassicalmethodsofthenineteenthcentury.TheimportanceofjointrotationwasalreadydemonstratedbyManderla（1880）andBendixen（1914）,whodevelopedrelationshipsbetweenjointmomentsandangularrotationsfromwhichtheunknownmomentscanbeobtained,thesocalledslope-deflectionmethod.MoresimplificationsinframeanalysisweremadepossiblebytheworkofCalisev（1923）,whousedsuccessiveapproximationstoreducethesystemofequationstoonesimpleexpressionforeachiterationstep.ThisapproachwasfurtherrefinedandintegratedbyCross（1930）inwhatisknownasthemethodofmomentdistribution.

Oneofthemostimportimportantrecentdevelopmentsintheareaofanalyticalproceduresistheextensionofdesigntocovertheelastic-plasticrange,alsoknownasloadfactororultimatedesign.PlasticanalysiswasintroducedwithsomepracticalobservationsbyTresca（1846）;andwasformulatedbySaint-Venant（1870）,TheconceptofplasticityattractedresearchersandengineersafterWorldWarⅠ,mainlyinGermany,withthecenterofactivityshiftingtoEnglandandtheUnitedStatesafterWorldWarⅡ.Theprobabilisticapproachisanewdesignconceptthatisexpectedtoreplacetheclassicaldeterministicmethodology.

Amainstepforwardwasthe1969additionoftheFederalHighwayAdiministration（FHWA）”CriteriaforReinforcedConcreteBridgeMembers“thatcoversstrengthandserviceabilityatultimatedesign.Thiswaspreparedforuseinconjunctionwiththe1969AmericanAssociationofStateHighwayOffficials（AASHO）StandardSpecification,andwaspresentedinaformatthatisreadilyadaptabletothedevelopmentofultimatedesignspecifications.Accordingtothisdocument,theproportioningofreinforcedconcretemembers（includingcolumns）maybelimitedbyvariousstagesofbehavior:

elastic,cracked,andultimate.Designaxialloads,ordesignshears.Structuralcapacityisthereactionphase,andallcalculatedmodifiedstrengthvaluesderivedfromtheoreticalstrengthsarethecapacityvalues,suchasmomentcapacity,axialloadcapacity,orshearcapacity.Atserviceabilitystates,investigationsmayalsobenecessaryfordeflections,maximumcrackwidth,andfatigue.

BridgeTypes

Anotablebridgetypeisthesuspensionbridge,withthefirstexamplebuiltintheUnitedStatesin1796.ProblemsofdynamicstabilitywereinvestigatedaftertheTacomabridgecollapse,andthisworkledtosignificanttheoreticalcontributionsSteinman（1929）summarizesabout250suspensionbridgesbuiltthroughouttheworldbetween1741and1928.

Withtheintroductionoftheinterstatesystemandtheneedtoprovidestructuresatgradeseparations,certainbridgetypeshavetakenastrongplaceinbridgepractice.Theseincludeconcretesuperstructures（slab,T-beams,concreteboxgirders）,steelbeamandplategirders,steelboxgirders,compositeconstruction,orthotropicplates,segmentalconstruction,curvedgirders,andcable-stayedbridges.Prefabricatedmembersaregivenseriousconsideration,whileinterestinboxsectionsremainsstrong.

BridgeAppearanceandAesthetics

Grimm（1975）documentsthefirstrecordedlegislativeefforttocontroltheappearanceofthebuiltenvironment.Thisoccurredin1647whentheCouncilofNewAmsterdamappointedthreeofficials.In1954,theSupremeCourtoftheUnitedStatesheldthatitiswithinthepowerofthelegislaturetodeterminethatcommunitiesshouldbeattractiveaswellashealthy,spaciousaswellasclean,andbalancedaswellaspatrolled.TheEnvironmentalPolicyActof1969directsallagenciesofthefederalgovernmenttoidentifyanddevelopmethodsandprocedurestoensurethatpresentlyunquantifiedenvironmentalamentitiesandvaluesaregivenappropriateconsiderationindecisionmakingalongwitheconomicandtechnicalaspects.

Althoughinmanycivilengineeringworksaestheticshasbeenpracticedalmostintuitively,particularlyinthepast,bridgeengineershavenotignoredorneglectedtheaestheticdisciplines.Recentresearchonthesubjectappearstoleadtoarationalizedaestheticdesignmethodology（GrimmandPreiser,1976）.Workhasbeendoneontheaest