钢筋混凝土外文翻译文献

钢筋混凝土外文翻译文献PAGE1中英文资料翻译1外文翻译1.1ReinforcedConcretePlainconcreteisformedfromahardenedmixtureofcement,water,fineaggregate,coarseaggregate(crushedstoneorgravel),air,andoftenotheradmixtures.Theplasticmixisplacedandconsolidatedintheformwork,thencuredtofacilitatetheaccelerationofthechemicalhydrationreactionlfthecement/watermix,resultinginhardenedconcrete.Thefinishedproducthashighcompressivestrength,andlowresistancetotension,suchthatitstensilestrengthisapproximatelyonetenthlfitscompressivestrength.Consequently,tensileandshearreinforcementinthetensileregionsofsectionshastobeprovidedtocompensatefortheweaktensionregionsinthereinforcedconcreteelement.Itisthisdeviationinthecompositionofareinforcesconcretesectionfromthehomogeneityofstandardwoodorsteelsectionsthatrequiresamodifiedapproachtothebasicprinciplesofstructuraldesign.Thetwocomponentsoftheheterogeneousreinforcedconcretesectionaretobesoarrangedandproportionedthatoptimaluseismadeofthematerialsinvolved.Thisispossiblebecauseconcretecaneasilybegivenanydesiredshapebyplacingandcompactingthewetmixtureoftheconstituentingredientsareproperlyproportioned,thefinishedproductbecomesstrong,durable,and,incombinationwiththereinforcingbars,adaptableforuseasmainmembersofanystructuralsystem.钢筋混凝土外文翻译文献全文共1页，当前为第1页。Thetechniquesnecessaryforplacingconcretedependonthetypeofmembertobecast:thatis,whetheritisacolumn,abean,awall,aslab,afoundation.amasscolumns,oranextensionofpreviouslyplacedandhardenedconcrete.Forbeams,columns,andwalls,theformsshouldbewelloiledaftercleaningthem,andthereinforcementshouldbeclearedofrustandotherharmfulmaterials.Infoundations,theearthshouldbecompactedandthoroughlymoistenedtoabout6in.indepthtoavoidabsorptionofthemoisturepresentinthewetconcrete.Concreteshouldalwaysbeplacedinhorizontallayerswhicharecompactedbymeansofhighfrequencypower-drivenvibratorsofeithertheimmersionorexternaltype,asthecaserequires,unlessitisplacedbypumping.Itmustbekeptinmind,however,thatovervibrationcanbeharmfulsinceitcouldcausesegregationoftheaggregateandbleedingoftheconcrete.钢筋混凝土外文翻译文献全文共1页，当前为第1页。Hydrationofthecementtakesplaceinthepresenceofmoistureattemperaturesabove50°F.Itisnecessarytomaintainsuchaconditioninorderthatthechemicalhydrationreactioncantakeplace.Ifdryingistoorapid,surfacecrackingtakesplace.Thiswouldresultinreductionofconcretestrengthduetocrackingaswellasthefailuretoattainfullchemicalhydration.Itisclearthatalargenumberofparametershavetobedealtwithinproportioningareinforcedconcreteelement,suchasgeometricalwidth,depth,areaofreinforcement,steelstrain,concretestrain,steelstress,andsoon.Consequently,trialandadjustmentisnecessaryinthechoiceofconcretesections,withassumptionsbasedonconditionsatsite,availabilityoftheconstituentmaterials,particulardemandsoftheowners,architecturalandheadroomrequirements,theapplicablecodes,andenvironmentalreinforcedconcreteisoftenasite-constructedcomposite,incontrasttothestandardmill-fabricatedbeamandcolumnsectionsinsteelstructures.Atrialsectionhastobechosenforeachcriticallocationinastructuralsystem.Thetrialsectionhastobeanalyzedtodetermineifitsnominalresistingstrengthisadequatetocarrytheappliedfactoredload.Sincemorethanonetrialisoftennecessarytoarriveattherequiredsection,thefirstdesigninputstepgeneratesintoaseriesoftrial-and-adjustmentanalyses.Thetrial-and–adjustmentproceduresforthechoiceofaconcretesectionleadtotheconvergenceofanalysisanddesign.Henceeverydesignisananalysisonceatrialsectionischosen.Theavailabilityofhandbooks,charts,andpersonalcomputersandprogramssupportsthisapproachasamoreefficient,compact,andspeedyinstructionalmethodcomparedwiththetraditionalapproachoftreatingtheanalysisofreinforcedconcreteseparatelyfrompuredesign.钢筋混凝土外文翻译文献全文共2页，当前为第2页。1.2Earthwork钢筋混凝土外文翻译文献全文共2页，当前为第2页。Becauseearthmovingmethodsandcostschangemorequicklythanthoseinanyotherbranchofcivilengineering,thisisafieldwheretherearerealopportunitiesfortheenthusiast.In1935mostofthemethodsnowinuseforcarryingandexcavatingearthwithrubber-tyredequipmentdidnotexist.Mostearthwasmovedbynarrowrailtrack,nowrelativelyrare,andthemainmethodsofexcavation,withfaceshovel,backacter,ordraglineorgrab,thoughtheyarestillwidelyusedareonlyafewofthemanycurrentmethods.Tokeephisknowledgeofearthmovingequipmentuptodateanengineermustthereforespendtinestudyingmodernmachines.Generallytheonlyreliableup-to-dateinformationonexcavators,loadersandtransportisobtainablefromthemakers.Earthworksorearthmovingmeanscuttingintogroundwhereitssurfaceistoohigh(cuts),anddumpingtheearthinotherplaceswherethesurfaceistoolow(fills).Toreduceearthworkcosts,thevolumeofthefillsshouldbeequaltothevolumeofthecutsandwhereverpossiblethecutsshouldbeplacedneartofillsofequalvolumesoastoreducetransportanddoublehandlingofthefill.Thisworkofearthworkdesignfallsontheengineerwholaysouttheroadsinceitisthelayoutoftheearthworkmorethananythingelsewhichdecidesitscheapness.Fromtheavailablemapsahdlevels,theengineeringmusttrytoreachasmanydecisionsaspossibleinthedrawingofficebydrawingcrosssectionsoftheearthwork.Onthesitewhenfurtherinformationbecomesavailablehecanmakechangesinjissectionsandlayout,butthedrawinglfficeworkwillnothavebeenlost.Itwillhavehelpedhimtoreachthebestsolutionintheshortesttime.Thecheapestwayofmovingearthistotakeitdirectlyoutofthecutanddropitasfillwiththesamemachine.Thisisnotalwayspossible,butwhenitcanbedoneitisideal,beingbothquickandcheap.Draglines,bulldozersandfaceshovelsandothis.Thelargestradiusisobtainedwiththedragline,andthelargesttonnageofearthismovedbythebulldozer,thoughonlyovershortdistances.Thedisadvantagesofthedraglinearethatitmustdigbelowitself,itcannotdigwithforceintocompactedmaterial,itcannotdigonsteepslopws,anditsdumpinganddiggingarenotaccurate.Faceshovelsarebetweenbulldozersanddraglines,havingalargerradiusofactionthanbulldozersbutlessthandraglines.Theyareanletodigintoaverticalclifffaceinawaywhichwouldbedangeroustorabulldozeroperatorandimpossibleforadragline.Eachpieceofequipmentshouldbeleveloftheirtracksandfordeepdigsincompactmaterialabackacterismostuseful,butitsdumpingradiusisconsiderablylessthanthatofthesameescavatorfittedwithafaceshovel.钢筋混凝土外文翻译文献全文共3页，当前为第3页。Rubber-tyredbowlscrapersareindispensableforfairlyleveldiggingwherethedistanceoftransportistoomuchtoradraglineorfaceshovel.Theycandigthematerialdeeply(butonlybelowthemselves)toafairlyflatsurface,carryithundredsofmetersifneedbe,thendropitandlevelitroughlyduringthedumping.Forharddiggingitisoftenfoundeconomicaltokeepapushertractor(wheeledortracked)onthediggingsite,topusheachscraperasitreturnstodig.Assoonasthescraperisfull,thepushertractorreturnstothebeginningofthedigtoheoptohelpthenestscraper.钢筋混凝土外文翻译文献全文共3页，当前为第3页。Bowlscrapersareoftenextremelypowerfulmachines;manymakersbuildscrapersof8cubicmetersstruckcapacity,whichcarry10m³heaped.Thelargestself-propelledscrapersareof19m³struckcapacity(25m³heaped)andtheyaredrivenbyatractorengineof430horse-powers.Dumpersareprobablythecommonestrubber-tyredtransportsincetheycanalsoconvenientlybeusedforcarryingconcreteorotherbuildingmaterials.Dumpershavetheearthcontaineroverthefrontaxleonlargerubber-tyredwheels,andthecontainertipsforwardsonmosttypes,thoughinarticulateddumpersthedirectionoftipcanbewidelyvaried.Thesmallestdumpershaveacapacityofabout0.5m³,andthelargeststandardtypesareofabout4.5m³.Specialtypesincludetheself-loadingdumperofupto4m³andthearticulatedtypeofabout0.5m³.Thedistinctionbetweendumpersanddumptrucksmustberemembered.dumperstipforwardsandthedriversitsbehindtheload.Dumptrucksareheavy,strengthenedtippinglorries,thedrivertravelsinfrontlftheloadandtheloadisdumpedbehindhim,sotheyaresometimescalledrear-dumptrucks.1.3SafetyofStructuresTheprincipalscopeofspecificationsistoprovidegeneralprinciplesandcomputationalmethodsinordertoverifysafetyofstructures.The“safetyfactor”,whichaccordingtomoderntrendsisindependentofthenatureandcombinationofthematerialsused,canusuallybedefinedastheratiobetweentheconditions.Thisratioisalsoproportionaltotheinverseoftheprobability(risk)offailureofthestructure.Failurehastobeconsiderednotonlyasoverallcollapseofthestructurebutalsoasunserviceabilityor,accordingtoamoreprecise.Commondefinition.Asthereachingofa“limitstate”whichcausestheconstructionnottoaccomplishthetaskitwasdesignedfor.Therearetwocategoriesoflimitstate:钢筋混凝土外文翻译文献全文共4页，当前为第4页。(1)Ultimatelimitsate,whichcorrespondstothehighestvalueoftheload-bearingcapacity.Examplesincludelocalbucklingorglobalinstabilityofthestructure;failureofsomesectionsandsubsequenttransformationofthestructureintoamechanism;failurebyfatigue;elasticorplasticdeformationorcreepthatcauseasubstantialchangeofthegeometryofthestructure;andsensitivityofthestructuretoalternatingloads,tofireandtoexplosions.钢筋混凝土外文翻译文献全文共4页，当前为第4页。(2)Servicelimitstates,whicharefunctionsoftheuseanddurabilityofthestructure.Examplesincludeexcessivedeformationsanddisplacementswithoutinstability;earlyorexcessivecracks;largevibrations;andcorrosion.Computationalmethodsusedtoverifystructureswithrespecttothedifferentsafetyconditionscanbeseparatedinto:(1)Deterministicmethods,inwhichthemainparametersareconsideredasnonrandomparameters.(2)Probabilisticmethods,inwhichthemainparametersareconsideredasrandomparameters.Alternatively,withrespecttothedifferentuseoffactorsofsafety,computationalmethodscanbeseparatedinto:(1)Allowablestressmethod,inwhichthestressescomputedundermaximumloadsarecomparedwiththestrengthofthematerialreducedbygivensafetyfactors.(2)Limitstatesmethod,inwhichthestructuremaybeproportionedonthebasisofitsmaximumstrength.Thisstrength,asdeterminedbyrationalanalysis,shallnotbelessthanthatrequiredtosupportafactoredloadequaltothesumofthefactoredliveloadanddeadload(ultimatestate).Thestressescorrespondingtoworking(service)conditionswithunfactoredliveanddeadloadsarecomparedwithprescribedvalues(servicelimitstate).Fromthefourpossiblecombinationsofthefirsttwoandsecondtwomethods,wecanobtainsomeusefulcomputationalmethods.Generally,twocombinationsprevail:(1)deterministicmethods,whichmakeuseofallowablestresses.(2)Probabilisticmethods,whichmakeuseoflimitstates.Themainadvantageofprobabilisticapproachesisthat,atleastintheory,itispossibletoscientificallytakeintoaccountallrandomfactorsofsafety,whicharethencombinedtodefinethesafetyfactor.probabilisticapproachesdependupon:(1) Randomdistributionofstrengthofmaterialswithrespecttotheconditionsoffabricationanderection(scatterofthevaluesofmechanicalpropertiesthroughoutthestructure);钢筋混凝土外文翻译文献全文共5页，当前为第5页。(2) Uncertaintyofthegeometryofthecross-sectionsandofthestructure(faultsandimperfectionsduetofabricationanderectionofthestructure);钢筋混凝土外文翻译文献全文共5页，当前为第5页。(3) Uncertaintyofthepredictedliveloadsanddeadloadsactingonthestructure;(4)Uncertaintyrelatedtotheapproximationofthecomputationalmethodused(deviationoftheactualstressesfromcomputedstresses).Furthermore,probabilistictheoriesmeanthattheallowableriskcanbebasedonseveralfactors,suchas:(1) Importanceoftheconstructionandgravityofthedamagebyitsfailure;(2)Numberofhumanliveswhichcanbethreatenedbythisfailure;(3)Possibilityand/orlikelihoodofrepairingthestructure;(4) Predictedlifeofthestructure.Allthesefactorsarerelatedtoeconomicandsocialconsiderationssuchas：(1) Initialcostoftheconstruction;(2) Amortizationfundsforthedurationoftheconstruction;(3) Costofphysicalandmaterialdamageduetothefailureoftheconstruction;(4) Adverseimpactonsociety;(5) Moralandpsychologicalviews.钢筋混凝土外文翻译文献全文共6页，当前为第6页。Thedefinitionofalltheseparameters,foragivensafetyfactor,allowsconstructionattheoptimumcost.However,thedifficultyofcarryingoutacompleteprobabilisticanalysishastobetakenintoaccount.Forsuchananalysisthelawsofthedistributionoftheliveloadanditsinducedstresses,ofthescatterofmechanicalpropertiesofmaterials,andofthegeometryofthecross-sectionsandthestructurehavetobeknown.Furthermore,itisdifficulttointerprettheinteractionbetweenthelawofdistributionofstrengthandthatofstressesbecausebothdependuponthenatureofthematerial,onthecross-sectionsandupontheloadactingonthestructure.Thesepracticaldifficultiescanbeovercomeintwoways.Thefirstistoapplydifferentsafetyfactorstothematerialandtotheloads,withoutnecessarilyadoptingtheprobabilisticcriterion.Thesecondisanapproximateprobabilisticmethodwhichintroducessomesimplifyingassumptions(semi-probabilisticmethods)。钢筋混凝土外文翻译文献全文共6页，当前为第6页。中文翻译1.1钢筋混凝土素混凝土是由水泥、水、细骨料、粗骨料（碎石或；卵石）、空气，通常还有其他外加剂等经过凝固硬化而成。将可塑的混凝土拌合物注入到模板内，并将其捣实，然后进行养护，以加速水泥与水的水化反应，最后获得硬化的混凝土。其最终制成品具有较高的抗压强度和较低的抗拉强度。其抗拉强度约为抗压强度的十分之一。因此，截面的受拉区必须配置抗拉钢筋和抗剪钢筋以增加钢筋混凝土构件中较弱的受拉区的强度。由于钢筋混凝土截面在均质性上与标准的木材或钢的截面存在着差异，因此，需要对结构设计的基本原理进行修改。将钢筋混凝土这种非均质截面的两种组成部分按一定比例适当布置，可以最好的利用这两种材料。这一要求是可以达到的。因混凝土由配料搅拌成湿拌合物，经过振捣并凝固硬化，可以做成任何一种需要的形状。如果拌制混凝土的各种材料配合比恰当，则混凝土制成品的强度较高，经久耐用，配置钢筋后，可以作为任何结构体系的主要构件。浇筑混凝土所需要的技术取决于即将浇筑的构件类型，诸如：柱、梁、墙、板、基础，大体积混凝土水坝或者继续延长已浇筑完毕并且已经凝固的混凝土等。对于梁、柱、墙等构件，当模板清理干净后应该在其上涂油，钢筋表面的锈及其他有害物质也应该被清除干净。浇筑基础前，应将坑底土夯实并用水浸湿6英寸，以免土壤从新浇的混凝土中吸收水分。一般情况下，除使用混凝土泵浇筑外，混凝土都应在水平方向分层浇筑，并使用插入式或表面式高频电动振捣器捣实。必须记住，过分的振捣将导致骨料离析和混凝土泌浆等现象，因而是有害的。钢筋混凝土外文翻译文献全文共7页，当前为第7页。水泥的水化作用发生在有水分存在，而且气温在50°F以上的条件下。为了保证水泥的水化作用得以进行，必须具备上述条件。如果干燥过快则会出现表面裂缝，这将有损与混凝土的强度，同时也会影响到水泥水化作用的充分进行。钢筋混凝土外文翻译文献全文共7页，当前为第7页。设计钢筋混凝土构件时显然需要处理大量的参数，诸如宽度、高度等几何尺寸，配筋的面积，钢筋的应变和混凝土的应变，钢筋的应力等等。因此，在选择混凝土截面时需要进行试算并作调整，根据施工现场条件、混凝土原材料的供应情况、业主提出的特殊要求、对建筑和净空高度的要求、所用的设计规范以及建筑物周围环境条件等最后确定截面。钢筋混凝土通常是现场浇注的合成材料，它与在工厂中制造的标准的钢结构梁、柱等不同，因此对于上面所提到的一系列因素必须予以考虑。对结构体系的各个部位均需选定试算截面并进行验算，以确定该截面的名义强度是否足以承受所作用的计算荷载。由于经常需要进行多次试算，才能求出所需的截面，因此设计时第一次采用的数值将导致一系列的试算与调整工作。选择混凝土截面时，采用试算与调整过程可以使复核与设计结合在一起。因此，当试算截面选定后，每次设计都是对截面进行复核。手册、图表和微型计算机以及专用程序的使用，使这种设计方法更为简捷有效，而传统的方法则是把钢筋混凝土的复核与单纯的设计分别进行处理。1.2土方工程由于和土木工程中任何其他工种的施工方法与费用相比较，土方挖运的施工方法与费用的变化都要快得多，因此对于有事业心的人来说，土方工程是一个可以大有作为的领域。在1935年，目前采用的利用轮胎式机械设备进行土方挖运的方法大多数还没有出现。那是大部分土方是采用窄轨铁路运输，在这目前来说是很少采用的。当时主要的开挖方式是使用正铲、反铲、拉铲或抓斗等挖土机，尽管这些机械目前仍然在广泛应用，但是它们只不过是目前所采用的许多方法中的一小部分。因此，一个工程师为了使自己在土方挖运设备方面的知识跟得上时代的发展，他应当花费一些时间去研究现代的机械。一般说来，有关挖土机、装载机和运输机械的唯一可靠而又最新的资料可以从制造厂商处获得。土方工程或土方挖运工程指的是把地表面过高处的土壤挖去（挖方），并把它倾卸到地表面过低的其他地方（填方）。为了降低土方工程费用，填方量应该等于挖方量，而且挖方地点应该尽可能靠近土方量相等的填方地点，以减少运输量和填方的二次搬运。土方设计这项工作落到了从事道路设计的工程师的身上，因为土方工程的设计比其他任何工作更能决定工程造价是否低廉。根据现有的地图和标高，道路工程师应在设计绘图室中的工作也并不是徒劳的。它将帮助他在最短的时间内获得最好的方案。钢筋混凝土外文翻译文献全文共8页，当前为第8页。费用最低的运土方法是用同一台机械直接挖方取土并且卸土作为填方。这并不是经常可以做到的，但是如果能够做到则是很理想的，因为这样做既快捷又省钱。拉铲挖土机。推土机和正铲挖土机都能做到这点。拉铲挖土机的工作半径最大。推土机所推运的图的数量最多，只是运输距离很短。拉铲挖土机的缺点是只能挖比它本身低的土，不能施加压力挖入压实的土壤内，不能在陡坡上挖土，而且挖。卸都不准确。钢筋混凝土外文翻译文献全文共8页，当前为第8页。正铲挖土机介于推土机和拉铲挖土机的之间，其作用半径大于推土机，但小于拉铲挖土机。正铲挖土机能挖取竖直陡峭的工作面，这种方式对推土机司机来说是危险的，而对拉铲挖土机则是不可能的。每种机械设备应该进行最适合它的性能的作业。正铲挖土机不能挖比其停机平面低很多的土，而深挖坚实的土壤时，反铲挖土机最适用，但其卸料半径比起装有正铲的同一挖土机的卸料半径则要小很多。在比较平坦的场地开挖，如果用拉铲或正铲挖土机运输距离太远时，则装有轮胎式的斗式铲运机就是比不可少的。它能在比较平的地面上挖较深的土（但只能挖机械本身下面的土），需要时可以将土运至几百米远，然后卸土并在卸土的过程中把土大致铲平。在挖掘硬土时，人们发现在开挖场地经常用一辆助推拖拉机（轮式或履带式），对返回挖土的铲运机进行助推这种施工方法是经济的。一旦铲运机装满，助推拖拉机就回到开挖的地点去帮助下一台铲运机。斗式铲运机通常是功率非常大的机械，许多厂家制造的铲运机铲斗容