土木工程專業(yè)英語(yǔ)lesson 2 Introduction to Structural Design

LESSON2IntroductiontoStructuralDesignStructuralDesignThestructuraldesignofbuildings，whetherofstructuralsteelorreinforcedconcrete,requiresthedeterminationoftheoverallproportionsanddimensionsofthesupportingframeworkandtheselectionofthecrosssectionsofindividualmembers．Inmostcasesthefunctionaldesign，includingtheestablishmentofthenumberofstoriesandthefloorplan，willhavebeendonebyanarchitect，andthestructuralengineermustworkwithintheconstraintsimposedbythisdesign．參考譯文

無(wú)論鋼結(jié)構(gòu)或鋼筋混凝土，建筑物的結(jié)構(gòu)設(shè)計(jì)需要確定整體比例，支持框架尺寸和選擇各個(gè)構(gòu)件截面。在大多數(shù)情況下，包括確定樓層的數(shù)目和平面圖的功能設(shè)計(jì)，將由建筑師和結(jié)構(gòu)工程師依據(jù)這一設(shè)計(jì)的限定條件來(lái)完成。framework['freimw?:k]n.框架，骨架；結(jié)構(gòu)，構(gòu)架constraint[k?n'streint]n.約束；強(qiáng)制；局促，態(tài)度

不自然impose[im'p?uz]vi.欺騙；利用；施加影響 vt.強(qiáng)加；以…欺騙；征稅StructuralDesignIdeally，theengineerandarchitectwillcollaboratethroughoutthedesignprocesssothattheprojectiscompletedinanefficientmanner．Ineffect，however，thedesigncanbesummedupasfollows:Thearchitectdecideshowthebuildingshouldlook：theengineermustmakesurethatitdoesn’tfalldown．Althoughthisisanoversimplification，itaffirmsthefirstpriorityofthestructuralengineer：safety．參考譯文理想情況下，工程師和建筑師將在整個(gè)設(shè)計(jì)過(guò)程中合作，以便以有效的方式完成工程。不管怎樣，實(shí)際上設(shè)計(jì)可以概括如下：建筑師決定建筑物的外觀：工程師必須確保它不會(huì)倒。雖然這是過(guò)于簡(jiǎn)單化，但它說(shuō)明了結(jié)構(gòu)工程師的第一要?jiǎng)?wù)：平安。collaborate[k?'l?b?reit]vi.合作；勾結(jié)，通敵oversimplification['?uv?,simplifi'kei??n]n.過(guò)度單純化；過(guò)分簡(jiǎn)單化StructuralDesignOtherimportantconsiderationsincludeserviceability(howwellthestructureperformsintermsofappearanceanddeflection)andeconomy．Aneconomicalstructurerequiresanefficientuseofmaterialsandconstructionlabor．Althoughthiscanusuallybeaccomplishedbyadesignthatrequiresaminimumamountofmaterial，savingscanoftenberealizedbyusingslightlymorematerialifitresultsinasimpler，moreeasilyconstructedproject．參考譯文其他要考慮的主要因素包括適用性〔如何合理表現(xiàn)結(jié)構(gòu)的外觀和偏差〕和節(jié)約。一個(gè)經(jīng)濟(jì)的建筑需要高效使用材料和施工工時(shí)。雖然這通常通過(guò)需要最少建材的設(shè)計(jì)來(lái)實(shí)現(xiàn)，但往往節(jié)約可通過(guò)使用稍多的建材而產(chǎn)生一個(gè)更簡(jiǎn)單、更易于施工的工程來(lái)實(shí)現(xiàn)。serviceability[,s?:vis?'biliti]n.可用性，適用性；使用可靠性；[計(jì)]可效勞性；可維修性StructuralDesignAgooddesignrequirestheevaluationofseveralframingplans--thatis，differentarrangementsofmembersandtheirconnections．Inotherwords，severalalternatedesignsshouldbepreparedandtheircostscompared．Foreachframingplaninvestigated，theindividualcomponentsmustbedesigned．Thisrequiresthestructuralanalysisoftheframe(s)ofthebuildingandthecomputationofforcesandbendingmomentsintheindividualmembers．參考譯文一個(gè)好的設(shè)計(jì)需要對(duì)多個(gè)設(shè)計(jì)規(guī)劃評(píng)估——構(gòu)件及其連接的不同組合。換句話說(shuō)，應(yīng)準(zhǔn)備幾種備用設(shè)計(jì)及其本錢比較。對(duì)每個(gè)設(shè)計(jì)規(guī)劃，都必須審查其單獨(dú)組件設(shè)計(jì)。這就要求有建筑框架的結(jié)構(gòu)分析和各個(gè)構(gòu)件的力與彎矩的計(jì)算。evaluation[i,v?lju'ei??n]n.評(píng)價(jià)；[審計(jì)]評(píng)估；估價(jià)；

求值Bendingmoment[力]彎矩；[力]彎曲力矩； [力]撓矩

StructuralDesignArmedwiththisinformation，thestructuraldesignercanthenselecttheappropriatecrosssection．Beforeanyanalysis，however，adecisionmustbemadeonthebuildingmaterialtobeused：itwillusuallybereinforcedconcrete，structuralsteel，orboth．Ideally，alternatedesignsshouldbepreparedwitheach．參考譯文有了這些信息，結(jié)構(gòu)設(shè)計(jì)者那么可以選擇適當(dāng)?shù)臋M截面。不過(guò)，在任何分析之前必須決定要使用的建筑材料：通常是鋼筋混凝土、鋼結(jié)構(gòu)或兼有。理想情況下，每個(gè)方案都應(yīng)準(zhǔn)備不同的設(shè)計(jì)。Loads

Theforcesthatactonastructurearecalledloads．Theybelongtooneoftwobroadcategories：deadloadandliveload．Deadloadsarethosethatarepermanent，includingtheweightofthestructureitself，whichissometimescalledtheself-weight．Otherdeadloadsinabuildingincludetheweightofnonstructuralcomponentssuchasfloorcoverings，suspendedceilingswithlightfixtures，andpartitions．參考譯文作用于結(jié)構(gòu)上的力被稱為荷載。所有荷載分屬于兩大類別：恒載與活載。恒載是那些永久的負(fù)荷，包括結(jié)構(gòu)本身的重量，有時(shí)也稱為自重。建筑物內(nèi)的其他恒載包括某些非結(jié)構(gòu)構(gòu)件的重量，諸如地板、有燈具的吊頂、隔斷等。fixture['fikst??]n.設(shè)備；固定裝置；固定于某處不

大可能移動(dòng)之物partition[pɑ:'ti??n]n.劃分，分開(kāi)；[數(shù)]分割；隔墻；

隔離物

vt.[數(shù)]分割；分隔；區(qū)分Deadload恒載；靜負(fù)荷Liveload動(dòng)荷；活負(fù)載；有效負(fù)載Loads

Alloftheloadsmentionedthusfarareforcesduetogravityandarereferredtoasgravityloads,liveloads，whichcanalsobegravityloads，arethosethatarenotaspermanentasdeadloads．Thistypemayormaynotbeactingonthestructureatanygiventime，andthelocationmaynotbefixed．參考譯文迄今為止所提到的所有負(fù)荷均源于重力，故稱之為重力荷載，活荷載也可以是重力荷載，是那些不像恒載那樣永久的荷載。這種類型的荷載可能會(huì)在任何給定時(shí)間作用于結(jié)構(gòu)，也可能不會(huì)；其作用位置也可能不固定。bereferredtoas被稱為…LoadsExamplesofliveloadincludefurniture，equipment,andoccupantsofbuildings．Ingeneral，themagnitudeofaliveloadisnotaswelldefinedasthatofadeadload，anditusuallymustbeestimated．Inmanycases，agivenstructuralmembermustbeinvestigatedforvariouspositionsoftheliveloadsothatapotentialfailuresituationisnotoverlooked．參考譯文活荷載的例子包括家具、設(shè)備和建筑物的住客。一般情況下，活荷載的大小無(wú)法像恒載那樣定義，通常必須估計(jì)。在許多情況下，必須對(duì)給定的結(jié)構(gòu)構(gòu)件進(jìn)行處在不同活載作用位置時(shí)的檢驗(yàn)，使?jié)撛诘钠茐牟槐粺o(wú)視。occupants['?kju:p?nts]n.居住者；購(gòu)置者；租賃人〔occupant的復(fù)數(shù)〕LoadsIftheliveloadisappliedslowlyandisnotremovedandreappliedanexcessivenumberoftimes.thestructurecanbeanalyzedasiftheloadswerestatic.Iftheloadisappliedsuddenly,aswouldbethecasewhenthestructuresupportsamovingcrane.wemustaccountfortheeffectsofimpact.Iftheloadisappliedandremovedmanytimesoverthelifeofthestructure.fatiguestressbecomesaproblem.andwemustaccountforitseffects.Impactloadingoccursinrelativelyfewbuildings,notablyindustrialbuildings,andfatigueloadingisrare,withthousandsofloadcyclesoverthelifeofthestructurerequiredbeforefatiguebecomesaproblem．參考譯文如果活荷載緩慢地施加且未被移除，并且重復(fù)施加次數(shù)極多，可以按荷載類似于靜止來(lái)分析結(jié)構(gòu)。如果突然施加荷載，就像結(jié)構(gòu)支撐一臺(tái)移動(dòng)起重機(jī)的情況，我們就必須考慮沖擊影響。如果負(fù)載施加移除次數(shù)超過(guò)了結(jié)構(gòu)壽命，疲勞應(yīng)力成為一個(gè)問(wèn)題，并且我們必須考慮其影響。相對(duì)較少的建筑物會(huì)有沖擊荷載，主要是工業(yè)建筑，在疲勞成為問(wèn)題之前，超越結(jié)構(gòu)壽命成千上萬(wàn)次的疲勞荷載周期很少予以考慮。LoadsWindexertsapressureorsuctionontheexteriorsurfacesofabuilding;becauseofitstransientnature,itproperlybelongsinthecategoryofliveloads.Becauseoftherelativecomplexityofdeterminingwindloads,however,windisusuallyconsideredaseparatecategoryofloading.Sincelateralloadsaremostdetrimentaltotallstructures，windloadsareusuallynotasimportantforlowbuildings，butupliftonlightroofsystemscanbecritical.Althoughwindispresentmostofthetime,windloadsofthemagnitudeconsideredindesignareinfrequentandarenotconsideredtobefatigueloads．參考譯文風(fēng)會(huì)對(duì)建筑物的外外表產(chǎn)生壓力或吸力；由于其短暫的性質(zhì)適合于歸類為活載。不過(guò)，由于確定風(fēng)荷載相對(duì)復(fù)雜，風(fēng)通常被認(rèn)為另一類荷載。由于側(cè)向荷載對(duì)高層結(jié)構(gòu)最不利，風(fēng)荷載對(duì)于低的建筑通常并不重要，但對(duì)輕型屋面系統(tǒng)上的隆起可能非常重要。雖然風(fēng)在大多數(shù)時(shí)間存在，但風(fēng)荷載在設(shè)計(jì)中考慮的很少，并不被認(rèn)為是疲勞荷載。exert[iɡ'z?:t]vt.運(yùn)用，發(fā)揮；施以影響transient['tr?nzi?nt,-si-,-??nt,'trɑ:n-]adj.短暫的； 路過(guò)的 n.瞬變現(xiàn)象；過(guò)往旅客；留鳥(niǎo)Loads[2]Earthquakeactionsareanotherspecialcategoryandneedtobeconsideredonlyinthosegeographiclocationswherethereisareasonableprobabilityofoccurrence．Astructuralanalysisoftheeffectsofanearthquakerequiresananalysisofthestructure’sresponsetothegroundmotionproducedbytheearthquake．Simplermethodsaresometimesusedinwhichtheeffectsoftheearthquakearesimulatedbyasystemofhorizontalloads,similartothoseresultingfromwindpressure,actingateachfloorlevelofthebuilding．參考譯文地震作用是另一個(gè)特殊的類別，只需要在那些有一定發(fā)生概率的地理位置考慮。地震影響的結(jié)構(gòu)分析需要分析結(jié)構(gòu)對(duì)地震產(chǎn)生的地面運(yùn)動(dòng)的響應(yīng)。有時(shí)，更簡(jiǎn)單的方法使用一個(gè)橫向荷載系統(tǒng)模擬，類似于作用在建筑物各層的風(fēng)壓力那樣。Loads[2]Earthquakeactionsareanotherspecialcategoryandneedtobeconsideredonlyinthosegeographiclocationswherethereisareasonableprobabilityofoccurrence.Astructuralanalysisoftheeffectsofanearthquakerequiresananalysisofthestructure’sresponsetothegroundmotionproducedbytheearthquake.Simplermethodsaresometimesusedinwhichtheeffectsoftheearthquakearesimulatedbyasystemofhorizontalloads,similartothoseresultingfromwindpressure,actingateachfloorlevelofthebuilding．參考譯文地震作用是另一個(gè)特殊的類別，只需要在那些有一定發(fā)生概率的地理位置考慮。地震影響的結(jié)構(gòu)分析需要分析結(jié)構(gòu)對(duì)地震產(chǎn)生的地面運(yùn)動(dòng)的響應(yīng)。有時(shí)，更簡(jiǎn)單的方法使用一個(gè)橫向荷載系統(tǒng)模擬，類似于作用在建筑物各層的風(fēng)壓力那樣。LoadsSnowisanotherliveloadthatistreatedasaseparatecategory.Addingtotheuncertaintyofthisloadisthecomplicationofdrift,whichcancausemuchoftheloadtoaccumulateoverarelativelysmallarea．Othertypesofliveloadareoftentreatedasseparatecategories.suchashydrostaticpressureandsoilpressure.butthecasesenumeratedabovearetheonesordinarilyencounteredinthedesignofbuildings．參考譯文雪是另一個(gè)被視為一個(gè)單獨(dú)類別的活荷載。增加此負(fù)載的不確定性是負(fù)載的漂移，其可能會(huì)導(dǎo)致在相對(duì)較小的區(qū)域內(nèi)更多荷載積累。其他類型的活載往往被視為獨(dú)立的類別，如靜水壓力和土壤的壓力，但以上列舉的在建筑設(shè)計(jì)中通常為遇到的個(gè)案。BuildingCodesBuildingsmustbedesignedandconstructedaccordingtotheprovisionsofabuildingcode,whichisalegaldocumentcontainingrequirementsrelatedtosuchthingsasstructuralsafety,firesafety,plumbing,ventilation,andaccessibilitytothephysicallydisabled.Abuildingcodehastheforceoflawandisadministeredbyagovernmentalentitysuchasacity,acounty,or,forsomelargemetropolitanareas,aconsolidatedgovernment．參考譯文建筑物必須依據(jù)建筑法規(guī)的規(guī)定設(shè)計(jì)和建造，這一法律文件包含了相關(guān)的要求，諸如結(jié)構(gòu)平安、消防平安、水暖、通風(fēng)和傷殘人士的輔助功能。建筑標(biāo)準(zhǔn)具有法律效力，而由一個(gè)政府實(shí)體，如縣市，或?yàn)橐恍┐蠖际袇^(qū)的政府管理。buildingcode建筑法規(guī)plumbing['pl?mi?]n.鉛工業(yè)；鉛管品制造v.探究；垂直懸掛；用鉛錘測(cè)量；灌鉛以增重〔plumb的現(xiàn)在分詞〕衛(wèi)生管道工程；水管設(shè)施；波導(dǎo)設(shè)備；水管裝置ventilation[,venti'lei??n]n.通風(fēng)設(shè)備；空氣流通BuildingCodesBuildingcodesdonotgivedesignprocedures,buttheydospecifythedesignrequirementsandconstraintsthatmustbesatisfied.Ofparticularimportancetothestructuralengineeristheprescriptionofminimumliveloadsforbuildings.Althoughtheengineerisencouragedtoinvestigatetheactualloadingconditionsandattempttodeterminerealisticvalues,thestructuremustbeabletosupportthesespecifiedminimumloads．參考譯文建筑法規(guī)不指定設(shè)計(jì)程序，但規(guī)定設(shè)計(jì)要求和所必須滿足的約束。對(duì)結(jié)構(gòu)工程師特別重要的是建筑物最低活載的規(guī)定。盡管鼓勵(lì)工程師調(diào)查實(shí)際加載條件并嘗試確定實(shí)際的數(shù)值，結(jié)構(gòu)必須能夠支撐這些指定的最小負(fù)荷。prescription[pris'krip??n]n.藥方；指示；慣例adj.憑處方方可購(gòu)置的BuildingCodesAlthoughsomelargecitieswritetheirownbuildingcodes,manymunicipalitieswilladopta“model〞buildingcodeandmodifyittosuittheirparticularneeds.Modelcodesarewrittenbyvariousnonprofitorganizationsinaformthatiseasilyadoptedbyagovernmentalunit.Currently,therearethreenationalmodelcodes:theBOCANationalBuildingCode,theUniformBuildingCode,andtheStandardBuildingCode.Arelateddocument,similarinformtoabuildingcode,isASCE7-98.MinimumDesignLoadsforBuildingsandOtherStructures.Thisstandardisintendedtoprovideloadrequirementsinaformatsuitableforadoptionbyabuildingcode．參考譯文雖然一些大城市制定自己的建筑標(biāo)準(zhǔn)，許多城市將采用建筑法規(guī)的"模式"并進(jìn)行修改，以適合其特定需要。這些法規(guī)模型以政府單位易于接受的形式由各種非營(yíng)利組織編寫(xiě)。目前，有三個(gè)國(guó)家的模型標(biāo)準(zhǔn)：博卡國(guó)家建筑標(biāo)準(zhǔn)、統(tǒng)一的建筑法規(guī)和標(biāo)準(zhǔn)建設(shè)標(biāo)準(zhǔn)。類似于建筑標(biāo)準(zhǔn)的相關(guān)文件是ASCE7——98，建筑物和其他結(jié)構(gòu)最小設(shè)計(jì)荷載。這一標(biāo)準(zhǔn)旨在以建筑標(biāo)準(zhǔn)適合采用的格式提出負(fù)載要求。DesignSpecificationsIncontrasttobuildingcodes,designspecificationsgivemorespecificguidanceforthedesignofstructuralmembersandtheirconnections.Theypresenttheguidelinesandcriteriathatenableastructuralengineertoachievetheobjectivesmandatedbyabuildingcode.Designspecificationsrepresentwhatisconsideredtobegoodengineeringpracticebasedontheirlatestresearch．參考譯文相對(duì)于建筑標(biāo)準(zhǔn)，設(shè)計(jì)標(biāo)準(zhǔn)給設(shè)計(jì)結(jié)構(gòu)構(gòu)件和其連接更具體的指導(dǎo)。其中提出的指導(dǎo)方針和標(biāo)準(zhǔn)，使結(jié)構(gòu)工程師來(lái)到達(dá)建筑標(biāo)準(zhǔn)強(qiáng)制規(guī)定的目標(biāo)。設(shè)計(jì)標(biāo)準(zhǔn)代表了建立在最新研究的根底上被認(rèn)為是良好的工程實(shí)踐。mandate['m?ndeit]n.命令，指令；委托管理；授

權(quán)；受命進(jìn)行的工作

vt.托管；授權(quán)guidelines['gaid,linz]n.指導(dǎo)方針DesignSpecificationsTheyareperiodicallyrevisedandupdatedbysupplementsorbycompletelyneweditions.Aswithmodelbuildingcodes,designspecificationsarewritteninalegalformatbynonprofitorganizations.Theyhavenolegalstandingontheirown,butbypresentingdesigncriteriaandlimitsintheformoflegalmandatesandprohibitions,theycaneasi