外文翻译--常用的结构体系 原件.pdf
CommonlyCommonlyUsedUsedstructuralstructuralSystemsSystemsWithloadsmeasuredintensofthousandskips,thereislittleroominthedesignofhigh-risebuildingsforexcessivelycomplexthoughts.Indeed,thebetterhigh-risebuildingscarrytheuniversaltraitsofsimplicityofthoughtandclarityofexpression.Itdoesnotfollowthatthereisnoroomforgrandthoughts.Indeed,itiswithsuchgrandthoughtsthatthenewfamilyofhigh-risebuildingshasevolved.Perhapsmoreimportant,thenewconceptsofbutafewyearsagohavebecomecommonplaceintodaystechnology.Omittingsomeconceptsthatarerelatedstrictlytothematerialsofconstruction,themostcommonlyusedstructuralsystemsusedinhigh-risebuildingscanbecategorizedasfollows:Moment-resistingframes.Bracedframes,includingeccentricallybracedframes.Shearwalls,includingsteelplateshearwalls.Tube-in-tubestructures.Tube-in-tubestructures.Core-interactivestructures.Cellularorbundled-tubesystems.Particularlywiththerecenttrendtowardmorecomplexforms,butinresponsealsototheneedforincreasedstiffnesstoresisttheforcesfromwindandearthquake,mosthigh-risebuildingshavestructuralsystemsbuiltupofcombinationsofframes,bracedbents,shearwalls,andrelatedsystems.Further,forthetallerbuildings,themajoritiesarecomposedofinteractiveelementsinthree-dimensionalarrays.Themethodofcombiningtheseelementsistheveryessenceofthedesignprocessforhigh-risebuildings.Thesecombinationsneedevolveinresponsetoenvironmental,functional,andcostconsiderationssoastoprovideefficientstructuresthatprovokethearchitecturaldevelopmenttonewheights.Thisisnottosaythatimaginativestructuraldesigncancreategreatarchitecture.Tothecontrary,manyexamplesoffinearchitecturehavebeencreatedwithonlymoderatesupportfromthestructuralengineer,whileonlyfinestructure,notgreatarchitecture,canbedevelopedwithoutthegeniusandtheleadershipofatalentedarchitect.Inanyevent,thebestofbothisneededtoformulateatrulyextraordinarydesignofahigh-risebuilding.Whilecomprehensivediscussionsofthesesevensystemsaregenerallyavailableintheliterature,furtherdiscussioniswarrantedhere.Theessenceofthedesignprocessisdistributedthroughoutthediscussion.Theprojectisonespecial,thismeantanengineermustacceptthecollegeeducation.Intheverymanygovernmentsincludesisemployedthepermissionprocedurefront,requestsofengineeringgraduatestobeemployedmustthroughe,isemployedlikeattorneymustthequalificationstestbeattorney.Becausewhensolvestheseproblems,involvestothe,thereforeinthepresentnearlyallengineeringallincludesthecomputerprogramming.Certainly,canbequickerthanthehumanity,accuratelysolvesthecomputationsaspectproblem.But,onlyifthecomputerclearandtheaccurateinstructionortheinformation,insistheprocedure,otherwisethecomputerwillbeuseless.Althoughtheengineeringcoursecurriculumemphasispointalwaystechnologyclasssubject,thecurrenttendencyrequeststotakeasanelectivethesocialsciencesandthedisciplinecurriculum.Theengineeringandthesocialaremoreandmoreclose,thushasthefullreasontomore:Engineerswork,isdifferent,theimportantwaywhichwithbyisaffectingthesociety.Engineeralsoneedstograsptherichlanguage,inorderorderlinessisclearmoreoverhasthepersuasivepowermanysituationsthereport.inordertopublishitspaperalsotoneedindetailitsdiscovery.Theengineeringcoursestudentfinallytwoyearswantstothespecializeddomainthespecializedsubject.assubjectandgeodesy,sorhydraulics.Inengineeringcoursestudentuniversitystagelastbefore,hasbeenextremelyactivetotheprojectactivity.Inrecentyears,verymanyandthegovernmentapparatusforattracttheengineersstocompete.Innowthescienceandtechnologysociety,theprocessskilltrainingtalentedextremelyisscarce.Forexample,youngengineerpossiblycanchoosetheascenthygienicengineering,becausethepeoplehavecreatedtheemploymentopportunitytotheenvironmentattention,perhapsenteraroadbuildingconstructionenterprise,ortheywillinginaresearchwaterresourcesgovernment.Inbrief,maychoosetheotrulyverymany.Wuniversitystageobtains.Heispossiblyappointedatthebeginningoftheworktowithgroupofengineers,obtainsinofficeengineertobeallowedtoexaminetheabilitywhichandthepracticeunifies.Civilengineeringispossiblyengagedintheworkhasthedesign,theconstructcontrol,theservice,evenisthemanagementThesedifferenttypeswork,tothe,theemphasispoint,theknowledgeandtherequestarevarious.Thescientificresearchisthescienceandtheprojectpracticesimportantaspect.Aresearcherusuallyis,hewantswithotherscientists,engineertoworktogetherpublicofficetothelaboratorysthegovernmentorthenewstructuralmaterialdevelopmentandexperiment.Civilengineeringdomainverymanyseniorengineersareengagedinwork.Justlikewesaw,civilengineeringsworkinvolveskindsoftypesthestructure,thereforespeakingofanthespecialtyinsomekindofstructureisonlyonekindofWhenarchitecturaldesign,engineerusuallyisdesigncompanyorconstructsenterprisesdike,thebridge,usuallyhireengineerfortheaqueoussystemprojectprojects,underinisresponsiblefortheentireengineerleadsthejointoperation.Alsocanhavesomeengineersamongverymanysituationstoinvolve,inadikeproject,electricpowerengineerandcanparticipateinthepowerstationthedesignanditssetup.Moreover,civilengineeringalsocanappointtoworkforotherforexample,whenimplementationspaceprogram,needstoparticipateinsuchasthelaunchingpadandthemagazinesuchstructuredesignandtheconstruction.Thenearlyallengineeringprojectconstructionprocessveryis.Whenconstructionmustformulatetheworkplan,theequipmentandthematerial,thusreducestheprojectfaraspossible.Thesafetyfactoralsomustconsider,becauseprocessisextremelydangerous,thereforeneedsveryengineeringtobeengagedintheconstructionstagethework.Inconsideringthissystem,isimportanttounderstandclearlythedifferencebetweentheshearandtheflexuralcomponentsofdeflection,thetermsbeingtakenfrombeamanalogy.Inaframedtube,theshearcomponentofdeflectionisassociatedwiththebendingdeformationofcolumnsandgirders(i.e,thewebsoftheframedtube)whiletheflexuralcomponentisassociatedwiththeaxialshorteningandlengtheningofcolumns(i.e,theflangesoftheframedtube).Inabracedtube,theshearcomponentofdeflectionisassociatedwiththeaxialdeformationofdiagonalswhiletheflexuralcomponentofdeflectionisassociatedwiththeaxialshorteningandlengtheningofcolumns.Followingbeamanalogy,ifplanesurfacesremainplane(i.e,thefloorslabs),thenaxialstressesinthecolumnsoftheoutertube,beingfartherformtheneutralaxis,willbesubstantiallylargerthantheaxialstressesintheinnertube.However,inthetube-in-tubedesign,whenoptimized,theaxialstressesintheinnerringofcolumnsmaybeashigh,orevenhigher,thantheaxialstressesintheouterring.Thisseeminganomalyisassociatedwithdifferencesintheshearingcomponentofstiffnessbetweenthetwosystems.Thisiseasiesttounder-standwheretheinnertubeisconceivedasabraced(i.e,shear-stiff)tubewhiletheoutertubeisconceivedasaframed(i.e,shear-flexible)tube.Coreinteractivestructuresareaspecialcaseofatube-in-tubewhereinthetwotubesarecoupledtogetherwithsomeformofthree-dimensionalspaceframe.Indeed,thesystemisusedoftenwhereintheshearstiffnessoftheoutertubeiszero.TheUnitedStatesSteelBuilding,Pittsburgh,illustratesthesystemverywell.Here,theinnertubeisabracedframe,theoutertubehasnoshearstiffness,andthetwosystemsarecouplediftheywereconsideredassystemspassinginastraightlinefromthe“hat”structure.Notethattheexteriorcolumnswouldbeimproperlymodelediftheywereconsideredassystemspassinginastraightlinefromthe“hat”tothefoundations;thesecolumnsareperhaps15%stifferastheyfollowtheelasticcurveofthebracedcore.Notealsothattheaxialforcesassociatedwiththelateralforcesintheinnercolumnschangefromtensiontocompressionovertheheightofthetube,withtheinflectionpointatabout5/8oftheheightofthetube.Theoutercolumns,ofcourse,carrythesameaxialforceunderlateralloadforthefullheightofthecolumnsbecausethecolumnsbecausetheshearstiffnessofthesystemisclosetozero.