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靳先聚 《水利电力机械》2007,29(8):54-54,94
Q300/20t/32/m门机采用单主梁、牵引小车、一刚一柔2个门腿的特殊结构形式。主梁跨度大,单件质量达100多t,跨内起拱,制造难度非常大,工艺复杂。介绍了该主梁在制造过程中采取的一些工艺措施。  相似文献   

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相关国家标准及设计规范中要求空载时桥式起重机主梁应有一定的上拱度。影响上拱度的因素复杂,不易控制。生产中通常采用下料时为腹板预制上拱的方法,该方法工艺复杂且不易控制。采用直边腹板,利用主梁本身的自重作用下的变形合理设计焊接过程中的主梁支承位置、焊接工艺及施焊顺序,能够保证合理的主梁上拱值,满足国家标准及设计规范要求,保证起重机的良好工作状态。该方法对于门式起重机主梁的设计和制造也有很好的借鉴作用。  相似文献   

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结合兰新铁路第二双线某连续梁,阐述了铁路连续梁满堂支架法施工的搭设方案,通过建立有限元模型分析了支架变形,与实测值进行比较分析,提出了衡量支架变形可靠性的方法和参考依据。并对施工预拱度的合理设置,支架间距和荷载变化建立了关联。通过这种方式处理,对于更加精确的保证施工质量、成桥线形具有很重要的实际意义。  相似文献   

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为了验证满堂支架的搭设质量、脚手架自身质量以及地基承载力情况,同时也为了准确掌握现浇箱梁施工过程中脚手架各工况的实际挠度和刚度,满堂支架在混凝土浇筑前需要在现场做静载试验,以确保支架在混凝土浇筑过程中的安全并消除结构的非弹性变形,掌握弹性变形数据,可以使预拱度设置的更合理.  相似文献   

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1 GeneralThethinreinforcedconcretewallsoftheThreeGorgespermanentshiplockchambersaresetagainsttheexcavatedrockwalls.Thethinconcretewallwascutinto 4 2sectionsinthedirectionoftheaxialline .Permanentstructuraljointswerearrangedbetweensections .Thedistancebetw…  相似文献   

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NOMENCLATURECmm ——theconcentrationatacertaintime ,Cell/mLCmf ——thechangeoftheconcentrationaftermicrobesareadsorbedD′——theconvection diffusioncoefficient,cm2 /sV——thefluid’sactualviscosity ,cm/sCzm ———theconcentrationoftheinjectedmicro bialCo ———theconcnetrat…  相似文献   

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1 GeneralThecementgroutingofhydraulictunnelisakindofgroutingworkswithfeatures .Therearelesspracticalexperi encesinthisaspect,comparedwiththecementgroutingofrockfoundation ,withitsqualityincidentoccurringagainandagain .Inrecentyears,authorwasengagedintheco…  相似文献   

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1 . INTRODUCTIONInthewesternequatorialPacificOcean ,thevigorousandcomplexcirculationischaracterizedbytheuniqueconvergenceofthesurfacecurrents,per manent,seasonalandmesoscaleeddies ,andsubsur facecurrents.Asanimportantcontributortothee quatorialandglobalmom…  相似文献   

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1 . INTRODUCTIONAgroupofcircularcylinderswerewidelyadoptedinmanypracticalstructuressuchaschimneystacks ,off shorestructures ,heatexchangertubesandcablesofca blestayedbridge .Investigationsontheflowaroundasinglecylinderhavebeenperformedsystematicallywithbo…  相似文献   

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1 . INTRODUCTIONJustaslightcanbedecomposedinto 7colorsandmusicinto 7notes,thecomplexverticalprofilesofoceandynamicalfactorsandsoundspeedcanalsobedecomposedintoaseriesofnormalmodes[1~ 5] .Basedonthisfact,intheearly 1 980sAmericaactu alizedtheOceanicAcousticTomog…  相似文献   

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先张法预应力空心板在桥梁施工中得到了广泛的应用,但在实际施工中经常会出现反拱度超过设计要求的现象。针对先张法预应力空心板反拱度产生的成因,文章对先张法预应力空心板反拱度进行计算,分析了引起反拱度偏差的各种原因,提出了施工时为避免反拱度过大应该注意的事项,为先张法空心板反拱度的施工控制提供了参考。  相似文献   

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1. PHYSICALMDOELSInsectflightcannotbeexplainedbytheconventionalaerodynamicprinciplesusedbyaircraftengineers.Conventionalaerodynamicsisconcernedmainlywithsteadymotion,suchasawingmovingatconstantvelocityorapropellerrotatingataconstantrate[1] .Incontr…  相似文献   

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1 HighConstructionIntensityTheTGPismainlycomposedofconcretegravitydam,powerhouses,andnavigationstructures.Theconstructionpreparationbeganin 1993.ThegrandchannelclosurewasrealizedonNov. 8,1997,smoothlyleadingtothesecondstageconstruction.Thesecondconstructio…  相似文献   

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1. INTRODUCTIONSidedischargesintoacrosschannelflowhaveawiderangeofapplicationsinenvironmentalandhydraulicengineering.Atypicalexampleisthedischargeofcoolingwaterfromapowerplantintotheriver.Thepredictionoftemperaturechangeduetothedischargeisofgreatimp…  相似文献   

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NUMERICAL SIMULATION OF TIP-CLEARANCE FLOW IN CASCADE   总被引:1,自引:1,他引:0  
1 . INTRODUCTIONTip clearanceflowsoccurinvariousengineer ingapplicationssuchasaxial flow pumpsandduct edpropellers .Theinertialforcesactinguponthefluidinthenarrow gapbetweenbladetipandthesurroundingwallaresufficientto generateatipleakagevortexonthesuctions…  相似文献   

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1. INTRODUCTIONOscillatingflowsoverperiodicripplesareofpracticalaswellasscientificinterestbecauseoftheirrelevancetobeachproces...  相似文献   

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1 . INTRODUCTIONTheannualmeanclimatology ,seasonalcycleandinterannualvarietiescharacteristicofseasurfacetemperature (SST)andupper oceanheatcontentaswellastheirrelationshipinL30T63,thethirdgen erationoftheoceanic generalcirculationmodel(GCM )developedintheStat…  相似文献   

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1 . INTRODUCTIONTheturbulentstructuresinnon circularductsandopenchannelsarecharacterizedbylongitudi nalvortices .Thesevorticesareth  相似文献   

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1 . INTRODUCTIONThemathematicaldifficultesinherentindeter miningtheevolutionofanincidentwavetrainandtheassociatedphenomenaresultmainlyfromtwononlin earboundaryconditionsattheinitiallyunknownfreesurface,akinematicconditionandadynamiccondi tion .Thustwoass…  相似文献   

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