澳洲电力建筑设计标准-风载荷

7/14/20111AS/NZS7000:2010WorkedExamples11kVSingleCircuitConcretePoles9.2m1.8mSingleCircuitLVor11kVWorkedExample111kVSinglecircuitpolelineGroundLine9.2m1.8mSingleCircuitMaximumchangeinlinedirectionis10degreesLineINLINEPOLE7/14/20112LineDesignParametersComponentDetailReferenceLocationCoastalplainNorthIslandTerrainFlat/undulatingExposureTerrainCat2AS/NZS1170.2Designworkinglife50yrsTable6.1AS/NZS7000DesignsecuritylevelLevel1Table6.1AS/NZS7000DesignWindRP50yrsTable6.1AS/NZS7000DesignWindvelocityVR39.0m/sRegionA7AS/NZS1170.2Table3.1LeewindareaNoFigB2AS/NZS7000TopographicmultiplierMt1.0Cl.B3AS/NZS7000DirectionalmultiplierMd1.0Cl.B3AS/NZS7000TerrainmultiplierMzcat1.0Table4.1AS/NZS1170.2IceloadNilAppendixEEAS/NZS7000SelectionofdesignwindreturnperiodAustralianPanelB2–OverheadLinesSeminar–AS/NZSOverheadLineDesignSydney28-29March20117/14/20113AustralianPanelB2–OverheadLinesSeminar–AS/NZSOverheadLineDesignSydney28-29March2011AustralianPanelB2–OverheadLinesSeminar–AS/NZSOverheadLineDesignSydney28-29March2011AS/NZS1170.27/14/20114LineDesignParametersComponentDetailReferencePoletype11.0mPrestressedconcreteConductor‘Dog’ACSREarthwireNilWindspan70mWeightspan70mDeviationangle10degreesPoledetailsItemAssumedPoleDetailsPoletype11mPSCRectangularIsectionEmbedmentDepth1.8mConductorattachmentHt9.2mTransverseBasewidth@GL430mmLongitudinalBasewidth@GL150mmTransverseTipwidth160mmLongitudinaltipwidth150mmPoletiploadlongitudinalcapacity8.0kNPoletiploadtransversecapacity22.0kNAssumemaxbendingmoment200mmbelowgroundlevel7/14/20115ConductordetailsDOGACSRVALUEUNITEverydayTemperature(EDT):10DegCMinimumTemperature:-5.76DegCMaximumDesignTemperature:50DegCStringingTemperature:15DegCStringingTension,10%UTS3.00kNStringingTension,(EDT)3.29kNNominalOverallDiam:14.2mmCrossSectionalArea:118.8m2InitialModOfElasticity:56.54x109PaUltimateTensileStrength:3357kg32.93kNSelfweight:0.396kg/m0.00388kN/mWindPressuresUnitDesignWindPressures:RegionalsitedesignwindvelocityUnitDesignWindPressureVsit,βqz==VRMdMz,catMsMt=39m/s(ClB3AS/NZS7000)=913PaElementDesignWindPressures:Conductors(Cd=1.0):=913x1.00(DesignWindPressurexDragForceCoef)=913PaPole(Cd=1.6):=913x1.6(DesignWindPressurexDragForceCoef)=1460PaCrossarmEnd(Cd=1.2):=913x1.2(DesignWindPressurexDragForceCoef)=1096PaInsulators(Cd=1.2):=913x1.2(DesignWindPressurexDragForceCoef)=1096Pa23,0.610(kPa)sitVβ-×(ClB5AS/NZS7000)7/14/20116AustralianPanelB2–OverheadLinesSeminar–AS/NZS7000:2010OverheadlineDesignSydney28-29March2011DesignLoadCombinationsConductorAppliedLoadsLoadConditionSymbolDesignLoadEverydayloadcondition,10DegC,nowindFat3.27kNSustainedloadcondition,-5.76DegC,nowindFat4.57kNSustainedloadcondition,00C,nowindFat3.99kNMaximumwindloadcondition,0DegC,Wind=913PaFtw8.76kNMaximumwindloadcondition,minimumtemperature-5.76DegC,Wind=913PaFtw9.26kNFailureContainment,10DegC,max.windx0.25Fb3.97kN7/14/20117CheckConductorDesignTensionsForultimateloadingconditions:UltimateTensileStrengthofconductorRn=32.93kNConductorCapacityØRn=23.05kN(MaterialØFactor=0.7Table6.2AS/NZS7000)Undermaximumwindcondition:Conductortension=1.25xFat=1.25x8.76=10.95kNØRnUnderminimumtemperaturecondition:Conductortension=1.25xFat=1.25x4.57=5.71kNØRnThereforeOKforDOGconductorCheckloadsonpininsulatorsMaximumtransversewindloadfromconductoroninsulatorTiw=AzxConductorwindpressure=(DiamxSpanxSRF)xConductorwindpressure=14.2/1000x70x1x913/1000=0.91kN(0.85x9.6)kNfor1130W,LinedeviationtransverseconductorloadundermaximumwindloadTid=2xFatx=2x8.76xsin(5)=1.53kNSumofdesignultimateloadsatconductorlevelontopofinsulator:∑kiTi=kixWindload+1.25xdeviationload=0.75x0.91+1.25x1.53=2.59kN(7÷2)or3.5kNfor1130W,(0.85x9.6)kNforM20hightensilepin,MaximumverticalloadfromconductorVu=Spanxweightperm(Noiceorsnow)=70x0.00388x1.1(LoadFactor1.1fromTable7.3AS/NZS7000)=0.30kN(7÷2)kNfor1130W,OKUse1130W,PinM20HighTensile2sinθ7/14/20118CheckConductorSeparationatMidspanClause3.7.3.2ofAS/NZS7000:2010providesWhere;X=Projectedhorizontaldistance(m)betweenconductorsmidspanY=Projectedverticaldistance(m)betweenconductorsmidspanU=r.m.s.vectordifferenceinpotential(kV)k=Constant,normallyequalto0.4D=Greateroftwoconductorsagscentreequiv.span,50DegC,stillairl=LengthinmetresofanyfreeswingconductorInthisstructurecaseY=0m;U=11kV;k=0.4;D=1.14m;andl=0mTherefore;X≥11/150+0.4x√(1.142+0)≥0.529mandX=(X1+X2)/2=(300+950)/2for1400x100x75HWcrossarm,IeX1=300,X2=950DistancebetweenconductorsmidspanX=0.625mMinimumrequiredseparation;≥0.529OKfor1400x100x75HWcrossarmandelectricalseparationsareOK22(1.2)150UXYkDl+≥++HWCrossarmDesignCheckconductorsverticalloadsVerticalBendingincrossarm:VerticalLoadofconductors=unitweightxweightspanx9.806=.00388x70=.27kNForintermediatesuspensionstructurestheconductorverticalloadsareverysmallandwouldonlygoverndesignwhereiceloadsapplyandfordesignspans250m.Here,span=70m.ThereforeOKCheckconductorshorizontalloads:(Assumingloadsaretransferredthroughtopoleviaasingleboltsinshearandstabilizedbystandardflatplatebraces)Ultimatehorizontalload∑Wu=(kixWindload+1.25xdeviationload)x3=((0.75x0.91)+(1.25x1.53))x