PLANNING AND DESIGN OF HYDROELECTRIC POWER PLANT STRUCTURES水电站规划与结构设计 3

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PLANNINGANDDESIGNOFHYDROELECTRICPOWERPLANTSTRUCTURES水电站规划与结构设计3

EM1110-2-300130Apr95Chapter5PhysicalSecurity5-1.ProtectionPlanForeveryhydropowerinstallationadetailed,writtenprotectionplanshallbedeveloped,whichwilluseavail-ableresourcesinthemostefficientmanner.Althoughtheprimaryareaofconcernshouldbeprotectionfromterroristthreats,allaspectsofprotectiondesignshouldbeaddressed.(ArecommendedsourceofadviceistheMissouriRiverDivision(MRD),theCorpsTechnicalCenterofExpertiseforProtectionDesign.)a.Typeofprotection.Indeterminingthetypeandextentofphysicalprotectionrequiredataninstallation,thefollowingpertinentfactorsshouldbetakenintoconsiderationintheindicatedsequence.(1)ImportanceofthepowersupplytoNationalSecurity,totheregionalpowerbase,andprojectopera-tionalrequirements.(2)Definitionandanalysisofareatobeprotected,andotherpertinentconsiderationinherenttotheproblemsuchasexistinghazards,eithernaturalorman-made.(Threatsfromthestoredwaterinthereservoir,fromlandslideoravalanche,fromforestorbrushfire,etc.)(3)Operation,maintenance,andotherrequirementswhichmustbeintegratedintothesecurityplan.(4)Environment-political,economic,legal,surroundingterrain,weatherandclimate.(5)Costsofmaterialandequipmenttobeinstalled,aswellasavailabilityoffundstoprovideatleastmini-mumprotectionforallcriticalareas.(6)Feasibility,personnelandequipmentcosts,andthebestmethodofprovidingadequatecosteffectiveprotection.b.Architecturaldesign.Thearchitecturaldesignofthestructureshouldincorporatenecessarysecuritydesignfeatures.(1)Aminimumofwindows,particularlyneargroundlevel.(2)Wellanchoredsteeldoorsandframes.(3)Transformersandpowertransmissionlineslocated,orprotected,todiscouragethreatactivities.c.Keyelementsindevelopingtheprotectionplan.Theresponseanalysisshouldbeassessed.Thecriticalitemtobeestimatedistheresponsetimeforsecurityforces(projectguards,locallawenforcementagents,etc.)toreachtheinstallationoncetheyarealerted.Thepowerhouseoperatorshouldnotbeconsideredapartofthesecurityforces.Oncetheresponsetimeisestimated,thenathreatanalysisshouldbeperformed.Thiswouldconsiderthemostprobablerouteofintruderstothemostvulnerableareasofthehydropowerinstallation.Thenvariousdelayzones(fences,walls,etc.)shouldbecon-sidered,eachwithitsownintrusiondetectionsystem.Thethreatanalysisshouldresultinaseriesofdelayzonessothatthetotaltimefortheintruderstoreachcriticalareaofthehydropowerinstallations,fromfirstdetection,exceedstheresponsetimebysecurityforces.5-1EM1110-2-300130Apr95Chapter6RetrofittingExistingProjects6-1.GeneralTheadditionofhydropowerfacilitiesattheexistingCorpsofEngineersprojectsmustnotjeopardizethepublicinterestrelativetowatercontrolmanagementforfloodcontrol,navigation,watersupply,waterquality,recreationandotherprojectproposes.Inaddition,thoseaspectsofthedesignthatcouldaffectthesafetyoftheprojectmustbeconsistentwithCorpsstandardsastorequirementsofthismanualandallreferencedmanualsandregulations.Toensurecompliancewiththispolicywhendevelopmentisbynon-federallicenses,theCorpsofEngineerswillreviewandapprovetheproposeddetaileddesignanalysisandplansandspecificationsforthosehydraulic,structuralandmechanicalfeaturesthatcouldaffecttheintegrityandsafetyofthetotalproject.Majoritemsofconcern,butnotnecessarilylimitedto,arediscussedasfollows:6-2.HydraulicDesignConsiderationsa.Proposals.Proposalstoaddhydropowerfacili-tiesatCorpsofEngineersprojectsmustthoroughlyaddressthehydraulicdesigndetailsandtheoverallfunc-tionalcapability.Itemsthatmustbeaddressedincludethefollowing.(1)Streamliningofentrancetopowerpenstockfromfloodcontrolconduitmustbeaddressed.(2)Streamliningtoprecludecavitationinfloodcon-trolconduitatjunctionswithpenstockorgateslotsmustbeaddressed.(3)Positiveandnegativepressuresurgesduetopowerhouseloadrejections,loadacceptance,andunitrunawayisanotherimportantitemtoaddress.(4)Reassessmentofwaterqualityprovisionstoincludesizeandlocationofmulti-levelintakesandcom-patibilityofpowerhousereleaserequirementswithwaterqualityrequirementsisanimportantitem.(5)Meansofdewateringpowerfacilitieswithoutinterruptingwaterqualityand/orfloodcontrolreleasesmustbeaddressed.However,somepowerhouseswithlongpenstocks,orthosewithonlygatesorvalvesimme-diatelyupstreamofthepowerplantneednotbedewateredexceptunderemergencyconditions.Thisprocedurecanbefollowedonlyifitdoesnotimpactupondamsafetyoffloodcontrolregulations.Thistypeofpenstockcanbeinspectedusingdiversorremotelyoperatedcameras.(6)Effectsofaddingtrashracksintheexistingintakeifrequiredforequipmentprotectionmustbeaddressed.b.Submittals.SubmittalsproposinginclusionoradditionofhydropowercombinedwithwaterqualityandorfloodcontrolfacilitiesatCorpsofEngineersprojectsmustincludeahydraulicdesignanalysiscoveringalloperatingandemergencyconditions.Presentationsneedtoaddressallitemsdiscussedabove.Informationonenergyandpressuregradelinesthroughoutthehydraulicpassagescoveringmaximumandminimumconditionswithlocalpressuredropsatsuchplacesasbends,junc-tions,transitions,gateslots,etc.,isnecessary.Thepre-sentationsmustincludeananalysisoftheeffectsofapowerhouseloadrejection.Thedegreeofdetailistobesufficientforthestudystagebeingpresented,althoughatfinaldesignstage.atransientanalysisutilizingstate-of-the-artcomputerprogramsmustbeperformedandreviewedbyaDesignCenter.Therequirementsapplytoproposalsfromothers(tobeaccomplishedattheirexpense)aswellastoin-houseproposals.c.Penstocks.Theexistingregulatingoutletconduitsofferanavailableconnectionbetweenthereservoirandpotentialhydropowerfacilities.Regulatingoutletcon-duitsarfloodcontrolorothernon-powerprojectsareusuallydesignedfornon-pressurized(openchannel)flowconditions.forthemostpart,theseconduitsareofrein-forcedconcretedesignedtowithstandexternalrockorembankmentloadsandexternalhydrostaticpressures.Oncehydropowerfacilityisconnected,theprimarystruc-turalconcernisthatanexistingregulatingoutletconduitbecomesapowerpenstocksubjecttointernalpressuresequaltofullpoolplusanytransientpressuresduetowatermannereffects.SubmittalsproposinginclusionoradditionoffacilitiesatCorpsofEngineersprojectsmustincludestructuralandgeotechnicalanalysiscoveringalloperatingandemergencyconditions.Presentationsneedtoaddressallitemscoveredinthisguidance.Thedegreeofdetailpresentedshouldbesufficientforthestudystagebeingpresented.Thisappliestoproposalsfromothers(tobeaccomplishedattheirexpense)aswellastoin-houseproposals.Thefollowingparagraphspresentacceptabledesigncriteriaforconvertingregulatingoutletconduitstopowerpenstock(downstreamcontrol).6-1EM1110-2-300130Apr956-3.GeotechnicalConsiderationsOriginalgeologicconditionsuponwhichprojectdesignwasbased,anduponwhichcutandcoverorlinesorunlinedtunnelswereconstructed,mustbeknownsothatsafetyandoriginaldesignbenefitsarenotreduced.Watermustnotbeallowedtoescapeintothedamabut-mentsfrompressurizedtunnelstocauseslopestabilityproblemsorgroundwaterchangesthatmightaffectthedam.Aninvestigationofgeologicconditionsrelativetothedesignproposedforapressurizedtunnelmustbemade.Existinglinedtunnelsmayconcealvoids,shearzones,rockoflowdeformationmodulus,etc.Whenmodifyingexistinglinedtunnels,designshallrecognizeandprovidefortheabovepossibilities,justasitwouldforunlinedtunnelscontaininggeologicweaknesses.Fulllengthgroutingbehindliningsorothermeasuresmaybenecessary.Ifanexistingtunnelisactingasadrainagefeatureinanabutment,intentionallyorunintentionally,thepossibilityofgroundwaterpressurechangesoccurringaftermodificationshouldbeevaluated.Thefunctionandmanyofthedetailsofconstructionanderectionforanintegrallyembeddedsteellineraresimilartoafree-standingpenstock;however,theloadingconditionsaredifferent.Thesteellining,concreteencasement,andifpresent,thesurroundingrockacttogethertoresistthepressures.EM1110-2-2901outlinesindetailtheloadingconditionsandallowablestressesforaconduitunderembankmentsorrock.Inbothinstances,externalpres-suresmustbeaccountedfroaswellastheinternalpressures.6-4.TunnelsinRockAbutmentsAnexistingoutlettunnel(unlinedorlinedwithotherthansteel)shouldbeinvestigatedtodeterminetowhatextentthetunnelshouldbelinedwithsteelplatetopre-ventleakagethatcouldpresentadangertothedamorabutment.Theextentofsteellinerplateshouldbesuffi-cienttopreventleakagealongrockfissuresorjointsthatinterceptthedamordownstreamoftheimperviouszone.Anexistingtunnellinermustbeinvestigatedforinternalpressuresthatwilloccuroncethehydropowerfacilityisinstalled.Inregionsofanexistingregulatingoutlettunnellinerwheretherockcoverisinsufficienttooffsetinternalpressures,orwheregeologicweaknessesexist,anewlinermayberequiredfrostructuralreasons.Asteellinerplatecouldbegroutedinplaceanddesignedascompositewithanexistingconcreteliner,providedtheexistinglinerreinforcementisadequateforallloads(seeEM1110-2-2901).Ifthetunnelisunlinedofiftheexistinglinerreinforcementisinadequate,aseparatefree-standingpenstockornewreinforcedconcretelinerwithcompositesteellinerplateshouldbeprovided.6-5.CutandCoverConduitsa.General.Initsexistingnon-pressurizedcondi-tion,theseconduitsaregenerallyreinforcedconcretestructureswithoutsteelplateliners.Topreventleakagethatwouldendangertheembankmentdam,asteelliningisrequiredfromtheupstreamfaceoftheimperviouszonetothepowerhouse.Areinforcedconcretelinercompositesteellinerplate,orafree-standingpenstock,mayberequiredtostructurallyaccommodatetheinternalfullpoolpressuresresultingfromdownstreamcontrolplusadditionalpressuresduetowaterhammereffects.b.Circularconduits.AsteellinergroutedtobeintegralwiththeexistingconcretelinermaybeusedprovidedtherequirementsofEM1110-2-2901aremet.Iftheexistingconcretereinforcementdoesnotmeettheaboverequirements,afree-standingtypepenstockornewreinforcedconcretelinerwithcompositesteellinerplateshouldbeprovided.c.Non-circularconduits.Afree-standingpenstock,erectedwithinandindependentoftheexistingregulatingoutletconduit,shouldbeprovided.6-6.Free-StandingPenstocksWithinConduitsFree-standingpenstocksconstructedwithinanexistingconduitshallbedesignedinaccordancewithpara-graph4-16,penstocksandsurgetanks.Platesandjointsshouldbedesignedforfullpressureduetostaticheadpluswaterhammeraswellasanynegativepressuresdevelopedbyhydraulictransients.Alljointsshouldbeweldedexceptfortheconnectionofthepenstocktothespiralcase,whichisnormallyaflexibletype.Free-standingpenstocksshouldbeconstructedsoastopermitanyleakagetodraintotailwaterwithoutpressurizingthesurroundingregulatingoutletconduit.Carefulattentionshouldbegiventoanchorageofthepenstockagainstlongitudinalthrust.a.Gatesandvalves.Theadditionofhydropowerfacilitiesmustincludeprovisionsforisolatingthepower-plantsoasnottointerferewiththeprojectoriginalpur-pose.Whentheexistingfloodcontrolconduitismodifiedforpenstockuse,aclosuredevicesuchasabutterflyorsphericalvalveoragatemustbeprovidedatthepowerhouseendofthepenstockforshutoffofflow6-2EM1110-2-300130Apr95duringemergencyclosureorduringnormalmaintenanceoftheequipment.(1)Theclosuredeviceshouldbedesignedformaxi-mumpenstockheadincludingwaterhammerandhydrostaticallytestedfor150percentofthemaximumdesignconditions.Thevalveoperatormustbecapableofclosingthedeviceinfrom2to5minutesaspracticalforitssize.Theclosurecapabilitymustbeachievablewithoutoutsidepower.Thus,anenergystoragedevicesuchasanaccumulatororcounterweightisrequired.(2)Theclosureofthenormalwaterpassageatthedownstreamendfordivertingflowtotheturbineissub-jecttothespecificprojectlayout.Gatesorvalvesusedforthispurposemustbedesignedforthemaximumwaterpressure,includingwaterhammer,andsubjecttohydrostatictestinginplace.b.Vents.Whentheexistingfloodcontrolfacilitiesareutilizedforhydropowerpurposes,alltheexistingcomponentsrequirecarefulanalyzingandinvestigationforanyadversecavitationorstructuraleffects.Onesuchitemsubjecttostructuralloadinggreaterthanoriginallythoroughanalysisoftheeffectssuchchangeswouldhaveonthesystemwhenusedintheoriginaloperationmodefortheprojectpurpose.Duringpowerhouseoperationtheventsaresubjecttofullhydrostaticpressureincludingwaterhammer,andthereforestructuraladequacyshouldbethoroughlyinvestigatedforthisconditionaswellastheseismiccondition.c.Bifurcation.Inmostinstances,theutilizationoftheexistingregulatingconduitrequiresdivertingthewaterflowfromtheconduittothepowerproducingfacilities.Themethodofaccomplishingthisobjectiverequiresabifurcationordivertingboxdependingofthespecificsiteconditions.Themethodchosenmustbethoroughlyanalyzedforpotentialcavitationorstructuraleffectsandmayrequiremodeltestingtoverifythedesign.Forfurtherstructuralrequirements,seeparagraph4-16e.6-3EM1110-2-300130Apr95AppendixAReferencesA-1.RequiredPublicationsTM5-809-1LoadAssumptionsforBuildingsTM5-809-10SeismicDesignofBuildingsTM5-810-1MechanicalDesign,HVACER1110-2-109HydroelectricDesignCenterER1110-2-1454Non-FederalHydropowerER1110-2-1806EarthquakeDesignandAnalysisforCorpsofEngineersDamsEM1110-2-1902StabilityofEarthandRockfillDamsEM1110-2-2000StandardPracticeforConcreteEM1110-2-2104StrengthDesignforReinforced-ConcreteHydraulicStructuresEM1110-2-2105DesignofHydraulicSteelStructuresEM1110-2-2200GravityDamDesignEM1110-2-2502RetainingandFloodwallsEM1110-2-2901TunnelsandShaftsinRockEM1110-2-2906DesignofPileFoundationsEM1110-2-3506GroutingTechnologyEM1110-2-4203DesignDataforPowerhouseCranesEM1110-2-4205HydroelectricPowerPlantMechanicalDesignETL1110-2-256SlidingStabilityforConcreteStructures(ETLsaretemporarydocumentsandsubjecttochange)ETL1110-2-301InterimProceduresforSpecifyingEarthquakeMotionsETL1110-2-303EarthquakeAnalysisandDesignofConcreteGravityDamsCE-1602DamGantryCranesCE-1603DraftTubeGantryCranesCE-1604.01IndoorElectricallyOperatedTravelingCranesCE-1604.02IndoorElectricallyOperatedTravelingCranesCE-4000Lump-SumContractforDesignofHydroelectricP