外文翻译原文-一种对应隧道掘进机的测量黏土附着量的方法.pdf -- 5 元

ORIGINALPAPERAmethodforassessingadhesionofclaystotunnelingmachinesI.SassÆU.BurbaumReceived21December2007/Accepted23August2008/Publishedonline31October2008C211SpringerVerlag2008AbstractTunnelboringmachinespassingthroughcohesivesoilssometimesexperiencesignificantclogging,leadingtodelaysandincreasedcosts.Thepaperdescribesatesttoassessthelikelihoodofadhesionproblemsoccurring,simulatingthesituationwhereaclaystickstothecuttingwheelofthemachine.Theresultsoftestsusingkaolinclaysuggestthattheadhesionchangeswiththecompressionforce.Furtherstudiesarebeingundertakentoelucidatethefactorswhichinfluencethis,includingclaymineralogyandroughnessofthefaceofthecuttingwheel.Itishopedthattheworkwillleadtoanindustrialstandardmethodofassessingadhesionwhichcanbeusedinsiteinvestigationandonsite.KeywordsAdhesionC1ClayC1SurfaceeffectsC1BoundarylayereffectsC1TunnelingC1SoilmechanicsRe´sume´Lestunnelierstraversantdessolscohe´sifssontparfoissujetsablocage,conduisantadesretardsetaugmentationsdecouˆts.Larticlede´crituntestpermettantde´valuerlesrisquesdencrassage,simulantlasituationouuneargilecolleaumolettedecoupedelamachine.Lesre´sultatsdutesteffectue´avecuneargilekaoliniquesuggerentqueladhe´rencechangeavecleffortdecompression.Denouvellese´tudessontentreprisespouridentifierlesfacteursresponsables,incluantlanaturemine´ralogiquedelargileetlarugosite´dumolettedecoupe.Onesperequeletravailre´alise´conduiraalade´finitiondunessainormalise´permettantde´valuerladhe´rencedunsolargileuxetpouvanteˆtremisenœuvrelorsdereconnaissancesdesterrainsetsurchantier.Motscle´sAdhe´renceC1ArgileC1EffetsdesurfaceC1EffetsdecouchelimiteC1TunnelierC1Me´caniquedessolsIntroductionInundergroundconstruction,theadherenceofclaystothesteelsurfacesofmachinerymaysignificantlyreducethemachinesefficiencyorindeedresultinatotallossofcapacity.Recently,thisproblemoccurredinsometunnelingprojectsdrivenbyahydroshieldTBMJanczecz1997Thewes1999.Figure1showsthecuttingwheelofatunnelboringmachinenearlycompletelycloggedwithclayeysoil.Whensuchcloggingoccurs,thetunneldrivingprocesshastobestoppedtoallowcleaningofthecuttingwheeland/orextractionchamber,withconsequentialdelaysandimpactonthebudget.Itisthereforeimportantthattheadhesivepropertiesofthesoilsaredetailedinthegeotechnicalsurveyreporttoprovidebothqualitativeandquantitativeinformation.Thesephenomenahavebeeninvestigatedsince1838.Intheearlydays,suchagriculturalworkastillingencounteredproblemswithstickycohesivesoils.Thefirstresearchstudiesfortheconstructionindustrywerereportedinthe1960swhilesystematicresearchontheadhesionofsoilsrelatedtotunnelinghasbeenundertakensincethelate1990s.Despitethis,theinteractionofsoilandthesteelsurfaceisstillnotveryclear.Avarietyofsoiladhesiontestmethodsandtestconditionsweredevelopedandinvestigatedbuttodatethereisnocommonlyacceptedtestmethodtoestablishtheadhesivepropertiesofsoils.Futuretunnelprojectsarelikelytobeundertakenmoreandmoreindifficultadhesivesoilconditions,thusitisI.SassC1U.BurbaumTechnischeUniversita¨tDarmstadt,Schnittspahnstraße9,64287Darmstadt,Germanyemailsassgeo.tudarmstadt.deU.Burbaumemailburbaumgeo.tudarmstadt.de123BullEngGeolEnviron20096827–34DOI10.1007/s1006400801786importantthatthereisanagreedindustrialstandardtestmethodwhichprovidesqualitativeandquantitativeinformationabouttheadhesivepropertiesofthesoilwhichcanbeusedbysiteinvestigation,tenderingandconstructioncontractorsaswellasforbudgetplanning.AdhesionofsoilsAdhesionoccursonlyincohesivesoilswithsome10–20minimumclaymineralcontent,dependingonthesoil.Theadhesionofcohesivesoilstosolidsurfacesisfoundtobedependentonawaterfilminsidethesoil–solidinterfaceandcanbeunderstoodasaboundarylayereffect.Theinteractionbetweenthiswaterfilmintheinterface,thewatercontent,theporewaterpressure,thewaterabsorption,theswellingcapacity,tensilestrength,capillaryforcesandotherphysicalpropertiesofthesoilandtheadhesionforcesaswellastheeffectsofthesteelsurfaceproperties,thewayinwhichtheTBMoperatesandtheboringslurryqualityarenotwellunderstoodFig.2.Thewes1999suggestedaphysicalsoilmodeltoexplaintheadhesiveeffectbetweensoilandasteelsurface.Thepaperproposesatestwhichmayassistinabetterunderstandingofthephysicalprocessesofadhesion.CharacteristicsofasoiladhesiontestmethodAlaboratorysoiladhesiontestmethodappropriateasanindustrialstandardinconstructionindustriesshouldincludeapreciselydefinedparametersbhighresolutionmeasurementchighreproducibilityinstandardgeotechnicallaboratoriesdeasyandquicktoperformingeneralsoiltestinglaboratoriesesimpletestequipment,appropriateforsiteusefsimpletestproceduregtheuseofotherestablishedstandardtestingmethods,ifpossiblehreferencetostandardizedsoilparameters.Thetestmethodhastobeacceptabletothemaintestinginstitutionsasmanyfutureprojectswithadhesionproblemsmaybeexpectedworldwide.Forthisreason,thetestequipmentandprocedureshouldbeassimpleaspossibleandshouldreferto/includeotherwellestablishedstandardtestingmethodsandsoilparameters.PrinciplesofsoiladhesiontestingThreemainprinciplesforthetestingofthebondingforcesbetweentwomaterialsareroutinelyusedHabenicht2006peeling,shearinganddirecttension.Peelingtestsareofinterestforthelooseningofsoilsinexcavations,trenching,etc.Sheartestswouldleadtoresultswhichinterferewiththeresultsoftheshearstrengthtestwhichistypicallyusedinsoilmechanics.Itwouldthennotbepossibletodistinguishshearstrengthfromadhesionforce.Furthermore,thestressconditionsofsheartestsmakethelocationoftheshearplaneveryundefined.Itislikelythatthemathematicalinterpretationofsoiltestswiththeshearprinciplewouldproducemisleadingresults.Withadirecttensiontestsimilartoaninverseunconfinedcompressiontestthematerialsareseparatedbyforcesnormaltotheirsurfaces.ForamonoaxiallayoutofthetestFig.1CuttingwheelofaTBMnearlycompletelycloggedwithclay,SydneyAirportRailLink,PhotoCopyrightFa.BouyguesAdhesionsoiltosteelsurfaceSoilSurface/handlingmannerGrainsizedistributionMineralogicalcompositionWatercontentPorosityCationexchangecapacitySpecificsurfaceWaterabsorptioncapacitySwellingcapacityContentofswellableclaymineralsPlasticityConsistencyCohesionandtensilestrengthSurfaceroughnessWettingofsurfaceForcesonsoilparticlesPressureforcessoilsurfaceContactdurationsoilsurfaceSlurrypropertiesFig.2Effectsonadhesion28I.Sass,U.Burbaum123themaximumtensionforceinseparatingsoilfromsteelistheadhesionforceoradhesionstrength.Thestressstateinthiscaseisverywelldefinedandsimplyinterpreted.Tocarrythisprincipleoverintothefieldofsoilmechanics,asolidmaterialhastobepressedonasoilsurfaceandpulledaway.ThistestprincipleisalreadyusedforsoiladhesiontestingSchachbasian1890Riek1963Schlick1989Fountaine1954Thewes1999.Thewes1999recommendedthisasanindustrialstandardtestingmethod.Onemajorproblemwiththistestprincipleistodistinguishadhesionstrengthinthematerialsinterfacefromtensilestrengthinthesoil.Iftheruptureisnotattheinterfacebetweenthesteelandthesoilbutinsidethesoilitself,theadhesionstrengthishigherthanthetensilestrengthofthesoilandhencecannotbemeasured.Onlyifthereisnosoilleftonthesolidsurfacecantheadhesionbemeasured.AdhesiontestAdhesiontestequipmentThesuggestedadhesiontestdeviceconsistsofasteelsampleringof9.0cmdiameterandaheightof4.9cm,whichisheldbetweenabaseplateandaheadplateFigs.3,4.Thesoilsampleisplacedintotheringunderdefinedconditions,e.g.watercontent,compaction,coagulatedorsinglegrained,etc.A6.2cmdiameteradhesiontestcylinderisusedasthesurfacetowhichthesoiladheres.Thecrosssectionsurfaceareaofthecylinderis30.2cm2.Thistestarrangementcanbeusedforvariousmaterials,e.g.metal,ceramics,plastics,etc.AdhesiontestprocedureFollowingsomepreliminaryinvestigationstoestablishthebestpracticeforinstallingthecohesivesoilsamplesinthesoilsampleringHug2007Hempel2008,itwasfoundthatthesoilisbestplacedinthreelayers,compactedasinthestandardProctortestusingthe2.5kgrammer.Aftercompaction,thesurfaceofthesoiliscarefullylevelled/smoothedandthesampleplacedinthecompressionandtensiontestingmachineFig.5withtheadhesiontestcylinder.Thetestprocedureisasfollows.Thesoilsurfaceiswettedwithdeionizedwater.Itisessentialtousedeionizedwatertoavoiduncontrolledevaporationandtoproduceanadhesionfilmbetweenthesteelofthecylinderandthesoil.ThewaterisdeionizedtoavoidundefinedionFig.3Adhesiontestdevice,crosssections11and22Fig.4AdhesiontestrigThemeasurementofadhesivepropertiesofcohesivesoils29123exchangeintheclayfractionofthesoilsample,althoughintheorythistestcanbecarriedoutwithotherfluids,e.g.tunnelboringordrillingfluids.Theadhesiontestcylinderisthenpressedverticallyontothewettedsoilsurface,usingacontrolledforcewhichshouldbemaintainedforaspecificperiodoftime.Theadhesiontestcylinderisthenpulledaway,whilecarefullymonitoringtheforceandvelocity.MeasurementsandinterpretationoftestresultsTointerpretthetestresults,themeasurementsrecordedduringthetensionphasesareplottedonaforce–timediagramFig.6.Thedifferencebetweenthemaximumtensileforceandtheabscissaifthedeadweightoftheadhesiontestcylinderisincorporatedinthetestprogramprovidestheadhesionforceorthetensileforceofthesoilsampleifthefailureisobservedinthesoilitself.Tocomparetheresultswiththosereportedbyotherauthors,theforceswereconvertedtostressesbydividingtheforcesbytheareaofsurfaceoftheadhesiontestcylindersurface.Tovalidatethetestmethod,aseriesofadhesiontestswereundertakenonindustrial,homogeneousclays.Ineachcase,onlyonetestparametere.g.consistencywasvariedwiththeothersparameterskeptthesame.SystemtestsThefirsttestserieswerecarriedouttochecktheoperationoftheadhesiontestdevice.Anadhesiontestcylinderwitharoughnessof0.1lmwasputonanotheradhesiontestcylinderofthesameroughness.Thesurfaceoftheadhesiontestcylinderwaswettedwithpurewater.Figure7showstheteststatejustbeforethetwocylindersareconnectedandjustbeforethewaterfilmintheinterfaceisseparatedfromonecylinder.ThemeasuredstresstimerelationshipisshowninFig.8.Themeasuredadhesionstresseswerebetween5.3and4.9kN/m2withanaveragevalueof5.1kN/m2andastandarddeviationof0.13kN/m2equalto2.7oftheaveragevalue.Theseresultsshowthatadhesionstressoccurswhenawaterfilmispresentanditcanbemeasuredveryprecisely.AdhesiontestsonclayTestclayThetestedclaywasindustrialpowderedkaolinofmediumplasticitywithaclaygradecontentofcirca50.TheFig.5AdhesiontestrigwithsoilsampleinacompressionandtensiontestingmachinetensionmaximumtensileforcedeadweighadhesiontestcylindercompressionforcetimeDisconnectionsoilsample/adhesiontestcylindercompressionFig.6Principleofinterpretationofthestress–timerelationshipFig.7Teststatebeforeconnectionleftphotoandbeforeseparationrightphoto30I.Sass,U.Burbaum123