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首页 土木工程毕业设计外文翻译1

土木工程毕业设计外文翻译1.doc

土木工程毕业设计外文翻译1

卖女孩儿的小火柴
2011-05-13 0人阅读 举报 0 0 暂无简介

简介:本文档为《土木工程毕业设计外文翻译1doc》,可适用于经济金融领域

DesignandExecutionofGroundInvestigationforEarthworksDESIGNANDEXECUTIONOFGROUNDINVESTIGATIONFOREARTHWORKSPAULQUIGLEY,FGSIrishGeotechnicalServicesLtdABSTRACTThedesignandexecutionofgroundinvestigationworksforearthworkprojectshasbecomeincreasinglyimportantastheavailabilityofsuitabledisposalareasbecomeslimitedandcostsofimportingengineeringfillincreaseAnoutlineofgroundinvestigationmethodswhichcanaugment‘traditionalinvestigationmethods’particularlyforglacialtillboulderclaysoilsispresentedTheissueof‘geotechnicalcertification’israisedandrecommendationsoutlinedonitsmeritsforincorporationwithgroundinvestigationsandearthworksINTRODUCTIONTheinvestigationandreuseevaluationofmanyIrishboulderclaysoilspresentsdifficultiesforboththegeotechnicalengineerandtheroaddesignengineerTheseglacialtillorboulderclaysoilsaremainlyoflowplasticityandhaveparticlesizesrangingfromclaytobouldersMostofourboulderclaysoilscontainvaryingproportionsofsand,gravel,cobblesandbouldersinaclayorsiltmatrixTheamountoffinesgovernstheirbehaviourandthesiltcontentmakesitveryweathersusceptibleMoisturecontentscanbehighlyvariablerangingfromaslowasforthehardgreyblackDublinboulderclayuptoforMidland,SouthWestandNorthWestlightgreyboulderclaydepositsTheabilityofboulderclaysoilstotakeinfreewateriswellestablishedandpoorplanningofearthworksoftenamplifiesthisThefinesoilconstituentsaregenerallysensitivetosmallincreasesinmoisturecontentwhichoftenleadtolossinstrengthandrenderthesoilsunsuitableforreuseasengineeringfillManyofourboulderclaysoils(especiallythosewithintermediatetypesiltsandfinesandmatrix)havebeenrejectedattheselectionstage,butgoodplanningshowsthattheycaninfactfulfilspecificationrequirementsintermsofcompactionandstrengthTheselectionprocessshouldaimtomaximisetheuseoflocallyavailablesoilsandwithcarefulevaluationitispossibletouseorincorporate‘poorormarginalsoils’withinfillareasandembankmentsFillmaterialneedstobeplacedatamoisturecontentsuchthatitisneithertoowettobestableandtrafficableortoodrytobeproperlycompactedHighmoisturecontentlowstrengthboulderclaysoilscanbesuitableforuseasfillinlowheightembankments(ietom)butnotsuitablefortraffickingbyearthworkplantwithoutusingageotextileseparatorandgranularfillcappinglayerHence,itisvitalthattheearthworkscontractorfullyunderstandsthehandlingpropertiesofthesoils,asformanyprojectsthisiseffectivelygovernedbythetrafficabilityofearthmovingequipmentTRADITIONALGROUNDINVESTIGATIONMETHODSForroadprojects,aprincipalaimofthegroundinvestigationistoclassifythesuitabilityofthesoilsinaccordancewithTablefromSeriesoftheNRASpecificationforRoadWorks(SRW),MarchThemajorityofcurrentgroundinvestigationsforroadworksincludesacombinationofthefollowingtogivetherequiredgeotechnicaldata:​ Trialpits​ Cablepercussionboreholes​ Dynamicprobing​ Rotarycoredrilling​ Insitutesting(SPT,variableheadpermeabilitytests,geophysicaletc)​ LaboratorytestingTheimportanceof‘phasing’thefieldworkoperationscannotbeoverstressed,particularlywhenassessingsoilsuitabilityfromdeepcutareasCablepercussionboreholesarenormallysunktoadesireddepthor‘refusal’withdisturbedandundisturbedsamplesrecoveredatmintervalsorchangeofstrataInmanyinstances,cablepercussionboringisunabletopenetratethroughverystiff,hardboulderclaysoilsduetocobble,boulderobstructionsSampledisturbanceinboreholesshouldbepreventedandlossoffinesiscommon,invariablythisleadstoinaccurateclassificationTrialpitsareconsideredmoreappropriateforrecoveringappropriatesizesamplesandforobservingtheproportionofclaststomatrixandsizesofcobbles,bouldersDetailedandaccuratefielddescriptionsarethereforevitalforcutareasandtrialpitsprovideanopportunitytoexaminethesoilsonalargerscalethanboreholesTrialpitsalsoprovideaninsightontrenchstabilityandtoobservewateringressanditseffectsAsuitablyexperiencedgeotechnicalengineerorengineeringgeologistshouldsupervisethetrialpittingworksandrecoveryofsamplesThecharacteristicsofthesoilsduringtrialpitexcavationshouldbecloselyobservedasthisprovidesinformationonsoilsensitivity,especiallyifwaterfromgranularzonesmigratesintothefinematrixmaterialVeryoften,theconditionofsoilonthesidesofanexcavationprovidesamoreaccurateassessmentofitsinsituconditionSOILCLASSIFICATIONSoildescriptionandclassificationshouldbeundertakeninaccordancewithBS()andtestedinaccordancewithBS()Theengineeringdescriptionofasoilisbasedonitsparticlesizegrading,supplementedbyplasticityforfinesoilsFormanyofourglacialtill,boulderclaysoils(ie‘mixedsoils’)difficultiesarisewithdescriptionsandassessingengineeringperformancetestsAsoutlinedpreviously,Irishboulderclaysusuallycomprisehighlyvariableproportionsofsands,gravelsandcobblesinasiltorclaymatrixLowplasticitysoilswithfinescontentsofaroundtooftenpresentthemostdifficultiesBS()nowrecognisesthesedifficultiesindescribing‘mixedsoils’–thefinesoilconstituentswhichgoverntheengineeringbehaviournowtakespriorityoverparticlesizeAkeyparameter(whichisoftenunderestimated)inclassifyingandunderstandingthesesoilsispermeability(K)InspectionoftheparticlesizegradingswillindicatemagnitudeofpermeabilityWherepossible,triaxialcelltestsshouldbecarriedoutoneitherundisturbedsamples(U’s)orgoodqualitycoresamplestoevaluatethedrainagecharacteristicsofthesoilsaccuratelyLowplasticityboulderclaysoilsofintermediatepermeability(ieKoftheorderoftoms)canoftenbe‘conditioned’bydrainagemeasuresThisusuallyentailstheinstallationofperimeterdrainsandsumpsatcutareasorborrowpitssoastoreducethemoisturecontentHence,withsmallreductioninmoisturecontent,difficultglacialtillsoilscanbecomesuitableasengineeringfillENGINEERINGPERFORMANCETESTINGOFSOILSLaboratorytestingisverymuchdictatedbytheproposedenduseforthesoilsTheengineeringparameterssetoutinTablepftheNRASRWincludeacombinationofthefollowing:​ Moisturecontent​ Particlesizegrading​ PlasticLimit​ CBR​ Compaction(relatingtooptimumMC)​ RemouldedundrainedshearstrengthAnumberofkeyfactorsshouldbeborneinmindwhenschedulinglaboratorytesting:​ CompactionCBRMCVtestsarecarriedouton<mmsizematerial​ Moisturecontentvaluesshouldrelateto<mmsizematerialtoprovideavalidcomparison​ Porepressuresarenottakenintoaccountduringcompactionandmayvaryconsiderablybetweenlaboratoryandfield​ PreparationmethodsforsoiltestingmustbeclearlystipulatedandagreedwiththedesignatedlaboratoryGreatcaremustbetakenwhendeterminingmoisturecontentofboulderclaysoilsIdeally,themoisturecontentshouldberelatedtotheparticlesizeandhaveacorrespondinggradinganalysisfordirectcomparison,althoughthisisnotalwayspracticalInthemajorityofcases,theMCVwhenusedwithcompactiondataisconsideredtoofferthebestmethodofestablishing(andchecking)thesuitabilitycharacteristicsofaboulderclaysoilMCVtestingduringtrialpittingisstronglyrecommendedasitprovidesarapidassessmentofthesoilsuitabilitydirectlyafterexcavationMCVcalibrationcanthenbecarriedoutinthelaboratoryatvariousmoisturecontentincrementsSampledisturbancecanoccurduringtransportationtothelaboratoryandthiscanhaveasignificantimpactontheresultantMCV’sIGSLhasfoundlargediscrepancieswhenperformingMCV’sinthefieldonlowplasticityboulderclayswiththosecarriedoutlaterinthelaboratory(todays)ManyoftheaforementionedlowplasticityboulderclaysoilsexhibittimedependantbehaviourwithsignificantlydifferentMCV’srecordedatalaterdate–increasedvaluescanbeduetothedrainageofthematerialfollowingsampling,transportationandstoragewhiledilatancyandmigrationofwaterfromgranularlensescanleadtodeteriorationandlowervaluesThistypeofinformationisimportanttoboththedesignerandearthworkscontractorasitprovidesanopportunitytounderstandthepropertiesofthesoilswhentestedasoutlinedaboveItcanalsoillustratetheadvantagesofpredraininginsomeinstancesWithmixedsoils,faceexcavationmaybenecessarytoacceleratedrainageworksCBRtestingofboulderclaysoilsalsoneedscarefulconsideration,mainlywiththepreparationmethodemployedDesignengineersneedtobeawareofthis,asitcanhaveanorderofmagnitudedifferenceinresultsStaticcompactionofboulderclaysoilsisadvisedascompactionwiththeorkgrammeroftenleadstohighexcessporepressuresbeinggenerated–henceverylowCBRvaluescanresultAlso,curingofcompactedboulderclaysamplesisimportantasthisallowsexcessporewaterpressurestodissipateENGINEERINGCLASSIFICATIONOFSOILSInaccordancewiththeNRASRW,generalcohesivefilliscategorisedinTableasfollows:​ AWetcohesive​ BDrycohesive​ CStonycohesive​ DSiltycohesiveThematerialpropertiesrequiredforacceptabilityaregivenandthedesignengineerthendeterminestheupperandlowerboundlimitsonthebasisofthelaboratoryclassificationandengineeringperformancetestsIrishboulderclaysoilsarepredominantlyClassCClauseoftheSRWsetsoutcompactionmethodsTwoproceduresareavailable:​ MethodCompaction​ EndProductCompactionEndproductcompactionisconsideredmorepractical,especiallywhengoodcompactioncontroldatabecomesavailableduringtheearlystagesofanearthworkscontractAminimumTargetDryDensity(TDD)isconsideredveryusefulforthecontractortoworkwithasameansofcheckingcompactionqualityOncethematerialhasbeenapprovedandmeetstheacceptabilitylimits,theninsitudensitycanbemeasured,preferablybynucleargaugeorsandreplacementtestswherethestonecontentislowAsplacingandcompactionofthefillprogresses,theinsituTDDcanbecheckedandnonconformingareasquicklyrecognisedandcorrectiveactiontakenThisprocessrequiresthedesignengineertoreviewthefielddensitieswiththelaboratorycompactionplotsandevaluateactualwith‘theoreticaldensities’SUPPLEMENTARYGROUNDINVESTIGATIONMETHODSFOREARTHWORKSThemoretraditionalmethodsandprocedureshavebeenoutlinedinSectionThefollowingareexamplesofmethodswhicharebelievedtoenhancegroundinvestigationworksforroadprojects:​ Phasingthegroundinvestigationworks,particularlythelaboratorytesting​ Excavationsamplingindeeptrialpits​ Largediameterhighqualityrotarycoredrillingusingairmistorpolymergeltechniques​ Smallscalecompactiontrialsonpotentiallysuitablecutmaterial​ PHASINGPhasinggroundinvestigationworksformanylargeprojectshasbeenadvocatedformanyyears–thisisparticularlytrueforroadprojectswheresignificantamountsofgeotechnicaldatabecomesavailableoverashortperiodOnthemajorityoflargegroundinvestigationprojectsnoperiodisleftto‘digest’orreviewthepreliminaryfindingsandreappraisethesuitabilityofthemethodsWithregardtosoillaboratorytesting,largetestingschedulesareoftenpreparedwithnorealconsiderationgiventotheirenduseInmanycases,thescheduleispreparedbyajuniorengineerwhiletheseniordesignengineerwhowillprobablydesigntheearthworkswillhavenorealinvolvementItishighlightedthattheengineeringperformancetestsareexpensiveandoflongduration(egpointcompactionwithCBRMCVateachpointtakesinexcessoftwoweeks)Whenclassificationtests(moisturecontents,particlesizeanalysisandAtterbergLimits)arecompletedthenamoreincisiveevaluationcanbecarriedoutonthedataandtheengineeringperformancetestsscheduledIfMCV’sareperformedduringtrialpittingthenagoodassessmentofthesoilsuitabilitycanbeimmediatelyobtained​ DEEPTRIALPITSTheexcavationofdeeptrialpitsisoftenperceivedascumbersomeanddifficultandthereforenotconsideredappropriatebydesignengineersExcavationofdeeptrialpitsinboulderclaysoilstodepthsofuptomisfeasibleusingbenchingtechniquesandsumppumpingofgroundwaterInrecentyears,IGSLhasundertakensuchdeeptrialpitsonseverallargeroadgroundinvestigationprojectsThedataobtainedfromthesehascertainlyenhancedthegeotechnicaldataandprovidedabetterunderstandingofthebulkpropertiesofthesoilsItisrecommendedthatthisworkbecarriedoutfollowingcompletionofthecablepercussionboreholesandrotarycoredrillholesThegroundwaterregimewithinthecutareawillplayanimportantroleingoverningthefeasibilityofexcavatingdeeptrialpitsTheinstallationofstandpipesandpiezometerswillgreatlyassisttheunderstandingofthegroundwaterconditions,hencethepurposeofundertakingthisworklateoninthegroundinvestigationprogrammeLargerepresentativesamplescanbeobtained(usingtrenchbox)andinsitushearstrengthmeasuredonblocksamplesThestabilityofthepitsidewallsandgroundwaterconditionscanalsobeestablishedandcomparedwithlevelsinnearbyboreholestandpipesorpiezometersOveraprominentcutareaofsaym,threedeeptrialpitscanproveinvaluableandthespoilmaterialalsousedtocarryoutsmallscalecompactiontrialsFromavalueengineeringperspective,thecostofexcavatingandreinstatingtheseexcavationscanbeeasilyrecoveredAprovisionalsumcanbeallocatedinthegroundinvestigationandusedforthiswork​ HIGHQUALITYLARGEDIAMETERROTARYCOREDRILLINGThissystementailstheuseoflargediameterrotarycoredrillingtechniquesusingairmistorpolymergelflushTripletubecoredrillingiscarriedoutthroughtheoverburdensoilswiththerecoveredmaterialheldinaplasticcorelinerCorerecoveryinlowplasticityboulderclayhasbeenshowntobeextremelygood(typicallyinexcessof)ThehighcorerecoverypermitsdetailedengineeringgeologicalloggingandprovisionofsamplesforlaboratorytestingIndrumlinareas,suchasthosearoundCavanandMonaghan,IGSLhasfoundtheuseoflargediameterpolymergelrotarycoredrillingtobeverysuccessfulinrecoveringverystiffhardboulderclaysoilsfordeeproadcutareas(wherecablepercussionboreholesandtrialpitshavefailedtopenetrate)Insitutesting(vanes,SPT’setc)canalsobecarriedoutwithinthedrillholetoestablishstrengthandbearingcapacityofdiscretehorizonsLargediameterrotarydrillingcostsusingtheaforementionedsystemsaretypicallytogreaterthanconventionalHQcoresize,butagainfromavalueengineeringaspectcanprovemuchmoreworthwhileduetothequalityofgeotechnicalinformationobtained​ SMALLSCALECOMPACTIONTRIALSTheundertakingofsmallscalecompactiontrialsduringthegroundinvestigationprogrammeisstronglyadvised,particularlywhere‘marginallysuitable’soilsarepresentinprominentcutareasInadditiontovalidatingthelaboratorytestdata,theyenablemorerealisticplanningoftheearthworksandcanprovideconsiderablecostsavingsThecompactiontrialcanprovidethefollowing:​ Achievablefielddensity,remouldedshearstrengthandCBR​ Establishingoptimumlayerthicknessandnumberofrollerpasses​ Responseofsoilduringcompaction(staticvdynamic)​ MonitortrafficabilitydegreeofruttingAtypicalsizetestpadwouldbeapproximatelyxminplanareaanduptominthicknessTheselectedareashouldbeclosetothecutareaorborrowpitandhaveadequateroomforstockpilingofmaterialEarthworkplantwouldnormallyentailatrackedexcavator(CATorequivalent),tdumptruck,DdozerandeitheratowedorselfpropelledrollerInsitudensitymeasurementonthecompactedfillbynucleargaugemethodisrecommendedasthisfacilitatesrapidmeasurementofmoisturecontents,dryandbulkdensitiesItalsoenablesalargesuiteofdatatobegeneratedfromthecompactedfillandtoassesstherelationshipbetweendegreeofcompaction,layerthicknessandnumberofrollerpassesBothdisturbedandundisturbed(U)samplesofthecompactedfillcanbetakenforlaboratorytestingandvalidationchecksmadewiththefielddata(particularlymoisturecontents)IGSL’sexperienceisthatwithgoodplanningasmallscalecompactiontrialtakestwoworkingdaystocompleteSUPERVISIONOFGROUNDINVESTIGATIONPROJECTSCloseinteractionandmutualrespectbetweenthegroundinvestigationcontractorandtheconsultingengineerisconsideredvitaltothesuccessoflargeroadinvestigationprojectsAseniorgeotechnicalengineerfromeachoftheaforementionedpartiesshouldliasecloselysothatthedirectionandscopeoftheinvestigationcanbechangedtoreflectthestratigraphyandgroundconditionsencounteredThenatureoflargegroundinvestigationprojectsmeansthattheremustbegoodcommunicationandflexibilityinapproachtoobtainingdataBepreparedtocompromiseasmethodsandproceduresspecifiedmaynotbeappropriateandsiteconditionscanquicklychangeFromasupervisionaspect(bothcontractorandconsultingengineer),theemphasisshouldbeonthequalityofsitebasedgeotechnicalengineers,engineeringgeologistsasopposedtoquantitywhereworkisduplicatedGEOTECHNICALCERTIFICATIONTheDepartmentofTransport(UK)preparedadocument(HD)inforhighwayschemesThissetsouttheproceduresanddocumentationtobeusedduringtheplanningandreportingofgroundinvestigationsandconstructionofearthworksRoadprojectsinvolvingearthmovingactivitiesorcomplexgeotechnicalfeaturesmustbecertifiedbytheDesignOrganisation(DO)consultingengineeroragentauthorityTheprofessionalresponsibilityforthegeotechnicalworkrestswiththeDOForsuchaproject,theDOmustnominateacharteredengineerwithappropriategeotechnicalengineeringexperienceHesheisreferredtoastheGeotechnicalLiaisonEngineer(GLE)andisresponsibleforallgeotechnicalmattersincludingpreparationofproceduralstatements,reportsandcertificatesSectionofHDstatesthat“oncompletionofthegroundinvestigationworks,theDOshallsubmitareportandcertificatecontainingallthefactualrecordsandtestresultsproducedbythespecialistcontractortogetherwithaninterpretativereportproducedeitherbythespecialistcontractororDO”TheDOshallthenprepareanEarthworksDesignReport–thisreportistheDesigner’sdetailedreportonhisinterpretationofthesiteinvestigationdataanddesignofearthworksTheextentandclosenessoftheliaisonbetweentheProjectManagerandtheGLEwillverymuchdependonthenatureoftheschemeandgeotechnicalcomplexitiesdiscoveredastheinvestigationanddesignproceedAftertheearthworksarecompleted,ageotechnicalfeedbackreportisrequiredandistobeprepared

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土木工程毕业设计外文翻译1

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