自然崩落法全英文四

SITEINVESTIGATIONSTheneedforbalanceCONTENTSInvestigationtechniquescoveredbyothersTheneedforbalanceandfocusKeylearning'sfromotherprojectsMRMRKeyfailure“Extensivegeotechnicalinvestigationsareconductedthatarenotfocusedonpracticalminingengineeringdesigninputparametersfortheproject”

InvestigationrulesAikhalprincipleWhatamIgettingoutofthis?EveryinvestigationmusthaveanprojectinputdeliverableEverypieceofdatamustrelatedtoinvestigationinputdeliverableTheabovemusthaveanauditstrailUseonlyestablishedinvestigationmethodsInvestigationaudittrailMeasurementofRQDInputintoRMR&MRMRDriftsupportmeasuresdeterminedfromempiricaltablesusingtheabovevaluesWhenareinvestigationsneeded?Laubscher’srules(1993)Greenfield'sprojectsNewminingblocks/orebodies(Brownfield's)Pit/undergroundtransitionWhengeotechnicalenvironmentscausetheneedtoreviewthecurrentminingmethodAimsofinvestigationsGeotechnicalinvestigationdataisusedtodetermine: -Whatisitgoingtobelikeminingdownthere? -Cavingmethodselection -Cavabilityassessment -Subsidence/gloryholedefinition -Mineinfrastructurelocationanddesign -Mininglayoutdesign -Supportdesign -Cavinghazardassessmentdata(e.g.soilassessmentsformudrushes -Estimatesofminewaterinflows -Fragmentationandproductionbuild-upstudies

ProjectstagesDesktopstudyScopingstudyPre-feasibilitystudyFeasibilitystudyDesktopstudyGeneralgeologicalinformationInformationfrompreviousstudiesInternetsites(SIMRAC)OtherminesEstimatesofrockparametersEstimatesclassificationvaluesfromgeologyLimitedconfirmationmappingorcoreloggingInternetinformationROCKTYPERMRQAmphibolite55–673.4–12.9BandedIronstone55–753.4–31.3Chromitite47–541.4–3.0Dolerite57–634.2–8.3Dolomite68–7114.4–20.1Granite/gneiss60–845.9–85.2Kimberlite35–550.37–3.4Massivesulphide63–748.3–28.0Metagabbro50–661.9–11.5Pyroxenite53–802.7–54.6Quartzite58–804.7–54.6Sandstone38–580.51–4.7Schist25–550.12–3.4Shale55–693.4–16.1Ventersdorplava55–723.4–22.4SCOPINGSTUDIESGeneralinformationClassificationmappingandloggingBasicdefinitionofgeotechnicaldomainsWhereistheweakareaintheorebodyAboverequiredforblockattackSomerocktestparameter’sGeologicalandstructuralinformationUnderstandingthegeotechicalcomplexityMRMRcanbeusedtoscopingstudyaccuraciesSomeAEmeasurementsGeneralinformationOtherstudiesInformationfrompit/otherminesClassificationvaluesStructuraltrendsMajorstructuresRockparametersMinepumpinginformationShaftsinkinghistory/declinedevelopmentCavinghistoryExcavationsupporthistoryMajorfailuresStructuraldataFaults.Dykes,weakzones,contacts,shearzonesOff-settingoforebodyFaults/contacts,tectonicstressesChimneycavingareasPre-maturecaving/cavetriggeringareasMassivewedgefailurecausinginfantriesdestructionWeakarea,caveinitationzones,dilutioningresszonesFaults/contactsareasofpointloaddestructionKeylearning’’sPutgeneralinformationtogetherbeforegeotechnicalinvestigationsstartConstructGDMorMRMMifconfusedUsegeneralinformationtofocusnewstudiesCheckqualityofpreviouscoreloggingCheckqualityofnewlogging&mapping(30%)FullylogallgeotechnicalcoreTraingeologistinreasonsfordatacollectionFullgeotechnicallogRQDHardnessNumberofjoints/jointspacingSmall/largescaleconditionJointinfillingAlterationDatacanbeturnedintoratingsPre-feasibility/feasibilitystudiesMajordrillingProgrammes30%ofgeologicalholesgeotechnicallyloggedDefinitionjointsets,200readspersetJointdatastatisticaldistributionsAdditionalholesformajorstructuresMappingofexplorationaditsConstructionofGDM/MRMMFullrangerockparameters(e.g.UCS,Eetc)Additioninvestigationsforshafts&declinesAdditionalexplorationofmajorstructuresHydrologicaldomainmodelanddataRockcommutationdata/AEorinstustressmeasurementsInvestigationoutputsClassificationresults:-GDM/MRMM-Weakareasforcaveinitiation/cavability-Infrastructurelocation/stability-subsidencegloryholedefinition-Supportestimates-DrawpointspacingJointdata:-Statisticaldistributionsfortracelength,spacing,dip/direction-Fragmentation&hang-upforproductionramp-deterministicanalysis(backwedge)supportdesign-Blastingfragmentationanalysis-Advancenumericalmodelinginputs(UDEC/3DEC)Outputs(continue)Rockparameters:-UCSvaluesforclassificationresults-numericalmodelingparameters-Shearstrengthvaluesforwedgeanalysisforsupportdesign-cavabilityassessmentRockstressdata:-Stresstrendsanddirections-Modesofexcavationfailure-directionofcavefrontretreat-Numericalmodelingdatainputs-cavabilityassessmentOutputs(Continue)Hydrogeological/rainfalldata:-Rockmassclassificationdatainputs-Minepumpingrequirements-Flood/mudrushassessmentrisks-supportdesigninputs(weatheringrock)Minerallogical-Weatheringpotential-mudrushpotential-Swelling/squeezingplasticdeformormingrocks-ShotCretebondingRockmassclassificationUse3ratingsystemsMRMR-Supportdesign-Drawpointspacing-Cavability-Gloryholedefinition-Rockmassstrengthestimates(DRMSvalues)Barton’’s‘Q”-orepassstabilityassessment(Stacey2001)-checksupportdesign,shotcretethickness-Decline/shaftsupportthroughsoftnearsurfacerocksRMR/GSI-ModelinginputparametersKeylearning'sDefinethedrillinggeometryatscopingAvoidjointsetbiasAvoiddrillingbasisUnderstandtheenvironmentbeforedetailedworkstartsKnowwhatthekeydeliverablesareUsemodelstounderstandtheenvironmentUsemodelstounderstandgeotechnicalvariabilityToavoidprojectcostblowouts,-Weknowhowtodesignforpoorground-Weneedtoknowwherethebadgroundis-WeneedtoknowhowmuchbadgroundthereisMiningRockMassRatingClassificationsystemdesignforcavingLaubscher1977&90RMRvaluesisadjustedtoaccountfortheminingenvironmentPowerfultoolProposednewsystem2000NewsystemcalledIMRMRNewsystemnotcorrelatedNotpopularinAustralia-Systemdifficulttounderstandbyengineers-Originalpapersdifficulttounderstand-Adjustmentssubjective-Adjustmentsrequireexperienceincaving-ConsultantswillnottellhowtheygettheadjustmentvaluesMRMRSYSTEMRQD