自然崩落法SITE INVESTIGATIONS培訓

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/declinedevelopmentCavinghistoryExcavationsupporthistoryMajorfailures

StructuraldataFaults.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 -cavabilityassessment

Outputs(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

-Modelinginputparameters

Keylearning'sDefinethedrillinggeometryatscopingAvoidjointsetbiasAvoiddrillingbasisUnderstandtheenvironmentbeforedetailedworkstartsKnowwhatthekeydeliverablesareUsemodelstounderstandtheenvironmentUsemodelstounderstandgeotechnicalvariabilityToavoidprojectcostblowouts, -Weknowhowtodesignforpoorground -Weneedtoknowwherethebadgroundis -WeneedtoknowhowmuchbadgroundthereisMiningRockMassRatingClassificationsystemdesignforcavingLaubscher1977&90RMRvaluesisadjustedtoaccountfortheminingenvironmentPowerfultoolProposednewsystem2000NewsystemcalledIMRMRNewsystemnotcorrelatedNotpopularinAustralia

-Systemdifficulttounderstandbyengineers -Originalpapersdifficulttounderstand -Adjustmentssubjective -Adjustmentsrequireexperienceincaving -ConsultantswillnottellhowtheygettheadjustmentvaluesMRMRSYSTEMRQDConcernofdifferentmeasurementmethods3mainmethodsofRQDmeasurement25%RQDerrorresultsina4rati