采矿过程中的岩土工程设计

GeotechnicalEngineeringDesigninMiningTaoLiPhDPrincipal&DirectorTLGeotechnics&Mining,TLgm,TLGeotechnicsandMining,Outline,GeotechnicalEngineeringinMiningDesignMethodologyandCriteriaMineExampleConclusionandSuggestion,TLgm,TLGeotechnicsandMining,ComparisonbetweenCivilEngineeringandMining,MiningEngineeringhasevolvedtogetherwithCivilEngineering(1800to1900),althoughearlyminingactivitywasfoundinSwazilanddatedback4100BCandcivilbetween4000-2000BCTherearemanysimilaritiesbetweencivilexcavationsandminingexcavationsMining,inparticularbulkmining,hasbeenincreasinglylarger,deeperandfasterMiningenvironmentandmaterialsaremorevariablespatiallyandtemporallyandoftenuncertainCivilEngineeringisoftenamajorpartinlargeminingprojectconstruction,hencecivilengineersemployed,TLgm,TLGeotechnicsandMining,GeotechnicalEngineeringinMining,Itwasestablishedthroughnecessityatminesites/projectsMtIsaMinesestablishedfirstrockmechanicsgroupin1962-1965Thefocushasalwaysbeenonthepracticaloutcomes:safety,efficiencyandinnovation(suchasbackfilldevelopedatMtIsaMines,mostrecentlyBlockandPanelCavingbytheInternationalCavingStudyGroup)Now,justaboutallAustralianmines,largeorsmall,pitsorunderground,havefulltimegeotechnicalengineersandonmostprojectstaff,TLGeotechnicsandMining,TLgm,GeotechnicalEngineeringinMining,TLGeotechnicsandMining,TLgm,GeotechnicalEngineeringinMining,ConcurrentlyminingSLCaboveandBCbelow6mtpaBC1100mbelowsurfaceandhighstresswithvariablerockmassstrengthsExperiencedmajorfailuresatundercutandpartialhighhang-ups,TLgm,TLGeotechnicsandMining,DesignMethodologyandCriteria,TLGeotechnicsandMining,TLgm,CriteriaFeasibility(technicalandfinancial)ConstructabilityOperabilityAdesignthatworksinrealworld-mine,UndergroundExcavationDesign,TLGeotechnicsandMining,TLgm,Excavationmethods:Blockcaving,Panelcaving,Sub-Levelcaving,benching,openstoping,Cuttrial&error,ObservationBasedDesignMethods,TheempiricalmethodssuchasMathewsStabilityGraphThetrial-and-errormethodswithmonitoringandnumericalmodellingsuchastrialslopeforstaterpitinlargeopenpitsandmorerecentlyBCandPChydro-fracturingTheback-analysismethodssuchasthe“calibrated”modellingapproach,TLGeotechnicsandMining,TLgm,RiskandReturnDesignApproach,TheRiskandReturnApproach(Lai2012)emphasisesonbothgeotechnicalengineeringaspectsandfinancialaspectstoreachanoptimumdeisgn.Theimpactsofmostkeydesignparametersandrecommendations,suchasminingmethodselection,sequenceandstopedimensions,cannotbeaccuratelyquantified.Arisk-basedassessmentapproachisincreasinglybeingadoptedtoexaminethedesignsfeasibility,constructability,andoperability,TLGeotechnicsandMining,TLgm,Lift1,Lift2,RockMassCharacterization,Bh=350m,Fl,RiskManagementConsiderations:Pit?BlockCave?,Afullyintegratedgeotechnicaldesignprocessforopenpits,TLGeotechnicsandMining,TLgm,FromCSIROLargePitDesignManual,CadiaHillOpenPitSteeperSlopes,TLGeotechnicsandMining,TLgm,GeotechnicalDomains,DesignSectorsandSlopeAngles,Inter-rampangle56-60degreesandupto200mheightinmorecompetentandlessstructureddomainsOthersectorsinter-rampangle35-46degreesupto150mheight,Northwall720m420,Northwestwall560m430,Westwall550m520,Southwall560m520,Eastwall580m460,TLgm,OptimumDesignMustbeSupportedbyOperationExcellenceandTechnology,TLGeotechnicsandMining,TLgm,CadiaExtendedPitFailure,Designed,MonitoredandVideoTapedwhenOccurred,TLGeotechnicsandMining,TLgm,Simplemonitoringandequationcandothetrickjustaswell,TLGeotechnicsandMining,TLgm,Completedmining625bench15/7/04,Tf=(T2-T1)2+T1(2T2T1-T3),ConclusionandSuggestion,Geotechnicalengineeringdesigninminingisa“living”processthatrequirestheconsiderationsofthelifecycleofamineinordertodealwiththemanyvariablesanduncertaintiesGeotechnicalengineeringdesignfocusesnotonlyontechnicalfeasibilityandfinancialfeasibility,butalsoonconstructabilityandoperabilityContinuousimprovementondesignme