InternationalSocietyforRockMechanics(ISRM)ChinaLectureTourThePast,PresentandFutureforRockMechanicsProfessorJohnAHudsonISRMPresident-elect2023-2023ImperialCollegeandRockEngineeringConsultants,London,UK第1頁(yè)Whatishappeninginrockmechanicsnowandwhatwillhappeninthefuture?第2頁(yè)Whatistheapproachforpredictingthefuture?Peoplesaythattopredictthefuture,oneshouldstudythepast,studyhistoryButwealsoneedtoconsiderwhatishappeningnowandwhatfactorscouldinfluenceusinthefuture第3頁(yè)So,tostudythefutureforrockmechanics,weadopttheapproachofHippocratesover2023yearsago:“Considerthepast,diagnosethepresent,foretellthefuture.”

Hippocrates,460-377BC第4頁(yè)Beforerockmechanicsbecameadisciplineinitsownrightinthe1960s,manymajorprojectswereconstructed–withoutthetechniquesandknowledgethatwehavetoday.ConsiderthepastStonehenge,UKBuilt~5000yearsago第5頁(yè)TheHooverDambuiltinthe1930sontheColoradoRiverbetweenNevadaandArizonastatesintheUSAisanexcellentexample.Theconcretegravitydamwasconstructedinthe1930s,is726ft(221m)highandhasa1.5GWcapacity第6頁(yè)HooverDam,USA,1930s1.5GWcapacity第7頁(yè)

RockmechanicsinChina:“CenturyAchievementsinChineseRockMechanicsandRockEngineering”,2023book,HoHaiUniversityPressChineserockmechanicsstartedin1958Atthatearlytime,ThreeGorgesRockFoundationResearchGroupestablishedProfessorTanJionKie,formerlyVice-DirectorofIRSM-CAS.(IvisitedProfZhuWeishenatIRSMatWuhanin1988).1970sGezhoubaDamnearThreeGorgesDamsite–wasdesignedandconstructedbypurelyChineseengineers–softrocklayersbeneaththedamfoundation,insitublocksheartesting第8頁(yè)ChineseNationalGroupoftheInternationalSocietyofRockMechanics(ISRM)formedin1978ChineseJournalofRockMechanicsandRockEngineeringformedin1986SeveralChineserockmechanicsconferenceshavebeenheld,includingSINOROCK2023whichwasheldattheThreeGorgesDamSite

ISRM2023CongressinBeijing第9頁(yè)IntheWest,alsointhe1960srockmechanicsbecomesarecognisedsubjectFormationoftheInternationalSocietyforRockMechanics,1962 FirstPresident:LeopoldMüller 1962-1966第10頁(yè)“Wedon’tknowtherockmassstrength.ThatiswhyweneedanInternationalSociety.”L.Müller,May1962

第11頁(yè)Griffithcriterion(fromtheUK)forruptureindirecttension,1921第12頁(yè)GriffithCrackinaUniaxialCompressionStressField第13頁(yè)Intheearlydays,rockmechanicswasdominatedbyelasticsolutionsforstressesandstrains“FundamentalsofRockMechanics”,1969byJCJaegerandNGWCookLaboratorytestingsignificantlyimprovedbytheuseofservo-controlledtestingmachinestocontrolfailure第14頁(yè)Beforethedaysofnumericalmodelling,photo-elasticitywasused--morecomplexshapesthanclassicalelasticity

第15頁(yè)Stifftestingmachine–Wawersik1968

(modifiedafterCook(1966))UniversityofMinnesota,USAAbilitytoobtainthecompletestress-straincurve:1968第16頁(yè)Examplesofthecompletestress-straincurvesobtainedbyWawersik第17頁(yè)ContinuumandDiscontinuumRegimesInelasticElasticElasticUnloadingForceDeformationDiscontinuum(Mining)(seismic)(aseismic)ContinuumWiththiscompletestress-straincurve,wecanunderstandwhathappensafterthepeakstrengthisreached第18頁(yè) Lateron,thesignificantroleoffractureswasrealised: CHILEvsDIANE

CHILE:Continuous,Homogeneous,Isotropic, Linearly Elastic–theassumptionoftenmadeinmodelling

DIANE:Discontinuous,Inhomogeneous,Anisotropic, NotElastic–therockreality Numericalmodellingwasintroducedin the1970sItwasn’tuntil1993thatthefirstencyclopaediainrock mechanicsandrockengineeringwasproduced: “Comprehensiverockengineering”1993,5volumes, 4407pages,Editor:JAHudson

第19頁(yè)DiagnosethepresentWhatiscurrentlybeingbuilt?andWhatiscurrentlyhappeninginrockmechanics?第20頁(yè)QingjiangrivergorgelocationoftheShuibuyahydroelectricproject.

Damis233mhigh.ProjectsinChina第21頁(yè)LongtanHydroelectricpowerstation,Hongshuiriver,GuangxiProvince,China

第22頁(yè)ThreeGorgesProjectontheYangtzeRiver,China,18GWLargesthydroelectricdamintheworldWorldwideinreaseinenergyconsumptionis20GW/year第23頁(yè)InternationalconferencesSponsoredbytheChineseAcademyofSciences(CAS)andtheInternationalJournalofRockMechanics&MiningSciencesThreeGorgesDamonYangzeRiver第24頁(yè)LastweekIwasatJinPingIIhydroelectricprojectontheYalongRiverTunnelswillhaveoverburdenof2,500mandsohighstressesandrockspalling第25頁(yè)印度板塊菲律賓板塊歐亞板塊太平洋板塊北美板塊DynamicregionsofChinaandadjacentareasSlidefrom:“TheRecentTectonicStressFieldandStrongEarthquakesinChina”XieFurenInstituteofCrustalDynamics,CEA第26頁(yè)Itisessentialforrockengineeringtounderstandthegeologyataprojectsite,forexampleattheJinPingIIsite第27頁(yè)

H/W=3H/W=1.5H/W=1H/W=2H/W=0.5SimulatedwithRFPA2DDrCATangCATangetal.(1999)Numericalstudiesoftheinfluenceofmicrostructure onrockfailureinuniaxialcompression,IJRMMS.RockFailureProcessAnalysis(RFPA)Numericalmodelling第28頁(yè)UndergroundResearchLaboratories第29頁(yè)Atpresent,therearemajorrockengineeringprojectsbeingconstructedweanticipatethiswillcontinueacrosstheworldgeologicalandsiteinvestigationtechniquesareimprovingnumericalmethodshaveimprovedsignificantlysothatthe rockcannowberealisticallyrepresentedinthemodellingthereisrapidtelephoneandinternetcommunicationthereisincreasedinternationalco-operationitisnoweasytoobtainscientificinformationthroughthe internetWhatisgoingtohappennext?第30頁(yè)ForetellthefutureLetusconsiderthepossibilitiesforthefutureintermsof:theshortterm(thenext20years)thelongerterm(thenext100years)第31頁(yè)Therockmechanicsfuture: Part1–theshortterm(thenext20years)Requirementsformaterials,energy,structuresTheglobalenvironmentSustainabledevelopmentEthicalengineeringThetechnologicalfuture

Therockmechanicsfuture: Part2–thelongerterm(thenext100years)第32頁(yè)SustainabledevelopmentIstheexploitationofundergroundspacecompatiblewiththeconceptofsustainabledevelopment?第33頁(yè)Whatissustainabledevelopment? Bruntland1987definition: “Developmentthatmeetstheneedsofthepresentgenerationwithoutcompromisingtheabilityoffuturegenerationstomeettheirownneeds”第34頁(yè)Givenanexistingsystem(whetheravirginspaceoradevelopedspace),isitacceptabletolocateanewfacilityinthesystem—withinthecontextofsustainabledevelopment?ExistingsystemProposednewproject第35頁(yè)EthicalengineeringThedecisionsandactionsofengineershaveaprofoundimpactontheworldwelivein,andsocietyatlarge.Makingaclearandpubliccommitmenttooperatingwithintegrityandhonestyisessentialtocreateagreaterleveloftrustandconfidence,andapositiveperceptionoftheengineeringprofession.第36頁(yè)ThetechnologicalfutureDuringconstruction,anexperiencedengineercanlookattheroofofanexcavationinrockanddecidewhetherornotitisdangerous.Howisthisdone?Byexperienceoperatingonthe1Mborsovisualinformationbeingreceivedthroughtheengineer’seyes.So,ifacameraismonitoringtheroof,itshouldbepossibleinthefutureforaneuralnetworkcomputerprogramtoevaluatetheconditionsvia,forexample,1Mbimagesinthesamewayastheengineer.第37頁(yè)ItisnowrecognizedthatGeological-Thermal-Hydrological-Mechanical-Chemical-Engineeringmodellingisrequiredtofullyunderstandthemechanismsthatoccurintherockmass.Geological: sitegeometry,lithology,fracturesThermal: heatloads,heatflowHydrological: waterpressures,waterflowMechanical: rockstress,stiffness,strengthChemical: waterchemistry,swellingrocksEngineering: effectsofexcavation第38頁(yè)RockexcavationBlastingorTunnelBoringMachines?第39頁(yè) Therockmechanicsfuture: Part2–thelongerterm(50-100years)So,weareabletohaveagoodfeelfortheshorttermfuture,butwhatislikelytohappeninthelongerterm?Thetechnologicaldevelopmentswillbedramaticandpossiblydifficultforustocomprehendnow.第40頁(yè)GrowthincomputingpowerNext50-100yearsNext20yearsAllhumanbrainsOnehumanbrainOnemousebrainOneinsectbrainNowCalculationspersecondper$1000第41頁(yè)Technologyisbeingimplementedincreasinglyrapidly第42頁(yè)Whatwillhappentobooks?Microsofthaveannouncedthattheywillmake25millionpagesofbooksanddocumentsavailablefromtheBritishLibraryonlineandfreeofcharge.GooglePrint–samethingsforUSlibraries…第43頁(yè)P(yáng)ublishing–InformationcommunicationComputerswillwritepapersaboutthecumulativeadvancesinrockmechanicsviaallthepaperspublishedeachyear,andabouttheirmonitoringexperiences,etc.Ifcomputersbecomeauthors,howshouldtheybeidentified,oridentifythemselves?Willwebeabletotelliftheauthorishumanoracomputer?第44頁(yè)Computerdesignofrockengineeringfacilities

Atthemoment,weashumanengineersdecidethatweneedarockengineeringfacility,thenwemakepreparations,operateadesignmodel,evaluatetheconsequences,etc.Isitpossiblethatallthiscouldbecomputerisedoneday?Couldthecomputerdecidewhatengineeringfacilitiesarerequired,thenindicatewhatsiteinvestigationisrequired,thenchoosethemostappropriatenumericalmodelfromitslibrary,andthendecideontheoptimalengineeringdesign?第45頁(yè)AttendanceatconferencesItwillbeanoptionwhetherweattendaconferencephysicallyorelectronically.Somepeoplewillwishtoattendphysicallybut,withmoreandmorepressureoneveryone’stime,theelectronicattendancewillbepreferredbymanyothers.Thishasmanyadvantages,notleastofwhichisthatonecouldattendmanymoreconferences.第46頁(yè)Futuretechnologicaldevelopments...Howlargecanacavernbe?RedwallcavernGrandCanyon,USA第47頁(yè)Futuretechnologicaldevelopments...Howlargecanacavernbe?Stressconcentrationisindependentofexcavationsize.So,inanunfracturedrockmass,thecaverncouldbeanysize. 100m,1000m?第48頁(yè)Willwebecomeanybetteratpredictinghazardsandfailure?第49頁(yè)P(yáng)orteauBluffonHighway99NorthofVancouver,CanadaCharacterizingthefracturesatasiteCivilengineering第50頁(yè)Mt.Tai:"thefirstamongthefivesacredmountainsofChina"and"thefirstmountainunderheaven".第51頁(yè)FailureofalargerockwedgeattheTeutonicBoreMine,WesternAustraliaMiningengineering第52頁(yè)Theengineermusthaveapredictivecapabilityfordesign,andthatpredictivecapabilitycanonlybeachievedifthekeyfeaturesoftherockrealityhaveindeedbeencapturedinthemodel.Issuesofspecialdifficultyandimportanceinnumericalmodellingarethefollowing: ·Systematicevaluationofgeologicalandengineeringuncertainties ·Understandingandrepresentationoflargerockfractures ·Quantificationoffractureshape,size,connectivityandeffectof fractureintersectionsforDFNandDEMmodels ·Representationofrockmasspropertiesandbehaviourasan equivalentcontinuumandexistenceoftheRepresentativeElemental Volume(REV) ·Representationofinterfacebehaviour ·Scaleeffects,homogenizationandupscalingmethods ·Numericalrepresentationofengineeringprocesses,suchas excavationsequence,groutingandreinforcement ·TimeeffectsfromLJingandJAHudson(2023)Numericalmet