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

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

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

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

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

第15頁Stifftestingmachine–Wawersik1968

(modifiedafterCook(1966))UniversityofMinnesota,USAAbilitytoobtainthecompletestress-straincurve:1968第16頁Examplesofthecompletestress-straincurvesobtainedbyWawersik第17頁ContinuumandDiscontinuumRegimesInelasticElasticElasticUnloadingForceDeformationDiscontinuum(Mining)(seismic)(aseismic)ContinuumWiththiscompletestress-straincurve,wecanunderstandwhathappensafterthepeakstrengthisreached第18頁 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DiagnosethepresentWhatiscurrentlybeingbuilt?andWhatiscurrentlyhappeninginrockmechanics?第20頁QingjiangrivergorgelocationoftheShuibuyahydroelectricproject.

Damis233mhigh.ProjectsinChina第21頁LongtanHydroelectricpowerstation,Hongshuiriver,GuangxiProvince,China

第22頁ThreeGorgesProjectontheYangtzeRiver,China,18GWLargesthydroelectricdamintheworldWorldwideinreaseinenergyconsumptionis20GW/year第23頁InternationalconferencesSponsoredbytheChineseAcademyofSciences(CAS)andtheInternationalJournalofRockMechanics&MiningSciencesThreeGorgesDamonYangzeRiver第24頁LastweekIwasatJinPingIIhydroelectricprojectontheYalongRiverTunnelswillhaveoverburdenof2,500mandsohighstressesandrockspalling第25頁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Itisessentialforrockengineeringtounderstandthegeologyataprojectsite,forexampleattheJinPingIIsite第27頁

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

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

Atthemoment,weashumanengineersdecidethatweneedarockengineeringfacility,thenwemakepreparations,operateadesignmodel,evaluatetheconsequences,etc.Isitpossiblethatallthiscouldbecomputerisedoneday?Couldthecomputerdecidewhatengineeringfacilitiesarerequired,thenindicatewhatsiteinvestigationisrequired,thenchoosethemostappropriatenumericalmodelfromitslibrary,andthendecideontheoptimalengineeringdesign?第45頁AttendanceatconferencesItwillbeanoptionwhetherweattendaconferencephysicallyorelectronically.Somepeoplewillwishtoattendphysicallybut,withmoreandmorepressureoneveryone’stime,theelectronicattendancewillbepreferredbymanyothers.Thishasmanyadvantages,notleastofwhichisthatonecouldattendmanymoreconferences.第46頁Futuretechnologicaldevelopments...Howlargecanacavernbe?RedwallcavernGrandCanyon,USA第47頁Futuretechnologicaldevelopments...Howlargecanacavernbe?Stressconcentrationisindependentofexcavationsize.So,inanunfracturedrockmass,thecaverncouldbeanysize. 100m,1000m?第48頁Willwebecomeanybetteratpredictinghazardsandfailure?第49頁PorteauBluffonHighway99NorthofVancouver,CanadaCharacterizingthefracturesatasiteCivilengineering第50頁Mt.Tai:"thefirstamongthefivesacredmountainsofChina"and"thefirstmountainunderheaven".第51頁FailureofalargerockwedgeattheTeutonicBoreMine,WesternAustraliaMiningengineering第52頁Theengineermusthaveapredictivecapabilityfordesign,andthatpredictivecapabilitycanonlybeachievedifthekeyfeaturesoftherockrealityhaveindeedbeencapturedinthemodel.Issuesofspecialdifficultyandimportanceinnumericalmodellingarethefollowing: ·Systematicevaluationofgeologicalandengineeringuncertainties ·Understandingandrepresentationoflargerockfractures ·Quantificationoffractureshape,size,connectivityandeffectof fractureintersectionsforDFNandDEMmodels ·Representationofrockmasspropertiesandbehaviourasan equivalentcontinuumandexistenceoftheRepresentativeElemental Volume(REV) ·Representationofinterfacebehaviour ·Scaleeffects,homogenizationandupscalingmethods ·Numericalrepresentationofengineeringprocesses,suchas excavationsequence,groutingandreinforcement ·TimeeffectsfromLJingandJAHudson(2023)Numericalmet