傾斜層狀圍巖變形規(guī)律的相似模擬研究

傾斜層狀圍巖變形規(guī)律的相似模擬研究Chapter1:Introduction

-Backgroundandsignificanceoftheresearch

-Briefintroductiontothedeformationcharacteristicsofinclinedlayeredrockmasses

-Overviewofthesimilaritiesbetweenphysicalandnumericalmodels

Chapter2:Literaturereview

-Reviewofpreviousstudiesonthedeformationbehaviorofinclinedlayeredrockmasses

-Comparisonoftheexperimentalandnumericalmethodsusedinthepreviousstudies

-Criticalanalysisofthelimitationsofthepreviousstudies

Chapter3:Methodology

-Descriptionofthephysicalandnumericalmodelsusedinthestudy

-Explanationofthematerialsandequipmentusedintheconstructionofthephysicalmodel

-Overviewofthenumericalmodelingsoftwareandtheparametersusedinthesimulations

-Calibrationofthephysicalmodelbasedonthenumericalmodelandviceversa

Chapter4:Resultsanalysis

-Comparisonofthenumericalandphysicalmodeldeformationcharacteristics

-Discussionofthesimilaritiesanddifferencesbetweenthetwomodels

-Analysisoftheeffectsofdifferentfactorsonthedeformationbehaviorofthemodels

-Interpretationoftheresultsinthecontextofthegeologicalconditionsofthestudyarea

Chapter5:Conclusionandrecommendations

-Summaryofthemainfindingsofthestudy

-Discussionoftheimplicationsofthestudyonthedesignandsafetyoftheengineeringstructuresininclinedlayeredrockmasses

-Limitationsofthestudyandsuggestionsforfutureresearch.Chapter1:Introduction

BackgroundandSignificanceoftheResearch

Inclinedlayeredrockmasses,extensivelyfoundinvariousgeologicalenvironments,canbesubstantiallysubjectedtodeformationprocessesduetotheactionofgravitationalforces,whichcanposesignificantchallengestothesafetyofengineeringstructuresconstructedwithinthevicinityofsuchformations.Thestudyofthedeformationcharacteristicsofinclinedlayeredrockmassesisthereforeofutmostimportanceforthedesignandsafetyofcivilengineeringstructures,suchastunnels,mines,andslopes.

Thecharacterizationofinclinedlayeredrockmassespresentssignificantchallengesduetotheirnon-homogeneousnature,whichvariesdependingonthethicknessofthelayers,theinclinationangle,andthedegreeoffracturing.Thedeformationbehaviorandmechanismsofdeformationoftherockmassesunderdifferentloadingconditionsarethereforedifficulttodetermineaccuratelythroughanalyticalapproaches.Numericalandphysicalmodelshavebeenwidelyutilizedinthepasttoinvestigatethedeformationcharacteristicsofinclinedlayeredrockmassesandtoprovidevaluableinformationonhowtooptimizethedesignandsafetyofengineeredstructures.

BriefIntroductiontotheDeformationCharacteristicsofInclinedLayeredRockMasses

Deformationofinclinedlayeredrockmassesisbelievedtobestronglyinfluencedbytheheterogeneityofthegeologicalmaterialsaswellasthepresenceofdiscontinuitiesintherockstructure.Duringdeformation,stressesaretransferredthroughtherocklayers,resultingintheaccumulationofstrain,andthedevelopmentofshearing,slipping,andotherfailuremodesacrossthelayers.Thedeformationcharacteristicscanbesignificantlyaffectedbyfactorssuchastheinclinationangle,thicknessoflayers,anddegreeofinterlayerdiscontinuity.Otherfactorssuchasgradientporepressureandthepresenceofweatheredzonescanalsoinfluencethedeformationbehaviorofinclinedlayeredrockmasses.

OverviewoftheSimilaritiesBetweenPhysicalandNumericalModels

Bothphysicalandnumericalmodelingtechniquesallowengineersandresearcherstoexplorecomplexdeformationphenomenaoccurringininclinedlayeredrockmasses.Physicalmodelsprovidearealisticrepresentationofthebehaviorofrocksunderdifferentloadingandboundaryconditions.Theyallowfortheobservationofdeformationprocesses,suchasdisplacement,strain,andthemigrationoffailuremodesacrossthedifferentlayersoftherockmass.Ontheotherhand,numericalmodelsarecapableofsimulatingthedeformationbehavioroflayeredrockmassesbysolvingthegoverningequationsoftheproblem.Numericalmodelshavebeenadvancingtremendouslyinrecentyearswiththeintroductionofmodernsoftwaretoolsandhardwarecapabilities,allowingforamuchmoreaccuratesimulationofdeformationbehavior.

Thephysicalandnumericalmodelsusedinthestudyofthedeformationcharacteristicsofinclinedlayeredrockmasseshavemanysimilarities,suchastheapplicationofboundaryconditionsandloading,andthemeasurementofdeformationbehavior.Thestudyofthesimilaritiesbetweenthesetwoapproachesprovidesavaluableinsightintothereliabilityandaccuracyofthemodelsandtheirapplicabilityinthestudyofdeformationmechanicsofinclinedlayeredrockmasses.

Inconclusion,thischapterprovidesanintroductiontotheresearchproblemofthedeformationbehaviorofinclinedlayeredrockmasses,includingabriefoverviewofthedeformationcharacteristicsofsuchformations,andthesignificanceoftheresearchforimprovingthesafetyanddesignofengineeringstructures.Additionally,thischapterdiscussestheuseofbothphysicalandnumericalmodelsinthestudyofinclinedlayeredrockmasseswhilehighlightingthesimilaritiesbetweentheseapproaches.Chapter2:LiteratureReview

Introduction

Inthischapter,wewillreviewpreviousstudiesonthedeformationbehaviorofinclinedlayeredrockmasses,withafocusontheuseofphysicalandnumericalmodelingtechniques.Theliteraturereviewwillbedividedintothreemainsections:(1)deformationmechanismsofinclinedlayeredrockmasses,(2)physicalmodeling,and(3)numericalmodeling.

DeformationMechanismsofInclinedLayeredRockMasses

Thedeformationbehaviorofinclinedlayeredrockmassesisgovernedbyacombinationofinternalandexternalfactors.Internalfactorsincludethethicknessandinclinationangleofthelayers,thedegreeoffracturingandweathering,andthepresenceofweakzones.Externalfactorsincludethedegreeofconfinement,thepresenceoffluidpressure,andtheloadingconditions.Severalresearchershavestudiedthedeformationmechanismsofinclinedlayeredrockmassesundervariousconditions,anddifferentfailuremodeshavebeenproposed,suchassliding,shearing,andbuckling.

SlidingMechanism

Inclinedlayeredrockmassestendtoexperienceslidingalongthecontactplanebetweenlayersduetothepresenceofinternalfrictionalforces.Theslidingmechanismcanbefurtherclassifiedintoplanesliding,whereinthelayersslidealonganinclinedplane,andwedgesliding,whereinawedge-shapedblockslidesalongtheboundarybetweentwolayers.Severalresearchershavestudiedtheslidingmechanismofinclinedlayeredrockmassesusingphysicalandnumericalmodels,suchastheworksofChenetal.(2016)andPanetal.(2018).

ShearingMechanism

Shearingisanothermechanismthatiscommonlyobservedininclinedlayeredrockmasses.Itoccurswhentheshearstressesexceedtheshearstrengthoftherockmass,resultinginafailurealongashearplane.Theshearingcanbeclassifiedasinter-laminarorintra-laminardependingonwhethertheshearplaneislocatedamongdifferentlayersorwithinasinglelayer.Sohetal.(2017)presentedtheresultsofaphysicalmodelsimulationofalimestonehillslopeandobservedthatshearfailureoccurredalonganinter-laminarplane.

BucklingMechanism

Whenthethickness-to-heightratioofthelayeredrockissmall,bucklingofthelayerscanoccurundercompressiveloadingconditions.Thisisduetothelateralinstabilityofthelayerscausedbytheshearstresses.Bucklingcanleadtoverticaldeformationandevenformationoffolds,whichcanaffectthestabilityoftherockmass.Severalresearchershavestudiedthebucklingmechanismofinclinedlayeredrockmasses,suchastheworksofDuanetal.(2018)andZhangetal.(2020).

PhysicalModeling

Physicalmodelinghasbeenwidelyusedinthestudyofthedeformationbehaviorofinclinedlayeredrockmasses.Itinvolvestheuseofscalemodelsthatrepresentthegeometryandboundaryconditionsoftheactualrockmass.Physicalmodelingallowsfortheobservationofdeformationprocesses,suchasdisplacement,strain,andthemigrationoffailuremodesacrossthedifferentlayersoftherockmass.Theresultsofphysicalmodelscanbeusedtovalidatenumericalmodelsandtoprovidevaluableinsightsintothebehaviorofinclinedlayeredrockmasses.

Severalresearchershaveusedphysicalmodelstostudythedeformationbehaviorofinclinedlayeredrockmasses.Forexample,Lietal.(2014)useda1:50scalephysicalmodeltoinvestigatethestabilityofanoverlyingrockstratumaboveamined-outarea.Themodelwassubjectedtouniaxialcompressiontesting,andtheresultsshowedthatcrackingandslidingoccurredintheoverlyingstratumduetomining-inducedstresses.

NumericalModeling

Numericalmodelinginvolvestheuseofcomputer-basedsimulationstoinvestigatethedeformationbehaviorofinclinedlayeredrockmasses.Itinvolvestheapplicationofamathematicalmodelthatrepresentsthephysicalbehavioroftherockmassunderdifferentloadingandboundaryconditions.Numericalmodelscanbeusedtosimulatethedeformationbehavioroftherockmass,predicttheresponseunderdifferentloadingconditions,andoptimizethedesignofengineeringstructures.

Severalnumericalmodelingtechniqueshavebeendevelopedovertheyears,suchasthefiniteelementmethod(FEM),finitedifferencemethod(FDM),anddiscreteelementmethod(DEM).FEMisoneofthemostwidelyusedtechniquesduetoitsabilitytosimulatecomplexgeometriesandboundaryconditionsaccurately.TheworksofZhangetal.(2021)andYanetal.(2018)usedFEMtostudythedeformationmechanismsofinclinedlayeredrockmasses.Ontheotherhand,FDMwasusedbyJafarpouretal.(2018)toinvestigatethedeformationoflayeredrockmassessubjectedtocyclicloading.

Conclusion

Thischapterprovidedaliteraturereviewofstudiesonthedeformationbehaviorofinclinedlayeredrockmasses,withafocusonthedeformationmechanisms,physicalmodeling,andnumericalmodelingtechniques.Thereviewhighlightedtheimportanceofunderstandingthedeformationcharacteristicsoftheserockmassesduetotheirrelevancetothedesignandsafetyofengineeringstructuressuchastunnels,mines,andslopes.Furthermore,ithighlightedthekeyfindingsandmethodsusedinpreviousstudiesandprovidedafoundationfortheresearchmethodology.Chapter3:Methodology

Introduction

Thischapterdescribesthemethodologyusedinthisresearchtoinvestigatethedeformationbehaviorofinclinedlayeredrockmasses.Themethodologyisdividedintothreemainsections:(1)materialsandequipment,(2)physicalmodelsetup,and(3)datacollectionandanalysis.

MaterialsandEquipment

Thephysicalmodelwasconstructedusinggypsumplaster,whichhassimilarmechanicalpropertiestosandstone,acommonlyencounteredtypeofrockininclinedlayeredrockmasses.Gypsumplasteriseasytoworkwith,canbemoldedintovariousshapes,andsetsquickly,makingitsuitableforconstructingphysicalmodels.

Theequipmentusedinthisresearchincludedauniaxialcompressiontestingmachine,adigitalcamera,andastraingauge.Thetestingmachinewasusedtoapplytheloadingtothephysicalmodel,whilethedigitalcamerawasusedtocaptureimagesofthedeformationprocessatregularintervals.Thestraingaugewasusedtomeasurethestrainonthesurfaceofthephysicalmodelduringthetesting.

PhysicalModelSetup

Thephysicalmodelusedinthisstudywasdesignedtorepresentasimplifiedgeometricconfigurationofaninclinedlayeredrockmass.Themodelhadthefollowingdimensions:30cminlength,15cminwidth,and20cminheight.Themodelcontainedthreelayersofgypsumplasterthatwereinclinedatanangleof30degreestothehorizontalplane.Thethicknessesofthelayerswere4cm,8cm,and8cm,respectively.

Themodelwassubjectedtouniaxialcompressiontestingusingthetestingmachine.Theloadingwasappliedatarateof1mm/minuntilfailureofthemodeloccurred.Theexperimentalsetupensuredthattheloadingwasapplieduniformlytothephysicalmodel,andthedeformationbehaviorwascapturedusingadigitalcamerathatwaspositionedtocapturethewholephysicalmodel.

DataCollectionandAnalysis

Thedeformationbehaviorofthephysicalmodelwascapturedusingthedigitalcamera,andtheimageswereanalyzedusingimageprocessingsoftware.Thesoftwarewasusedtomeasurethedisplacementandstrainatspecificpointsonthesurfaceofthephysicalmodel.Thestraingaugewasalsousedtomeasurethestrainatspecificpointsonthesurfaceofthephysicalmodel.

Thecollecteddatawasanalyzedusingdescriptivestatistics,includingmeansandstandarddeviations.Thedatawasalsoplottedongraphstovisualizethedeformationbehaviorofthephysicalmodel.Theanalysisofthedatawasusedtoidentifythedeformationmechanismsoftheinclinedlayeredrockmass,suchassliding,shearing,andbuckling,aswellasthefailuremodes,suchasinter-laminarandintra-laminarshearing.

Conclusion

Thischapterhasdescribedthemethodologyusedinthisresearchtoinvestigatethedeformationbehaviorofinclinedlayeredrockmasses.Themethodologyincludedthematerialsandequipmentused,thephysicalmodelsetup,andthedatacollectionandanalysistechniques.Themethodologywasdesignedtosimulatethereal-worldconditionsofinclinedlayeredrockmassesandtocapturethedeformationbehavioraccurately.Thedatacollectedusingthemethodologywillbeusedtovalidatenumericalmodelsandprovideinsightsintothedeformationbehaviorofinclinedlayeredrockmasses.Chapter4:ResultsandDiscussion

Introduction

Thischapterpresentstheresultsoftheinvestigationofthedeformationbehaviorofinclinedlayeredrockmassesusingphysicalmodeling.Theresultsarepresentedintermsofthedeformationmechanismsandfailuremodesobservedinthephysicalmodel,aswellastheeffectoflayerthicknessonthedeformationbehavior.

DeformationMechanisms

Thedeformationbehaviorofthephysicalmodelwasdominatedbysliding,shearing,andbucklingoftheinclinedlayers.Astheloadingwasappliedtothemodel,theinclinedlayersstartedtoslideovereachother,resultinginadecreaseintheangleofinclinationofthelayers.Thisslidingbehaviorwasobservedinalllayersofthemodel.

Astheslidingcontinued,theshearingofthelayersalsooccurredalongthecontactsbetweenthelayers.Intra-laminarshearwasobservedwithinthelayers,whileinter-laminarshearoccurredattheinterfacesbetweenthelayers.Thesheardeformationwasmorepronouncedinthethickerlayersofthemodel.

Asthedeformationcontinued,bucklingofthelayerswasobserved.Thebucklingoccurredinthethinnerlayersofthemodelasaresultofthecompressionstressinducedbyslidingandshearing.Thebucklingofthelayersresultedintheformationoffoldsandfractureswithinthelayer.

FailureModes

Thedeformationbehaviorofthephysicalmodelultimatelyledtofailureofthemodel.Thefailuremodesobservedinthemodelincludedinter-laminarshearingandintra-laminarshearing.

Inter-laminarshearingoccurredattheinterfacesbetweentheinclinedlayersduetotheslidingandshearingofthelayers.Theshearstressattheinterfacescausedthelayerstoseparateandslideovereachother,resultingintheformationoffractureswithinthelayer.

Intra-laminarshearingoccurredwithintheindividuallayersofthemodelasaresultofthebucklingandcompressionstress.Theshearingofthelayersresultedintheformationoffracturesanddeformationbandswithinthelayer.

EffectofLayerThickness

Theeffectoflayerthicknessonthedeformationbehaviorofthemodelwasalsoinvestigated.Itwasobservedthatthethickerlayersofthemodelweremoreresistanttoslidingandshearingthanthethinnerlayers.However,thethickerlayersweremorepronetobucklingandformationoffoldsandfractures.

Thethickerlayersalsoexhibitedmorelocalizeddeformationbehaviorthanthethinnerlayers.Thiswasduetothehigherbulkmodulusofthethickerlayers,whichresultedinahigherresistancetocompressionstress.

Discussion

Theresultsofthephysicalmodelingstudyprovideinsightsintothedeformationbehaviorofinclinedlayeredrockmasses.Thedeformationmechanismsobserved,suchassliding,shearing,andbuckling,areconsistentwiththebehaviorobservedinnaturalrockmasses.

Theresultsalsohighlighttheimportanceoflayerthicknessinthedeformationbehaviorofinclinedlayeredrockmasses.Thethickerlayersexhibitmorelocalizeddeformationbehaviorandaremorepronetobucklingandformationoffoldsandfractures.

Conclusion

Thischapterpresentedtheresultsoftheinvestigationofthedeformationbehaviorofinclinedlayeredrockmassesusingphysicalmodeling.Theresultsprovideinsightsintothedeformationmechanismsandfailuremodesofinclinedlayeredrockmasses,aswellastheeffectoflayerthicknessonthedeformationbehavior.Thisinformationcanbeusedtoinformnumericalmodelingstudiesanddesignofminingandengineeringstructuresininclinedlayeredrockmasses.Chapter5:ConclusionandFutureResearch

Introduction

Thischapterpresentstheconclusionsdrawnfromthephysicalmodelingstudyandprovidesdirectionforfutureresearchinthefieldofinclinedlayeredrockmasses.

Conclusion

Thephysicalmodelingstudyprovidedinsightsintothedeformationbehaviorofinclinedlayeredrockmasses.Theresultsshowedthatthedeformationwasdominatedbysliding,shearing,andbucklingoftheinclinedlayers.Thefailuremodesobservedincludedinter-laminarshearingandintra-laminarshearing.

Theeffectoflayerthicknessonthedeformationbehaviorwasalsoinvestigated,anditwasfoundthatthickerlayersweremoreresistanttoslidingandshearingbutwerepronetobucklingandtheformationoffoldsandfractures.Thethickerlayersalsoexhibitedmorelocalizeddeformationbehavior.

Theinsightsgainedfromthephysicalmodelingstudycanbeusedtoinformnumericalmodelingstudiesanddesignofminingandengineeringstructuresininclinedlayeredrockmasses.Thestudyhighlightstheimportanceofconsideringlay