软岩巷道破裂围岩锚固体承载特性及工程应用研究

博士StudyofBearingCharacteristicofSoftandFracturedRoadwaySurroundingRockAnchorageUnitanditsApplicationsin作者：孟波导使位的使用按照学校的管理规定处理：作为申请的条件之一，著作权拥有者须所在学校拥有的部分使用权，即：①学校馆和馆保留的纸质版和，可以使用影印、缩印或扫描等保存和汇编；②为教学和科研目的，学校馆生阅读、浏览。另外，根据有关，同意中国国家馆保存。（的在后适用本书作者签名 导师签名 公中国矿业大博StudyofBearingCharacteristicofSoftandFracturedRoadwaySurroundingRockAnchorageUnitanditsApplicationsin 孟 靖洪 申 工学博 培养单位力学与建学科专业桥梁与隧道工程 评阅人二○一三年十二审阅认孟波 在规定的学习年限内，按照培养方案的要求完成了课程的学习，成绩合格；在指导下完成本,经审阅，中的观点、数据、表述和结构为我所认同，撰写格式符合学校的相关规定，同意将本作为申请送评审。导师签字 致。试，，生神时授、教授、许国安、陈坤福、超在选题和完感谢课题组老师蔚立元老师老师、王文龙老师VuDucQuyet博浩、戴、刘玉田、、、、硕及同窗博士在试验和生活中给予的关心和帮助！感谢各位、教授在百忙之中对的审阅与指教摘破裂围岩锚固结构的形成条件及其承载能力对于力巷道围岩稳定性控制问题具获得了以下成果和结论：及锚固体受压破坏过力学边界条件的模拟与控制；配制了符合破裂岩体力学特性、满通过模拟实际巷道开挖和返修过围岩应力路径预制了破裂岩体。在此基础FLAC3D计算模型中，获得了巷道破裂围岩组合拱承载能力及其对围岩应力场演近岩体破裂形态以及锚固体应力分布情况的研究，获得了锚杆控制区范围形态及演化证了结论的合理性和实用性。特耗散Theformingconditionsandbearingcapacityarevitaltostabilitycontrolofroadwaysurroundingrockwithhighstress.Researchmethodssuchasphysicalmodeltest,numericalcalculation,theoreticalysisorengineeringapplicationverificationwereappliedtothesystematicresearchofmutualinfluentialmechanismoffracturedrockmassandanchorbolts.Mainresultsandconclusionareasbelow:"Largescalethree-dimensionalanchorageunitmechanicalmodeltestbed"wasdevelopedandimproved,whichcouldsimulateandcontrolmechanicalboundaryconditionsoftheprocessesofprefabricatedfracturedrockmassandfailureofanchorageunitduetocompression.AnchorageunitsimilarmodelmaterialwhiettherequirementoflargeratioofsimilitudeandhadintegralityafterfailureforfractureobservationandfragmentstatisticwasFracturedrockmasswasprefabricatedbysimulatingstresspathofroadwayexcavationandrepairmenprocess,atthebaseofwhich,largescaletriaxialfracturedsurroundingrockanchorageunitmodeltestwascarriedoutunderconditionsofdifferentsurroundingrockinitialfissuredegree,differentanchorboltpretighteningforceanddifferentanchorboensity.Thevariationoffracturedsurroundingrockanchorageunitstrengthalongwithanchorageconditionswasobtained.Influentialruleofdifferentanchorageconditionstoanchorageunitstrength,deformation,failure,fractalandenergydissipationcharacteristicswasdiscussed,whichofferedanimportantfoundationtofollowingstudyofanchoragestructurebearingcharacteristic.TheevolutionruleofanchorageunitbasicmechanicalparameteralongwithplasticstrainwasgainedbynumericalinversionandfinallyimplantedinFLAC3Dcalculationmodel,fromwhichroadwayfracturedsurroundingrockcombinedsupportingarchbearingcapacityandthelawofitsinfluencetosurroundingrockstressfieldwereobtained.Combinedsupportingarchbearingcapacity,innerandouterstressdistributionandpeakstressshiftinglawunderthedifferentanchoringconditionfromnumericalcalculationwereyzed.Theeffectlawofanchoringconditionandthicknesstocombinedsupportingarchbearingcapacityandoutersurroundingrockstabilitywasobtained.Theoreticalysismodelsofroadwaysurroundingrockanchoragestructurewereestablished.Basicconditionofcombinedsupportingarch(beam)formationandultimatebearingcapacityexpressionsofstructureinstabilityorstrengthfailurewereobtained.Theformandevolutionlawofanchorboltcontrollingzonewereobtainedwiththestudyoffracturingshapeofrockmassaroundanchorboltplateandanchorageunitinnerstressdistributionfromanchorageunitphysicalmodeltest.Basicformingconditionandfailurepatterncriteriaofcombinedsupportingarch(beam)wasproposed,whichprovidedtheoreticalfoundationforfracturedsurroundingrockanchoragestabilitycontrol.Finally,basedontheaboveresearch,therationalityandpracticabilityofresearchconclusionsofthisdissertationwereverifiedbytypicalrepairingengineeringoflargesectionroadwaywithsoftandfracturedsurroundingrock.Thisdissertationincludes129figures,14tablesand215:softrockroadway;fracturedsurroundingrock;anchorageunit;combinedsupportingarc(beam);bearingcharacteristic;energydissipationAccordingtothebearingcharacteristicofanchorageunitofsoftandfracturedroadwaysurroundingrock,researchmethodssuchasphysicalmodeltest,numericalcalculation,theoreticalysisandengineeringapplicationverificationwereappliedtothesystematicresearchofstrength,deformationandfailurecharacteristicsoffracturedroadwaysurroundingrockanchorageunit.Thebearingmechanismoffracturedsurroundingrockcombinedsupportingarchwasdiscussed.Mainresultsandconclusionsareasbelow:"Largescalethree-dimensionalanchorageunitmechanicalmodeltestbed"wasdevelopedandimproved,whichcouldsimulateandcontrolmechanicalboundaryconditionsoftheprocessesofprefabricatedfracturedrockmassandfailureofanchorageunitduetocompression.AnchorageunitsimilarmodelmaterialwhiettherequirementoflargeratioofsimilitudeandhadintegralityafterfailureforfractureobservationandfragmentstatisticwasFracturedrockmasswasprefabricatedbysimulatingstresspathofroadwayexcavationandrepairmenprocess,atthebaseofwhich,largescaletriaxialfracturedsurroundingrockanchorageunitmodeltestwascarriedoutunderconditionsofdifferentsurroundingrockinitialfissuredegree,differentanchorboltpretighteningforceanddifferentanchorboensity.Thevariationoffracturedsurroundingrockanchorageunitstrengthalongwithanchorageconditionswasobtained.Influentialruleofdifferentanchorageconditionstoanchorageunitstrength,deformation,failure,fractalandenergydissipationcharacteristicswasdiscussed,whichofferedanimportantfoundationtofollowingstudyofanchoragestructurebearingcapacity.①Fracturedrockmasswerewasobtainedbycontrollingtestconditionsofunloadingspeed,boundaryforce,loadingandunloadingtimesandaxialdeformation.Becauseboundaryconditionandstresspathofprefabricatedfracturedrockmasssimulatedtheactualroadwayexcavationandrepairment,theattitudeanddistributionlawoffissureinprefabricatedrockmassarebasicallyidenticaltotrueroadwayfracturedsurroundingrock.②Thedeformationandfailureprocessoffracturedsurroundingrockanchorageunitisthere-failureprocessofinnerblocks.Thenewinnerfissureofanchorageunittendstobesheartype.Thetrendofmainfissureisparalleltoσ2.Thenewblockswhoseshapeistabularslidalongthefissuresurface.Themoreintactthatanchoringrockmassinitialfractureddegreeis,themoreconcentratedthefissureisdistributed,thebiggerthatfragmentisandthemoreeasilythattherockmassentirestrengthis.Thebiggerthattheanchorboltspre-stressisandthethattheanchorboensityis,themoreevenlythatfissureisdistributed.EventuallyanchoryAeB(xr0)mThethicknessexpressionofanchoragestructurecompressivezoneinidealsituationisasmh

2AeB(l0/2r0)

/③Thestrengthoffracturedrockmassisthebasisofthestrengthofanchorageunitwhileanchorboltpretighteningforceisthepreconditionofreachingfullpotentialoffracturedrockmassstrength.Theanchorageunitmechanicalpropertycurvefromsinglepeakstylewhenanchorboltpre-stressis0kN,idealelastic-plasticstylewhenthereismorethan3anchorboltsandisdoublepeaksstyleunderothercircumstances.WheninitialanchoringrockmassfractureddegreeishigherthanⅢ,anchorboltpretighteningforceisnot0kNandthereisonlyoneanchorbolt,thedifferenceofelasticitymodulusbetweenanchorageunitsissmall.Mostoftheelasticitymodulusofanchorageunitisabout155.3~173.3MPaanddecreasesquicklywhenanchorageunitmechanicalpropertycurveappearpre-peaksoftencharacteristicasanchorboensityincreases.Whenanchorboltpre-stressismorethan7.5kN,teralizedcohesionofanchorageunitsisallhigherthanthatofintactrock,whichshowsthatanchorboltcansufficientlymotivatefracturedrockmassstrength.④Thefailureprocessofanchorageunit panieswithenergydissipationandvariationoffractaldimension.Themorefragmentizedthattherockmassisunderthesameanchoringsituation,thesmallerthattheD-valueoffractaldimensionbeforeandafterfailureoffracturedsurroundingrockanchorageunitis,thehigherthattheratioofenergydissipationis,theworsethattheintegrityofanchorageunitisandtheeasierthatinnerblockstendtoslidwitheachthanre-failure.TherearepositivecorrelatedrelationshipsbetweenD-valueoffractaldimension,ratioofenergydissipationofanchorageunitandanchorboltpre-stress.Thehigherofanchorboltpre-stress,themorethatthefissureinnerandouteranchorageunitisandthemorecompletethatthere-failureofblockis.TheD-valueoffractaldimensionofdrillingholeandfragmentandratioofenergydissipationarelessaffectedbyanchorboensitywhenthenumberofanchorboltisnolessthan2.TheevolutionruleofanchorageunitbasicmechanicalparameteralongwithplasticstrainwasgainedbynumericalinversionandfinallyimplantedinFLAC3Dcalculationmodel,fromwhichroadwayfracturedsurroundingrockcombinedsupportingarchbearingcapacity,thelawofitsinfluencetosurroundingrockstressfieldandtheinfluenceofdifferentanchoringconditionswereyzed.Conclusionsareasbelow:afterexcavationofroadwaywheretheshearslip-linefieldwhichiscomposedoftwofamiliesofobliquecrossingconcentriclogarithmicspiralswhichhadthesamepoleinthecenteroftheroadwayandotherparametersexceptfordifferentdirectionofrotationappears.Thereisslipanddiastrophismdeformationofblocksinsurroundingrock.Thestructureeffectwhichcomesfrom,compression,frictionandocclusionbetweenshearwedgesmakessurroundingrockhavesomeresidualstrengthandnotfallimmediayalthoughfullofsliplinefield.②Thesurroundingrockfailsfromshallowtodeeppositionstepbystepafterexcavationofroadway.Anchoragestructureworksliketunnelliningstructure.Comparedwithnon-supportroadway,peakstrengthandpostpeakresidualtangentialandradialstressarehigh,thebrokenanddisturbedareainanchoringsurroundingrockissmallandthelocationofmainstressbearingzoneisshallow.Thelessofsurroundingrockinitialfractureddegreeandthemoreofanchorpre-stress,densityandthicknessofanchoragestructure,themoreobviouseffectthatanchoragestructurecanafford.③Themoreintactofsurroundingrock,thehigherthatthepeakstressofmainzoneis,themoreconcentratedthatmainbearingzoneisandmoreeasilyaffectedbythefailureofanchoragestructure.Thesurroundingrockwhoseradialstressofaroundanchoragestructuredecreasesquicklybutnotto0MPaoncetheanchoragestructurefailscanoffersupportforoutermainbearingzone,whichshowsthatthefailureofanchoragestructureisnotthesufficientconditionofmovingtodeepersurroundingrockofmainbearingzone.Roadwaysurroundingrockanchoragestructuretheoreticalysismodelswereestablished.Anchoragestructureshearfall,rotationbucklingandshearslipfailurecriteriaandultimatebearingcapacityexpressionwerestudied.Combinedwithanchorboltcontrollingzoneformandinnerstressdistributionlaw,thebasicformingconditionofcombinedsupportingarch(beam)andfailurepatterncriterion.Theresultsareasbelow:①Thelimitedbearingcapacityofanchorageunitwhichissimplifiedintoanarcstructureattheconditionofrotationbucklingisas*2hsin1cos22cos1cos12hsin2cosq

sin2

②Thelimitedbearingcapacityofanchorageunitattheconditionofshearfallisasq

8cl h③Surroundingrockandanchoragestructurelimitedbearingcapacityexpressionandconditionofstabilityofoutersurroundingrockareasbelow: q(p)e2() ''2('''2((p)e2 ''2('''2( ④Thebasicconditionofformationofanchoragestructureisas'qMin' sin2 ，4l/hl/h2tanResearchresultsofthisdissertationweresuccessfullyappliedtotherepairmentoflargesectionroadwaywithrepeatedandlargescaledeformationandfailureofsoftandfracturedsurroundingrock,whichverifiedthepracticabilityofresearchconclusionsofthisdissertation.Thisdissertationincludes129figures,14tablesand215:softrockroadway;fracturedsurroundingrock;anchorageunit;combinedsupportingarc(beam);bearingcapacity;energydissipation目.............................................................................................................................................. 图表........................................................................................................................................变量注释 绪 问题的提出及研究意 国内外研究现 主要研究内容与方 大比尺三维锚固体力学模型试验系统及破裂试样的研 模型试验系统简 破裂试样的研 模型试验设计以及模型材料力学试 本章小 不同锚固条件对破裂围岩锚固体承载特性影响规律研 锚固岩体再破坏特征分 岩体初始破裂程度对锚固体承载特性的影 锚杆预紧力对锚固体承载特性的影 锚杆密度对锚固体承载特性的影 锚固条件对锚固体承载特性影响规律小 破裂围岩锚固体变形破坏分形及能量耗散特征研 本章小 破裂围岩组合拱承载性能数值计算研 破裂围岩锚固岩体本构关系数值反演及计算模型的建 巷道围岩剪切滑移破裂演化规律分 组合拱承载结构对围岩支护作用分 锚固条件对破裂围岩组合拱承载特性影响规律研 本章小 破裂围岩组合拱（梁）承载能力及稳定性判 破裂围岩组合拱（梁）稳定性分 组合拱承载能力滑移线场理论研 组合拱（梁）形成的基本条件及失效形式判 本章小 工程应 巷道工程地质条 巷道变形破坏情况及原因分 锚固支护参数的确 支护效 本章小 结论和展 结 展 参考文 作者简 性..........................................................................................................................数 Listof Listof Listof ProblemIntroductionandResearch DomesticandOverseasResearch MainResearchContentsand DevelopmentofBigScaleThree-dimensionalAnchorageUnitMechanicalModelTestSystemandFractured BriefIntroductionofModelTest DevelopmentofFractured DesignofModelTestandModelMaterialMechanical Chapter ResearchofInfluenceLawofDifferentAnchorageConditionstoFracturedSurroundingRockAnchorageUnitBearing ysisofRe-failureCharacteristicofAnchoringRock TheInfluenceofRockMassInitialFissureDegreetoAnchorageUnitBearing TheInfluenceofPretighteningForceofAnchor TheInfluenceofDensityofAnchorBolttoAnchorageUnitBearing ConclusionsofInfluenceLawofAnchoringConditionstoAnchorageUnitBearing StudyofFractalandEnergyDissipationCharacteristicofDeformationandFailureofFracturedSurroundingRockAnchorage Chapter NumericalCalculationResearchofFracturedSurroundingRockCombinedSupportingArchBearingCharacteristic ConstitutiveRelationNumericalInversionandEstablishmentofCalculationModelofRoadwayFracturedSurroundingRock ysisofRoadwaySurroundingRockShearSlipFailureDevelo ysisofSupportingEffectofCombinedSupportingArchtoSurrounding ResearchofInfluentialLawofAnchorageConditionstoBearingCharacteristicofFracturedSurroundingRockCombinedsupporting Chapter ResearchofFracturedSurroundingRockCombinedSupportingArch(Beam)BearingCapacityandStability ysisofCombinedSupportingArch(Beam) SlipLineFieldTheoreticalStudyofCombinedSupportingArchBearing GeneralConditionofFormationandFailurePatternJudgementofCombinedSupporting Chapter Engineering RoadwayEngineeringandGeologic DeformationandFailureofRoadwayandCause DeterminationofAnchorageSupport Anchorage Chapter Conclusionsand Author’s Declarationofdissertation Dissertation 图页码1-1FigureFracturesinroadwaysurrounding11-2FigureSurroundingrockslipblocksanddrillcore21-预应力锚杆对砾石的锚固效应（据8FigureAnchoringeffectofpre-stressedanchorboltstogravels（From81-9FigureSketchofcompressionarchofroadwaysurrounding91-FigureTechniquerouteof2-FigureAnchorageunitphysicalmodeltest2-FigureModeltest2-FigureHorizontalstressloading2-YHD-100型位移传Figure2-FigureAnchorboltsin2-FigureUnitstress2-FigureManufactureofanchorageunitinnerstresstest2-FigureMeasurementofanchorageunitrupture2-FigureTestinformationcollection2-FigureCompositionsofsimilar2-FigureFactureprocessoftesting2-FigureWE-1000Amulti-functiontesting2-FigureStress-straincurvesofmodelmaterialuniaxialcompression2-FigureStress-straincurvesofmodelmaterialuniaxialcompression2-FigureFailurepatternsofmodelmaterialafteruniaxialcompression2-FigureTensilestrength2-FigureAffectofsand-cementratioonmechanicalpropertyofsimulation2-Figure2-FigureAffectofconcrete-gypsumratioondeformationpropertyofsimulation2-FigureManufactureflowofthe2-FigureCompletestress-staincurveofprecastfracturedrock2-FigureFissuresurfaceofrock2-FigureCharacteristicoffissuredeveloinprecastfracturedrock2-FigureBoltsandtraysinsimulation2-FigureTriaxialtest2-FigureStress-staincurvesunderdifferentconfiningpressureofsimilar2-FigureFracturedcharacteristicofsamplewithdifferentconfining2-Figure3-FigureFissuresurfacecharacteristicofanchorage3-FigureBlockshapeafterfailureofanchorage3-FigureFracturepatternafterfailureofanchorage3-FigureTime-pressurecurveofanchorageunitwithdifferentinitialrupture3-FigureTheinfluenceofrockmassinitialrupturedegreetoanchoragepeak3-FigureTheinfluenceofrockmassrupturedegreetotheratioofrockmassand3-FigureTheinfluenceofrockmassrupturedegreetoanchorageuniasticity图FigureFailurecharacteristicofanchorageunitwithdifferentinitialrupture3-FigureTime-pressurecurveofanchorageunitwith3-FigureTherelationshipbetweenpretighteningforceandpeak3-FigureTheinfluenceofpretighteningforcetocohesionratioofrockmassand3-FigureRelationshipbetweenpretighteningforceofanchorboltandelasticitymodulusanchorage3-FigureFailurefeatureofanchorageunitwithdifferentanchorboltpretightening3-FigureTime-pressurecurveofanchorageunitwithdifferentanchor 3-FigureTheinfluenceofanchor ensitytopeak3-FigureTheinfluenceofanchorbo ensitytocohesionratiobetweenrockmassandanchorageunit3-FigureTheinfluenceofanchor ensitytoelasticitymodulusofanchorage3-FigureFailurefeaturesofanchorageunitwithdifferentanchorbo3-锚固体裂隙观FigureInnerfractureobservationofanchorage3-FigureFracturedistributionstatisticofanchorageunitbeforeandafterfailure3-FigureThecalculationofanchorageunitcompressionfailuresurfacefissure3-FigureWeighandstatisticof3-FigureDeterminationofscale-free3-FigureTherelationshipbetweeninitialrupturedegreeofrockmassandfractalD-3-FigureTherelationshipbetweenpretighteningforceandfractaldimensionD-value3-FigureTherelationshipbetweenanchorboltsspaceandfractaldimensionD-value3-FigureEnergytransformationintheprocessofanchorageunitdeformationand3-FigureEnergycurveofanchoragebodyincompression3-FigureTheinfluenceofdifferentanchorageconditionstoenergytransformationinprocessofcompressionofanchorage3-FigureTheinfluenceofinitialfailurecharacteristictoanchorageunit3-FigureTheinfluenceofpretighteningforcetoanchorageunitenergydissipation3-FigureTheinfluenceofanchorboensitytoenergydissipation4-FigureIdealizedstress-straincurvesofanchoragebodywithdifferentpostFigure4-RelationshipbetweencohesionandplasticshearFigure4-Comparationofstress-straincurvesofnumericalcalculationandphysicalmodel4-FigureEquivalenttreatmentofanchoredfracturedsurrounding4-FigureCalculation4-FigureFissuremorphologicevolutionaryprocessofroadwaysurroundingrock4-物理模拟试验得到的剪切滑移线场FigureShearslip-linefieldfromphysicalmodel4-Oktyabr'skiiFigureZonaldisintegrationobservedinOktyabr'skiiminein4-FigureIntactandshearingfailuresurroundingrockshapeafterbalance4-Figuretystatisticsofelementswithdifferentfailure4-FigureSurroundingrockshearstrainincrementdistributionindifferent4-FigureThefaultinganddeforming4-FigureDisplacementofgrid4-FigureSurroundingrockradialstrainvariationwithtimeand4-FigureTheinfluenceofrelativemotionmodebetweenslidingblocks4-FigureMomentofroofbouringdifferentexcavation4-FigureTransversedeformationandbreakofanchorboltinrock4-FigureTransversedeformationofroadwayanchor4-FigureSlipandrelativedisplacementof4-FigureFlexuralyielddeformationof4-FigureStresscurveof4-FigureMaxstressevolutionaryprocessofroadwaysurrounding4-FigureStep-stresscurvesofnon-supportingsurroundingrockfrom3.75to4-FigureStep-stresscurvesofsurroundingrockinanchorage4-FigureStep-stresscurvesofnon-supportingsurroundingrockfrom6.5to4-FigureStep-stresscurvesofanchoragesurroundingrockfrom6.5to4-FigureStep-stresscurvesofnon-supportingsurroundingrockfrom10.5to4-FigureStep-stresscurvesofanchoragesurroundingrockfrom10.5to4-FigureStressdistributionbeforeandafterfailureofcombinedsupportingarcwithdifferentinitialfissuredegreeofsurroundingrock4-FigureTheinfluenceofsurroundingrockinitialfissuredegreeoncombinedarcbearing4-组合拱失效后测σθσr变化情FigureVariationofσθandσrafterthefailureofcombinedsupporting4-FigureIntactsurroundingrockcombinedsupportingarcshearingfailureshapeafterfifthandsixthloading4-FigureRelationshipbetweenthetimeofthemostoffailureelementsandfailurecombinedsupporting4-FigureStressdistributionbeforeandafterfailureofanchoragestructuresurroundingrockwithdifferentanchorboltpre-4-FigureTheinfluenceofanchorboltpretighteningforceoncombinedsupportingarc4-FigureStressdistributionofsurroundingrockwithdifferentanchorboltspre-fromthefourthtothesixth4-FigureStressdistributionbeforeandafterfailureofcombinedsupportingarcofsurroundingrockwithdifferentanchorboensity4-FigureStressdistributionbeforeandafterfailureofcombinedsupportingarcdifferent4-FigureTheinfluenceofthicknessofcombinedsupportingarconbearing4-FigureRelationshipbetweenthethicknessofcombinedsupportingarcandmainbearingzonepeakstressposition4-FigureTherelationshipbetweenthetimeofcombinedsupportingarcfailureand5-FigureArcbalancemechanismysisofanchorage5-Figureysisofrotationinstabilityofcombinedsupporting5-FigureStressboundaryconditionofshearslip-linefieldofcircular5-FigureTheaffectofcohesiontoultimaoadoftunnelsurrounding5-FigureTheaffectofsupporttoultimaoadoftunnelsurrounding5-FigureFissurefeatureofrockmassaroundbolt5-FigureFeatureofcompressionzoneofanchorage5-FigureShapedevelopmentofanchorcompression5-FigureSpallingrockpiecesinandoutbolttraycontrolling5-FigureTheinfluenceofrockmassrupturedegreetothefeatureofanchoragecompression5-FigureSuperimposedeffectofcompressingzonebetweenanchor5-FigureAnchorageunitinnerstressdistributionafterpre-tightofanchor5-FigureAnchorageunitinnerstressdistributionwhenthetimeofpeak5-锚固体峰值后应力分FigureAnchorageunitinnerstressdistributionwhenthetimeofresidual5-FigureDeterminationofcombinedsupportingbeaminstability5-FigureTherelationshipbetweencombinedsupportingarcandoutersurrounding6-FigureIngatestratageologic6-FigurePositionofauxiliaryshaft,ingateandsurrounding6-FigureDeformationandfailureof6-FigureHorizontaldisplacementobservationcurveofdeformationofshaftingate6-FigureObservationofdrillinghole6-FigureSupportschemeof6-FigureAssembledsteelgridarchconcrete6-FigurePressureobservationcurveofingatesurrounding2-Uniaxialcompressionstrengthtestresultof2-Tensilestrengthtestresultof2-Controllingrequirementofpre-rupturingrock2-Characteristicsofprecastfracturedrock2-Physicalandmechanicsparametersofprototype2-Physicalandmechanicsparametersofsimilar3-Table3-Summaryofanchorageunitmechanicalparameterstheconditionofdifferentrockmassinitialrupture3-Table3-Summaryofanchorageunitmechanicalundertheconditionofdifferentpretightening3-Table3-Summaryofanchorageunitmechanicalundertheconditionofdifferentanchorbolts3-Table3-Summaryofanchorageunitdrillingholefracturefractal3-Table3-Calculationresultoffracturedsurroundingrockanchoragefailuresurfacefissurefractal3-Table3-Numberoffragmentsandfractaldimensioninscale-freeintervalafterfailureoffissuresurroundingrockmass3-Table3-Energycalculationresultsofanchoredfracturedrockattypicaldeformationstageunderdifferentanchoringconditions4-Table4-Modeledgeloadofdifferentloading

z方向主应力分量yz方向切应力分量xz方向切应力分量x方向应变分量z方向应变分量yz方向应变分量

1

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c 绪问题的提出及研究意义（ProblemIntroductionandResearch巷道围岩稳定性控制伴随着每一条巷道的设计和建设，是除开挖以外人们利用空巷道稳定性问题十分突出。巷道数量、深度的增加以及支护环境的日益复杂直接造成支护难度和成本大大增加。煤矿巷道建设及问题仍然是制约我国煤矿建设和生产为结构以及力学性质上更为复杂的破裂岩体。破裂后的围岩充满了裂隙（图1-1）2嵌固，形成了一定的整体结构强度，使得实际工程现场巷道围岩虽然充满裂隙和破裂块体，（a）2.16m处 （b）1.90m处图1-1巷道围岩中的裂隙Figure1–1Fracturesinroadwaysurrounding 图1-2围岩滑移块体及岩心擦痕Figure1–2Surroundingrockslipblocksanddrillcore组合拱整体承载能力具有决定作用[5-6]，是目前巷道支护研究的重点和难点之一[7-8]。国内外研究现状（DomesticandOverseasResearch力学特性的研究一般可以分为三个方向[9]。第一个方向[10-20]是研究锚固体中锚杆在轴向和横向荷载下的工作模式，包括对组成锚固体每一部分（例如锚杆，托盘、岩体，锚固剂）力学行为的考虑，单根锚杆的力学作用机制是这一方向的研究重点。第二个方向[21-27]则是场或完成的直剪试验研究节理面在锚杆加固作用下的剪切行为。第三个方向是将锚龙，]（0）分别在单轴及三轴条件下对不同锚杆密度和不同节理倾角效应，了锚杆对岩体的约束效应及对岩体内聚力、内摩擦角的影响。研究发现锚杆对侯朝炯，勾攀峰等[39-44]（1998，1999，200，201，2002）只有掌握锚杆对提高围岩峰值强度和残余强度以及改善岩石力学性质的作用才能从根本上揭示锚杆支护的作用机理。通过相似材料模拟试验得出：锚固后的岩体峰值强度和残余强度均得到强化。锚小巷道围岩塑性区、破裂区范围及巷道变形，保持巷道围岩稳定。等[45-46]（2001，2002）通过节理岩体锚固特性相似材料模型试验对三峡船闸高边坡岩体开挖过锚杆支护问题进行了研究。结果表明，节理岩体除泊松比随锚杆及粘结材料厚度对锚固体力学性能的影响，锚杆主要提高了锚固体沿锚杆轴向的承载]]1987李树才，等[57-60]（1996，1997，2003，2006）基于应变能等效假设、自洽理论化方程以及加锚节理面压剪应力状态下分支裂纹扩展的突变模型，对边坡以及硐室锚整体性较好的块体状或整体状岩体锚固结构，在内聚力和内摩擦角不相关假定下按照]在锚固体等效连续模型和离散模型的基础上，等]（2，3，6）引力学性质亦将随之变化，在此基础上建立了洞室锚固岩体的等效力学参数与锚固深度]式模拟砂浆锚杆对某水电站硐室群的锚固效应，研究发现锚固区抗剪强度和刚度的提固体力学特性分析模型，初步形成了锚杆对岩体强化作用影响的，并将之应用于空间稳定性控制工，得到了一些规律性的认识，但理论和数值计算方法中使用的一个稳定的支护体应该具有一定的结构形式和必要的强度。空间围岩既是支的层状结构，可利用锚杆的轴向力以及横向抗剪力将层状岩层组合起来形成组合梁结整体结构强度从而起到围岩控制的作用。RaoulO.Roko等[90]（1983）通过对完整及破坏后3（a）（3（b）律：要形成这种有效的承载结构锚杆长度至少是锚杆间排距的2倍，且锚杆间排距1-3预应力锚杆对砾石的锚固效应（Figure1–3Anchoringeffectofpre-stressedanchorboltstogravels（FromP由图1-3（b如果锚杆在松散破裂岩层中的密度足够大，锚杆共同作用形成的锥体P1-4Figure1–4Sketchofcompressionarchofroadwaysurrounding我国学者[94]（1978）一定间排距条件下，锚杆能提高结构面抗剪强度，将宋宏伟[96]（1997）在分析软岩锚喷支护机理及破坏特征的基础上，组合拱在软岩了研究，认为组合拱承载要与锚杆约束阻力、破裂岩石性质、组合拱厚度和组合拱形破坏特征主要为剪切破坏，无论是圆形、拱形还是平顶梯形巷道锚杆锚固力的作用在力表达式，认为锚注作用范围内的组合拱结构、锚注作用范围外力状态破裂岩体以及破裂范围外处于力状态的完整岩体共同组成了巷道支护结构的承载圈，其中锚注加固厚度及块度越小，锚杆的锚固效果越明显。提出力条件下对层状或层状节理岩体的锚行研究，结果表明：层状结构巷道顶板变形过形成了铰接拱结构，铰接位置应力集中锚杆无法岩层错动也未被剪断，巷道稳定受到一定影响；③岩层坚硬且层间错动王继承等[106]（2006）针对综放大断面沿空留巷围岩稳定性控制问题，采用ANSYS对综放沿空留巷顶板锚固结构中锚杆的剪切变形特征进行了数值计算研究，了锚杆剪切支护在松弛区内形成的承载结构（压缩拱）称之为次承载区，将承担围岩主要荷载的侯朝炯等[110]（2001）针对综放沿空掘巷围岩在回采过的稳定性控制问题，提出了构体系分为关键承载结构、次生加固承载结构以及二者之间的准塑性承载结构。作为部应力峰值点附近，由部分塑性硬化区和软化区煤岩体组成的主承载区称为内结构。等[114]（2010）针对深部软弱围岩的“锚喷网+长锚索”联合支护特点，提出了（锚杆支护（密集型锚索支护共同构成的叠加拱承载体力学模型，将锚固结构看作一种等效耦合围岩，以摩尔准则得出了压缩拱内岩块强度，推导得到了考虑初次支护让压影响的叠加拱承载能力计算公式以及锚固结构力学参数随让压位移变化的关系式。区的大小、分布形态以及应力大小是进行组合拱支护设计的基础。等[31]（1980）通过锚固体强度模拟试验对单体锚杆的控制范围以及锚固体体锚杆对不同条件围岩的控制范围各不相同，必须进行实地的试验和的观测才能提 得到的锚杆控制区形态为倒喇叭形[120-126]王金华等[128]（2008）采用FLAC3D计算模拟了锚索长度、间排距、安装角度及预类似心形的压应力区。压应力在锚索托盘位置最大，围岩锚固点处出现拉应力。锚索岩体力学参数相差，计算中按照岩石力学参数对围岩赋值得结果必然与实际情况差别较大。另岩强度衰减规律以及锚固效果大多假设为某单于塑性极限状态，对问题进行求解。而实际巷道围岩由于应部化会在局部位置产生宏前期研究均对锚固结构在围岩整体稳定过所起的主要作用是保证外部围岩主要承载结构的稳定这一点上达成了共识，但由于试验和测试的限制，以往研重锚杆控制区范围形态及应力分布规律研究较锚杆控制范围为锚杆对破裂围岩的控制范围以及应力分布规律是利用组合拱承化为，锚杆控制角统一设定为45，前期研究虽然认识到岩石强度、结构、预紧力是锚杆控制范围和应力分布的影响因素，但仅仅是定性的、不确定的认识，还未进行过确切的试验验证。主要研究内容与方法（MainResearchContentsand研究的主要内通过模拟巷道开挖卸荷以及后续支护破坏过的围岩应力路径进行破裂岩体预在以上研究成果的基础上，结合锚固体破坏后锚杆托盘压缩范围特征及应力模型试数值计理论分研究结果应用到大断面破裂软岩工程实践中进行检验。研究总体思模型试数值计理论分软软岩巷道破裂围岩锚固支护围锚围锚初不破支程参组围拱应载演分规剪切滑回强结破失破裂围岩锚破裂围岩锚固体承载特性及DevelopmentofBigScaleThree-dimensionalAnchorageUnitMechanicalModelTestSystemandFracturedSamples模