2413Vol.24No.1320057ChineseJournalofRockMechanicsandEngineeringJuly20052004032420040512(50204010)(04232)(03JTY2005)(1971)1992E-mailxhfdyl@sohu.comFLAC2D1212(1.4112012.221008)FLAC2DO241A10006915(2005)13230406RESEARCHONCOUPLINGLAWSBETWEENEMEANDSTRESSFIELDSDURINGDEFORMATIONANDFRACTUREOFMINETUNNELEXCAVATIONBASEDONFLAC2DXIAOHong-fei1HEXue-qiu2FENGTao1WANGEn-yuan2(1.SchoolofEnergyandSafetyEngineeringHunanUniversityofScienceandTechnologyXiangtan411201China2.SchoolofEnergyScienceandEngineeringChinaUniversityofMiningandTechnologyXuzhou221008China)AbstractThedistributionlawsofstressfieldsinthecourseofminetunnelexcavationaresimulatedbymeansofFLAC2Dsoftware.Accordingtothestressvaluesandthecouplinglawsbetweenelectromagneticemission(EME)andstressfieldsduringthedeformationandfractureofcoalorrockthechanginglawsofEMEduringminetunnelexcavationarealsoresearched.Theresearchingresultsshowthattheelectromagneticemissionsignalshavethebiggestvalueinthemiddleoftunnel.ThemonitoredEMEvaluesareveryvariedunderdifferentloadingstresses.ThehighertheloadingstressisthestrongertheEMEsignalproducedis.TheEMEvaluesreceivedinthedetectingplacewilldecreaseinlinewithpowerraterelationwiththeincreasingofEMEfrequency.AnditisfeasibletoregardthestressconcentratingareaasEMEresources.TheEMEinthesamemonitoringplaceincreasesfirstlyandthenincreasesslightlywiththeincreaseoftime.ThechangingofEMEstrengthreflectsthechangingofinnerstressafterexcavation.TheexperimentalresultsofEMEhavethesamechangingtendencyasthesimulatedresultswhichalsotestifythefeasibilityofthecouplingmethodbetweenEMEandstress.Thusitisofferedakindofnewresearchapproachtoelectromagneticemissionmonitoringtechnologyforthepurposeoftheapplicationof2413.FLAC2D•2305•monitoringEMEinthepredictionofcatastrophedynamicphenomenasuchascoalorrockoutbursts.Keywordsnumericalanalysisdeformationandfractureofcoalorrocktunnelexcavationelectromagneticemission(EME)couplesbetweenEMEandstressstressfields1[16][7]FLAC22.1FLAC2DFLAC(fastLagrangiananalysisofcontinua)Itasca6a1992ANSYSADINA(1)(2)(3)(FISH)(4)(5)FLAC[810]FLAC10(1)(2)(3)(4)(5)(6)(7)Mohr-Coulomb(8)(9)(10)2.2FLAC2DMohr-Coulomb41/262m48m()4m3m()5006007008009001000m1(kGE′cϕσ1Table1Mechanicalpropertiesofcoalandrock/mk/GPaG/GPaE′/GPac/MPaϕ/()σ/MPaρ/(kNm3)152.41.23.101.00322.02400310.02.26.151.00301.51300152.41.23.101.00322.02400155.33.28.001.56355.02500•2306•2005ρ)15Hσ151(H=600mσ=15MPa)Fig.1Isolineofstressalongtunnelwall(H=600mσ=15MPa)2(H=600mσ=15MPa)Fig.2Changeofstressindepthoftunnelwall(H=600mσ=15MPa)3(H=600mσ=15MPa)Fig.3Plasticareaalongtunnelwall(H=600mσ=15MPa)664(H=800mσ=36MPa)Fig.4Plasticareaalongtunnelwall(H=800mσ=36MPa)5(H=1000mσ=25MPa)Fig.5Isolineofstressalongtunnelwall(H=1000mσ=25MPa)6Fig.6Peakstresspositionvs.excavationdepthandstressFLAC2D33.1[11]/m/m/m/Pa/m/m/m/m/m/m024681012050010001500/m/mσ=1.0σ0σ=1.2σ0σ=1.8σ0σ=1.5σ02413.FLAC2D•2307•εεεd+1σσσσd+∫+==εεεϕd0d)(xxNNσεσσεσσεσσσdexp0311031d00−−−−+∫mmEEmN(1)Nεεεd+N031σσ0εmWeibull)(xϕεm=1==32σσconst==32σσ01σ)1(1σ)2(1σ(1)−++⋅⋅⋅++=−−])2()2()2([0111111aaaaNnnnnσσσ])1()1()1([0111111aaaannnn++⋅⋅⋅++−−σσσ(2))1()2(11σσσ−=∆(2)0111aaaaNnnnn+∆+⋅⋅⋅+∆+∆=−−σσσ(3)n0111m)(bbbbfEnnnn+∆+⋅⋅⋅+∆+∆==−−σσσσ(4))(i23imee)(eertrrtdcbaEEβωαγωσσσ−−−+++==(5)mEσabcdEαεµσω−+=εωσεµωα222(6)3.23.2.120m40m3mEME1.05EME7H=600mf=500kHz0.01s/m6EMEa=0.0012b=0.0313c=0.5400d=8.54497(4%8%)7EMEFig.7ComparisonofsimulatedEMEvalueindifferentcalculationranges3.2.281213(0100002000030000400000246/104EME(a)050001000015000200002500030000350000102030/MPaEME(b)•2308•20058EMEFig.8EMEdistributioncurvealongtunnelheight9EME(z=1.5m)Fig.9EMEstrengthvs.frequency(z=1.5m)10EME(z=1.5mf=100kHz)Fig.10EMEstrengthvs.loadingstress(z=1.5mf=100kHz)11EME(σ=1.5σ0)Fig.11EMEstrengthvs.frequency(σ=1.5σ0))(1)8EME(z)12EME(σ=1.0σ0)Fig.12EMEstrengthvs.frequency(σ=1.0σ0)13()Fig.13Loadingstressvs.time(simulatedresults)(2)9100kHzEME500kHz34(3)910EME(4)EMER0.991112(5)13EME144(1)FLAC2D52005250530053505400545055005550560001234/mEME020000400006000080000100000050010001500/kHzEMEσ=1.0σ0σ=1.2σ0σ=1.5σ0σ=1.8σ00200004000060000800001000000102030/MPaEME0102030400246/104/MPay=901888x0.6486R2=0.981401000020000300004000050000050010001500/kHzEMEy=347286x0.677R2=0.983505000100001500020000050010001500/kHzEME2413.FLAC2D•2309•14()Fig.14Loadingstresslevelvs.time(experimentalresults)(2)FLACEMEEME(3)(References)[1].[J].200019(5)470473.(LiuMingjuHeXueqiu.Characteristicsofelectromagneticresponseofoutburstspronecoal[J].JournalofLiaoningTechnicalUniversity200019(5)470473.(inChinese))[2]WangEYHeXQLiuZT.Thefractalruleofelectromagneticemission(EME)duringcoalorrockdeformationandfracture[A].InProceedingsofthe′98InternationalSymposiumonSafetyScienceandTechnology[C].[s.l.][s.n.]1998.356361.[3].[][D].1997.(WangEnyuan.Studyonelectromagneticandacousticemissioneffectduringfractureofcoalorrockcontaininggasanditsapplication[Ph.D.Thesis][D].XuzhouChinaUniversityofMiningandTechnology1997.(inChinese))[4]NieBSHeXQWangEYetal.Macroandmicro-mechanismofeffectofEMEonCBMadsorptionincoal[A].InFirstMineEnvironm