含瓦斯煤岩破裂过程流固耦合数值模拟

2410Vol.24No.1020055ChineseJournalofRockMechanicsandEngineeringMay20052003092920040224(50134040)(5020400350374020)(1975)[e-mail]121212(1.1166222.110004)(RFPA2D)RFPA2DFlowRFPA2DFlow34RFPA2DFlowTD713A10006915(2005)10166707NUMERICALSIMULATIONOFCOUPLEDGASFLOWINFAILUREPROCESSOFGASSYCOAL-ROCKXUTao1TANGChun-an2SONGLi1YANGTian-hong2LIANGZheng-zhao12(1.ResearchCenterforNumericalTestsonMaterialFailureDalianUniversityDalian116622China2.CentreforRockInstabilityandSeismicityResearchNortheasternUniversityShenyang110004China)AbstractBasedonthebasictheoryofcoal-rockdeformationandgasflowincoalandrockformationsconsideringtheheterogeneityofthecoal-rockthenonlinearvariationcharacteristicsofgaspermeabilityandthecoupledfluid-solidinteractionbetweengasflowandsoliddeformationduringthecoal-rockdeformationandfailureprocessanumericalmodel(RFPA2DFlow)oncoupledgasflowincoal-rockformationsduringthefailureprocessofgassycoal-rockisestablishedandthenumericalsolutionmethodforthemodelisalsopresented.ThenusingtheRFPA2DFlowcodethecatastrophicdelayoutburstofcoalandgasinducedbycross-cuttingundergroundcoalmineisnumericallymodeledtoinvestigatethemechanismofcoalandgasoutbursts.Thenumericalsimulationsreproducethewholeprocessoftheinitiationpropagationinteractioncoalescenceofthemicrocracksunderthecombinedactionofgaspressurein-situstressandphysicalandmechanicalpropertiesofcoal-rock.Itisindicatedthatdelayoutburststogetherwithinstantaneousoutburstsarebothcausedbycombinedactionofgaspressurein-situstressandphysicalandmechanicalpropertiesofcoal-rockandtheoutburstsprocesscanbesubdividedintofourphasesnamelystressconcentrationstagecoal-rockfracturingandsplittinginducedbythecombinationsofgaspressureandin-situstresscrackspropagationdrivenbygaspressureandtheabrupt•1668•2005ejectionofcoalandgas.Andsoitofferssometheoreticalbasisandevidencetofurtherinvestigatethemechanismsofgasdrainagetopreventtheoccurrenceofcoalandgasoutburstsinundergroundcollieries.Keywordsminingengineeringgassycoal-rockfailureprocesscoupledgasflowRFPA2DFlowcodenumericalsimulation11/3[1][26](RFPA2D)22.1()[7])(gradPqijiλ−=(1)iq(i=123)(m/d)ijλ(ij=123)(m2/(MPa2d))2pP=p(MPa2)[7]pAX=(2)X(m3/m3)A(m3/(m3MPa1/2))tPPp∂∂=∇2α(3)75.014PAp−=λα2.23[4]0)(=++′jijijijpfδασ(4)jijσ′(321=ji)(MPa)if(MPa)α()01αijδKronecker)(21ijjiuuij+=ε(5)ijε(321=ji)uijijijGεεκδσ2v+=′(6)Gκ+=11vεε3322εε+2410.•1669•(4)(6)[4]0)()(=++++ijjijijpfGuuGiακ(7)2.30)1(EDE−=(8)DEE0ϕϕσσsin1sin131−+−cf(9)ϕcfD−=0c0cr0c10εεεεεEfD(10)crf0cε[8]==−−−−0e0e)(0)(011DDppασβασβξλλλ(11)0λpξαβ(1)tf3σtf−(12)1Fig.1ElasticdamageconstitutivelawforelementunderuniaxialcompressivestressandtensilestressD−=tut0tu0trt0110εεεεεεεεEfD(13)trf=′==−−−−−−1e10e0e)(0)(0)(0333DDDpppσβασβασβλξξλλλ(14)ξ′[910](D=1)2.40σ()RFPA2DFlow[11][12])exp()(0Bt−−+=∞∞σσσσ(15)0σ∞σ2B2Fig.2Relationshipbetweenlong-termstrengthandtransientstrengthofrock•1670•2005[13]RFPA2DFlow(15)(3)(7)(11)(14)(15)3RFPA2DFlow[45]RFPA2DFlow11}]{[}]}{[]{[−−=+∆∆+jjtttPSPStλ(16)][λ][S}{PRFPA2DFlow}{}]{[FK=δ(17)][K}{δ}{F((16)(17))343RFPA2DFlowFig.3FlowchartofRFPA2DFlowRFPA2DFlow4.14310m×18m100×18002.5MPa1.5MPa500m14Fig.4Numericalmodelfordelayoutbursts2410.•1671•1Table1MechanicalandseepageparametersfornumericalmodelmE0/GPaσ0/MPaϕ/()/(gcm3)µλ/(m2MPa2d1)A/(m3(m3MPa1/2)1)αβB2510030.02.70.300.1002.000.500.200.150.50105030032.01.40.250.0010.100.100.100.080.7521015030.02.00.300.0100.100.100.100.100.704.256(6)56Step3735Fig.5Delayoutburstprocessbynumericalsimulation6Fig.6Stressfieldsinoutburstprocessbynumericalsimulation7()0.2d2(0.4d)0.4d[14]4()4(6Step22Step37)6Step22Step3778Step11Step22Step37Step312Step318Step316Step11Step22Step37Step312Step318Step316•1672•20057Fig.7Abutmentpressurecurvesindelayoutburstprocessbynumericalsimulation8Fig.8Gaspressurecurvesindelayoutburstprocessbynumericalsimulation78834()()5()(RFPA2DFlow)RFPA2DFlow3(References)[1]LamaRDBodzionyJ.Managementofoutburstinundergroundcoalmines[J].Int.J.CoalGeology199835(1)83115.[2]LitwiniszynJ.Amodelfortheinitiationofcoal-gasoutbursts[J].Int.J.RockMech.Min.Sci.&Geomech.Abstr.198522(1)3946.[3]PatersonL.Amodelforoutburstincoal[J].Int.J.RockMech.Min.Sci.&Geomech.Abstr.198623(4)327332.[4].[J].199413(3)229239.(ZhaoYangsheng.Coupledmathematicalmodeloncoalmass-gasanditsnumericalmethod[J].ChineseJournalofRockMechanicsandEngineering199413(3)229239.(inChinese))[5].[J].199615(2)135142.(LiangBingZhangMengtaoWangYongjia.Mathematicalmodelandnumericalmethodforcoupledgasflowincoalseamsandcoaldeformation[J].ChineseJournalofRockMechanicsandEngineering199615(2)135142.(inChinese))[6]DziurzynskiWKrachA.Mathematicalmodelofmethaneemissioncausedbyacollapseofrockmasscrump[J].ArchivesofMiningSciences200146(4)433449.[7].[M].0.00.51.01.52.02.50369121518/m/MPa0.00.51.01.52.02.50369121518/m/MPa2410.•1673•1998.14165758.(ZhouShiningLinBaiquan.TheTheoryofGasFlowandStorageinCoalSeams[M].BeijingChinaCoalIndustryPublishingHouse1998.14165758.(inChinese))[8]TangCAThamLGLeePKKetal.Coupledanalysisofflowstressanddamage(FSD)inrockfailure[J].Int.J.RockMech.Min.Sci.200239