断裂物理力学性质对其附近地应力场的影响

200212326()JournalofNorthwestUniversity(NaturalScienceEdition)Dec.2002Vol.32No.6:2001211216:(19999024719,RFDP):(19632),,,,1,2,1,3,STEPHANSSONOve4(1.,200092;2.,710054;3.,610059;4.,10044):,:,;,,;,(U):;;;;;:P542+.3:A:10002274Ò(2002)0620655204[1],,,,[2],Forsmark,[3],,,,,,,,,,,[4][5],,,,,,(Kb)(U),()1,:;;;;,,,A©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.(1),(R1),(R2)(R1öR2)(Kb),1Fig.1Geometryandboundaryconditionsofthemodel2,:;;;2.1(Kn)(Ks)Kn=$Rn$un,Ks=$Ss$us,:$Rn,$un,$Ss,$usKn=2GPaöm,(),Ks2,1,500,100,50,10MPaöm,,,,,,Ks100MPaöm,Ks100MPaöm,Ks=200MPaöm,Kn,2.2,,,,,,,(2)2:,,,;15,,,(),,,,2Fig.2Relationshipbetweenstressdifferenceonbothsidesofthefractureandinternalfrictionangleofthefrac2ture,,4,:,,,;,,656()32©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,,3aU1=18,U2=8,(3b)ab3(U1=18,U2=8)(:MPa)(a)(b)Fig.3Maximumprincipalstressvariation(a)andstressreorientation(b)inthemodelwithdifferentinter2nalfrictionangleindifferentsgementsoffracture2.3,,,,,2.4,,,,,4,A1A25,,,,,,,:A,A;A,A,,,,,4Fig.4Geometryandboundaryconditionsformodellingzigzag2shaped2fracture5Fig.5Stressreorientationinthevicinityofzigzag2shapedfracture31),7566:©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.(U),,2),,,,,,,(Kb),3),,,,,,,A,A;A,A:[1].[M].:,1996.[2].[D].:,2001.[3]CARLSSONA,CHRISTIANSSONR.RockstressesandgeologicalstructuresintheForsmarkarea[A].STEPHANS2SONO.ProceedingsoftheInternationalSymposiumonRockStressandRockStressMeasurements[C].Stockholm:CentekPublishers,1986.4572465.[4]SUSR,STEPHANSSONO.Effectofafaultoninsitustressstudiedbydistinctelementmethod[J].IntJRockMech&MiningSci,1999,36(8):150121506.[5],.[J].,2000,22(3):3272331.()TheeffectoffracturepropertiesonstressfieldinthevicinityofafractureSUSheng2rui1,2,ZHUHe2hua1,WANGShi2tian3,STEPHANSSONOve4(11DepartmentofGeotechnicalEngineering,TongjiUniversity,Shanghai200092,China;2.DepartmentofGeologicalEngi2neering,ChanganUniversity,Xian710054,China;3.CollegeofEnvironmentalandCivilEngineering,ChengduUniversityofTechnology,Chengdu610059,China;4.SchoolofCivilandEnvironmentalEngineering,RoyalInstituteofTechnology,Stockholm10044,Sweden)Abstract:UsingsystematicnumericalmodelingofthedistinctelementmethodwithUDECcode,thefea2turesofrockstressperturbationcausedbytheexistenceoffracturesandtheirvariationwithfractureprop2ertieslikestiffness,internalfrictionangleandcohesionareanalyzed.Itisshownthatchangesofallofthesepropertiesmaycausethechangeofstressfieldsinthevicinityofafault.Theorientationandmagni2tudeofstressesaroundfractureschangesindifferentextent,andmostofthiskindofchangeoccursinacertainrangearoundthefault.However,theorientationofprincipalstressestrendstobeinlinewithre2gionalstressfarfromthefracture.Itisfoundfrommodelingthattherangeandmagnitudeofstressvaria2tionisstronglydeterminedbythefrictionangle(U)ofthefractures.Keywords:stressfield;fractures;variationofstresses;boundarycondition;numericalmodelingbythedistinctelementmethod;deformableblocks856()32©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.