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Mechanical properties of soft rock and rock mass
69A
833049 BRq.[AV!OUR OF A BRlq~l~ SAhD:~ONE IN uL~-o~EKAIN LO;~!NG CONDITIOES :~tavrooouiou, V G Proc 23rd SymposiUm on Rock Vechanics, Berkeley, 25-27 A~.~ust 1982, F351-358. Publ .New York: A~.,E, ] 982 Plane strain tests using a s;ecieD-ly designed aplaratus were carried cut on a brittle sandstone. The be_haviour of the sandstone in the plane strain cor~Ition was found to be significently different fron~ that in uniaxial compression. The values of Young's modulus and Poisson's ratio for the plane strain condition were lG;er than the ur.~s~xial values. Dilatancy w a s ~Iso reduced in plate, stral~, whereas the ~re-f~llure brittleness of the rock increased. T h e strer4rth of the sandstone increased by 49 per cent in comparison to its unlaxi~/~ v~lue. 833050 EZ~41NATI0:~ OF _o~E TENSILE 3TRENGTH OF B R ~ I ~ ROCK Ratigan, J L Proc 23rd Sy~,posium on Rock !'eehanics, Berkeley, 25-27 August 1982, I~23-~0. Publ New York: % IM~, 1982 Theories of tensile strength are reviewed and crltic~lly examined with respect to laboratory uni~xlal e rzl multi~xial tension tests, particularly with reg~rd to size effect. The ecr.tlnuum strength epproach is found incapable of reproducing any of the observed r¢,~L]t~:. ~.terministic and statistlc'~l fracture mechanics can be used to explain ~ c h of the behavlour, but the statistical approach w~s found to be able to re!~oduee test results that deterministic fracture mechanics c,=rmot reproduce. PROJECTILE 833051 E3OPKRr,~h'2AL IhVE~IGATION OF ~ ~E}YET~,ITION INTO ~OFT, POROUS ROCK U ~ ) ~ DRY AND LIQUTD-FYIIF/O CO~DITIONS Kumano, A; G(fcsmith, "J Proc 23rd Symposium on Rock :.'echanics, Berkeley, 25-27 August 1982, I~488-~95. Publ N~; York: AITXE, 1982 Eight impact tests were carried out c n d r y and kerosene-saturated dlsk-sh~ped specimens of green shale, with ~oJectile velocities r~ngIng from 18 to 42m per s. Results Indicate that, for the dry c~se, penetration depth is proportion~l to the ssuare root of the initial projectile kinetic energy, conforming well with a simple linear viscous model. In the fluld-filled case, penetration depth is found to be directly ~roportlo~l to the I n i t i ~ projectile kinetic energy, s~eeing "~Ith a Coulomb friction~ model. 833052 ZT;TL-3TIC2 IN AID OF ILqVLRPR~Ih~ FRACTURE DATA LaJtai, E Z Proc 23rd 3~nposi~m on ROCk V ech.an!cs, Berkeley, 25-27 August 1982, ~96-503. Publ New Y ~ k : .:..I?~, 1982 The tensile strength of Lac du Bonnet granite forms a bimod~l _~rob'~bility distribution when determined through line lo~dimg as in the Brazilian test. The s~une date obtained from three point heels tests ~ e unimod~l. The bimod~*lity can in p:~mt be removed by distributing the line load over a finite ereu. MOisture has the effect of lowering, both the average compressive ond the average tensile strength. The reduction in strer~th h~;ever is not uniform within the probability distribution: the change
is the largest at low ~nd the s~llest ~t high strength. Conversely, long-term lo~ding is more damaging to the high strength members of the distribution. The large scatter of fo~ilure times in static fatigue experiments can in Im~-t be removed when the probability distribution of instantaneous strength is taken into account. 833053 S!k'PT.E R-CITRVE ,~PPRO,CH TO FR,',CTURE TOUG}L~SS TE~Iq~JG OF ROCK CORE. SPEC!'.~N-" Ouchterlor~, F Proc 23rd ~ymposi~z on Rock ~!ech,_~nics, Berkeley, 25-27 August 1982, P515-522. Publ New York: AIME, 1982 A simple biline~rR-curve description of crack extension resistance is Rppliedto the testing of sub-size core specimens. The curve consists of a linear sub-criticall>~t end a flat postcritical part. Formulae for the energy rate crack resistance quantities ~re developed. E×perimental results from tests on notched samples of Ekeberg m~rble, Bohus granite, and 2trlpa granite are comp~red with these predictions. BE}5\VIOR OF 833054 EFFECTS OF BLOCK SIZ]~ ON T}[E ~ R JOINTED ROCK Barton, N; Bandls, S Proc 23rd ~ymposium on Rock Vech'~nlcs, Berkeley, 25-27 August 1982, P739-760. Publ New York: A I ~ , 1982 A large body of test data w~s reviewed to determine the influence of block size on the displacement required to mobilize peak strength. It is shown that the shear strength and shear stiffhess reduce with increosed block size due to reduced effective Joint roughness, and due to reduced asperity strength. Both are a function of the delayed mobiliz~.tion of roughness with increasing block size. ; method of scaling shear strength and she~r displ~cement from l~bcratory to in situ block sizes is suggested° It is based or the assumption that size effects dls:~ppear when the n a t u r ~ block size is exceeded. Recent laborator?/ tests on model block assemblies Illustrate sc~e important effects of block size on deformability and Poisson's ratio. 833055 MECKANICg/L PROPERTIES OF 9OFT ROCK AND ROCK >'ASS Adechi, T; Ogawa, T; Hay~shi, M Proc lOth Internatior~:l Conference on SOll ~.[echanlcs and Foundation Engineering, Stockholm, 15-19 June 1981 , VI, P527-530. Publ Rotterdam: i. i. Balkema, 1981 Triexial compression tests were performed on intact specimens of porous tuff and on specimens with a szw cut plane (to model discontinuities l~esent in the actual rock mass). New failure criteria for peak %nd residual strengths of intact rocks are proposed. Results show that the upper bound of rock mass strength corresponds to the peak strength of the intact rock, whereas the lower limit is bounded by the residual strength of the intact rock, and that the rock mass strength in the field lies at least within these limits. 833056 ~HEI~ ~ E N 3 T H OF INORGANIC Bi-LTY SOILS Barges son, L Proc lOth !nternntlon~l Conference on ~oil !.~echanlcs and Foundation Engineering, Stockholm, 15-19 Jlme 1981, VI, P567-572. Publ Rotterd~m: ~. A. Balkema, 1981
833049 BRq.[AV!OUR OF A BRlq~l~ SAhD:~ONE IN uL~-o~EKAIN LO;~!NG CONDITIOES :~tavrooouiou, V G Proc 23rd SymposiUm on Rock Vechanics, Berkeley, 25-27 A~.~ust 1982, F351-358. Publ .New York: A~.,E, ] 982 Plane strain tests using a s;ecieD-ly designed aplaratus were carried cut on a brittle sandstone. The be_haviour of the sandstone in the plane strain cor~Ition was found to be significently different fron~ that in uniaxial compression. The values of Young's modulus and Poisson's ratio for the plane strain condition were lG;er than the ur.~s~xial values. Dilatancy w a s ~Iso reduced in plate, stral~, whereas the ~re-f~llure brittleness of the rock increased. T h e strer4rth of the sandstone increased by 49 per cent in comparison to its unlaxi~/~ v~lue. 833050 EZ~41NATI0:~ OF _o~E TENSILE 3TRENGTH OF B R ~ I ~ ROCK Ratigan, J L Proc 23rd Sy~,posium on Rock !'eehanics, Berkeley, 25-27 August 1982, I~23-~0. Publ New York: % IM~, 1982 Theories of tensile strength are reviewed and crltic~lly examined with respect to laboratory uni~xlal e rzl multi~xial tension tests, particularly with reg~rd to size effect. The ecr.tlnuum strength epproach is found incapable of reproducing any of the observed r¢,~L]t~:. ~.terministic and statistlc'~l fracture mechanics can be used to explain ~ c h of the behavlour, but the statistical approach w~s found to be able to re!~oduee test results that deterministic fracture mechanics c,=rmot reproduce. PROJECTILE 833051 E3OPKRr,~h'2AL IhVE~IGATION OF ~ ~E}YET~,ITION INTO ~OFT, POROUS ROCK U ~ ) ~ DRY AND LIQUTD-FYIIF/O CO~DITIONS Kumano, A; G(fcsmith, "J Proc 23rd Symposium on Rock :.'echanics, Berkeley, 25-27 August 1982, I~488-~95. Publ N~; York: AITXE, 1982 Eight impact tests were carried out c n d r y and kerosene-saturated dlsk-sh~ped specimens of green shale, with ~oJectile velocities r~ngIng from 18 to 42m per s. Results Indicate that, for the dry c~se, penetration depth is proportion~l to the ssuare root of the initial projectile kinetic energy, conforming well with a simple linear viscous model. In the fluld-filled case, penetration depth is found to be directly ~roportlo~l to the I n i t i ~ projectile kinetic energy, s~eeing "~Ith a Coulomb friction~ model. 833052 ZT;TL-3TIC2 IN AID OF ILqVLRPR~Ih~ FRACTURE DATA LaJtai, E Z Proc 23rd 3~nposi~m on ROCk V ech.an!cs, Berkeley, 25-27 August 1982, ~96-503. Publ New Y ~ k : .:..I?~, 1982 The tensile strength of Lac du Bonnet granite forms a bimod~l _~rob'~bility distribution when determined through line lo~dimg as in the Brazilian test. The s~une date obtained from three point heels tests ~ e unimod~l. The bimod~*lity can in p:~mt be removed by distributing the line load over a finite ereu. MOisture has the effect of lowering, both the average compressive ond the average tensile strength. The reduction in strer~th h~;ever is not uniform within the probability distribution: the change
is the largest at low ~nd the s~llest ~t high strength. Conversely, long-term lo~ding is more damaging to the high strength members of the distribution. The large scatter of fo~ilure times in static fatigue experiments can in Im~-t be removed when the probability distribution of instantaneous strength is taken into account. 833053 S!k'PT.E R-CITRVE ,~PPRO,CH TO FR,',CTURE TOUG}L~SS TE~Iq~JG OF ROCK CORE. SPEC!'.~N-" Ouchterlor~, F Proc 23rd ~ymposi~z on Rock ~!ech,_~nics, Berkeley, 25-27 August 1982, P515-522. Publ New York: AIME, 1982 A simple biline~rR-curve description of crack extension resistance is Rppliedto the testing of sub-size core specimens. The curve consists of a linear sub-criticall>~t end a flat postcritical part. Formulae for the energy rate crack resistance quantities ~re developed. E×perimental results from tests on notched samples of Ekeberg m~rble, Bohus granite, and 2trlpa granite are comp~red with these predictions. BE}5\VIOR OF 833054 EFFECTS OF BLOCK SIZ]~ ON T}[E ~ R JOINTED ROCK Barton, N; Bandls, S Proc 23rd ~ymposium on Rock Vech'~nlcs, Berkeley, 25-27 August 1982, P739-760. Publ New York: A I ~ , 1982 A large body of test data w~s reviewed to determine the influence of block size on the displacement required to mobilize peak strength. It is shown that the shear strength and shear stiffhess reduce with increosed block size due to reduced effective Joint roughness, and due to reduced asperity strength. Both are a function of the delayed mobiliz~.tion of roughness with increasing block size. ; method of scaling shear strength and she~r displ~cement from l~bcratory to in situ block sizes is suggested° It is based or the assumption that size effects dls:~ppear when the n a t u r ~ block size is exceeded. Recent laborator?/ tests on model block assemblies Illustrate sc~e important effects of block size on deformability and Poisson's ratio. 833055 MECKANICg/L PROPERTIES OF 9OFT ROCK AND ROCK >'ASS Adechi, T; Ogawa, T; Hay~shi, M Proc lOth Internatior~:l Conference on SOll ~.[echanlcs and Foundation Engineering, Stockholm, 15-19 June 1981 , VI, P527-530. Publ Rotterdam: i. i. Balkema, 1981 Triexial compression tests were performed on intact specimens of porous tuff and on specimens with a szw cut plane (to model discontinuities l~esent in the actual rock mass). New failure criteria for peak %nd residual strengths of intact rocks are proposed. Results show that the upper bound of rock mass strength corresponds to the peak strength of the intact rock, whereas the lower limit is bounded by the residual strength of the intact rock, and that the rock mass strength in the field lies at least within these limits. 833056 ~HEI~ ~ E N 3 T H OF INORGANIC Bi-LTY SOILS Barges son, L Proc lOth !nternntlon~l Conference on ~oil !.~echanlcs and Foundation Engineering, Stockholm, 15-19 Jlme 1981, VI, P567-572. Publ Rotterd~m: ~. A. Balkema, 1981