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Source function for a dynamic brittle unilateral shear fracture
I!6A
1089 WILSON, GH H ~ K O Y I C H , CT Application of a microprocessor for acquisition of load, strain stud acoustic emission data. 8F,2R. EXP . ~ H , V16, N3,MARCH 1976, Plll-ll5. A dedicated microprocessor is used in conjunction with a digital cassette tape unit. The system has the capability to transmit the data from the tape unit to a large computer for plotting. It is elai~i that data Ixcocessir~ time is reduced by a factor of 15-20.
this article these systems are s~,~:lated by a model. A physical mechanism is then presented, which appears to explain the phesom~a shown by the model both qualitatively and to a certain extent quantitatively. Its application to geology is c~nsidered.
Fracture processes See also abstract: 1131.
1o.~,
Texture, structure, composition and density lO9O CHARLES~ORTH, HA UN IV.ALB~qTA, EC~0.V~0N,CDN L ~ N G ~ B ~ G , CW UNIV .ALBerTA,~4DNTON, CI~ RAMSD~, J UNIV. A L~RTA, EDMONTON, CE~ Determiuir~ axes, axial plan-.s, and sections of macroscopic folds using computer-based ms~hods.14F,13R. CAN.J .EARTH SCI .,VI3,NI,JAN .1976,P54-65. The paper first discusses how to determine fold-axes. AIthough the n~nerlcal method discussed has been d~-scribed l~evio-sly, the available literature does not help t h e average geologist understand how and why it works. Therefore, a rigorous but simple explsmation is Eive~ as an addendum. Before calculating fold-axes and axial planes sad plotting sections, the folds in ~uestion ~Ast be s h ~ a to be cylindrical. One advantage of the m-~-~ical method is that it p r o v i d e s %he basis for statistical tests of whether or not a fold is cylindrical. After describing how to constru=t sections end d e t e r m i n e axial planes, all the above numerical procedures are illustrated by s.u~lyzing four folds from the Canadian Rocky Mountains. Auth. 1091 RANALLI, G CARLE~ON tr~IV.0T~A~A, CDN Length distribution of strike-slip faults and the process of breakage in continental crust. IF,gR. CAN.J.EARTH SCI.,VI3,NS,MAY 1976,1~/0~-707. The distribution of lengths of regional strike-slip faults in continental crust is adequately described by the lo~ormal probability distribution. It is t~herefore suggested that the fa~tltln~ process can be modelled as a random process obeying the law of proportionate effect (Kolmogorov type). In this paper, (i) the l~robabilistic model is outlined, (~) the hyl~thesis is checked and several parameters of the- process are calculated, and (3) some general i~licati~ns of the results are discussed. Auth.
1o~ ~,AM T '~--AVIV UNIV, IL FRE~JND,R HE~REg UNIV .JERUSA~, IL Buckling of stclke-slip fs~its in a model and in nature. 5F,IOR. GEOPHYS .J .R .ASTR .SOC.,V~3,N2, NOV.1975, P~17.530. Strike-slip faults appear to be buckled in nature. The buckling is simulated in a m~del experiment, and a theory is presented to explain the model. ~uantitative co~arisons between theory and model a r e made on various parameters of the mo~el: t h e w i d t h o f t h e faulted bl~ks, their thickness, the w ~ v e l e ~ of buckling, the amplitude of bucklln~, end the displacement s ~ 1 ~ the fsA~ite. In ~d~_tion the effect of viscosity on the buckling is mentioned. The application of the model to faults in M s ~ i b o r o ~ , New Zealand is considered, to@ether with its i~licaticn on the character of the u n d e r l y ~ crust. MERZ~,AM TEL-AVIV UNIV, IL FREUND, R H ~ R E W UNIV,JKqU~LEM, IL Equal spacin6 of strlke-slip faul~. 8F,SR. GEOFHYS .J .R .ASTR.SOC. ,Vh5, NI,APRIL, 1976, PIYT-188. Strlke-slip fault systems on continents frequently occur in ~roups of several roughly equally-spaced faults. In
INGLES,OG CSIR0, SYUNDAL, AUS HOELINGSWORTH, JA CSIRO, SYUNI~L,AUS Rock fracture and its continuity. 1OR. FROC.IST AUST.CONF.ON ~NGNG MAT~IqlAI-~,~,I6-28 AUG .197~,P~97-507. The d e v e l o l ~ t o f f r a c t u r e d u r i n g t h e s e p a r a t e unconf i n e d compression of two coatiguous section- of a Hs~k. esbury sandstone core is described. The n~chanical beha. viour of the specimens was followed beyond failure by means o f a programmable s e r v o f r a m e , and t h e i n t a c t b u t f r a c t u r e d specimens t h e ~ s e c t i o n e d f o r f a b r i c a n a l y s i s . The i n t e r n a l f r a c t u r e s f o l l o w a v i r t u a l l y i d e n t i c a l s p a t i a l and ori~tational pattern, despite somewhat diff. e r ~ t end conditions and the presence of an inclined plane of weakness in one specimen. The implications of such internal fabric features for rock fracture behaviour are discussed. 1095 HANSON,ME SANFORD,AR SHAFF~,BJ Source fu~uction for a dynmmlc brittle unilateral shear fracture. 9F,12R. GEOPHYS. J .R .AS~R.SOC., V38, N2, AUG. 1974, P365 -376 • A 2-dimansicmal brittle unilateral shear fracture was n,,m~Ically s1-,,lated %0 form and stOp in an elastic Isotropic continuum. Th_- final dlsplacememts and stresses were found to be similar to those for bilateral framture, air.hough during and shortly after fracture dynamic d i f f e r e n c e s i n t h e 2 t y p e s o f f r a c t u r e do e x i s t . In t h e unilateral case the instantaneous centre of rotation of the fracture PASt move, while for the bilateral • shear fracture, it does not. YAGUPOV,AV ORE MIN. INST,KRIVOI ROG, SU VELIKI,MI ORE MIN.INST, KRIVOI ROG, SU Acoustic effects in the t h ~ l fracture of to=ks.
6~. SOV .MIN.SC I,VII, N2, MARCH-APR IE,1975, PI04-I07. Reports ~ I m ~ n t s to s t u ~ the influence of acoustic action on the process of thermal rock breaking. 1097 BOBRYAKOV,AP ACAD SCI US~,NOVOSIBIRSK,~j POEROVSKII,GN ACAD SCl USSR,NOVDSIB]I~SK,SU SERP~INOV,BN ACAD SCI USSR~NOVOSIBIRSK, SU Developmants of methods of exper4m~tal investigatlon on the d~n~nic strength and fracture criteria o f r o c k s . 8R. SOV .MIN.SO I,VII,N3, MAY.JUNE, 1975, F212 -215 • Discusses instrumentation and measurement ~rocedures.
1098 DANIEL, IM ROWIANDS, RE On wave and fracture p r o M t i o n in rock m,-dia. 20R. EXP .MECH.VIS,NI2,DEC .1975,P~d~9.457. Experlms~tal stress-analysls techniques were use~. Marble and g r a n i t e p l a t e s ware l o a d e d e x p l o s i v e l y . Wave p r o I ~ gation was observed through Isochromatie.fringe ~attemuls on bonded photoelastic c o a t i u ~ and molre-frlmge ~%terns, recorded with a Beckmsn and Whitle~ camera operating at rates from 250,000 to 1,000,000 frames ~ second. Experimental results obtained ere discussed and interpre-
1089 WILSON, GH H ~ K O Y I C H , CT Application of a microprocessor for acquisition of load, strain stud acoustic emission data. 8F,2R. EXP . ~ H , V16, N3,MARCH 1976, Plll-ll5. A dedicated microprocessor is used in conjunction with a digital cassette tape unit. The system has the capability to transmit the data from the tape unit to a large computer for plotting. It is elai~i that data Ixcocessir~ time is reduced by a factor of 15-20.
this article these systems are s~,~:lated by a model. A physical mechanism is then presented, which appears to explain the phesom~a shown by the model both qualitatively and to a certain extent quantitatively. Its application to geology is c~nsidered.
Fracture processes See also abstract: 1131.
1o.~,
Texture, structure, composition and density lO9O CHARLES~ORTH, HA UN IV.ALB~qTA, EC~0.V~0N,CDN L ~ N G ~ B ~ G , CW UNIV .ALBerTA,~4DNTON, CI~ RAMSD~, J UNIV. A L~RTA, EDMONTON, CE~ Determiuir~ axes, axial plan-.s, and sections of macroscopic folds using computer-based ms~hods.14F,13R. CAN.J .EARTH SCI .,VI3,NI,JAN .1976,P54-65. The paper first discusses how to determine fold-axes. AIthough the n~nerlcal method discussed has been d~-scribed l~evio-sly, the available literature does not help t h e average geologist understand how and why it works. Therefore, a rigorous but simple explsmation is Eive~ as an addendum. Before calculating fold-axes and axial planes sad plotting sections, the folds in ~uestion ~Ast be s h ~ a to be cylindrical. One advantage of the m-~-~ical method is that it p r o v i d e s %he basis for statistical tests of whether or not a fold is cylindrical. After describing how to constru=t sections end d e t e r m i n e axial planes, all the above numerical procedures are illustrated by s.u~lyzing four folds from the Canadian Rocky Mountains. Auth. 1091 RANALLI, G CARLE~ON tr~IV.0T~A~A, CDN Length distribution of strike-slip faults and the process of breakage in continental crust. IF,gR. CAN.J.EARTH SCI.,VI3,NS,MAY 1976,1~/0~-707. The distribution of lengths of regional strike-slip faults in continental crust is adequately described by the lo~ormal probability distribution. It is t~herefore suggested that the fa~tltln~ process can be modelled as a random process obeying the law of proportionate effect (Kolmogorov type). In this paper, (i) the l~robabilistic model is outlined, (~) the hyl~thesis is checked and several parameters of the- process are calculated, and (3) some general i~licati~ns of the results are discussed. Auth.
1o~ ~,AM T '~--AVIV UNIV, IL FRE~JND,R HE~REg UNIV .JERUSA~, IL Buckling of stclke-slip fs~its in a model and in nature. 5F,IOR. GEOPHYS .J .R .ASTR .SOC.,V~3,N2, NOV.1975, P~17.530. Strike-slip faults appear to be buckled in nature. The buckling is simulated in a m~del experiment, and a theory is presented to explain the model. ~uantitative co~arisons between theory and model a r e made on various parameters of the mo~el: t h e w i d t h o f t h e faulted bl~ks, their thickness, the w ~ v e l e ~ of buckling, the amplitude of bucklln~, end the displacement s ~ 1 ~ the fsA~ite. In ~d~_tion the effect of viscosity on the buckling is mentioned. The application of the model to faults in M s ~ i b o r o ~ , New Zealand is considered, to@ether with its i~licaticn on the character of the u n d e r l y ~ crust. MERZ~,AM TEL-AVIV UNIV, IL FREUND, R H ~ R E W UNIV,JKqU~LEM, IL Equal spacin6 of strlke-slip faul~. 8F,SR. GEOFHYS .J .R .ASTR.SOC. ,Vh5, NI,APRIL, 1976, PIYT-188. Strlke-slip fault systems on continents frequently occur in ~roups of several roughly equally-spaced faults. In
INGLES,OG CSIR0, SYUNDAL, AUS HOELINGSWORTH, JA CSIRO, SYUNI~L,AUS Rock fracture and its continuity. 1OR. FROC.IST AUST.CONF.ON ~NGNG MAT~IqlAI-~,~,I6-28 AUG .197~,P~97-507. The d e v e l o l ~ t o f f r a c t u r e d u r i n g t h e s e p a r a t e unconf i n e d compression of two coatiguous section- of a Hs~k. esbury sandstone core is described. The n~chanical beha. viour of the specimens was followed beyond failure by means o f a programmable s e r v o f r a m e , and t h e i n t a c t b u t f r a c t u r e d specimens t h e ~ s e c t i o n e d f o r f a b r i c a n a l y s i s . The i n t e r n a l f r a c t u r e s f o l l o w a v i r t u a l l y i d e n t i c a l s p a t i a l and ori~tational pattern, despite somewhat diff. e r ~ t end conditions and the presence of an inclined plane of weakness in one specimen. The implications of such internal fabric features for rock fracture behaviour are discussed. 1095 HANSON,ME SANFORD,AR SHAFF~,BJ Source fu~uction for a dynmmlc brittle unilateral shear fracture. 9F,12R. GEOPHYS. J .R .AS~R.SOC., V38, N2, AUG. 1974, P365 -376 • A 2-dimansicmal brittle unilateral shear fracture was n,,m~Ically s1-,,lated %0 form and stOp in an elastic Isotropic continuum. Th_- final dlsplacememts and stresses were found to be similar to those for bilateral framture, air.hough during and shortly after fracture dynamic d i f f e r e n c e s i n t h e 2 t y p e s o f f r a c t u r e do e x i s t . In t h e unilateral case the instantaneous centre of rotation of the fracture PASt move, while for the bilateral • shear fracture, it does not. YAGUPOV,AV ORE MIN. INST,KRIVOI ROG, SU VELIKI,MI ORE MIN.INST, KRIVOI ROG, SU Acoustic effects in the t h ~ l fracture of to=ks.
6~. SOV .MIN.SC I,VII, N2, MARCH-APR IE,1975, PI04-I07. Reports ~ I m ~ n t s to s t u ~ the influence of acoustic action on the process of thermal rock breaking. 1097 BOBRYAKOV,AP ACAD SCI US~,NOVOSIBIRSK,~j POEROVSKII,GN ACAD SCl USSR,NOVDSIB]I~SK,SU SERP~INOV,BN ACAD SCI USSR~NOVOSIBIRSK, SU Developmants of methods of exper4m~tal investigatlon on the d~n~nic strength and fracture criteria o f r o c k s . 8R. SOV .MIN.SO I,VII,N3, MAY.JUNE, 1975, F212 -215 • Discusses instrumentation and measurement ~rocedures.
1098 DANIEL, IM ROWIANDS, RE On wave and fracture p r o M t i o n in rock m,-dia. 20R. EXP .MECH.VIS,NI2,DEC .1975,P~d~9.457. Experlms~tal stress-analysls techniques were use~. Marble and g r a n i t e p l a t e s ware l o a d e d e x p l o s i v e l y . Wave p r o I ~ gation was observed through Isochromatie.fringe ~attemuls on bonded photoelastic c o a t i u ~ and molre-frlmge ~%terns, recorded with a Beckmsn and Whitle~ camera operating at rates from 250,000 to 1,000,000 frames ~ second. Experimental results obtained ere discussed and interpre-