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On the stress ratio relation in the simple shear test
AUS .NAT .CoNF .PUBL.NO .75/~,P31-B 5. Four basic componeats of the response of sands to cyclic l o ~ n g are illustrated by results from cyclic simple shear and cyclic trisxial tests. Auth.
Strength characteristics
ture shows that the critical energy level required for crack propagation may vary with initial crack or discontinuity size, mode of fracture, sad homoge~qeity of the stress distribution. Each of these factors e~n produce size effects. The results of Imalch bearing tests verify a theoretical conclusion that stress gradients can intr¢ duce apparent size effects. Auth.
587 See also abstract: 6~2.
582 GARGA,VK PONTIFICAL CATHOLIC UNIV.RIO DE JANE~O,BR SEKAPHIM, LA A note on some observations on a mlgmatic residual soil from Rio de J~elro. SOILS FOUND .VI5,N4,1975, Pl-ll. The anthors investigate the shear strengths of two types of residual soll derived from m ~ t i t e . Drained direct shear tests were performed to compare the shear strength of undisturbed and isboratory compacted samples in both saturated and partially saturated conditions. In addition a number of characterization tests were perform.~i to evaluate the variation of physical properties along the weathering profile.
MII/~R, PJ M~RTIN, GR A note on the strength of rock Joints in direct she~r. 6F, IT,9R. 2ND AUS-N.Z.CONF.GEOMECH,BRISBANE,1975, INST.ENGRS, AUS.NAT. CONF .PUBL.NO.75/~, P248- 252. A brief outline of factors contributing to rock Joint strengths is presented, and the validity of usil%g "normal load" stage testing procedures to obtain Joint strength envelopes is examined. An apl~ex~mate method f. determlning the dilatant component of Joint strength from laboratory direct shear tests is outlined, ~nd it suggested that such a procedure may be of value in extr polatlng test results to field ~oints of variable rough ness. The concept of residual strength as applied to ro Joints is briefly reviewed and the c~irved nature of res dual strength envelopes is examined. Auth.
5~ MIURA, N YAMANOUCHI, T Effect of water on the beha~iour of a quartz-rich sand under high stresses. SOILS FOUND .V15,N4,1975, F23-34. The authors investigate the high pressure behaviour of a quartz rich sand in both dry and saturated states, and show that water increases the compressibility end decreases the shear strength. They show that the im~esemee of water has a marked effect as the activation of partlcle crushing, ~ud postulate that the acceleration of particle crushing of sand by wettln~ is due to the surface energy change of cracks produced in the particles under high stresses.
5~ MASANOFU, O SAITAMA UNIV .SAITAMA,JAPAN Om the stress ratio relation in the simple shear test. SOILS FOi~.VlS, N4,1975, P~ 5-~i. The author investigates the physical meanin~ of the constant which relates t h e tangent of t h e in-~lination angle of the msximam principal stress to the ratio of the shear to the normal stress on the apparent shear plane. He shows how to estimate its value for a given gran~!-r material.
585 OHTA,H YOSHITANI,S HATA, S Anisotropic stress-strain relatiasship of clay and its application to finite element analysis. SOILS FOUND .VI5~N~ ~1975, P61-79. The authors attempt to derive the incremental stressstrain relations for enisotropically preconsolidated cls~s. Using these relations as the constitutive equa~ tions they compute the effective and total stress distributions and the deformation in a clay layer l~aded by a uniform strip load. The finite element technique is used for these computations.
5~ BR(Y~N,ET ~ONAND,BE An analysis of size effect behaviour in brittle rock. 2F,2~R. 2ND AUS-N. Z .CONF .G~OMECH~BR ISBASE, 1975, INST. ENGRS, AUS .NAT .CONF .PUBL.NO.75 ~ , P139-I~3. Statistical and empirical methods of describing the frequent/y observed size-strength depandency in rock are unsatisfactory. An ans/ysis of the energetics of frac-
588 PENG, SS W.VIRGINIA UNIV .MORGANTOWN, Ui~ Stress analysis of cylindrical rock discs subjected to axial double point load. 9F,5R. INY.J.ROCK MECH.MIN. SC I .GEOMECH. ABSTR .VI3,N3,1976, P97-101. 589 PELLS, PJN ON IV.sYDNEY, AUS The use of the point load test in predicting the compressive strength of rock materials. Technical note. 2F,6T, 10R. AUST .GEOMECH .J.G5, NI, 1975, P54- 56.
Deformation characteristics See also abstract: 648.
590 BROWN, ET IMP. COLL. SC I.TECHNOL., LONDON,GB Volume changes in models of Jointed rock. Technical note. 2F,6R. J .GFOTD3H.ENGNG DIV.ASCE,VI02, GT3,MARCH,1976, F273.276. A technique developed for cylinlrical rock cores is aE~lied to the measurem_~_t of volume c h ~ s in plaste models of Jointed rock tested in triaxial compression. For some m~dels, initially contracts~it behaviour is followed by dilatsncy as crackin~ develops near the peak load. For other models containing multiple inclin ed ~oints, mechanisms of ~oint slip and block rotation cause the volume change to be dilatant from the corn-men~em~nt of lo~ding. The behaviour of the more dila. tant specimens is highly confining pressure dependent.
59l RICHARDS, BG The determination of experimentally based load. deformation l~ol~-rtles of a mine fill. 13F fIR. 2ND AUS.N .Z.CONF .GEOMECH ,BRISBANE, 1975, INST. ENGRS, AUS .NAT.CONF .PUBL .NO .75/~,P56-62. This paper Investig~tas the problem of load response of a mine fill usin~ concepts of non-linear material behaviour based on experimentally d e t e r m i n e d stressstrain curves. Since the laboratory ssmple is treated as a heterogeneous sample with stress-dependent p r o perties~ complications su-,h aa rough e~d plates usual. ly encountered in the trisxial test can be avoided. A= a result, the d e t e r m i n a t i o n o f more relevant material parameters is less dependant on the test Procedure an( the results can be used more confidently in geotechni cal applications. Auth.
Strength characteristics
ture shows that the critical energy level required for crack propagation may vary with initial crack or discontinuity size, mode of fracture, sad homoge~qeity of the stress distribution. Each of these factors e~n produce size effects. The results of Imalch bearing tests verify a theoretical conclusion that stress gradients can intr¢ duce apparent size effects. Auth.
587 See also abstract: 6~2.
582 GARGA,VK PONTIFICAL CATHOLIC UNIV.RIO DE JANE~O,BR SEKAPHIM, LA A note on some observations on a mlgmatic residual soil from Rio de J~elro. SOILS FOUND .VI5,N4,1975, Pl-ll. The anthors investigate the shear strengths of two types of residual soll derived from m ~ t i t e . Drained direct shear tests were performed to compare the shear strength of undisturbed and isboratory compacted samples in both saturated and partially saturated conditions. In addition a number of characterization tests were perform.~i to evaluate the variation of physical properties along the weathering profile.
MII/~R, PJ M~RTIN, GR A note on the strength of rock Joints in direct she~r. 6F, IT,9R. 2ND AUS-N.Z.CONF.GEOMECH,BRISBANE,1975, INST.ENGRS, AUS.NAT. CONF .PUBL.NO.75/~, P248- 252. A brief outline of factors contributing to rock Joint strengths is presented, and the validity of usil%g "normal load" stage testing procedures to obtain Joint strength envelopes is examined. An apl~ex~mate method f. determlning the dilatant component of Joint strength from laboratory direct shear tests is outlined, ~nd it suggested that such a procedure may be of value in extr polatlng test results to field ~oints of variable rough ness. The concept of residual strength as applied to ro Joints is briefly reviewed and the c~irved nature of res dual strength envelopes is examined. Auth.
5~ MIURA, N YAMANOUCHI, T Effect of water on the beha~iour of a quartz-rich sand under high stresses. SOILS FOUND .V15,N4,1975, F23-34. The authors investigate the high pressure behaviour of a quartz rich sand in both dry and saturated states, and show that water increases the compressibility end decreases the shear strength. They show that the im~esemee of water has a marked effect as the activation of partlcle crushing, ~ud postulate that the acceleration of particle crushing of sand by wettln~ is due to the surface energy change of cracks produced in the particles under high stresses.
5~ MASANOFU, O SAITAMA UNIV .SAITAMA,JAPAN Om the stress ratio relation in the simple shear test. SOILS FOi~.VlS, N4,1975, P~ 5-~i. The author investigates the physical meanin~ of the constant which relates t h e tangent of t h e in-~lination angle of the msximam principal stress to the ratio of the shear to the normal stress on the apparent shear plane. He shows how to estimate its value for a given gran~!-r material.
585 OHTA,H YOSHITANI,S HATA, S Anisotropic stress-strain relatiasship of clay and its application to finite element analysis. SOILS FOUND .VI5~N~ ~1975, P61-79. The authors attempt to derive the incremental stressstrain relations for enisotropically preconsolidated cls~s. Using these relations as the constitutive equa~ tions they compute the effective and total stress distributions and the deformation in a clay layer l~aded by a uniform strip load. The finite element technique is used for these computations.
5~ BR(Y~N,ET ~ONAND,BE An analysis of size effect behaviour in brittle rock. 2F,2~R. 2ND AUS-N. Z .CONF .G~OMECH~BR ISBASE, 1975, INST. ENGRS, AUS .NAT .CONF .PUBL.NO.75 ~ , P139-I~3. Statistical and empirical methods of describing the frequent/y observed size-strength depandency in rock are unsatisfactory. An ans/ysis of the energetics of frac-
588 PENG, SS W.VIRGINIA UNIV .MORGANTOWN, Ui~ Stress analysis of cylindrical rock discs subjected to axial double point load. 9F,5R. INY.J.ROCK MECH.MIN. SC I .GEOMECH. ABSTR .VI3,N3,1976, P97-101. 589 PELLS, PJN ON IV.sYDNEY, AUS The use of the point load test in predicting the compressive strength of rock materials. Technical note. 2F,6T, 10R. AUST .GEOMECH .J.G5, NI, 1975, P54- 56.
Deformation characteristics See also abstract: 648.
590 BROWN, ET IMP. COLL. SC I.TECHNOL., LONDON,GB Volume changes in models of Jointed rock. Technical note. 2F,6R. J .GFOTD3H.ENGNG DIV.ASCE,VI02, GT3,MARCH,1976, F273.276. A technique developed for cylinlrical rock cores is aE~lied to the measurem_~_t of volume c h ~ s in plaste models of Jointed rock tested in triaxial compression. For some m~dels, initially contracts~it behaviour is followed by dilatsncy as crackin~ develops near the peak load. For other models containing multiple inclin ed ~oints, mechanisms of ~oint slip and block rotation cause the volume change to be dilatant from the corn-men~em~nt of lo~ding. The behaviour of the more dila. tant specimens is highly confining pressure dependent.
59l RICHARDS, BG The determination of experimentally based load. deformation l~ol~-rtles of a mine fill. 13F fIR. 2ND AUS.N .Z.CONF .GEOMECH ,BRISBANE, 1975, INST. ENGRS, AUS .NAT.CONF .PUBL .NO .75/~,P56-62. This paper Investig~tas the problem of load response of a mine fill usin~ concepts of non-linear material behaviour based on experimentally d e t e r m i n e d stressstrain curves. Since the laboratory ssmple is treated as a heterogeneous sample with stress-dependent p r o perties~ complications su-,h aa rough e~d plates usual. ly encountered in the trisxial test can be avoided. A= a result, the d e t e r m i n a t i o n o f more relevant material parameters is less dependant on the test Procedure an( the results can be used more confidently in geotechni cal applications. Auth.