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Plain plastic flow of granular media
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~ study was underto~ken to determine the microstructural changes which occur in pure orthoqusrtzite as Jt is loaded through strength failure. Vicrocrack m~ps ~nd st~tistlcs were prepared from optic~l .~nd electron ~dcroscopy observations. The rock appears to fail through the development of arrays of microcracks which farm around grain bounlaries and are initiated at notches in pore s~ces. 833072 COMI~REssION ~
AI~,'~, 1982 The effects of temperature and orientation on the plastic behaviour of an impure magnetite have been Investigated. Prismatic samples were axially compressed along 3 different, crystallographic planes. The critical resolved shear stresses measured were found to decrease with temperatur e. 833073 TIME AND TE~r2ERATU2LE ~ N T STRESS AND DISFLAC~{ENT FIELDS FOR SAlT D~4ES Duddeck, H W; Nipp, H K Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, _=596-603. Publ Ne~ YOrk: AIMZ, 1982 A m/tactical model is proposed for the ar~lysis of displacements and stresses including their time ar~ temperature induced change. The HcokeKelvln-Bingham-Newton rheologlc model was chosen to represent the constitutive behaviour. The model is applied to 2 examples: a cavern fOr sterage of natural gas, and a non-stationary heat source. 83307~ ELASTIC BENDING OF THICK ROCK FL%_~Es Singh, J G; Up~dhyay, P C Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, 9564-672. Publ New YOrk: A]}4E, 1982 Reissner's thick plate bending theory has been modified for rocks ex~ibitingdouble plasticity: different Young's modulus and Polsson's ratio in compression and extension. The effect of the ratio of Young's modulus in compression to that in extension on the maximum plate deflection and the m~xlm~mbending moments is examined. It is concluded that this ratio affects the shear deformation of the plate to such an extent that the bi-modular effect cannot be overlooked, especially if the ratio is greater than 2. 833075 EXTERN#7~ DISPLACEMENT }.~HOD FOR DETTi~NING THE IN-SITU DEFOP#~-ABILITY OF ROCK }.'~SSES de la Cruz, R V Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, I~78-789. Publ New York: AIME, 1982 Presents a new technique for determining the in sltu deformability of rock masses by measuring the displacement of points on a borehole wall that are outside of the loaded ~reas. Borehole Jacks are used to apply the unidirectional loads to opposite quadrants of the borehole diameter. The deformability can then be e~-Iculated from the radial displacements and spplied loads using elastic theory. It is shown that boundary pressure distribution ard contact area have
negligible effect on the results, :~rn that the presence of fractures has less i~luence th~n in existing techniques. 833076 ~ , ~ CONSIDERATION OF IN-sITU 7FjTIrJG ON "~CHT~C~ PROFERTIES OF ROCK ~t.Jf Z~u Welshe~ Xu DongJun Proc 23rd Symposium on Rock "ec.harics, Berkeley, 25-27 August !982, P~64-871. Publ N ~ York: ~ . ~ , 1982 Results from several in situ methods for measuring moduli of elasticity and defor~bility are compared: true triaxial compression tests, uniaxial compression tests, flat-jack tests, stiff plate bearing tests, and the acoustic wave method. The results vary greatly from method to method, and the slit flat-jack method is recommended as the most reasonable. A new method for determining the deformation and strength properties of a weak plane in a rock mass is then described. 833o77 S(~4~ ~OPFARTIES OF R~J,OI~DED C/dgBONATE SOILS Akili, W Proc 10th International Conference on ~oil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981, V1, P537-542. Publ Rotterdam: %. <. Balkema, 1981 Tests were carried out on two selected carbonate soils (a siliceous carbonate sand ~nd a marl) frc~ the vicinity of D~.-m~am, saudl %xabla. The experiments included California Besting Ratio tests at different water contents, undrained trlaxlal, and repeated load tests on compacted samples. The data permitted the use of linear relationships (log-log plots) to represent the increase of axial plastic strain with repeated load cycles. A critical stress, about 40 per cent of the unlralned shear strength, separated the samples' plastic and resilient defOrmation behavlour. The resilient modulus decreased with increased stress, and approached a constant value after 1000 cycles at stresses lower than the critical. Auth. 833o78 FLAIN PLASTIC FLOW OF GRANUL&R ~ D I A Baloushev, E B Prom 10th International Conference on Soll Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981, Vl, P551-556. Publ Rotterdam: :. :\. Balkem~, 1981 A theoretical and physical model study of plastic flow in granular media. Punch tests were carried out on a perfectly granular media of lead spheres to determine the behaviour of the plastic field induced below a foundation. A theOretical model using the Mohr yield criterion was developed snd tested in numerical examples and compared with the experimental results. The bearing capacity of the model was calculated. 833079 LABORATORY AND PRESSURE~,~-TEE TESTS ON ,: STIFF CLAY Denby, G M; Costa, C A; Clough, G W Prom lOth International Conference on Soll Mechanics and Foundation Engineering, Stockholm, 15o19 June 1981, VI, P577-580. Publ Rotterdam: A. A. Balkema, 1981 Laboratory and field tests were carried out to evaluate the strength and deformation response of soll on the site of the SR 90 Washington State highway project, USA. Laberatc~y tests included consolidated and unconsolidated, undrained trlaxlal tests and pl,~ne str~in tests.
~ study was underto~ken to determine the microstructural changes which occur in pure orthoqusrtzite as Jt is loaded through strength failure. Vicrocrack m~ps ~nd st~tistlcs were prepared from optic~l .~nd electron ~dcroscopy observations. The rock appears to fail through the development of arrays of microcracks which farm around grain bounlaries and are initiated at notches in pore s~ces. 833072 COMI~REssION ~
AI~,'~, 1982 The effects of temperature and orientation on the plastic behaviour of an impure magnetite have been Investigated. Prismatic samples were axially compressed along 3 different, crystallographic planes. The critical resolved shear stresses measured were found to decrease with temperatur e. 833073 TIME AND TE~r2ERATU2LE ~ N T STRESS AND DISFLAC~{ENT FIELDS FOR SAlT D~4ES Duddeck, H W; Nipp, H K Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, _=596-603. Publ Ne~ YOrk: AIMZ, 1982 A m/tactical model is proposed for the ar~lysis of displacements and stresses including their time ar~ temperature induced change. The HcokeKelvln-Bingham-Newton rheologlc model was chosen to represent the constitutive behaviour. The model is applied to 2 examples: a cavern fOr sterage of natural gas, and a non-stationary heat source. 83307~ ELASTIC BENDING OF THICK ROCK FL%_~Es Singh, J G; Up~dhyay, P C Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, 9564-672. Publ New YOrk: A]}4E, 1982 Reissner's thick plate bending theory has been modified for rocks ex~ibitingdouble plasticity: different Young's modulus and Polsson's ratio in compression and extension. The effect of the ratio of Young's modulus in compression to that in extension on the maximum plate deflection and the m~xlm~mbending moments is examined. It is concluded that this ratio affects the shear deformation of the plate to such an extent that the bi-modular effect cannot be overlooked, especially if the ratio is greater than 2. 833075 EXTERN#7~ DISPLACEMENT }.~HOD FOR DETTi~NING THE IN-SITU DEFOP#~-ABILITY OF ROCK }.'~SSES de la Cruz, R V Proc 23rd Symposium on Rock Mechanics, Berkeley, 25-27 August 1982, I~78-789. Publ New York: AIME, 1982 Presents a new technique for determining the in sltu deformability of rock masses by measuring the displacement of points on a borehole wall that are outside of the loaded ~reas. Borehole Jacks are used to apply the unidirectional loads to opposite quadrants of the borehole diameter. The deformability can then be e~-Iculated from the radial displacements and spplied loads using elastic theory. It is shown that boundary pressure distribution ard contact area have
negligible effect on the results, :~rn that the presence of fractures has less i~luence th~n in existing techniques. 833076 ~ , ~ CONSIDERATION OF IN-sITU 7FjTIrJG ON "~CHT~C~ PROFERTIES OF ROCK ~t.Jf Z~u Welshe~ Xu DongJun Proc 23rd Symposium on Rock "ec.harics, Berkeley, 25-27 August !982, P~64-871. Publ N ~ York: ~ . ~ , 1982 Results from several in situ methods for measuring moduli of elasticity and defor~bility are compared: true triaxial compression tests, uniaxial compression tests, flat-jack tests, stiff plate bearing tests, and the acoustic wave method. The results vary greatly from method to method, and the slit flat-jack method is recommended as the most reasonable. A new method for determining the deformation and strength properties of a weak plane in a rock mass is then described. 833o77 S(~4~ ~OPFARTIES OF R~J,OI~DED C/dgBONATE SOILS Akili, W Proc 10th International Conference on ~oil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981, V1, P537-542. Publ Rotterdam: %. <. Balkema, 1981 Tests were carried out on two selected carbonate soils (a siliceous carbonate sand ~nd a marl) frc~ the vicinity of D~.-m~am, saudl %xabla. The experiments included California Besting Ratio tests at different water contents, undrained trlaxlal, and repeated load tests on compacted samples. The data permitted the use of linear relationships (log-log plots) to represent the increase of axial plastic strain with repeated load cycles. A critical stress, about 40 per cent of the unlralned shear strength, separated the samples' plastic and resilient defOrmation behavlour. The resilient modulus decreased with increased stress, and approached a constant value after 1000 cycles at stresses lower than the critical. Auth. 833o78 FLAIN PLASTIC FLOW OF GRANUL&R ~ D I A Baloushev, E B Prom 10th International Conference on Soll Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981, Vl, P551-556. Publ Rotterdam: :. :\. Balkem~, 1981 A theoretical and physical model study of plastic flow in granular media. Punch tests were carried out on a perfectly granular media of lead spheres to determine the behaviour of the plastic field induced below a foundation. A theOretical model using the Mohr yield criterion was developed snd tested in numerical examples and compared with the experimental results. The bearing capacity of the model was calculated. 833079 LABORATORY AND PRESSURE~,~-TEE TESTS ON ,: STIFF CLAY Denby, G M; Costa, C A; Clough, G W Prom lOth International Conference on Soll Mechanics and Foundation Engineering, Stockholm, 15o19 June 1981, VI, P577-580. Publ Rotterdam: A. A. Balkema, 1981 Laboratory and field tests were carried out to evaluate the strength and deformation response of soll on the site of the SR 90 Washington State highway project, USA. Laberatc~y tests included consolidated and unconsolidated, undrained trlaxlal tests and pl,~ne str~in tests.