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Finite element implementation of a new model for rock joints
271A 915045
915049
Variance on Ladanyi and Archambault’s shear strength
Fuzzy-set-theoretic interpretation of strength of rock joints
criterion
Qing Zhang Proc international Symposium on Rock Joints, Loen, 4-6 June 1990 P787-790. Pub1 Rotterdam: A A Balkema, 1990
Saeb, S hoc Inremotionul Symposium on Rock Joints, Loen, 4-6 June 1990 P701-705. Pub1 Rotterdam: A A Balkema, 1990 Peak shear strength of rock joints is an important parameter in rock engineering, and the relation between shear strength and normal stress has been widely examined. The model of Ladanyi and Archambault, which is based on the dilatancy theory of sand, is re-examined, and from this a modified shear strength criterion is developed which contains the mechanisms of sliding and shear through asperities in describing joint shear strength.
Rock joint properties and behaviour are governed by many factors which often exhibit a range of values. Fuzzy set theory is thus ideal for analysis of jointed rocks. Barton’s empirical formula for strength of rock joints is interpreted using fuzzy set theory to deal with uncertainty in its parameters. This allows expression of a range of values, which may be more useful in applications than a single deterministic and possibly inaccurate value.
915oso 915046 Fiite
element implementation of a new mode1 for rock joints
Strength properties of rock mass with bidirectional intermittent cross joints
Saeb, S; Amadei, B Roe International Symposium on Rock Joints, Loen, 4-6 June 1990 P707-712. Pub1 Rotterdam: A A Balkema, 1990
Zhu Kheshan; Liu Dongyan; Fan Jingwei Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P791-795. Pub1 Rotterdam: A A Balkema, 1990
Finite element analysis is a common method for modelling the behaviour of rock masses. The history of the joint element is first briefly reviewed, then the finite element implementation of a new model for joint behaviour (Saeb, 1989) is discussed. Simple examples are used to illustrate the features of the model.
Gypsum blocks containing thin strips of PTFE to simulate joints were tested under plane stress, uniaxial, and biaxial loading. Regular cross joint patterns were used and orientation relative to loading varied. Stress strain relations and failure mechanisms were examined to study influence of joint directions and lateral stresses on rock mass strength. A strength criterion is developed. Finite element analyses of the tests are also presented.
915047 Geomechanical modelling of joints in rock foundations of structures
Sapegin, D D; Karpov, N M; Nikitin, A A Roe International Symposium on Rock Joints, Loen, 4-6 June 1990 P713-717. Pub1 Rotterdam: A A Balkema, 1990 The pattern and condition of joints in a rock mass are of prime importance to engineering design. Some problems associated with study and evaluation of shear strength properties of rock joints are outlined. Joints can initially be described as homogeneous or heterogeneous. Sample selection so that representative parameters can be obtained in laboratory testing is considered. Statistical treatment of measured shear properties to obtain input values for modelling of jointed rock masses is examined with reference to case studies.
915051 Estimating the shear stiffness of rock joints Infanti, N; Kanji, M A Proc international Symposium on Rock Joints, Loen, 4-6 June 1990 P799-804. Pub1 Rotterdam: A A Balkema. 1990 Stress strain behaviour of rock joints in shear has been studied. Results of 133 in situ tests have been analysed and dependence of unit shear stiffness (Kt) on normal stress, joint thickness, roughness, and tested area examined. Despite the range of test methods and conditions, the following conclusions were arrived at: for the same type of joint, log Kt is linearly related to normal stress; Kt is more dependent on joint characteristics than rock lithology; and there is general correlation between Kt, joint shear strength, and peak tangential displacement. Size effects were not confirmed.
915048 Kinematic mechanisms of shear deformation and validity of Barton’s shear models Xu, S; de Freitas, M H
915052
Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P767-774. Pub1 Rotterdam: A A Balkema, 1990 The shear behaviour of clean rough joints with regular toothshaped profiles has been investigated in a rotary shear machine. Measurements of dilation and shear stress and displacements plus visual observation of the surfaces have been used in critical analysis of the mechanisms of shear deformation and failure. A third kinetic deformation mechanism, flattening of asperity profiles, is proposed in addition to dilation and asperity shear. These results can explain the shape of the peak shear strength envelope of clean rough joints and sup. port Barton’s empirical criteria. Results are presented which indicate Barton’s criteria can be extended to infilled joints. 0
Use of large scale shear boxes for Rhone alluvium materials (In French)
Bourdeau, Y; Lareal, P; Marchal, J froc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P695-696. Pub1 Rotterdam: A A Balkema, 1989 Large shear box devices have been used to investigate shear characteristics of alluvial soils with large and variable grain size. Two apparatuses and two test techniques were applied, one in situ, one in the laboratory. Soils from a number of sites were studied. Results suggest that in situ a weak cohesion (less than 30kPa) exists at normal stress 50-160kPa. Residual friction angles at large strains were also measured.
1991 Pergamon Press plc. Reproduction
not permitted
915049
Variance on Ladanyi and Archambault’s shear strength
Fuzzy-set-theoretic interpretation of strength of rock joints
criterion
Qing Zhang Proc international Symposium on Rock Joints, Loen, 4-6 June 1990 P787-790. Pub1 Rotterdam: A A Balkema, 1990
Saeb, S hoc Inremotionul Symposium on Rock Joints, Loen, 4-6 June 1990 P701-705. Pub1 Rotterdam: A A Balkema, 1990 Peak shear strength of rock joints is an important parameter in rock engineering, and the relation between shear strength and normal stress has been widely examined. The model of Ladanyi and Archambault, which is based on the dilatancy theory of sand, is re-examined, and from this a modified shear strength criterion is developed which contains the mechanisms of sliding and shear through asperities in describing joint shear strength.
Rock joint properties and behaviour are governed by many factors which often exhibit a range of values. Fuzzy set theory is thus ideal for analysis of jointed rocks. Barton’s empirical formula for strength of rock joints is interpreted using fuzzy set theory to deal with uncertainty in its parameters. This allows expression of a range of values, which may be more useful in applications than a single deterministic and possibly inaccurate value.
915oso 915046 Fiite
element implementation of a new mode1 for rock joints
Strength properties of rock mass with bidirectional intermittent cross joints
Saeb, S; Amadei, B Roe International Symposium on Rock Joints, Loen, 4-6 June 1990 P707-712. Pub1 Rotterdam: A A Balkema, 1990
Zhu Kheshan; Liu Dongyan; Fan Jingwei Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P791-795. Pub1 Rotterdam: A A Balkema, 1990
Finite element analysis is a common method for modelling the behaviour of rock masses. The history of the joint element is first briefly reviewed, then the finite element implementation of a new model for joint behaviour (Saeb, 1989) is discussed. Simple examples are used to illustrate the features of the model.
Gypsum blocks containing thin strips of PTFE to simulate joints were tested under plane stress, uniaxial, and biaxial loading. Regular cross joint patterns were used and orientation relative to loading varied. Stress strain relations and failure mechanisms were examined to study influence of joint directions and lateral stresses on rock mass strength. A strength criterion is developed. Finite element analyses of the tests are also presented.
915047 Geomechanical modelling of joints in rock foundations of structures
Sapegin, D D; Karpov, N M; Nikitin, A A Roe International Symposium on Rock Joints, Loen, 4-6 June 1990 P713-717. Pub1 Rotterdam: A A Balkema, 1990 The pattern and condition of joints in a rock mass are of prime importance to engineering design. Some problems associated with study and evaluation of shear strength properties of rock joints are outlined. Joints can initially be described as homogeneous or heterogeneous. Sample selection so that representative parameters can be obtained in laboratory testing is considered. Statistical treatment of measured shear properties to obtain input values for modelling of jointed rock masses is examined with reference to case studies.
915051 Estimating the shear stiffness of rock joints Infanti, N; Kanji, M A Proc international Symposium on Rock Joints, Loen, 4-6 June 1990 P799-804. Pub1 Rotterdam: A A Balkema. 1990 Stress strain behaviour of rock joints in shear has been studied. Results of 133 in situ tests have been analysed and dependence of unit shear stiffness (Kt) on normal stress, joint thickness, roughness, and tested area examined. Despite the range of test methods and conditions, the following conclusions were arrived at: for the same type of joint, log Kt is linearly related to normal stress; Kt is more dependent on joint characteristics than rock lithology; and there is general correlation between Kt, joint shear strength, and peak tangential displacement. Size effects were not confirmed.
915048 Kinematic mechanisms of shear deformation and validity of Barton’s shear models Xu, S; de Freitas, M H
915052
Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P767-774. Pub1 Rotterdam: A A Balkema, 1990 The shear behaviour of clean rough joints with regular toothshaped profiles has been investigated in a rotary shear machine. Measurements of dilation and shear stress and displacements plus visual observation of the surfaces have been used in critical analysis of the mechanisms of shear deformation and failure. A third kinetic deformation mechanism, flattening of asperity profiles, is proposed in addition to dilation and asperity shear. These results can explain the shape of the peak shear strength envelope of clean rough joints and sup. port Barton’s empirical criteria. Results are presented which indicate Barton’s criteria can be extended to infilled joints. 0
Use of large scale shear boxes for Rhone alluvium materials (In French)
Bourdeau, Y; Lareal, P; Marchal, J froc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P695-696. Pub1 Rotterdam: A A Balkema, 1989 Large shear box devices have been used to investigate shear characteristics of alluvial soils with large and variable grain size. Two apparatuses and two test techniques were applied, one in situ, one in the laboratory. Soils from a number of sites were studied. Results suggest that in situ a weak cohesion (less than 30kPa) exists at normal stress 50-160kPa. Residual friction angles at large strains were also measured.
1991 Pergamon Press plc. Reproduction
not permitted