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Zoned finite strip method and its applications in geomechanics
173A
Analysis Techniques and Design Methods 923268
Application of neural network models to rock mechanics and rock engineering. Technical note Quing Zhang; Jiarong Song; Xiaoyan Nie Int J Rock Mech Min Sci V28, N6, Nov 1991, 1'535-540 The behaviour of geological materials is complex, affected by many factors relating formation processes and geological and engineering environment. Conventional mathematical analyses consider only some of these factors, and are often at variance with experimental behaviour. Neural networks, a concept in artificial intelligence, can potentially solve this problem, considering governing factors as a whole. The concepts of a neural network and its algorithm are outlined and applied to assessment of pressure exerted on a coal mine and physical properties of a sandstone, taking account of the many influences on each.
Rock block analysis 923269 Modelling of jointed rock masses using the distinct element method Choi, S K; Coulthard, M A Proc International Conference on Meckamcs of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P471-477. Publ Rotterdam: A A Balkema, 1990 The three main approaches to modelling of jointed rock masses are outlined, explicit modelling of joints, equivalent continuum models, and generalised continuum models. The application of the DEM using the UDEC code is illustrated for two cases. Results from analysis of simple active and passive trapdoor problems are compared to Cosserat continuum limit load calculations. Subsidence due to underground mining is also modelled and results compared to field and laboratory observations. The main advantages and disadvantages of the DEM are discussed. 923270 Some practical aspects of numerical simulation of jointed rock mass by distinct element method Iofis, I M; Maksimov, A V; Mironov, V V Proc lntermaiomd Conference on Meckattcs of Jointed and Faulted Rock, Viemm, 18-20 April 1990 1'479-486. Publ Rotterdam: A A Balkema, 1990 The implementation and practical uses of the DEM are discussed. A general concept of the implicit time integration technique and specifics for use of the DEM with explicit time integration are presented. The functional structure of the programs is described. Two computational examples are illustrated, deformation of the bedrock of a gravity dam with sliding and dilating joints, and analysis of stability of a large cavern in blocky rock. 923271 Probabilistic analysis of keybiock failures Hoerger, S F; Young, D S Proc lntersmtiotml Conference om Meclmnics of Jointed aml Faulted Rock, giemm, 18-20 April 1990 P503-508. Publ Rotterdam: A A Balkema, 1990
constant orientation. This allows calculation of the positional probabifity of failure, and combined effects of all shapes of keybiocks can be analysed at the same time. The most likely positions of keyblock failure are determined. Joint simulation and identification of keyblock procedures are described, and an example of selection of tunnel orientation in a rock mass is illustrated.
Stress analysis See also: 923063, 923111, 923116, 923253, 923396 923272 Yielding and damage of intact rock Ofoegbu, G I; Curran, J H Can Geotech J V28, N4, Aug 1991, P503-516 A procedure to describe the elastic deformability and strength of intact rock is presented. The decrease in load bearing capacity and elastic stiffness caused by structural defects such as microcracks is accounted for using a continuum damage variable. Values of this are calculated using an incremental evolution law. Elastic deformability is described in terms of the damage variable and stiffness of the uncracked rock. Rock strength is defined in terms of the ratio of the distortional to hydrostatic intensities of the stress tensor. Measurement of damage and shear resistance is illustrated using results of laboratory triaxial tests on norite. 923273 Constitutive model for the effective stress stress-strain behaviour of oil sands Wan, R G; Chart, D H; Kosar, K M Can Pet Teclmol V30, N4, July-Aug 1991, P89-98 A non-associated generalised plasticity model for oil sands in 3D stress conditions has been developed on the basis of drained triaxiai tests at different temperatures and confining pressures. Hardening, softening, dilatancy, and contraction are incorporated into the formulation. When implemented within the finite element code ABAQUS, numerical results are in reasonable agreement with observed behaviour. 923274 Zoned finite strip method and its applications in geomechanies Oskoorouchi, A M; Novrouzian, B; De Roeck, G; Van Den Brock, J Compmt Geotoch V11, N4, 1991, P265-294 The technique of the finite strip method has been extended for zoned strips, each of which can have several different materials (including dummy materials) in the horizontal direction. The ZFS method is presented and applied to three geotechnical problems which could not be solved by the original finite strip method: displacement and stresses at the face of a vertical excavation and within the soil media; design and analysis of tunnels; and stresses and displacement along embankment dams and their foundations. Comparisons are made with finite element solutions, which show the ZFS method gives excellent accuracy with low computational effort. 923275 Numerical simulation of idealized granular assemblies with
plane elliptical particles Rothenburg, L; Bathurst, R J Compmt Geoteck VII, N4, 1991, t'315-329
Development of algorithms for use in computer simulation of An approach to prediction of size and frequency of keyblock • behaviour of ideafised granular materials consisting of elliptifailure is presented in which joint orientation is treated as a cal particles is described. The contact model, contact detecprobabilistic variable, rather than forcing each set to have a tion, contact list updating, assembly generation, and typical © 1992 Pergamon Press Ltd. Reproduction not permitted
Analysis Techniques and Design Methods 923268
Application of neural network models to rock mechanics and rock engineering. Technical note Quing Zhang; Jiarong Song; Xiaoyan Nie Int J Rock Mech Min Sci V28, N6, Nov 1991, 1'535-540 The behaviour of geological materials is complex, affected by many factors relating formation processes and geological and engineering environment. Conventional mathematical analyses consider only some of these factors, and are often at variance with experimental behaviour. Neural networks, a concept in artificial intelligence, can potentially solve this problem, considering governing factors as a whole. The concepts of a neural network and its algorithm are outlined and applied to assessment of pressure exerted on a coal mine and physical properties of a sandstone, taking account of the many influences on each.
Rock block analysis 923269 Modelling of jointed rock masses using the distinct element method Choi, S K; Coulthard, M A Proc International Conference on Meckamcs of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P471-477. Publ Rotterdam: A A Balkema, 1990 The three main approaches to modelling of jointed rock masses are outlined, explicit modelling of joints, equivalent continuum models, and generalised continuum models. The application of the DEM using the UDEC code is illustrated for two cases. Results from analysis of simple active and passive trapdoor problems are compared to Cosserat continuum limit load calculations. Subsidence due to underground mining is also modelled and results compared to field and laboratory observations. The main advantages and disadvantages of the DEM are discussed. 923270 Some practical aspects of numerical simulation of jointed rock mass by distinct element method Iofis, I M; Maksimov, A V; Mironov, V V Proc lntermaiomd Conference on Meckattcs of Jointed and Faulted Rock, Viemm, 18-20 April 1990 1'479-486. Publ Rotterdam: A A Balkema, 1990 The implementation and practical uses of the DEM are discussed. A general concept of the implicit time integration technique and specifics for use of the DEM with explicit time integration are presented. The functional structure of the programs is described. Two computational examples are illustrated, deformation of the bedrock of a gravity dam with sliding and dilating joints, and analysis of stability of a large cavern in blocky rock. 923271 Probabilistic analysis of keybiock failures Hoerger, S F; Young, D S Proc lntersmtiotml Conference om Meclmnics of Jointed aml Faulted Rock, giemm, 18-20 April 1990 P503-508. Publ Rotterdam: A A Balkema, 1990
constant orientation. This allows calculation of the positional probabifity of failure, and combined effects of all shapes of keybiocks can be analysed at the same time. The most likely positions of keyblock failure are determined. Joint simulation and identification of keyblock procedures are described, and an example of selection of tunnel orientation in a rock mass is illustrated.
Stress analysis See also: 923063, 923111, 923116, 923253, 923396 923272 Yielding and damage of intact rock Ofoegbu, G I; Curran, J H Can Geotech J V28, N4, Aug 1991, P503-516 A procedure to describe the elastic deformability and strength of intact rock is presented. The decrease in load bearing capacity and elastic stiffness caused by structural defects such as microcracks is accounted for using a continuum damage variable. Values of this are calculated using an incremental evolution law. Elastic deformability is described in terms of the damage variable and stiffness of the uncracked rock. Rock strength is defined in terms of the ratio of the distortional to hydrostatic intensities of the stress tensor. Measurement of damage and shear resistance is illustrated using results of laboratory triaxial tests on norite. 923273 Constitutive model for the effective stress stress-strain behaviour of oil sands Wan, R G; Chart, D H; Kosar, K M Can Pet Teclmol V30, N4, July-Aug 1991, P89-98 A non-associated generalised plasticity model for oil sands in 3D stress conditions has been developed on the basis of drained triaxiai tests at different temperatures and confining pressures. Hardening, softening, dilatancy, and contraction are incorporated into the formulation. When implemented within the finite element code ABAQUS, numerical results are in reasonable agreement with observed behaviour. 923274 Zoned finite strip method and its applications in geomechanies Oskoorouchi, A M; Novrouzian, B; De Roeck, G; Van Den Brock, J Compmt Geotoch V11, N4, 1991, P265-294 The technique of the finite strip method has been extended for zoned strips, each of which can have several different materials (including dummy materials) in the horizontal direction. The ZFS method is presented and applied to three geotechnical problems which could not be solved by the original finite strip method: displacement and stresses at the face of a vertical excavation and within the soil media; design and analysis of tunnels; and stresses and displacement along embankment dams and their foundations. Comparisons are made with finite element solutions, which show the ZFS method gives excellent accuracy with low computational effort. 923275 Numerical simulation of idealized granular assemblies with
plane elliptical particles Rothenburg, L; Bathurst, R J Compmt Geoteck VII, N4, 1991, t'315-329
Development of algorithms for use in computer simulation of An approach to prediction of size and frequency of keyblock • behaviour of ideafised granular materials consisting of elliptifailure is presented in which joint orientation is treated as a cal particles is described. The contact model, contact detecprobabilistic variable, rather than forcing each set to have a tion, contact list updating, assembly generation, and typical © 1992 Pergamon Press Ltd. Reproduction not permitted