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Characteristics and integration of undrained response of silty soils
37A 911286 Comparison of single and doable hardening constitutive models for frictional materials
Lade, P V; Pradel, D Proc 3rd International Symposium on Numerical Models in Geomechaaics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P147-154. Pubi London: Elsevier Applied Science, 1989 Two constitutive models, one with a single isotropic yield surface (Kim and Lade, 1988) and one with two intersecting yield surfaces (Lade, 1977),are examined. Their ability to model soil behaviour under a variety of stress paths and their ease of application in large computer programs are compared. Both model stress strain behaviour well, the double hardening model having greater accuracy along stress paths near to the hydrostatic axis. The single hardening model is computationally simpler and more economic. 911287 Constitutive model for soils evaluating principal stress rotation and its application to finite element analysis Matsuoka, H; Suzuki, Y; Murata, T Proc 3rd International Symposium on Numerical Models in Geomechaalcs (NUMOG i!!), Niagara Falls, 8-11 May 1989 P155-162. Pubi London: Elsevier Applied Science, 1989 A constitutive model is presented in which general strain increments are directly related to general stress increments. To evaluate influence of rotation of principal stress axes on strain, experiments using a circular stress path were carried out on a stack of aluminium rods in a two dimensional general stress apparatus. The general stress path dependency of strains was also examined using this apparatus, and analysed with the proposed model. Finite element simulation of a soil foundation under uniform strip load shows settlements and lateral displacements are affected by principal stress rotation. 911288 Characteristics and integration of undrained response of silty soils Axelsson, K; Runesson, K, Sture, S; Yu, Y; Alawaji, H Proc 3rd International Symposium oa Numerical Models in Geomeclumics (NUMOG !!1), Niagara Falls, 8-11 May 1989 P195-203. Pubi London: Elsevier Applied Science, 1989 Undrained triaxial tests on silts show contractive behaviour at small strain, then dilatant behaviour leading up to failure. A constitutive model based on elastoplasticity is presented and investigated numerically. Volumetric hardening/softening and deviatoric hardening are included and non-associated yielding is accounted for in dilatant behaviour. The Closest Point Projection method is used for integration of the constitutive relations, and an iterative solution strategy derived to resolve the incremental stress strain relation subjected to incompressibility constraints. 911289 Continuum approach for plastic-brittle materials with application to u reinforced concrete structure
Jiang, J; Pietrusczak, S Proc 3rd International Symposium on Numerical Models in Geomeckanics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P223-232. Publ London: Elsevier Applied Science, 1989 A simple, rate-independent constitutive model for concrete or rock-like materials, developed within the theory of plasticity, is presented. Its application to model the response of concrete subjected to low confining pressures is illustrated. Transition from stable to unstable behaviour is governed by an appropriate criterion for inception of strain Iocalisation. An additional
criterion allows unique determination of ductile-brittle transition pressure. The model is used in a finite element analysis of reinforced concrete slabs. 911290
Simulations of Prevost's pressure sensitive model Derradji-Aouat, K; Evgin, E Proc 3rd International Symposium on Numerical Models in Geomeehanics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P256-263. Publ London: Elsevier Applied Science, 1989 Prevost's pressure sensitive multisurface plasticity model for soil takes into account the effect of hydrostatic pressure on yielding, and can be used to simulate drained conditions. It was implemented in a three dimensional stress driven computer code to model triaxial tests on crushed quartz sand, and published data on simple shear and cyclic triaxial behaviour of sand. In all cases shear stress-strain behaviour was simulated satisfactorily, but predictions of volume strain were not always accurate.
Design methods See also: 911308 911291
Computerized mine planning at Rio Tinto Mincra's Cerro Colorado open-pit operation, southern Spain - a case study. Technical note Preller, A; Rich, C Trcms last MIU Metall (Sect A MIU lad) V99, Jan-April 1990, PA42-A46 The system, based on a dedicated minicomputer, was designed to upgrade ore reserve calculation and mine planning at Cerro Colorado. It includes an open pit design module for long term planning and a mine scheduling system for intermediate scheduling. Input data from initial diamond drilling is continually updated with that from reverse circulation blasthole drilling. Further enhancements will improve very short term operational aspects. 911292 Application of Minenet softwave system at Enonkoski mine, Finland. Technical note Pulkkinen, M; Pihko, A; Tanskanen, P; Loven, P Traus last Mia Metall (Sect A MIU Iad) V99, Jan-April 1990, PASO-AS3 The Minenet package has been used at Outokumpu's Enonkoski underground mine for more than 3 years. Information from core logging, rock type, jointing, RQD, is first used in rough modelling of the orebody. Assay data are used to refine this model, and ore grades and reserves estimated by conventional and geostatistical methods. Economic feasibility, mine layout design, stope planning, and drilling design are then evaluated. Each stope can be assessed for scheduling in both the long and short term. 911293
Mine activity and resource scheduling with use of 'Threedimensional component modelling'. Technical note Houlding, S W; Stoakes, M A Trans last MIU Metall (Sect A MIU lad) V99, Jan-April 1990, PA53-A59 The 'Three-dimensional component modelling' concept separates evaluation of ore deposits and mine design and planning into their intuitive parts: three dimensional modelling to represent solid shapes, geostatistical modelling to represent variation of numerical attributes, and surface modelling to
© 1991 Pergamon Press plc. Reproduction not permitted
Lade, P V; Pradel, D Proc 3rd International Symposium on Numerical Models in Geomechaaics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P147-154. Pubi London: Elsevier Applied Science, 1989 Two constitutive models, one with a single isotropic yield surface (Kim and Lade, 1988) and one with two intersecting yield surfaces (Lade, 1977),are examined. Their ability to model soil behaviour under a variety of stress paths and their ease of application in large computer programs are compared. Both model stress strain behaviour well, the double hardening model having greater accuracy along stress paths near to the hydrostatic axis. The single hardening model is computationally simpler and more economic. 911287 Constitutive model for soils evaluating principal stress rotation and its application to finite element analysis Matsuoka, H; Suzuki, Y; Murata, T Proc 3rd International Symposium on Numerical Models in Geomechaalcs (NUMOG i!!), Niagara Falls, 8-11 May 1989 P155-162. Pubi London: Elsevier Applied Science, 1989 A constitutive model is presented in which general strain increments are directly related to general stress increments. To evaluate influence of rotation of principal stress axes on strain, experiments using a circular stress path were carried out on a stack of aluminium rods in a two dimensional general stress apparatus. The general stress path dependency of strains was also examined using this apparatus, and analysed with the proposed model. Finite element simulation of a soil foundation under uniform strip load shows settlements and lateral displacements are affected by principal stress rotation. 911288 Characteristics and integration of undrained response of silty soils Axelsson, K; Runesson, K, Sture, S; Yu, Y; Alawaji, H Proc 3rd International Symposium oa Numerical Models in Geomeclumics (NUMOG !!1), Niagara Falls, 8-11 May 1989 P195-203. Pubi London: Elsevier Applied Science, 1989 Undrained triaxial tests on silts show contractive behaviour at small strain, then dilatant behaviour leading up to failure. A constitutive model based on elastoplasticity is presented and investigated numerically. Volumetric hardening/softening and deviatoric hardening are included and non-associated yielding is accounted for in dilatant behaviour. The Closest Point Projection method is used for integration of the constitutive relations, and an iterative solution strategy derived to resolve the incremental stress strain relation subjected to incompressibility constraints. 911289 Continuum approach for plastic-brittle materials with application to u reinforced concrete structure
Jiang, J; Pietrusczak, S Proc 3rd International Symposium on Numerical Models in Geomeckanics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P223-232. Publ London: Elsevier Applied Science, 1989 A simple, rate-independent constitutive model for concrete or rock-like materials, developed within the theory of plasticity, is presented. Its application to model the response of concrete subjected to low confining pressures is illustrated. Transition from stable to unstable behaviour is governed by an appropriate criterion for inception of strain Iocalisation. An additional
criterion allows unique determination of ductile-brittle transition pressure. The model is used in a finite element analysis of reinforced concrete slabs. 911290
Simulations of Prevost's pressure sensitive model Derradji-Aouat, K; Evgin, E Proc 3rd International Symposium on Numerical Models in Geomeehanics (NUMOG !!!), Niagara Falls, 8-11 May 1989 P256-263. Publ London: Elsevier Applied Science, 1989 Prevost's pressure sensitive multisurface plasticity model for soil takes into account the effect of hydrostatic pressure on yielding, and can be used to simulate drained conditions. It was implemented in a three dimensional stress driven computer code to model triaxial tests on crushed quartz sand, and published data on simple shear and cyclic triaxial behaviour of sand. In all cases shear stress-strain behaviour was simulated satisfactorily, but predictions of volume strain were not always accurate.
Design methods See also: 911308 911291
Computerized mine planning at Rio Tinto Mincra's Cerro Colorado open-pit operation, southern Spain - a case study. Technical note Preller, A; Rich, C Trcms last MIU Metall (Sect A MIU lad) V99, Jan-April 1990, PA42-A46 The system, based on a dedicated minicomputer, was designed to upgrade ore reserve calculation and mine planning at Cerro Colorado. It includes an open pit design module for long term planning and a mine scheduling system for intermediate scheduling. Input data from initial diamond drilling is continually updated with that from reverse circulation blasthole drilling. Further enhancements will improve very short term operational aspects. 911292 Application of Minenet softwave system at Enonkoski mine, Finland. Technical note Pulkkinen, M; Pihko, A; Tanskanen, P; Loven, P Traus last Mia Metall (Sect A MIU Iad) V99, Jan-April 1990, PASO-AS3 The Minenet package has been used at Outokumpu's Enonkoski underground mine for more than 3 years. Information from core logging, rock type, jointing, RQD, is first used in rough modelling of the orebody. Assay data are used to refine this model, and ore grades and reserves estimated by conventional and geostatistical methods. Economic feasibility, mine layout design, stope planning, and drilling design are then evaluated. Each stope can be assessed for scheduling in both the long and short term. 911293
Mine activity and resource scheduling with use of 'Threedimensional component modelling'. Technical note Houlding, S W; Stoakes, M A Trans last MIU Metall (Sect A MIU lad) V99, Jan-April 1990, PA53-A59 The 'Three-dimensional component modelling' concept separates evaluation of ore deposits and mine design and planning into their intuitive parts: three dimensional modelling to represent solid shapes, geostatistical modelling to represent variation of numerical attributes, and surface modelling to
© 1991 Pergamon Press plc. Reproduction not permitted