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Exact formulation of axisymmetric interface-element stiffness matrix. Technical note
107A
932276 Consistent formulation of a dilatant interface element Snyman, M F; Martin, J B Int J Num Anal Meth Geomech V16, N7, July 1992, P493527
932280 Finite element procedure for simulating excavations in elastoplastic soils (In French) Comodromos, E; Pitilakis, K; Hatzigogos, T Rev Fr Geoteeh N58, 1992, P51-66
An interface element suitable for implementation with a standard nonlinear finite element code is presented. It models discontinuities with rough surfaces, such as rock joints, where dilatant behaviour is possible. It can handle all possible histories of opening, closing, and sliding, with dilation or contraction, in any direction. The nonlinear incremental constitutive equations are formulated in a manner appropriate for a backwards difference discretization in time along the path of loading. The concepts are illustrated for sawtooth asperity and limited dilation joint models. The equations are demonstrated within the computer code ABAQUS.
An efficient finite element procedure to simulate multi-stage excavations in elastoplastic soils is presented. It is based on variational principles and includes ghost elements to satisfy the assumption of a stress free excavated surface. The validity of the proposed algorithm is justified theoretically by zero internal virtual work of the excavated domain and numerically with examples assuming linear elasticity and elastoplasticity (perfect and/or with strain hardening).
932277 Finite element slideline approach for calculating tunnel response in jointed rock. Application brief Schwer, L; Lindberg, H E lnt J Num Anal Meth Geomech V16, N7, July 1992, P529540 The general purpose, public domain finite element code D Y N A D 2 D is used to study the effect of rock jointing on response of an unlined tunnel. Sliding interfaces represent the joints. The model problem has previously been approached using the discrete element code UDEC. Results are evaluated for two cases, frictionless joints and resistance to joint motion, and compared to those from UDEC.
932278 Two-dimensional direct boundary method for multilayered elastic media Crouch, S L; Selcuk, S Int J Rock Meeh Min Sci V29, N5, Sept 1992, P491-501 The Direct Boundary Integral Method is described and its numerical implementation illustrated. It is extended to layered systems by use of a substructuring approach. It can be used to provide reasonably quick and accurate solutions for stresses and displacements around surface and underground excavations in a multilayered rock mass. Three sets of example problems are used to verify the method described: circular hole in an infinite strip loaded in tension at infinity; circular hole near the surface of a half-plane; and circular cavity within one of two bonded half planes.
932279 Exact formulation of axisymmetric interface-element stiffness matrix. Technical note Yuan, Z; Chua, K M J Geotech Engng Div ASCE Vl18, NS, Aug 1992, P12641271 A new closed form stiffness matrix for an axisymmetric interface or joint element is presented. It can model rock joints or soil-structure or soil-soil interfaces in the finite element analysis of axisymmetric solids of revolution. It is exact and accurate under all conditions and easily implementable in analysis. The planar interface element is a special case of this element. It is compared to other published stiffness matrix formulations. An example of its use in the case of a circular rigid footing is illustrated.
932281 Nonlinear elastic analysis of jointed rock by Equivalent Volume Defect Method Kaneko, K; Tanaka, Y; Koike, K Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P755-758. Publ Rotterdam: A A Balkema, 1991 Various methods have been proposed to analyse the deformability of jointed rock using a mathematical model in which the rock is considered as an elastic material containing distributed cracks. The Equivalent Volume Defect Model (Kaneko and Shiba) idealises the rock as an elastic material containing volume defects, namely Equivalent Volume Defects. An improvement to the EVDM is proposed for nonlinear elastic analysis of jointed rock. A nonlinear stress strain relation is formulated for a body containing cracks, considering crack closure, frictional sliding, and crack opening. Numerical examples indicate this approach allows reasonable simulation of the behaviour of jointed rock.
932282 Complex investigations in geomechanics on the basis of numerical simulation Kazikaev, D M; Grigoriev, A M; Fomin, B A Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P759-764. Publ Rotterdam: A A Balkema, 1991 Complete description of the geometrical properties of rock masses is extremely difficult, if not impossible. Many design procedures are therefore based on numerical analysis of a simplified geology, combined with physical modelling using equivalent materials and engineering judgement based on in situ observations. Two cases of this sort of approach are described. The first considers stress distribution and safety of pillars in a room and pillar working, the second the effects of deep dewatering of a saturated laminated rock mass on stresses and displacements.
932283 Distinct element analysis of the Fenner-Pacher type characteristic curve for tunnelling Kiyama, H; Fujimura, H; Nishimura, T; Tanimoto, C Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P769-772. Publ Rotterdam: A A Balkema, 1991 One of the main principles of the New Austrian Tunnelling Method is the Fenner-Pacher type characteristic curve. This type of characteristic curve has not yet been determined theoretically, probably due to the limitations of the continuum approaches applied. Discontinuum modelling of tunnelling using the Distinct Element Method is presented. The nature of the characteristic curve revealed is dependent on the initial
© 1993 Pergamon Press Ltd. Reproduction not permitted
932276 Consistent formulation of a dilatant interface element Snyman, M F; Martin, J B Int J Num Anal Meth Geomech V16, N7, July 1992, P493527
932280 Finite element procedure for simulating excavations in elastoplastic soils (In French) Comodromos, E; Pitilakis, K; Hatzigogos, T Rev Fr Geoteeh N58, 1992, P51-66
An interface element suitable for implementation with a standard nonlinear finite element code is presented. It models discontinuities with rough surfaces, such as rock joints, where dilatant behaviour is possible. It can handle all possible histories of opening, closing, and sliding, with dilation or contraction, in any direction. The nonlinear incremental constitutive equations are formulated in a manner appropriate for a backwards difference discretization in time along the path of loading. The concepts are illustrated for sawtooth asperity and limited dilation joint models. The equations are demonstrated within the computer code ABAQUS.
An efficient finite element procedure to simulate multi-stage excavations in elastoplastic soils is presented. It is based on variational principles and includes ghost elements to satisfy the assumption of a stress free excavated surface. The validity of the proposed algorithm is justified theoretically by zero internal virtual work of the excavated domain and numerically with examples assuming linear elasticity and elastoplasticity (perfect and/or with strain hardening).
932277 Finite element slideline approach for calculating tunnel response in jointed rock. Application brief Schwer, L; Lindberg, H E lnt J Num Anal Meth Geomech V16, N7, July 1992, P529540 The general purpose, public domain finite element code D Y N A D 2 D is used to study the effect of rock jointing on response of an unlined tunnel. Sliding interfaces represent the joints. The model problem has previously been approached using the discrete element code UDEC. Results are evaluated for two cases, frictionless joints and resistance to joint motion, and compared to those from UDEC.
932278 Two-dimensional direct boundary method for multilayered elastic media Crouch, S L; Selcuk, S Int J Rock Meeh Min Sci V29, N5, Sept 1992, P491-501 The Direct Boundary Integral Method is described and its numerical implementation illustrated. It is extended to layered systems by use of a substructuring approach. It can be used to provide reasonably quick and accurate solutions for stresses and displacements around surface and underground excavations in a multilayered rock mass. Three sets of example problems are used to verify the method described: circular hole in an infinite strip loaded in tension at infinity; circular hole near the surface of a half-plane; and circular cavity within one of two bonded half planes.
932279 Exact formulation of axisymmetric interface-element stiffness matrix. Technical note Yuan, Z; Chua, K M J Geotech Engng Div ASCE Vl18, NS, Aug 1992, P12641271 A new closed form stiffness matrix for an axisymmetric interface or joint element is presented. It can model rock joints or soil-structure or soil-soil interfaces in the finite element analysis of axisymmetric solids of revolution. It is exact and accurate under all conditions and easily implementable in analysis. The planar interface element is a special case of this element. It is compared to other published stiffness matrix formulations. An example of its use in the case of a circular rigid footing is illustrated.
932281 Nonlinear elastic analysis of jointed rock by Equivalent Volume Defect Method Kaneko, K; Tanaka, Y; Koike, K Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P755-758. Publ Rotterdam: A A Balkema, 1991 Various methods have been proposed to analyse the deformability of jointed rock using a mathematical model in which the rock is considered as an elastic material containing distributed cracks. The Equivalent Volume Defect Model (Kaneko and Shiba) idealises the rock as an elastic material containing volume defects, namely Equivalent Volume Defects. An improvement to the EVDM is proposed for nonlinear elastic analysis of jointed rock. A nonlinear stress strain relation is formulated for a body containing cracks, considering crack closure, frictional sliding, and crack opening. Numerical examples indicate this approach allows reasonable simulation of the behaviour of jointed rock.
932282 Complex investigations in geomechanics on the basis of numerical simulation Kazikaev, D M; Grigoriev, A M; Fomin, B A Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P759-764. Publ Rotterdam: A A Balkema, 1991 Complete description of the geometrical properties of rock masses is extremely difficult, if not impossible. Many design procedures are therefore based on numerical analysis of a simplified geology, combined with physical modelling using equivalent materials and engineering judgement based on in situ observations. Two cases of this sort of approach are described. The first considers stress distribution and safety of pillars in a room and pillar working, the second the effects of deep dewatering of a saturated laminated rock mass on stresses and displacements.
932283 Distinct element analysis of the Fenner-Pacher type characteristic curve for tunnelling Kiyama, H; Fujimura, H; Nishimura, T; Tanimoto, C Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P769-772. Publ Rotterdam: A A Balkema, 1991 One of the main principles of the New Austrian Tunnelling Method is the Fenner-Pacher type characteristic curve. This type of characteristic curve has not yet been determined theoretically, probably due to the limitations of the continuum approaches applied. Discontinuum modelling of tunnelling using the Distinct Element Method is presented. The nature of the characteristic curve revealed is dependent on the initial
© 1993 Pergamon Press Ltd. Reproduction not permitted