New rheological model for soils

New rheological model for soils

276A the flow continuity equation in its formulation to account for temperature induced effects. It is used within the finite element code CONOIL II a...

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276A the flow continuity equation in its formulation to account for temperature induced effects. It is used within the finite element code CONOIL II and its results validated by comparison with closed form solutions and laboratory data. 9150!34 Complete creep curves under uniaxial compression. Technical note

Okubo, S; Nishimatsu, Y; Fukui, K tnt J Rock Mech Min Sci V28. Nl. Jan 1991, P77-82 Complete creep curves were obtained for cement-mortar and 5 rock samples using a specially developed testing machine with a computer aided measurement system able to cope with very low secondary creep rates and high rates in the tertiary phase. Strain rate increases in inverse proportion to remaining life in tertiary creep, providing possibility of predicting failure time. A constitutive equation is developed which is in good agreement for the 5 rock types but not for the case of cement mortar. A more general form may be required in this last case. 915085 Unified viscoplastic model for the inelastic flow of alkali halides

Aubertin, M; Gill, D E; Ladanyi, B Mech Mater VII. Nl, March 1991, P63-82 The SUVIC (Strain-rate-history-dependent Unified Viscoplastic model with Internal variables for Crystalline materials) to describe inelastic behaviour of alkali halides is presented. It consists of a kinematic law and three evolution laws associated with three state variables. Two are internal stresses, opposing the applied stress and inducing kinematic and isotropic hardening respectively. The third is a scalar used to normalise the active stress and contributing to the isotropic hardening. The unified model is physically based, describes plastic and creep deformation, and gives results in close agreement with test data. 9150% Evaluation of the long-term stability of creep-prone slopes

Zaretskii, Y K; Vorobev, V N Soil Mech Found Engng V27. N3, May-June 1990, PI25132

A numerical approach to long term stability of slopes is presented which is based on finite element analysis and the principle of virtual work in the form of virtual displacements. It takes into account interrelations between stress and strain states of the soil and can be used to study the effects of natural and additional loads posed by drainage or structures. Times to failure predicted by this method are significantly longer than those. from conventional analysis assuming strength characteristics corresponding to the ultimate long term strength. 915087 Investigation of shear strength of slurry clay

Inoue, T; Tan, T S; Lee, S L Soils Found V30, N4, Dee 1990. PI-10 A penetration test method to determine shear strength of clay slurries is proposed in which a thin tube or plate is held vertically in equilibrium with the slurry such that only vertical yield shear stress is mobihsed, allowing a simple boundary value problem. Validity of the method is checked using results from a series of viscometer tests. The rheology of clay slurries has been examined. They act according to Bingham and power law models, respectively, at low and high strain rates. For different clays, a unique relation is obtained for a plot of shear strength against the ratio of water content to liquid limit. When this ratio is below 2, the slurry behaves as a paste. 0

915088 Cone penetrometer tests in permafrost - ‘Ihe Fox tunnel, Alaska

Ladanyi, B; Huneault, PA Proc 1st International Symposium on Mining in the Arctic, Fairbanks, 17-19 July 1989 P75-82. Pub1 Rotterdam: A A Balkema, 1989 Cone penetration tests (CPT) were carried out in a permafrost tunnel in order to estimate more general soil parameters needed in permafrost engineering practice. Two Furgo penetrometers of 5 and 10 ton capacity were instrumented for measuring point resistance. Time dependent behaviour of frozen silt was examined at relatively slow strain rates ranging over several orders of magnitude. Creep parameters determined using cavity expansion theory compare favourably with published data on Fairbanks silt.

915089 New rheological model for soils Kanoun, F Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 Vl, P719-721. Pub1 Rotterdam: A A Balkema, 1989 A spring/sliding block/dashpot rheological model is presented. It simulates the stress path of the soil and considers its influence on soil behaviour and strength. Collapse of the soil structure during loading is simulated. Drained and undrained behaviour, including Terzaghi’s consolidation model, can be described.

915090 Physico-chemical fundamentals of soil microrheology

Osipov, V I Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August IWO Vl, P713-724. Pub1 Rotterdam: A A Balkema. 1990 Deformation, in particular time dependent deformation, of soils is analysed from the point of nature and behaviour of individual points of contact between particles in a soil mass. Separate contacts are examined, and rheologic models are developed which represent systems of parallel element groups to simulate behaviour of specific contact types. The basic rheologic behaviour patterns of soils can be explained by these models.

915091 Comparison of rheological models in view of prediiting the behaviour of a deep clay host rock during the construction of a radwaste repository De Bruyn, D; Aubry, D; Rousset, G

Proc 3rd International Symposium on Numerical MoaW in Geomechanics (NUMOG III), Niagara Fails, 8-11 May I989 P724-732. Pub/ London: Elsevier Applied Science, 1989 The Boom clay formations in Belgium are under investigation as potential repository host materials. Excavation of galleries for the final repository was simulated using the viscoplastic finite element codes GEFDYN and GEOMEC. Rheological parameters were chosen on the basis of laboratory testing and adjusted according to parameter fitting obtained from numerical simulation of a small experimental drift. Predictions are compared to measurements from construction of a full scale drift.

1991 Pergamon Press plc. Reproduction

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