Strain path controlled shear tests on an analogue granular material

A series of strain controlled tests have been performed on a two-dimensional analogue granular material, composed of three different sizes of rods, in a special laboratory apparatus which permits full control of plane deformations, including rotation of principal axes. These tests have been designed and used to explore certain constitutive conjectures concerning the mechanical behaviour of granular materials. The results, within the accuracy of the apparatus, show that irrespective of the initial stress history of the material, proportional strain paths (if continued for long enough) lead to proportional stress states (asymptotic states). The asymptotic states appear to be independent of the fixed imposed rotation of principal strain axes and at these states coaxiality between the principal stress direction and the principal incremental strain direction seems to be reached. A stress dilatancy relationship between the imposed dilatancy and the corresponding asymptotic stress ratio has been identified.

[1]  Jian Chu,et al.  Strain‐Softening Behavior of Granular Soil in Strain‐Path Testing , 1992 .

[2]  M. Fahey,et al.  Deformation of granular materials due to rotation of principal axes , 1998 .

[3]  Hackmet Aly Joer.  Une nouvelle machine de cisaillement pour l'étude du comportement des milieux granulaires : 1[gamma]2[epsilon] , 1991 .

[4]  J. R. F. Arthur,et al.  Induced anisotropy in a sand , 1977 .

[5]  Gerd Gudehus,et al.  Observed stress-strain behaviour of remoulded saturated clay under plane strain conditions , 1990 .

[6]  Isam Shahrour,et al.  INSTABILITY AND STATIC LIQUEFACTION ON PROPORTIONAL STRAIN PATHS FOR SAND AT LOW STRESSES , 2004 .

[7]  Yoginder P. Vaid,et al.  LABORATORY CHARACTERIZATION OF STRESS-STRAIN BEHAVIOR OF SOILS BY STRESS AND/OR STRAIN PATH LOADING , 2001 .

[8]  Yoginder P. Vaid,et al.  Instability and liquefaction of granular soils under undrained and partially drained states , 1998 .

[9]  Félix Darve,et al.  Instabilities in granular materials and application to landslides , 2000 .

[10]  Giulia M.B. Viggiani,et al.  Experimental observation of the behaviour of a 2D granular material with inclusions , 2002 .

[11]  David M. Potts,et al.  NUMERICAL ANALYSIS OF DRAINED DIRECT AND SIMPLE SHEAR TESTS. DISCUSSION AND CLOSURE , 1993 .

[12]  Jacques Desrues,et al.  1γ2ε' : a new shear apparatus to study the behavior of granular materials , 1992 .

[13]  Jian Chu,et al.  Asymptotic behaviour of a granular soil in strain path testing , 1994 .

[14]  Jian Chu,et al.  Instability of Granular Soils under Strain Path Testing , 1993 .

[15]  K. S. Chua,et al.  Principal stress rotation: A missing parameter , 1980 .

[16]  Andrew Palmer,et al.  Plasticity theory without yield surfaces , 1973 .