1γ2ε' : a new shear apparatus to study the behavior of granular materials

In this paper, we present a new kinematic shearing apparatus named “1γ2ɛ,” which has been developed at the Institut de Mecanique de Grenoble (IMG) with the financial support of the GRECO Geomateriaux. Thanks to its kinematic control, a specimen may be subjected to conditions found in general plane strain. Our aim is to study the rheology of granular material in situations with rotation of strain or stress principal axes. Following the initial description of our technical choices for the design of this new apparatus, we present results concerning isotropic tests and tests at constant volume with and without rotation of principal axes. It should be noted that the cyclic effect of rotation of principal axes may induce liquefaction.