Antoine Le Bouil

Experimental studies of precursors to failure in granular material

We investigate experimentally the deformation of granular material before failure occurs. We use different experimental geometries: Couette cell, tilted box, and biaxial test. The deformations are measured with a technique based on the interferences of scattered light, which gives access to a visualization of the heterogeneities of the deformations. We find similarities in the three experiments. At low applied stress, deformations occur in very localized zones. As the stress increases, the sizes of the deformed zones increase, and finally the formation of a shear band occurs.