Stress propagation in granular media: Breaking of any constitutive state equation relating
local stresses together by a change of boundary conditions
Abstract: The stress response of a granular assembly subject to different changes
of boundary conditions is studied experimentally in order to define the stress
propagation characteristics. These results demonstrate that no simple and
single relationship between local stresses exists, which would be imposed by
the local structure of the granular assembly only in general. On the contrary,
it is demonstrated that these results are controlled by the boundary conditions
themselves and that a tiny change of them may lead to strong variations in the
incrememental-stress relation; furthermore, in other cases, these changes may
generate large variations of the stress field and can allow to understand
partly the fluctuations already observed in these media.
PACS: 46.10+z ; 46.30.-i ;
81.05.Rm
poudres & grains 7, 1-18 (octobre 1999)