Shear strength of granular materials

Farhang Radjai (1) , Emilien Azéma (2)

1 PMMG - Physique et Mécanique des Milieux Granulaires
2 LMGC - Laboratoire de Mécanique et Génie Civil

The shear strength properties of granular materials reflect their inherent force and fabric anisotropy. We analyze the role of fabric and force anisotropies with respect to the critical-state shear strength. Then, a model of accessible geometrical states in terms of particle connectivity and contact anisotropy is presented. This model incorporates in a simple way the fact that, due to steric exclusions, the highest levels of connectivity and anisotropy cannot be reached simultaneously, a property that affects seriously the shear strength. We also analyze the force anisotropy in the light of the specific role of weak forces in sustaining strong force chains and thus the main mechanism that underlies anisotropic force patterns. Finally, we briefly discuss the effect of interparticle friction, particle shape, and adhesion.

Mots clés: weak and strong forces; granular media; shear strength; fabric anisotropy; weak and strong forces.

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Farhang Radjai, Emilien Azéma. Shear strength of granular materials. European Journal of Environmental and Civil Engineering, 2009, 13 (2), pp.203-218. ⟨10.3166/ejece.13⟩. ⟨hal-00413398⟩