Résumé
Using extensive Contact Dynamics simulations, we present a systematic analysis concerning the effects of particle shape angularity on the quasi-static shear strength properties of cohesive granular packings under biaxial conditions for various confining stresses sigma(0). We consider irregular polygons with an increasing number of sides, ranging from triangles to discs. The packings behavior depends on the dimensionless Cohesive Index eta = f(0)/(sigma(0)d), where f(0) is the contact adhesive force and d is the mean grain diameter. eta is varied between 0 (dry) to 0.6 (strongly cohesive) by varying sigma(0). We find that the macroscopic friction angle increases with grain angularity and saturates at larger angularity, as in the dry case. In contrast, the cohesive strength is an increasing function of grain angularity. Our results contribute to a better understanding of the effects of grain shape on the behaviour of cohesive granular materials, by complementing a number of results obtained mainly in the dry case.