Effect of bedding plane orientation on the behavior of granular systems
- Univ. of Massachusetts, Lowell, MA (United States)
- Geotechnical Consultants, Inc., North Andover, MA (United States)
The fabric anisotropy of granular materials profoundly influences the aggregate strength and deformation of granular systems. For geological materials, this anisotropy may be the result of depositional processes leading to preferred bedding planes. This paper presents the results of a study on the effects of preferred bedding on the overall mechanical behavior of Granular systems using Discrete Element Method numerical simulations conducted on two dimensional elliptical particles. Samples consisting of multiple sized particles of varying particle aspect ratio were formed by packing particles with their major axes along preferred bedding orientations ranging from horizontal to vertical bedding. Individual particle aspect ratio (major axis : minor axis) ranged from 1:1 to 3:1. The samples were initially compressed to isotropic conditions, then sheared in biaxial shear. Results from these tests exhibit distinctly different stress-strain-strength behavior, as well as different controlling deformational mechanisms, as a function of both bedding plane angle and particle flatness. Shear band formation was observed in some bedding and particle flatness combinations. Interparticle interlocking, dilatancy and inhibition of particle rolling were all observed and significantly affected the overall mechanical behavior. Overall, the samples with bedding orientation normal to the principal stress direction exhibited the highest shear resistance, as well as the largest dilatancy. In systems composed of flat particles with bedding parallel to one of the planes of maximum obliquity, the shear band sometimes formed in the maximum obliquity plane opposite to the bedding plane.
- OSTI ID:
- 175252
- Report Number(s):
- CONF-950686-; TRN: 95:006111-0205
- Resource Relation:
- Conference: Joint applied mechanics and materials summer meeting, Los Angeles, CA (United States), 28-30 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of AMD - MD `95: Summer conference; PB: 520 p.
- Country of Publication:
- United States
- Language:
- English
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