شبكة التخطيط العمراني بسم الله الرحمن الرحيم
للكاتب
Omar Al-Hattamleh
Department of Civil Engineering – Hashemite University – Jordan
ABSTRACT:
Localisation of deformation into narrow shear bands is a fundamental phenomenon in
granular materials. Constitutive equations that do not consider the effect of higher order
deformation gradients fail to predict deformation patterns that persist and eventually dominate
shear bands. This paper presents a higher order gradient multi-slip formulation to model the
effect of inhomogeneous deformation in granular materials. The effects of inherent
anisotropy within the multi-slip formulation are accounted for directly. The mobilized
friction in a pressure dependent yield surface is assumed to be a direct function of the fabric
tensor. The formulation with two active slip systems has been implemented into a finite
element code and used to simulate biaxial shear tests on dry sand. The analysis is quantifies
most of the shear band characteristics observed by past experimentation. It is found that
initial fabric lead to very different localised behaviour in granular materials.