On the mechanical response of anisotropic granular materials

The subject of this thesis is the mechanical response of inherently anisotropic granular materials. The study comprises both the experimental and numerical aspects and provides a rigorous methodology for the solution of geotechnical problems involving anisotropic frictional materials.;The numerical part of this work was associated with development and. implementation of a constitutive framework that describes the mechanical response of transversely isotropic frictional materials. The framework is based on elasto-plasticity and accounts for the effects of strain localization and inherent anisotropy of both the deformation and strength characteristics. An implicit scheme was proposed for identification of material parameters/functions, which incorporates predictions based on critical plane analysis. As a part of constitutive modeling, a suitable numerical algorithm was also developed to integrate the constitutive equations.;The constitutive framework has been implemented in a commercial FE package (ABAQUS). A series of numerical simulations were carried out focused on the assessment of the bearing capacity of a shallow foundation in transversely isotropic granular medium. The results of numerical simulations have been compared with the experimental data. A parametric study was also carried out aimed at examining the influence of various simplifications in the mathematical framework on its predictive abilities.;The experimental investigation has been carried out at both the material and structural levels. The material tests involved a series of direct shear, triaxial and hollow cylinder experiments on crushed limestone sand, whose mechanical characteristics are strongly affected by the orientation of the sample. In addition, a scaled foundation setup was designed and a series of experimental tests was carried out to examine the effects of anisotropy on bearing capacity.