SMALL-STRAIN RESPONSE OF RANDOM ARRAYS OF SPHERES USING DISCRETE ELEMENT METHOD

Granular soil is represented in this work by a three-dimensional rando m array of rough quartz spheres using the discrete element method. Thr ee-dimensional simulations have previously been performed to study the dynamic small-strain behavior as well as the large-strain behavior of sand at macroscopic level. The three-dimensional small-strain simulat ion presented herein includes the determination of constrained moduli for isotropically and anisotropically loaded random arrays of spheres at microscopic level. The results are in reasonable agreement with the experiments performed on the large triaxial cubical specimen at the U niversity of Texas. It is found that the change of the distribution of contact forces plays a very important role in the above phenomena. Du ring the simulations, the observed macroscopic response is related to the microscopic phenomena at the interparticle contact level.