Despite of being a vigorous constituent of natural and built environment, three dimensional interaction and behavior of the granular media is not yet convincingly understood. As a part of the progressive effort to achieve this goal, a three dimensional numerical model , based in Discrete Element Method (DEM), is developed and validated for fundamental principal of energy conservation and elasto-plasticity of the material. The model successfully simulates the conservation of total energy, pure elastic and elasto-plastic behavior of granular material. A plain strain compression test is also performed on the three dimensional specimen of the material, with- and with-out the pre-consolidation pressure to reproduce field conditions. A typical behavior of stress ratio with a peak value followed by strain softening has been successfully replicated. The void ratio has shown a trend of first decreasing and then dilating before becoming constant, which is in close agreement to the actual behavior.
Key words: Numerical modelling,discrete element method, granular media, validation, visco-elasticity, plain strain compression