Numerical modeling by distinct element method is applied to assess microscopic behavior of
granular materials and to technical scheme for numerical laboratory actively. It is difficult, however, to model
initial specimen condition and stress-strain behavior of geotechnical materials by 2-dimensional numerical code.
A study on 3-dimensional distinct element modeling for triaxial compression test was conducted using PFC3D.
Also scale effects for the ratio of numerical model size to particle size on final stress-strain behavior, strength
and deformation properties were investigated.