Mechanical Behavior of Granular Materials Considering Confining Pressure Dependency

The mechanical behaviors of granular materials change significantly with the variation of confining pressure. In this study, the effect of confining pressures on the mechanical behavior of granular materials was observed using the discrete element method (DEM). Seven triaxial compression tests were conducted covering a range from extremely low to high confining pressure. Each isotropically compacted specimen contains similar number of spherical particles of same porosity. The stressstrain- volumetric responses show good agreement with the experimental behavior of granular materials under extremely low to high confining pressures. Total shear work done per unit volume increases with the increase of confining pressure. However, a unique relationship was observed between normalized work and axial strain under different confining pressures. Microscopic parameter such as coordination number increases with the increase of confining pressure both for extremely low and low to high confining pressures. However, the tendency of the evolution of coordination number is quite different in extremely low and low to high confining pressures.