Numerical study of one-dimensional compression in granular materials

Abstract

The discrete element method has been employed to simulate vertical one-dimensional compression of an idealised soil. Direct measurement of the full stress tensor was possible and the results show that K_0 (the ratio of horizontal to vertical effective stresses) increases with void ratio, which is consistent with previous experimental studies. The anisotropic fabric induced during compression was quantified by considering the orientations and magnitudes of the normal contact forces. For the denser samples there was a definite bias towards more vertically oriented contacts, resulting in lower stresses being transmitted in the horizontal direction for a given vertical stress. In contrast, the contacts were oriented more isotropically in the looser samples, allowing more similar stresses to be transmitted in the horizontal and vertical directions