ABSTRACT
One of the intriguing problems that have captured the interest of engineers and scientists is the vertical stress distribution at the base of a granular heap. Many experiments on conical piles of granular materials have indicated, contrary to simple intuition that the maximum vertical stress does not occur directly beneath the sand-pile vertex, but rather at some distance from the apex location resulting in a ring of maximum vertical stress. The literature is now replete with experiments and simulations examining the profiles under static piles of granular materials (see Savage, 1997 & 1998). The dramatic dip in the stress reported by Smid and Novosad (1981) motivated many physicists to examine this problem in detail. Such studies have brought forth conflicting results and competing constitutive models for explaining the observed behavior. While some studies have shown that depending on the construction history little or no stress dip was observed (Vanel et al. 1999), in others the dip was significant (Savage, 1997; Wittmer et al. 1996; Brockbank et al. 1995).
