ABSTRACT
Despite the highly uniform density of a random pack ing of noncohesive particles, photoelastic visualizations provide a striking evidence of the heterogeneous distribu tion of contact forces on a scale definitely larger than the typical particle size [1-3]. A quantitative characteriza tion of these distributions is relevant both to mechanical processing (compression, compaction, flow, grinding) and fundamental understanding (mesoscopic scales, instability thresholds) of granular media [4-7].
