Numerical Investigation of Stress Distributions in Stope Backfills

Abstract

Stope backfill is important in avoiding mine collapse during and after extraction phases, ground subsidence in abandoned mines, and environmental damages. The stress distribution is one of the key factors in designing stope backfills. In this paper, we perform a numerical modeling study to investigate the stress distribution within and around the stope backfill. Importantly, our simulation results are in agreement with Marston’s (1930) plain-strain arching theory. The results show that the stress arch is critical in stope backfills. The potential effects of internal friction angle, aspect ratio, and Poisson’s ratio on stress distributions are also analyzed. The stress decreases when the aspect ratio, internal friction angle, and Poisson’s ratio increase. Our results suggest that decreasing the aspect ratio and choosing materials with a high internal friction angle and Poisson’s ratio are important for designing the stope backfill. The cohesive force index and elastic modulus also have significant effects on the stress distribution. Our findings have practical implications in designing stope backfills.