Use of a reduced scale physical model of a mine stope for assessing waste rock barricades potential instabilities due to early age pastefill pressure

ABSTRACT: This paper presents a reduced scale physical model of a mine stope used to reproduce the underground stope backfilling practiced in some Canadian mines. The objective is to study the geomechanical behavior of the waste rock barricades in interaction with the mine backfill. The instrumentations along with visual observations and preliminary results are presented. The main results demonstrated that: i) the stability of barricade depends on the properties of the barricade (size, position, particles gradation and compaction) and the friction between the barricade and the drift walls; ii) for two backfills containing 76% and 70% of solid percentage (by weight), the volumetric strain after the self-weight consolidation inside the filling chamber varied from 2% to 10%, respectively. In addition, the results showed the importance of using shotcrete around the barricade especially at the top of the downstream side to close the gaps and bind the barricade particles, which improves the barricade stability.