Analyse numérique de la stabilité des piliers-dalles en remblai cimenté : une vérification des modèles de Mitchell

The mining industry is facing several challenges on the technological, economic and environmental fronts. Mine backfill is one of the most suitable solution to improve ground control in underground operations and increase ore extraction rate. It also allows reducing the quantity of mine waste to dispose at the surface, therefore reducing the environmental impact. In practice, mine backfill is used in different ways. When the walls and ore bodies are of poor quality, an underhand cut-and-fill mining method is adopted. In such cases, cemented backfill sill mats must be built to replace the ore sill pillars. If the sill mat is well designed and built, working under a cemented backfill sill mat would be much safer than working under ore sills. A critical aspect is to determine the necessary strength for such cemented backfill sill mats. An overestimation of the required strength induces unnecessary additional expenses linked to the excessive use of cement, and can consequently compromise the profitability of mining operations. An underestimation of the required sill mat strength can have more serious consequences, given that a failure of these sill mats can harm, even kill the personnel working under the sill mat and also damage the equipment.