Probabilistic and Deterministic Approach to Define the Vertical Stress in Inclined Mine Stopes

Due to its environmental utility and capacity to increase the stability of mine excavations, underground mine backfilling is a proven technique and has become a common practice in the mining industry. The backfilling of underground stopes is a technique that has been used for decades in Canada and worldwide. In the last few years, several contributions reported the potential of analyzing backfill stress in mine stopes through analytical equations, numerical modeling, and in situ measurements. Using a probabilistic stress analysis approach, this study proposes an analytical solution to determine the stress of a backfill on the pillar of an inclined mine stope to rectify its mathematical and physical limitations. The backfill parameters utilized in these analyses were obtained from laboratory investigation data conducted at the Canadian Niobec mine in Quebec. Monte Carlo simulations were employed to generate a comprehensive database encompassing both analytical and numerical results. The obtained results exhibited comparability across multiple cases, revealing that the standard deviation of vertical stress decreases with increasing stope inclination and increases with the augmentation of stope height. Additionally, simulations were conducted to assess the feasibility of the proposed solution, demonstrating an accurate approximation of the actual stresses applied to various stope geometries in the Niobec mine. Furthermore, conducting a simulation specific to the data and geometry of the Niobec mine construction sites allows for the quantification of the stresses present in this scenario.