OPTIMIZATION OF STOPE DIMENSIONS IN A GEOTECHNICALLY COMPLEX MINE USING AUTOMATED STABILITY ANALYSIS

Stope stability is a critical factor in underground mining, directly influencing safety, productivity, and overall mining efficiency. Traditional stope design methods often employ uniform stope lengths, disregarding geotechnical variability and thereby increasing the risk of instability or suboptimal dimensions. This study introduces an automated stability analysis approach that iteratively evaluates multiple stope dimension scenarios based on the Modified Stability Number (N’) to identify the optimum stable configuration. By conducting detailed stability assessments for each stope wall, the method provides a more accurate representation of geotechnical conditions compared to the conventional methods with uniform stope length. The case study demonstrates that this approach effectively reduces the total number of stopes while maintaining geotechnical stability, in contrast to conventional methods where 14%–40% of stopes exhibit instability. Furthermore, the optimization method achieves a balanced outcome between dilution control and operational efficiency resulted in lower stope production cost. The optimized configurations generated by the proposed method deliver the lowest total production cost, with estimated savings of approximately USD 1.6–2.4 million compared to conventional designs. These findings confirm that the optimization framework not only enhances geotechnical stability but also provides a demonstrable economic advantage, underscoring the importance of integrating geotechnical variability into stope design.