Geotechnical design of the sublevel stoping method for the Poder and TrabajoVeins in the San Genaro Mine - Peru

The study consists of determining the dimensions of the stable open stopes according to the geological and geomechanical conditions of the various sectors analyzed in the Poder and Trabajo Veins in the San Genaro mine (Peru). This is achieved by conducting basic geotechnical investigations and evaluating characteristics such as maximum openings and pillar dimensions. The analysis of the data from geological mapping and discontinuity characterization, as well as the results of the laboratory testing, allow for the characterization and geomechanical classification of the rock mass and the ore body. The RMR, Q and GSI rock mass classification systems are used in the geomechanical characterization. Rock mass strength is estimated using the Hoek and Brown (2002) failure criterion. Stope stability assessment is carried out by means of the Mathews (1980) stability graph method. For this study, the latest version, updated by C. Mawdesley & R. Trueman (2000), was used. Rib pillars were designed using the empirical method, which involves designing inclined pillars based on their strength, first estimating the induced stress field acting on the pillar with the Obert and Duvall method, and then estimating pillar strength using the Lunder and Pakalnis methods (1997). Finally, as a supplement to the empirical methodology applied, a stress-strain analysis was performed by means of the geomechanical software Phase2. © 2012 Taylor & Francis Group, London.