Diseño del sistema de sostenimiento. Caso de estudio de una mina subterránea en El Oro

Abstract

CONDITION FOR PUBLICATION OF PROJECT. The present project aims to evaluate and verify the performance of a support system based on metallic frames made of petroleum tubes in an underground mining excavation, considering real operating conditions and different depth scenarios. The hypothesis states that the currently used support system presents structural limitations under increasing in situ stresses, particularly in the vertical elements. The justification of the study is based on the need to develop a technical design that ensures adequate safety and stability conditions while optimizing the use of reused materials. For the development of the project, a geotechnical characterization of the rock mass was carried out, along with a geometric and mechanical characterization of the support system. This included laboratory testing on rock samples and steel tube specimens under both normal and weathered conditions. Analytical convergence–confinement models were applied, using John Bray’s equations to calculate safety factors. The results showed that at depths less than 50 m, the crown of the frame exhibits safety factors higher than the minimum recommended values (FS > 1.5), while the vertical posts govern the design due to buckling and lateral thrust. Additionally, it was demonstrated that reducing the spacing between frames and incorporating bracing significantly increase the structural capacity of the support system. In conclusion, the design proposals evaluated at different depths improve the performance of the support system and allow compliance with established safety criteria. Keywords: underground support, steel frames, convergence–confinement, structural stiffness, mining safety.