MINERÍA la mejor puerta de acceso al sector minero MINERÍA / ENERO 2022 / EDICIÓN 532 63 Abstract Empirical analysis by means of geomechanical classifications - and among them the Q index - is an internationally accepted methodology for pre-design and selection of supports since the 1970s. On the other hand, although wood as a support is an old method, it is still used worldwide in small and artisanal mining. There are very few references to the use of geomechanical classifications when analyzing this type of supported mines. Most of these artisanal mines lack any kind of engineering criteria in their designs, and the methodologies based on geomechanical mapping and empirical design are easy and inexpensive to implement. In this research we have analyzed supports with wooden frames in drifts and stopes of active mines and abandoned mines. In total there have been 19 references in Peru, Bolivia, Spain, and Slovenia, and in andesitic, limestone, dolomite, shale, and coal type host rocks. Our objective was to draw an empirical graph that relates rock quality according to the Q index with the width of the mining drift and the type of reinforcement recommended, with emphasis on the timbering technique. Based on the analysis of several cases, a graph is developed in which we can introduce the rock quality and drift width we are projecting, resulting in a graph showing whether timber support is recommended, or the drift is self-stabilized. This graph can be useful for pre-dimensioning and planning support needs in small-scale and artisanal mining at pre-feasibility stages. The graph has been based on the considerations of authors who have studied the subject, such as Vallejo (2000, 2007) and our own field analysis carried out for this research, considering real drifts that have operated with support. The span - Q have been represented in a semi-logarithmic graph considering the ESR values recommended by the most recent publications (NGI, Vallejo, Grimstad and Barton) ESR = 1.6 for permanent mining drifts and 3 for temporary drifts. As a result, we present a revision and adaptation of the empirical graph of Q index for timber-supported mines. We also recommend new values of the Excavation Support Ratio (ESR) for Q-index applied to permanent and temporary drifts of supported mine. A graph like the one proposed here can serve as a preliminary guide in many mines that are excavated without modern technical criteria but with a base of traditional empirical "know how" that can be valid. Como resultado presentamos una revisión y adaptación del gráfico empírico del índice Q para minas entiba- das en madera. También recomendamos unos nuevos valores del Excavation Support Ratio (ESR) para índice Q aplicado en galerías permanentes y temporales de minas entibadas. Un gráfico como el que proponemos puede servir de guía preliminar en muchas minas que se excavan sin criterios técnicos modernos, pero con una base de know how empírico tradicional que puede ser válido. Introducción La entibación con madera es uno de los métodos más antiguos para sostener techos de galerías y controlar inestabilidades subterráneas. La madera no solo se ha empleado para cuadros en las galerías, sino que han servido como técnica
RkJQdWJsaXNoZXIy MTM0Mzk2