Naturally supported mining methods

Abstract

A mining method based on natural support seeks to control rock mass displacements throughout the zone of influence of mining, while mining proceeds. This implies maintenance of the local stability of rock around individual excavations and more general control of displacements in the mine near-field domain. As a first approximation, stope local stability and near-field ground control might be considered as separate design issues, as indicated schematically in Figure 13.1. Stopes may be excavated to be locally self-supporting, if the principles described in Chapters 7–9 are applied in their design. Near-field ground control is achieved by the development of load-bearing elements, or pillars, between the production excavations. Effective performance of a pillar support system can be expected to be related to both the dimensions of the individual pillars and their geometric disposition in the orebody. These factors are related intuitively to the load capacity of pillars and the loads imposed on them by the interacting rock mass.