Integrating Empirical and Numerical Models to Develop Stability Tools for Crown Pillars in Sublevel Open Stoping

The design of near-surface crown pillars involves the interaction between excavation geometry, rock mass quality, and the in situ stress state. This study proposes a formulation that integrates numerical modeling and empirical criteria to construct a unified framework for stability interpretation. The Modeled Span index is introduced as a hybrid measure that incorporates geometric relationships and the pre-mining stress state, which, when compared with rock mass quality, allows the definition of