ABSTRACT
Pillars in stratified ground are routinely formed between entries and crosscuts during development of main entries, sub-main entries, and panel entries. Main entries that provide primary mine access usually last the life of a mine. Ventilation entries also have relatively long service lives. Sub-mains have shorter design lives. Panel entry service life is typically just a few years at most. Regardless, the purpose of all pillars is to prevent collapse of the adjacent entries.
