Abstract

The term "surface pillar" refers to the layer of rock left in place above underground mine excavations. These structures must be quite solid in order to contain water and excavated earth. This project was undertaken to validate a new technique for the analysis of surface pillar stability which takes into account actual geomechanical conditions, particularly the number, dimensions and orientation of rock fissures, soil infiltration, and hydraulic pressure. Implementation of this technique should help prevent cave-ins.

Data was collected at two sites, and a computer model of surface pillar stability developed. The results of this study are generally applicable to near-surface underground excavations, particularly in the construction sector.