Assessment of horizontal pillar burst in deep hard rock mines

The paper examines three methods for assessing the stability of horizontal pillars in deep underground hard rock mines. Such pillars could suffer from strain-type rockburst when they become too thin in an environment characterized by high in situ stress and hard, brittle rock. The methods presented are: potential stress failure (PSF), energy release rate (ERR) and the Burst Potential Index (BPI). It is shown through a numerical model of a characteristic crown pillar problem that the BPI is the most suitable of the three. Contrary to the PSF method, the BPI method accounts for the rock mass strength and deformability.