Itasca has developed unique and robust approaches to pillar design that recognizes the importance of understanding the rock behavior from intact rock and bedding to joints and faults. Itasca’s software can model the stress-strain response of continuous, blocky, or bedded materials exhibiting plastic, brittle, or creep behaviors. Consequently, any combination of lithology comprising the pillar-floor-roof system can be analyzed. This includes reproducing the complex combination of pillar sloughing (rib rash) and floor heave experienced at different extraction levels and vertical stress levels throughout a mine. Information derived from these pillar-scale models forms an essential input to larger-scale models, which have been used extensively for design of individual panels (width, remnant stub width, and extraction ratio) as well as barrier pillars, and the overall mine layout and extraction ratio. These larger-scale models have been validated through successful back-prediction of the timing and nature of large-scale catastrophic collapses experienced in the region.
