An evaluation of roof support plans at two coal mines in Illinois using numerical models

•Roof control plans at two mines are compared using strain-based rock mass failure criteria.•Shearing strains at pillar corners near the roof and floor are critical for failure initiation.•Shear and tensile strains at the coal-floor interface are also critical.•High compressive strains along the pillar ribs in entries result in cutter roof.•Failure initiation occurs around the mid-height of pillar ribs and progresses downward.