Mining induced stresses
Mining operations cause the stress to concentrate at the corners of the
solid coal, the edges of the workings and at the pillars. Room and pillar
mining is more prone to outburst than longwall mining due to the stresses
inherent in the pillars. However, the removal of support pillars is nearly
always completely safe as the gas has diffused from the pillars over time.
As stresses concentrate at the ends of longwall faces, longwall mining
should use a straight working face and complete extraction of the coal. (Lama & Bodziony, 1996)
