Causes and mechanisms of massive pillar failure in a southern West Virginia coal mine : Min Engng V37, N4, April 1985, P323–328

Abstract

This paper deals with the causes and mechanisms of pillar failure in a southern West Virginia coal mine. Conclusions are based on in-mine observations and analysis of mining methods, eyewitness accounts of the sequence of events, topographic and geologic conditions, and mechanical properties of mine roof, coal, and floor. The study indicated that massive pillar failure was caused by the collapse of the mine roof. The collapse was due to the combined effects of high lateral compressive stress and high extraction ratio causing excessive bending of the roof beyond its limit. It was assumed that the higher lateral compressive stress under such a shallow cover was probably due to the drastic change in the structural geology of the area and possible residual stresses. Based on the analytical study, it was concluded that the sudden release of elastic energy (shock) due to the rupture of the roof caused the squeezing of approximately 80 mine pillars.