Risk Assessment and Control Strategy of Residual Coal Pillar in Room Mining: Case Study in Ecologically Fragile Mining Areas, China

Gradual instability of coal pillars left behind underground with room mining is one of the main reasons for sudden roof caving in the gob, surface subsidence, and other significant hazards. Moreover, room mining implies great losses of coal resources. In this paper, the main failure mode and room mining coal pillar process were analyzed according to the coalfield regional engineering geological and hydrogeological conditions. A numerical model...