Study on Coal Pillar Width and Surrounding Rock Control of Gob-Side Entry in Extra-thick Coal Seam

This paper adopts an integrated method of field test and numerical simulation to study coal pillar width and surrounding rock control of gob-side entry in extra-thick coal seam. Field test showed that when the coal pillar width was 30 m, the average plastic failure areas of the roof, coal pillar rib and virgin coal rib were 7.6 m, 4.9 and 3.8 m, respectively, and severe roof subsidence and large deformation of coal pillar rib occurred during the...