Width Analysis of Chain Pillars of Butt Entry in Wusiyidu Coal Mine

Taking the first fully-mechanized caving mining face named 6101 of Wusiyidu coal mine as the engineering background,by theoretical analysis, numerical simulation and field measurement method, using the coal pillar width of yielding zone theory to analyze the relationship between the coal pillar elastic-plastic range and coal pillar width. And using numerical simulation to study the parameters of coal stress distribution, deformation of surrounding rocks and fracture of coal pillar. The results showed that with the increase of coal pillar width, the vertical stress in the pillar of coal and the shear stress gradually reduce, the amount of deformation of surrounding rock gradually decrease.When the coal pillar width increases to a certain value, the deformation of surrounding rock to stabilize.