Width of Coal Pillar of Gob-side Entry Driving in Island Working Face of High Gas Mine

The methods of numerical simulation and field monitoring are used to analyze the width of coal pillar of gob-side entry driving in island working face of high gas well. The vertical stress in the side coal pillar in the goaf area of the roadway is distributed in a parabolic shape along the width of the roadway. The maximum vertical stress is located in 1/2 of the width of the roadway, and the stress and deformation of the coal pillar in the middle of the roadway are significantly greater than those in the upper and lower parts of the roadway. When the width of coal pillar on the side of goaf is 6 to 7 m, the coal pillar has a high bearing capacity and can effectively control the deformation of roadway surrounding rock. It is safer to use cuttings gas desorption index to evaluate gas outburst risk than cuttings quantity index. By using local gas outburst risk assessment and monitoring of gas content in the roadway, the safety construction of tunneling along gob in isolated working face of high gas mine can be effectively guaranteed.