Abstract: Gob entry driving in the large pillar is a new technology based on double U-shaped roadway layout of the face. According to the geological conditions, certain method of reasonable width of narrow pillar in gob entry driving in the large pillar is obtained based on the combination of limit equilibrium theory, numerical calculation and field practice. It takes into account six parameters for the narrow pillar width from distribution of stress of the section of the lateral support goaf, stress distribution of coal pillars, stress distribution of surrounding rock, plastic zone distribution of surrounding rock, the relationship between deformation of surrounding rock and pillar width and limit equilibrium theory of narrow pillar width, and finally it is determined that the narrow pillar width is five meters. Then deep analysis is conducted to the impact of stress distribution law between narrow pillar and wide pillar to this section face mining.

Key words: large pillar, narrow pillar, roadway in gob entry driving, pillar width, double U-shaped