Abstract: Gob-side entry driving in large pillar is a technology of roadway layout and maintenance. This paper, according to the specific geological conditions, based on the limit equilibrium theory, numerical calculation and the combination of industrial field tests, and through the stress field analysis, has concluded that if the coal width is of 3-5 m, the vertical stress distribution approximation shows obtuse angle triangle, the coal width of 5-8 m, the vertical stress distribution approximation shows acute angle triangle, the coal width of 8-10 m, the vertical stress distribution approximation shows trapezoidal. According to the analysis of the displacement field, pillar displacement of the roadway is generally greater than that of gob side, and as the pillar width increases to the roadway displacement, lateral displacement to the gob-side is relatively less affected. Finally certain method to determine the width of gob-side entry driving has been found, which needs workers to take five aspects into consideration including distribution of stress of the section of the lateral support goaf, stress field distribution, displacement field distribution, the relationship between deformation of surrounding rock and pillar width and limit equilibrium theory of narrow pillar width, and then that the narrow pillar width is five meter has been finalized. Industrial field tests have shown that the status quo of large deformation and severe damage of the roadway in the gob-side entry driving has been improved.

Key words: gob-side entry driving, narrow pillar, roadway, pillar width, stress field, displacement field