Abstract: In view of the phenomenon of roof subsidence, fracture and breakage in the advanced influence area of gobside entry retaining section in the mining process of 9204 roofcutting and pressurerelief coal face in Dianping Coal Mine, the traditional hydraulic single pillar support not only has high labor intensity and low automation level, but also is easy to deform and pressurerelief of single pillar, which reduces the roof.The support effect seriously affects the safe and efficient mining of coalfree face.To this end, a set of retractable advance support is designed through technical research and applied in practice, which solves the technical problems of poor support effect and difficult headlamp, and makes the roof subsidence below 0.12 m,and achieves remarkable application results.

Key words: No pillar mining, Retaining roadway along goaf, Advanced impact zone, Advance bracket, Support application