Abstract: In order to solve the loss of coal resources of Dianping Coal Mine,the technology of retaining roadway along goaf is used to recover coal pillars in sections and reduce the loss of coal pillars in sections.Meanwhile,the technology of automatic roadway formation by roof cutting and pressure unloading is used in this coal mine to reduce the transmission of stress on the roadway roof caused by the interlocking of adjacent fracture blocks.Moreover,the optimal height and Angle of roof cutting make it possible for the direct roof to slip and collapse smoothly after roof cutting and pressure relief,which will not cause stress concentration of roadway roof and make roadway support difficult to stay along gob.Through numerical simulation and engineering practice,the optimal height and angle of roof cutting are verified.Finally,the maximum amount of roof and floor moving of the working face is only 250 mm is measured through engineering practice,the significant engineering effects is obtained,besides that,it can provide reliable reference for the simialr mines.

Key words: Gobside entry retaining,Roof cutting and pressure relief,Section coal pillar,Roof cut height,Roof cut angle