Prevention and control technology of coal rib spalling in the area affected by collapse column in fully mechanized caving face

The coal and rock in the area affected by the collapse column are often broken, and it is easy to appear rib spalling and roof fall when the working face is mining over collapse column, which affects the safe mining of the working face. In order to ensure the safety mining of working face, the 2309 working face of Zhaozhuang No.2 Coal Mine was taken as the engineering background, the stress evolution law and roof structure characteristics of fully mechanized caving face when passing the collapse column were analyzed.Through adopting the comprehensive prevention and control technology of coal rib spalling, which was characterized by detailed working face management in stages and advanced grouting reinforcement in key areas, the coal rib spalling and roof falling were effectively prevented. Field industrial tests show that after taking the comprehensive control measures, the coal wall of the working face is upright and smooth, it can effectively prevent coal wall slicing and roof falling in working face, and there are at most two rib spallings in succession, and the depth of the rib spalling is not more than 400 mm. The advancing speed of the working face is 2.46 m/d, which is 81.7% of the normal area.