Abstract: In this paper, the general mechanism of rib spalling was analyzed in detail, the main failure form of coal wall was summarized combined with the real conditions of 2612 coal face in Dongpang Mine, and the mechanical model of rib spalling in topple mining face with large mining height was established. The results show that the roof pressure, dirt band thickness, topple mining angle, coal cohesion, et al, have a great influence on the coal wall stability, and relieving the roof pressure of coal wall is the most effective measure to prevent coal wall failure. Meanwhile, the reasonable drilling position and grouting reinforcement parameters of coal seam with dirt band were studied by theoretical analysis, UDEC numerical simulation, etc. The studies show that the grouting holes drilled in the breakdown point of rib spalling is the best solution. In addition, the coal wall grouting process and implementation effect in 2612 coal face with large mining height was introduced.

Key words: large mining height, topple mining, coal wall failure, grouting reinforcement technique