Abstract: It is known that the phenomenon of leakage frequently occurs in the roof of the fully mechanized working face with large mining height in thin bedrock coal seam of Huainan mining area. In this study, laboratory tests, theoretical analysis, and field measurements were conducted to investigate the mechanism and control technology for the leakage in the thin bedrock mining face. The results show that coal seam with large mining height in the thin bedrock had a periodic weighting phenomenon in the roof of the fully mechanized working face. The deformation potential energy of the immediate roof was proportional to the dead weight of the overlying strata next to the immediate roof, while was inversely proportional to the elastic modulus of rock mass. When the periodic weighting of working face roof took place, the deformation potential energy of the immediate roof increased. As a result, the primary cracks propagated and the secondary cracks developed, which caused the growth of the probability of the roof leakage. Therefore, a combined procedure of waste steel wire rope and grouting was applied to reinforce weak areas in the immediate roof, forming a unique spatial grid reinforcement structure. It turns out that this technique presents an obvious reinforcement effect and can prevent the occurrence of the phenomenon of roof leakage effectively.

Key words: thin bedrock, immediate roof, roof leakage, long anchor cable