针对淮南矿区薄基岩煤层大采高综采工作面漏顶事故频发现象,采用实验室试验、理论分析及现场实测的方法对薄基岩工作面漏顶机制及控制技术进行深入研究。研究结果表明:薄基岩煤层大采高综采工作面顶板存在大小周期来压现象;直接顶的变形能与其所承接的上覆岩层自重成正比、与其岩体的弹性模量成反比关系;工作面漏顶与顶板来压密切相关,工作面顶板周期来压(关键层断裂回转)时,直接顶的变形能增加,导致直接顶岩体原生裂隙扩展、次生裂隙发育,从而增加漏顶的几率;采用废旧钢丝绳与注浆联合加固的方法对直接顶薄弱区域进行预加固,形成一个独特的空间网格加固结构,加固效果明显,能够有效防止工作面漏顶现象地发生。
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 combitied procedure of waste steel wire rope and grouting was appliedt~ 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.