Research on Roof Control Technology with Penetrating Strongly Weathered Sandstone Zone under Shallow Buried Thick Coal Seam

Aiming at the problem that penetrating strongly weathered sandstone zones under the shallow buried thick coal seam fully mechanized mining face is prone to occur large-scale loess collapse, which leads to accidents such as working face air leakage, water collapse and sand inrush and others that threaten production safety in Shenfu Dongsheng Coalfield, through analyzing the roof failure mechanism of strongly weathered sandstone, a comprehensive governance scheme of “filling loose body boundary + advanced cyclic grouting reinforcement” is proposed, which can form an "artificial pressure-bearing arch" through the boundary filling, actively restrain the surrounding rock deformation, and the construction period is shortened by 32% compared to the traditional passive grouting scheme. And the on-site application research is carried out on the 2204 working face of Zhangjiamao Coal Mine. Through multiple rounds of grouting reinforcement governance, the strongly weathered sandstone zone on the roof of the 2204 fully mechanized mining face is effectively controlled, the large-scale collapse of roof loose bodies is reduced and normal stoping of the working face is achieved.