Research on characteristic recognition and  danger prevention while mining through collapse column of Pansan Minefield, China

To find out the characteristics of geological structure exposed in the mining process of 12,318 working face in Pansan Mine and grasp its influence law on subsequent coal seams mining, the structure was first determined as the collapse column by means of 3D seismic, transient electromagnetic detection, SYT detection and other methods, and its development characteristics, conductivity and water enrichment were identified. FLAC3D numerical simulation software was used to analyze the characteristics of vertical stress and plastic failure zone in different coal seams during mining. Finally, by comparing the ultimate failure depth of floor and the thickness of waterproof layer in the process of each coal seam directly pushing through the collapse column, the risk of water inrush and the prevention are analyzed. The results show that the exposed geological structure is characterized by weak water-rich collapse column. Under the influence of the mining of the previous coal seam and the activation of the collapse column, the subsequent coal seam is in the low-stress area before mining, which increases the floor failure and causes the activation of the collapse column more easily during mining.