Research of ground cracks caused by fully-mechanized sublevel caving mining based on field survey

Abstract Fully-mechanized sublevel caving mining have been widely used due to its efficiency, however, the accompanied breakage such as ground cracks caused by which is much bigger than traditional mining methods. The study of ground cracks caused by fully-mechanized sublevel caving mining can give supports to the prevention or repairation of them. Through field investigation of the plane distribution of cracks on a road and plantation in Yanzhou mining group caused by exploitation, this paper got the distribution rule of cracks and the characteristic of superficial soil’s effect on their development. Through surveying of the width of cracks on the main section, the distribution function of the width have been obtained; the crack width on the main section was fitted into a function, which indicates its direct connection with horizontal deformation got through inversion. Remarkably, ground cracks can not reflect the immediate situation of horizontal deformation and only 52% of horizontal deformation can be reflected through cracks. Meanwhile, four typical cracks was caved. The result suggests that the depth of cracks is proportional to their width and step fall and the shape of crack in depth present as “V”, and the depth is finite, less than 3.5m.