Analysis of deformation and failure characteristics of steep rock under repeated mining

Abstract

In view of the influence of underground repeated mining on the bedding steep rock with weak interlayer, this paper uses the discrete element numerical software UDEC to simulate the upward mining in the gently inclined short-distance coal seam group under the steep rock, and analyzes the deformation and failure characteristics of the steep rock. The results show that the variation trend of subsidence curve, horizontal displacement curve, vertical stress curve and shear stress curve of basement rock is basically the same in the process of repeated mining when different coal seams are mined; the unloading crack of the steep rock slope shoulder will penetrate the weak interlayer downward and form a dangerous rock body at the slope shoulder after the mining of the upper coal seam. After the middle and lower coal seams are mined, the mining fissures will continue to extend from top to bottom into the slope body and near the basement rock layer, resulting in steep rock mountain fracture; with the increase of repeated mining times, the deformation and failure degree of steep rock will increase sharply.

Keywords

• underground coal mining
• section ascending
• failure of steep rock
• dangerous rock collapse
• repeated mining