关键词: 浅埋煤层, 厚煤层, 煤层群, 周期来压, 相似模拟

Abstract: In response to the problem of rules of overlying rock fracture and difficulty in determining the stability of overlying thin coal seams in shallow buried thick coal seam mining faces, a large-scale similarity simulation model was constructed based on the working face of the eight panel area of Sandaogou Coal Mine. The theoretical analysis, similarity simulation, and on-site measurement methods were combined to study the fracture and migration laws of overlying rock and the stability of overlying thin coal seams after mining. The research results showed that: ① the second layer of fine-grained sandstone layer on the 5-2 coal seam of Sandaogou Coal Mine is the basic strata, and the first strata of fine-grained sandstone strata above the 4-3 coal seam is the main key strata. The basic strata cycle fracture step distance is about 14 meters. ② With the backfilling of the 5-2 coal seam, the collapse fracture zone above the working face develops in an inverted trapezoidal shape upwards. When pushed up to 160 meters, the stability of the overlying 4-4 coal seam will significantly decrease, resulting in a large number of oblique fractures. Separation will also occur between the 4-3 coal seam and key stratas. When pushed up to 240 meters and beyond, it will affect the surface.③ After the completion of the 5-2 coal seam mining, the overlying 4-4 coal seam and 4-3 coal seam both exhibit a disc-shaped sinking shape, and the stability of both coal seams decreases, resulting in a large number of cracks. However, the overall continuity is still maintained, and delamination may occur in the rock beam hinge zone.