浅埋近距离煤层重复采动下覆岩隔水层破坏特征分析OA

The Jurassic coalfield in northern Shaanxi is mainly composed of shallow buried close-distance coal seams.Affected by the activation and development of overlying rock fractures caused by repeated mining,it is easy to penetrate the aquiclude and lead to its instability,resulting in the loss of groundwater resources.The stability of aquiclude is an important prerequisite for realizing water-preserved mining.Upward fracture development height and downward fracture development depth are the important means to judge the stability of the aquiclude.Based on the working conditions of 4-2 and 5-2 coal seams in Hongliulin Coal Mine,the research was carried out in combination with numerical simulation experiments.The aquiclude failure characteristics of fracture development law under single coal seam mining and repeated mining are studied.The results show that the upper and lower fractures are not connected during the mining of single coal seam in 4-2 coal seam,and the aquiclude can maintain stability;during the repeated mining of 5-2 coal seam,the upper and lower fractures are penetrated and the aquiclude is unstable.Therefore,measures such as high-limiting mining and stratified mining should be taken in order to realize the water-retaining mining in this area.