Quite a number of shallow buried coal seams (SBCS) are distributed in China. The overburden is easily damaged due to the mining of SBCS, resulting in water resources loss and surface damage. Taking 12403 working face of Wulanmulun coal mine in Shendong mining area as an example, this paper analyzed the overburden migration and failure characteristics after mining SBCS with thick loose layer based on actual measurement data and simulation results. The results show that the subsidence of strata in caving zone has no skewness feature along strike direction, while the subsidence of strata in fracture zone and bending subsidence zone shows skewness subsidence phenomenon. An interface exists in the overburden, and the movements of upper and lower strata at the interface have different characteristics. The cracks penetrating the whole strata exist in bedrock, not in aeolian sand. The height of water flowing fracture zone is 35.74 m–62.89 m according to the loss of fluid in the borehole and consistent with the results of numerical simulation and similar simulation. This study can provide a reference for the prediction of the height of water flowing fracture zone and the overburden migration in mining SBCS.

During the mining process of the near-vertical seam, there will be movement and collapse of the “roof side” rock layer and the “overlying coal seam,” as well as the emergence of the “floor side” rock layer roof which is more complicated than the inclined and gently inclined coal seams, which causes problems with slippage or overturning damage. With the increase of the inclination of the coal seam, the impact of the destruction of the immediate roof on the stope and roadway gradually becomes prominent, while the impact of the destruction of the basic roof on the stope and the roadway gradually weakens. The destruction of the immediate roof of the near-vertical coal seam will cause a large area of coal and rock mass to suddenly rush to the working face and the two lanes, resulting in rapid deformation of the roadway, overturning of equipment, overturning of personnel, and even severe rock pressure disaster accidents, all of which pose a serious threat to coal mine safety and production. It is necessary to carry out research on the mechanical response mechanism of the immediate roof of near-upright coal seams, to analyse the weighting process of steeply inclined thick coal seam sub-level mining. A four fixed support plate model and top three clamped edges simply supported plate model for roof stress distribution are established before the first weighting of the roof during the upper and lower level mining process. The bottom three clamped edges simply supported plate model and two adjacent edges clamped on the edge of a simply supported plate model are established for roof stress distribution before periodic weighting of the roof during the upper and lower level mining process. The Galerkin method is used to make an approximate solution of deflection equation under the effect of sheet normal stress, and then roof failure criterion is established based on the maximum tensile stress strength criterion and generalized Hooke law. This paper utilizes FLAC^3D finite element numerical simulation software, considering the characteristics of steeply inclined thick coal seam sub-level mining. It undertakes orthogonal numerical simulation experiment in three levels with different depths, coal seam angles, lateral pressure coefficient, and orientation of maximum horizontal principal stress, and translates roof stress of corresponding 9 simulation experiment into steeply inclined roof normal stress. We conclude that the distribution law of normal stress along dip and dip direction of a roof under the circumstance of different advancing distances and different sub-levels. The caving pace of first weight and periodical weight were counted under the effect of the roof uniform normal stress. It can better predict the weighting situation of the working face and ensure the safe, efficient, and sustainable mining of coal mines.

Considering the large mined area, wide strata moving range, strong mine pressure occurrence, and difficult roof control for the fully mechanized top coal caving in 20 m ultra‐thick coal seams, this study analyzes the strata structure evolution and mine pressure occurrence behavior through field test, numerical simulation, and theoretical analysis. Based on the mine condition of the Tashan Coal Mine in the Datong mining area, mechanical models are established for the compound overlying structures. The following can be demonstrated from this study: (1) The hard strata can form three different compound spatial structures at different positions in the overlying rock strata, including the lower combined cantilever structure I, the middle combined cantilever structure II, and the upper hinged structure. (2) Failure of the higher structure can induce compression on the lower structure, which changed the break span of the lower structure. (3) “Simultaneous and nonsimultaneous structural failures” of the compound spatial structure were caused by the variation of the break span of the multilayered structure. (4) Based on the weighting characteristics, there were three stages during work face weighting, including a gradual pressure increase stage (Stage I), an accelerated pressure increase stage (Stage II), and a fast pressure increase stage (Stage III). (5) The mine pressure occurrence demonstrated a “small to medium and to large” feature. (6) Prefracturing techniques should be additionally incorporated to prevent simultaneous failure of the multilayered structure. Findings of the work can demonstrate the emergence of strong mine pressure in the Datong mining area and have theoretical significance and reference value for maintaining safe mining in similar conditions.