Abstract:
In order to study the surface movement and deformation law caused by the middle deep buried thick coal seam mining in northern Shaanxi Province, the first working face (112201 working face) of Xiaobaodang Coal Mine which lies in the middle of the third phase planning area of Yushen Mining Area was taken as the research area. The surface movement and deformation characteristics, the movement deformation parameters and development laws of surface cracks caused by coal mining are obtained through the combination of observation station, GNSS observation station and theoretical analysis. The results show that: the maximum subsidence and the maximum subsidence coefficient were 3 840 mm and 0.66 respectively caused by mining of 112201 coal face. The duration of surface movement and deformation was about one and a half years. The start-up stage last 18 days, and the active stage last 110 days. Among the active stage, the surface movement and deformation are mainly concentrated in 43 days. The surface subsidence in the active stage was 91.4% of total subsidence value. The degree of development of surface crack induced by mining of 112201 coal face was weak. Relatively speaking, the development degree of surface cracks above the cut hole was greater than that above the trough, and the degree of the surface cracks above the goaf was weakest. The surface crack in the 112201 coal face was developed behind the mining position, and the width showed a “single peak” dynamic characteristic. There is coupling synchronization between the dynamic change characteristic and the velocity of surface subsidence.