Formation Mechanism and Detection Method of Overburden Abscission Layer in Mining Coal Seam Under Thick Sandstone

In order to study the development characteristics and formation location of mining overburden in thick coal seam under thick sandstone, the overburden movement caused by mining of thick coal seam at 2301 working face in a Datong mine is taken as an example. Theoretical calculation formula ultrasonic imaging and color drilling television system are used to calculate and quantitatively detect the development position of overburden strata in mining thick coal seam under thick sandstone. The results show that there are several sub-key layers in the overlying strata of coal seam, but there is only one main key layer, the abscission layer is mainly generated under each key layer, and the upward development height ends at the main key layer. the development depth of the abscission layer under the giant thick sandstone is respectively 343, 346.5, 328.61 m. It is proved that the stratum separation will be formed in the mining of the thick coal seam under the huge thick sandstone.