Movement Behavior of Overlying Strata in Shallow Seam High Cutting Height Fully Mechanized Mining

Three methods of spot observation,theoretical analysis and numerical simulation are applied integrally to focus on the large mining height overburden mechanics with shallow buried coal seam in Changhangou 15105 working face.The results showed that due to the non-synchronization of the fractures and interaction between the two key-layers existing in the overburden strata,the periodic weighting step is extremely uneven and presented as a large and a small period alternately;during the large period,the dynamic load appears obviously and sloughing and roof fall are serious with slightly ground subsidence level