Characteristics of overburden-surface movement of high-intensity mining in Shangwan coal mine under the influence of advancing speed
In order to obtain the characteristics of overburden-surface movement of high-intensity mining in the super high mining height(8.8 m)longwall face of Shangwan coal mine,systematic observations were made for overburden breaking and movement,surface subsidence and cracking,and mining-induced pressure behavior.The observation results showed that the migration characteristics of overburden were different from that dominated by traditional thick-hard strata.A three-layer controlling stratum,the main roof,the primary key stratum and the thick-soft rock layer at the top(buffer stra-tum),influenced the mining movement characteristic of 12401 longwall face,and due to the influence of the advancing speed,an overburden fracture mode consisting of"two zones"or"three zones"was formed.Low-level main roof and primary key stratum jointly determined the appearance of mining-in-duced pressure of the mining face;The fracture of the primary key stratum incurred the violent settlement of the whole overburden.At the same time,certain buffering effect on the movement transition of the overburden was formed due to the occurrence of the buffering thick-soft sandy mudstone layer and its strong expansibility,which contributed to the key factor of the formation of the"three zones"structure.This paper outlined the main conducting mechanism of surface fissure development based on the movement law of overburden-surface,which provided a scientific basis for preventing sur-face damage caused by mining and implementing loss-reduction mining based on the analysis of the movement law of overburden-surface.
万方数据
维普
