Study on Surface Movement Law Above Underground Deep Mining Under Thick Unconsolidated Overburden Strata

In order to study the surface movement law above the deep underground coal mining under ultra thick unconsolidated overburden in Huainan Mining Are a, an analysis was conducted on the measured data of the surface subsidence above the No.11118 coal mining face under a unconsolidated overburden strata with a thi ckness of 400 m and with a mining depth of 500 m.The surface movement statics, dynamics law and surface movement parameter above the deep underground coal mi ning with thick unconsolidated overburden were obtained.The results showed that the subsidence curve of the surface above the deep high mining with the thick uncons olidated overburden in Huainan Mining Area had the strike and inclination double directional symmetrical features and the strike boundary.The strike boundary angle, th e dip and rise boundary angles were small and the three angles were all 35° .The convergence of the surface movement boundary was slow, a long distance slow subsid ence zone was occurred and the buildings on the surface were failed slightly.The subsidence of the surface above the mining goaf was centralized, the movement defor mation value of the surface was high and the failure of the buildings was serious.Under the condition of the same mining, the miming degree of the surface above the si ngle coal mining face with thick unconsolidated overburden would be higher than the conventional mining condition and would be easy or reach full mining status.