Abstract:

The key stratum movement has important significance to ground behavior of coal mining face, overlying strata movement, surface subsidence and fracture fields distribution. In order to confirm the position of key stratum, this paper adopts strata control observation, density test of rock, uniaxial compression, deformation test and other methods, and the mechanical properties of overlying rock strata and periodic weighting is confirmed on 601 great mining heihgt workface of Meihua Coal Mine, and the hard rock and key stratum are calculated through computer programming. The results show that the C6 formation is given priority to key layer and C8 formation is the key layer. C6 key layer interval is 17.88 m, contrast to observation results of mine pressure, main roof weighting interval is 18.25 m. Two kinds of results are consistent with each other.

Key words: key stratum, large cutting height, drawing pace, hard rock