Abstract: In this paper, to resolve the problem of rock cross-cut coal uncovering in the super thick and gently inclined outburst coal seam, a new idea through the pressure relief of roof rock tunnel was proposed for rock cross-cut coal uncovering. Theoretical analysis has identified the energy stored in tectonic coals with high pressure gas, which was formed under high ground stress, is the main driving force of outburst in rock cross-cut coal uncovering. Meanwhile, stress distribution of surrounding rock in roof tunnel of thick coal seam was simulated to study the stress variation of coal mass in uncovering coal face. The results show that the roof tunnel can reduce the original stress, transfer the mining-induced stress, weaken the stress concentration effect of deep coal-rock mass affected by mining operation in uncovering coal process, and reduce the influence scope. The roof tunnel can transfer and bear 15% concentrated stress in rock cross-cut coal uncovering, and the pressure relief width in front of the face can be increased by 2~3 m. Thus, duo to the forwarding of pressure relief frontal surface, together with gas drainage by boreholes through coal seam in roof tunnel, the ground stress, gas pressure and elastic energy of coal mass can be reduced significantly. Moreover, the closer the distance between roof tunnel and coal seam is, the better the pressure relief effect is.

Key words: rock cross-cut coal uncovering, rock tunnel pressure relief, outburst prevention, pressure relief frontal surface