Technology of Uncovering Coal and Outburst Prevention in Hengdong Work Area of Tianping Tunnel

In order to ensure that Tianping Tunnel smoothly passes through the Longtan Formation from DK127+710 section to DK127+850 section, the geological conditions of the sections were analyzed, and the operation procedures of the tunnel uncovering coal and the operation of the outburst prevention measures were formulated; according to coal seam characteristics, the advanced geological drilling, regional comprehensive outburst prevention measures and local comprehensive measures of uncovering coal were designed specifically, and the implementation effect of this plan was verified by the drill cutting index method. The results show that after the implementation of the outburst prevention plan, the prediction index K₁ of outburst risk in working face decreased to 0.31 mL/(g·min^1/2), which can ensure the smooth passage of tunnel construction through the coal seam area.