Study on Optimized Layout Plans of Floor Gas Drainage Gateway in Single Outburst Seam

In order to investigate the outburst eliminated effect of the gas pre-drainage in the floor gas drainage gateway in a single outburst seam, a floor gas drai nage gateway was set at 10 m below the single outburst seam of a mine in Pingbao Company.There were four borehole layout plans proposed, including the center to C enter vertical projective distance of 0, 10 and 20 m between the two gateways, a vertical projective distance of 1 m between the outer wall of the seam gateway and the inner wall of the rock roadway and others. The results showed that in comparison with No.1 and No.2 plans, the drilling distance of each group boreholes for No.3 and N 0.4 plans could reduce 2083 m and 1174 m individually, the construction time of No.3 and No.4 plans could reduce 1001 80 min and 801 50 min individually, the maintena nce and repair period of the 100 m gateway could reduce 23 days and the volume fraction of the gas drainage of No.3 and No.4 plans would be improved by 10% .After t he No.3 and No.4 plans applied, though the stress distribution of the gateway would be concentrated and the deformation of the gateway would be high, but with the hig h strength bolt/steel mesh/anchor support, the gateway could meet the requirements of the mine production and safety.