"Three Steps Drainage" Comprehensive Gas Control Technology in Soft Coal Floor Roadway

In order to control gas outburst and gas overrun problems in soft coal seam, the "three steps drainage" comprehensive gas control technology is proposed and applied at 21031 working face of Ligou Mine. The results show that the technology, including borehole through strata pressure relief extraction, pressure relief belt poking hole drainage and goaf drainage three parts, can rapidly eliminate coal and gas outburst accident, effectively extract gas in goaf and upper corner, prevent the gas overrun accidents in mining process of working face and guarantee the safety mining of working face.