Comprehensive Gas Prevention and Control Technology of Fully Mechanized Gateway Driving Face in Seam with Coal and Gas Outburst

In order to solve the serious outburst danger of the fully mechanized gateway driving face in No.15 seam and high gas emission problem during the drivi ng process in Sijjazhuang Mine,a gas outburst prevention and control four combined one technology including the hydraulic fracturing,crossing boreholes,coal wall drilli ng with the gateway driving and gas drainage was provided,A site trial with the technology was conducted. The results showed that the application of the gas outburst pr evention and control four combined one technology to the fully mechanized gateway driving face could make the seam permeability improved by 210 times and could m ake the regional gas pre-drainage pure value improved by 55%.During the gateway driving period,the gas value in mine air retuning was reduced by 17%.The max volu me fraction of gas in the air retuning flow would not be over 0.65% After the outburst prevention measures conducted,the performance inspection showed that there wa s no index over the limits occurred and safety and rapid driving of the fully mechanized gateway driving face could be realized.