Research and Application of “Three Sealing and One Grouting” Sealing Technique of Boreholes Drilled Along Seam

According to 3316 auxiliary air return roadway of Wangpo Mine, FLAC^3D numerical simulation software is used to analyze the stress and strain characteristics of supporting roadway, and the reasonable hole sealing depth is not less than 15 m, and then the three sealing and one grouting sealing technique is optimized. After the comparison and analysis of two sealing and one grouting, the research show that the total and the maximum average concentration of extraction drilling of three sealing and one grouting increased by 9.5% and 16.5% than that of two sealing and one grouting, and the concentration of extraction is as high as 40% after the boreholes has been extraction for 70 days. So the three sealing and one grouting sealing technique can effectively improve the efficiency of gas drainage.