Adjacent seam pressure-relief gas drainage technique based on ground movement for initial mining phase of longwall face

摘要: Disallowed gas concentration (DGC), i.e., a cease in production due to exceeding the allowable limits, occurs frequently during initial mining phase of longwall faces Yangquan Coalfield, and seriously affects safety. The mechanism DGC face is determined by analyzing outflow behavior methane. results show that can induce ground movement lead pressure relief, leading desorption migration adjacent seams. Gas drainage from high-level roadway unsuccessful because it normally located too high connect vertical broken crevices overlying strata timely manner phase, subsequently, released methane seams flows into goaf. This occurrence at face. Thus, based on analysis flow characteristics seams, we propose an technique large-diameter blind shaft joined (LDBS-HGDR) for phase. A computational fluid dynamics simulation was conducted obtain optimal design layout parameters LDBS-HGDR Panel 15201. Compared with conventional rear technique, advantageous terms ease construction, low cost, sufficiently long hours. Moreover, be effectively decreased this thereby eliminating hazards originating frequent DGC.