Study on combined support technology of goaf floor roadway under the conditions of close coal seam spacing and several coal pillars
Hou Diankun1, Jin Huilong1,2, Bu Qingwei1
1. Inner Mongolia University of Science and Technology, Baotou 014010, China; 2. Qinghai Branch, China Huaneng
Group Corporation Ltd., Xining 810001, China
The No. 14-2 coal seam centralized roadway in the Xinzhouyao Mine was taken as the engineering background. Surrounding rock control technology of goaf floor roadway under the conditions of close coal seam spacing and several coal pillars was studied. The analysis showed that the stress environment of goaf floor under the conditions of close coal seam spacing and several coal pillars can be roughly divided into two types, the mining stress concentration area under the goaf pillar and the mining stress reduction area under the goaf, and the two were alternately distributed. As a result, under different stress environments at different goaf floor locations, the characteristics of roadway pressure appearance were obviously different; in the mining stress concentration area under the goaf floor of coal pillar, the horizontal stress was obviously lower than the vertical stress, but the goaf floor stress environment was relatively high, which led to the relatively serious stress damage degree of roadway surrounding rock; in the mining stress reduction area under the goaf floor, the horizontal stress was higher than the vertical stress, but the goaf floor stress environment was relatively low, which led to the relatively light stress damage degree of roadway surrounding rock; in addition, because the roadway layout was close to the overlying goaf floor, the mining failure of overlying goaf floor was connected with the near distance roadway roof failure, so the passive support was more effective than the active support; there was fracture connection between the mining failure of the overlying goaf floor and the surrounding rock failure of the roadway roof, so the passive support was more effective than the active support. The active and passive combined support technology scheme of anchor bolt + anchor cable + metal mesh + wood pile wall back filling + U-shaped steel support in No. 14-2 coal seam centralized roadway was given in west No.2 panel. The feedback of support effect in industrial practice showed that the stability of surrounding rock was well controlled by active and passive combined support technology, which met the expected application requirements.
侯殿坤1,金慧龙1,2,卜庆为1. 近层间距、多煤柱条件下采空区底板巷道联合支护技术研究[J]. 煤炭与化工, 2021, 44(1): 1-6,12.
Hou Diankun1, Jin Huilong1,2, Bu Qingwei1. Study on combined support technology of goaf floor roadway under the conditions of close coal seam spacing and several coal pillars. CCI, 2021, 44(1): 1-6,12.