【摘要】 为确保水库下特厚煤层综放开采安全,合理留设防水安全煤岩柱,大平煤矿采用钻孔冲洗液耗失量法对覆岩破坏进行了观测研究。经对7个工作面测站12个覆岩破坏观测钻孔实测资料分析研究得出:煤层采出厚度7.54～15.17m,工作面推过36～40d,滞后工作面距离110～120m时覆岩破坏发育最充分。实测导水裂缝带高度为采高的15.31～19.97倍,明显大于类似软弱覆岩地层条件普通长壁全陷法开采覆岩破坏导水裂缝带发育高度。导水裂缝带上方,明显有集中发育的离层破碎带存在,实测离层破碎带高度为181.58～390.75m,是采高的24.22～36.00倍。更多还原

【Abstract】 Overburden strata’s failure was observed through measuring the loss of drilling rinses to protect the fully-mechanized sublevel caving mining of specially thick coal seam.Based on the data of the 12 drillings of 7 working face,concluded that the overburden strata’s water flowing fractured zone fully developed after the working face had passed 36~40d while the lag working face distance was 110~120m under the situation that the mining thickness was 7.54~15.17m and the average moving speed was 3m/d.The height was 148.23~234.10m which was 15.31~19.97 times of the mining thickness.Overburden strata’s separation and failure developed to become a band above the water flowing fractured zone.The height was 181.58~390.75m which was 24.22~36.00 times of the mining thickness.更多还原