小煤矿破坏区关键承载层的构建机理与应用

Construction Mechanism and Application of Key Bearing Layer in Failure Area of Small Coal Mines

矿井井田开采范围被小煤矿破坏的现象普遍存在,为避免煤炭资源的浪费,提出以构建关键承载层为基础的小煤矿破坏区先充填后复采的处理方法。建立了破坏区顶板垮冒冲击关键承载层的力学模型,研究了破坏区关键承载层厚度的确定方法、充填材料的选择及分层充填技术。结果表明:平朔井工二矿复采面关键承载层厚度达到5 m能保障顶板和煤壁的稳定性;用无机材料对破坏区进行分层充填形成强度不同的截割层和关键承载层,使其达到正常煤层的回采要求并降低了成本。研究结果对类似条件下的煤层开采有理论价值和实际指导意义。

In the light of the fact that many underground mine fields are damaged by small coal mines,and in order to avoid serious damages to the limited coal resources,a secondary mining technology after backfilling was put forward based on building a key bearing layer in the failure area of small coal mines.The mechanical model of roof caving impacting on key bearing layer in destruction area was built,and the determining method of the thickness of key bearing layer in the failure area,the choice of backfilling materials,and the layered backfilling method were investigated respectively.The results showed that the key bearing layer with less than 5 m in thickness can ensure the stability of both roof and the coal walls in secondary mining of Pingshuo second coal mine.Inorganic materials were filled in failure areas of the small coal mines by levels to form cutting layer and key bearing layer with different strength,which made them meet the mining requirements of the normal coal seam and reduced the cost.The research results are of great theoretical and practical significance for the coal seam with similar conditions.