特厚煤层综放工作面小煤柱巷道支护技术研究

Study on Small Coal Pillar Roadway Support Technology of Extremely Thick Coal Seam in Fully-mechanized Caving Face

为解决特厚煤层高强度综放开采工作面小煤柱巷道维护困难的问题,以同忻矿8305特厚煤层综放工作面5305小煤柱巷道为研究背景,运用理论计算及数值模拟分析了不同支护参数对支护效果的影响,结果表明:提高预紧力,“三径”匹配保证锚固力,适当减小锚杆索长度增加支护密度以形成连续的预应力场,再配合相应的组合锚索可提高小煤柱巷道整体的围岩稳定性。基于此提出了特厚煤层高强度综放开采工作面小煤柱巷道锚网索联合支护方案,并通过现场实测验证了方案的合理性。现场应用表明:小煤柱巷道在采用高预紧力锚网索联合支护方案后,掘进期间顶底板最大移近量为63 mm,两帮最大移近量为96 mm;回采期间巷道顶底板最大移近量为420 mm,两帮最大移近量为729 mm,支护效果良好,巷道围岩变形得到了有效控制。

In order to solve the problem of small pillar roadway maintenance difficulties in high-strength top coal caving face of extrathick coal seam,based on the research background of 5305 small pillar roadway of the 8305 top-coal caving face of extra-thick coal seam in Tongxin Coal Mine,the influence of different support parameters on the support effect is analyzed by theoretical calculation and numerical simulation.The results show that,increasing the preload,“three kinds of diameter”matching to ensure the anchorage force,appropriately reducing the length of bolts and cables and increasing the supporting density to form a continuous prestress field,and then with the corresponding combination cables can improve the whole surrounding rock stability of small pillar roadway.Based on this,the anchor-net-cable coupling support plan for high-strength top coal caving face of extra-thick coal seam of small pillar roadway,and its rationality is verified by field measurement.The field application shows that,after the small pillar roadway adopts the anchor-net-cable coupling support plan,during tunneling,the maximum displacement of roof and floor of roadway is 63 mm,and that two sides of roadway is 96 mm.During mining,the maximum displacement of roof and floor of roadway is 420 mm,and that two sides of roadway is 729 mm.The supporting effect was good,and the surrounding rock deformation of the roadway was effectively controlled.