特厚煤层回采巷道顶板变形特征及控制技术

Roof Deformation Characteristics and Control Technology of Mining Roadway in Extra Thick Coal Seam

为了解决特厚煤层回采巷道顶板变形严重、支护困难等问题,通过现场观测和理论分析得出特厚煤层回采巷道变形因素及其特征,并利用FLAC3D数值模拟软件分析了在原支护和高强恒阻让压锚网索联合支护2种护巷方式下巷道围岩变形情况。研究结果表明:含软弱夹层的特厚煤层回采巷道自稳时间短,变形速度快,顶板破碎严重,塑性区破坏范围较大,巷道顶板整体变形明显;高强恒阻让压锚网索支护系统能够适应围岩高应力的特点,遏制顶板过度变形破坏,满足该地质条件下巷道顶板大变形的趋势。工程实践表明,高强恒阻让压锚网索支护时巷道顶板最大下沉量为206 mm,并且现场未出现锚杆(索)破断失效的情况,支护结构能够满足巷道顶板变形特征,保障综放工作面的安全高效生产。研究结果可为类似条件下的巷道顶板控制提供参考。

In order to solve the problems of serious roof deformation and support difficulties in the extra-thick coal seam,the deformation factors and characteristics of the extra-thick coal seam's mining roadway were obtained through field observation and theoretical analysis.The FLAC3D numerical simulation software was used to analyze the original support and high-strength constant deformation of the surrounding rock of the roadway under two kinds of roadway protection methods with the combined support of anchor,mesh and cable under pressure and pressure.The results of the study show that the roadway in extra-thick coal seams with weak interlayers has short self-stabilization time,fast deformation speed,severe roof fracture,large plastic zone damage range,and obvious overall deformation of the roadway roof.The high-strength constant-resistance pressure bolt-mesh-cable support system can adapt to the characteristics of high stress of surrounding rock,curb excessive roof deformation and damage,and meet the trend of large deformation of roadway roof under the geological conditions.Engineering practice shows that the maximum subsidence of the roadway roof is 206 mm when the high-strength constant-resistance allows the anchor-net-cable support,and there is no failure of anchor rods(cables)on site.The supporting structure can meet the deformation characteristics of the roadway roof and ensure comprehensive safe and efficient production of the working face.The research results can provide references for roadway roof control under similar conditions.