切顶参数对沿空留巷围岩稳定性的影响研究

Influence of roof cutting parameters on stability of surrounding rock of gob-side entry retaining

  • 摘要: 切顶参数作为切顶卸压沿空留巷技术的核心问题之一,对留巷围岩稳定性影响较大。本文以曙光矿1226工作面为工程背景,通过理论分析初步得到了切顶高度和切顶角度的参考值分别为7.1~9.5 m和11.4°;通过数值模拟从切顶效果和围岩变形两种角度对切顶高度分别为4 m、7 m、10 m、13 m及切顶角度分别为0°、10°、15°、20°、30°时顶板垮落形态、顶板下沉量和实体煤帮应力分布进行了分析,结果表明最优切顶参数为切顶高度10 m、切顶角度15°;通过现场爆破试验,确定了最佳炮孔间距、爆破方式及装药量;留巷后对工作面后方巷道围岩变形进行了监测,巷道围岩变形量小,留巷效果良好。

     

    Abstract: As one of the core issues of roof cutting pressure relief gob-side entry retaining technology, roof cutting parameters have a great influence on the stability of surrounding rock.Taking the 1226 working face of Shuguang Mine as the engineering background, the reference values of cutting top height and cutting top Angle are 7.1~9.5 m and 11.4° respectively through theoretical analysis.Through numerical simulation, the roof collapse form, roof subsidence and stress distribution of solid coal side are analyzed when the roof cutting height is 4 m, 7 m, 10 m, 13 m and the roof cutting Angle is 0°, 10°, 15°, 20° and 30° respectively from two angles of roof cutting effect and surrounding rock deformation.The results show that the optimal cutting top parameters are the cutting top height 10 m and the cutting top Angle 15°.The optimum hole spacing, blasting method and charge quantity are determined by field blasting test.The surrounding rock deformation of the rear roadway of the working face was monitored after the roadway retaining.The deformation of the surrounding rock of the roadway was small and the effect of the roadway retaining was good.

     

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