大倾角特厚煤层悬顶结构能量分布特征与防冲方法

Energy distribution characteristics and rock burst control methods of steeper inclined thick coal seam hanging roof

针对大倾角特厚煤层由悬顶大量弹性能聚集后突然释放引发的冲击地压现象,建立了"倾斜悬顶结构"力学模型。分析了该结构的能量分布特征,确定了悬顶上弯曲变形能集中程度较高的两个重点卸压区域。利用数值模拟分析,发现了超前顶板重点卸压区域的弹性能释放后由能量转移与积聚而形成"人"字型能量分叉形态,构成了顶板防冲卸压后的主要灾源。据此提出了大倾角特厚煤层弹性能定向释放防冲方法,将方法分为悬顶能量释放与次生能量消耗2个阶段,并分析了各阶段的作用与防冲手段。通过顶板动态监测与地音监测检验,证明此方法能够在有效的缩短悬顶面积,减小工作面顶板压力与来压步距的同时,降低由顶板防冲卸压造成次生灾害的可能。

Based on the phenomenon of the rock burst due to a great deal of elastic energy gathering and suddenly releasing on the steeper inclined thick coal seam hanging roof. The inclined roof hanging structure mechanical model was established. The character of this structure energy distribution was analyzed,as well as two key release areas on the hanging roof was confirmed. The herringbone energy bifurcation after elastic energy release on the ahead of mining face roof was found through the numerical simulations,which was the most principal disaster source after pressure relief on the roof. The directional elastic energy releasing method for control rock burst was put forward accordingly. The monitoring data show that this method is significance in reduction of the roof pressure,the weighting interval,as well as the probability of secondary disaster.