深部强冲击厚煤层开采上、下解放层卸压效果相似模拟试验研究

Similar material simulation experiment on destressing effects of the deep thick coal seam with high burst liability after mining upper and lower protective seams

为了研究深部强冲击厚煤层开采上、下解放层的卸压效果,采用相似材料模拟试验的方法,通过监测解放层开采过程中及稳定后被解放层应力变化情况,分析应力变化规律,计算下解放层下部合理卸压角,确定了被解放层下平巷的合理位置;比较两次开采上解放层模拟试验的卸压程度,确定了上解放层工作面的合理位置;证明了开采下解放层后,被解放层上平巷附近区域仍是高应力集中区,易发生冲击地压,而开采上解放层后,该区应力明显减小,说明上解放层卸压效果明显;验证了井下发生大能量冲击地压之前,地表沉降出现"反弹"的异常现象。该研究为工作面开采设计提供理论指导,对防治冲击地压具有重要的现实意义。

In order to study the destressing effects of the deep thick coal seams with high burst liability after mining upper and lower protective seams, the method of similar material simulation experiment is adopted to analyze the rule of the stress change, to compute the lower reasonable distressing angle of the lower protective seam, and to find the lower tunnel＇s reasonable position of the protected seam by monitoring the stress change of the protected seam in the process of mining the protective seam and the stable state. The reasonable position of the upper protective seam workface is chosen by comparing the distressing effects of the twice simulation experiments of mining the upper protective seam. The upper tunnel region of the protected seam is still a high concentrative area with easy occurrence of rock burst despite mining the lower protective seam. After mining the upper protective seam, the stress in this area falls obviously, so it proves that the upper protective seam distresses obviously. The experiment verifies that the ＂rebound＂ phenomenon occurs on the earth surface before rock burst with high energy in mining. This study provides the theoretical guidance for the mining design of the workface and it is very important to prevent rock burst in practice.