冲击地压煤层局部保护层开采的减压机理研究

保护层开采是区域性防治冲击地压的有效方法,但当开采保护层不具有经济价值、不开采保护层又不能保证主采煤层防冲安全的条件下,提出了开采局部保护层的防冲方案并进行了防冲和防大变形灾害的机理研究。为了论证开采局部保护层防冲方案的安全性,通过建立局部保护层和被保护层的力学关系模型,推导了在局部保护层作用下岩体应力的计算公式,绘制了不同宽度局部保护层条件下引起冲击的垂直应力和剪应力分布云图,给出了发生冲击和大变形边界的应力判据,为设计被保护层巷道的安全位置提供了理论依据。结合河南某煤矿的实际情况,给出局部保护层减压效果的计算方法,计算结果在该煤矿强冲击危险工作面设计中得到了应用。

Pressure-releasing mechanism of local protective layer in coal seam with rock burst

The exploitation of protective layer is a regional effective method for prevention of rock burst. However, when the exploitation of protective layer has little economic value and the safety of main coal seam cannot be guaranteed without it, a new method called local protective layer is proposed, and the mechanism of prevention of rock burst and large deformation is studied. In order to prove the security of the proposed method, a formula for calculating the stress of rock mass under the action of local protective layer is derived by establishing the mechanical relationship model for the local protective layer and the protected layer. The distribution of the main stress and shear stress under different widths of local protection layer is plotted. The stress criterion for the occurrence of shock and large deformation boundary is given. Based on the actual situation of a coal mine in Henan, the calculation method for the effects of the local protection layer is given. The calculated results are applied in the design of a dangerous rock burst face in the coal mine.