近距离上保护层开采下伏被保护层卸压效应研究

使用ZKBY-Ⅱ型顶板离层仪对戊_9-10煤层的变形膨胀进行观测，对近距离上保护层回采时下伏被保护层应力分布和膨胀变形规律进行了研究。结果表明，近距离上保护层开采后，在采空区下方的一定范围内被保护层产生卸压膨胀变形，煤体弹性潜能得以释放，透气性增大，消除或减小了被保护层煤与瓦斯突出危险性，研究取得了显著的经济技术效益。

Research on pressure relief effect of protected strata under protective layer mining at close range

The ZKBY-Ⅱ type roof separation meter was used to observe the deformation and expansion of the coal seam of the Ⅴ_9-10 coal seam，the stress distribution and the deformation law of the under-covered protective layer were studied.The results showed that，after the protection layer is mined at a short distance，the protected layer is deformed by pressure relief and expansion under a certain range below the goaf，the elastic potential energy of the coal is released，the permeability is increased，and the gas outburst danger of the protected layer coal is eliminated or reduced.The research results have achieved significant economic and technological benefits.