研究了大同燕子山煤层顶板岩石的显微空隙、粒度分布的分形特征及其与岩石强度的关系。

The microscopic statistical analyses and the mechanical tests show that the rock microvoid and grains distribution are all fractal in nature, and can be expressed by their fractal dimensions.

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超前支护锚杆锚固后与顶板岩石构成一体，这样使超前锚杆形成组合梁作用，放炮后，能够阻止顶板岩石冒落。

Forward support bolt combined with roop rock by bolting can play a roll of combined beam, which can prevent roof rock caving immediately after explosion.

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前言： 通过对“三软”不稳定煤层采煤工作面瓦斯来源的分析，介绍了采用顶板岩石钻孔抽放解决瓦斯问题的原理和方法。

Based on the analysis of gas source at the working face with "three-soft" unsteady coal seam, the authors introduce the principle and method of gas suction by roof-rock drilling.

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