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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金厂峪金矿部分顶板不稳定的缓倾斜薄至中厚矿体，其开采难度很大。

Part of ore body in Jinchangyu Gold mine is this kind of gently inclined thin and medium thick ore body with unstable roof, it is hard to mine.

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数值分析结果表明：夹沟矿采空区的顶板是不稳定的，顶板岩体容易发生垮落事故。

The results of numerical analysis on mined-out area indicate that the roof at mined-out areas is unstable and the rock in the roof is easy to collapse in this mine.

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