Most rock roof of roadway is sediment rock, so its intensity is low, the stratification is a common rock mass structure in coal mines.

煤巷顶板多数是岩体强度较低的沉积岩，层状岩体结构是沉积岩的主要特征之一。

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The differences between the coal drawing face and non-coal drawing face are low stowing factor in the goaf, vigorous movement of roof, and high stress peak abutment pressure along the strike.

放顶煤工作面与非放顶煤工作面的区别是，采空区充填系数小，顶板岩层运动剧烈，走向方向超前支承应力峰值较大。

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