急倾斜煤层放顶煤分段高度的合理确定

RATIONAL DETERMINATION OF SUBLEVEL HEIGHT OF TOP COAL IN STEEP SEAM

应用弹塑性理论分析了矿山压力对急倾斜煤层顶煤破碎的作用 ,认为在低瓦斯急倾斜煤层中只有当顶煤在支承压力的作用下进入应力极限平衡状态时 ,顶煤才可放出 ,据此计算顶煤可能的分段高度。但分段高度的确定还需考虑煤层厚度变化的影响 ,将煤层厚度视为一个随机变量 。

The effect of rock pressure on the crack of top coal of steep seam is analyzed by elastic-plastic theory. It is put forward that the top coal of low gaseous steep seam can be caved only when the top coal is in the limiting equilibrium state of stress under the abutment pressure. The sublevel height of top coal is calculated. However, the change of seam thickness has to be thought over when the sublevel height of top coal is determined. Therefore the seam thickness is considered as a random variable, and the reasonable sublevel height of top coal is determined by the reliability.