基于组合体模型的阻挡层厚度对突出延期时间的影响分析

Effect Analysis of Barrier Layer Thickness on Outburst Delay Time Based on Combination Model

为了对突出延期发生的原因进行分析,建立了延期突出的"阻挡层-软煤"组合体模型,该模型说明突出延期发生的原因是工作面空间和软煤之间存在的阻挡层,阻挡层发生破坏需要一定的时间,进而导致软煤的暴露并形成延期突出。根据该模型,采用数值模拟的方法,分析了阻挡层厚度对突出延期时间的影响。结果表明,当阻挡层厚度减小时,阻挡层进入加速蠕变阶段的速度变快。因此,当一次掘进进尺长度较长,使得预留阻挡层厚度变小,应以最快的速度实施支护,将可避免延期突出事故的发生。

In order to analyze the reasons of delay outburst of coal and gas, a combination model composed of ＂barrier layer and soft coal＂is established. The model demonstrates that it is the barrier layer between the work space and the soft coal that defers the occurrence of an outburst accident. The damage of the barrier layer needs a period of time to cause the exposure of the soft coal and finally lead to a delay outburst. According to the combination model, the effect of barrier layer thickness on delay time is analyzed using the method of numerical simulation. Result shows that the barrier layer enters into the acceleration creep in a shorter time as the thickness of the barrier layer decreases. Therefore, in order to prevent a delay outburst, the miners should support the roof very fast after a relatively long driving footage which results in a thin barrier layer.