含瓦斯煤体爆破裂纹扩展规律试验研究

Experimental Study on Regularity of Blasting Crack Spread in a Coal Contained Gas

为进一步研究含瓦斯煤体爆破作用机理,从理论上分析了含瓦斯煤体爆破裂纹的形成与扩展机理,并设计了含瓦斯煤体爆破裂纹扩展规律测试试验,利用探针法对含瓦斯煤体中的爆破裂纹扩展速度进行了测试,并对其中的爆炸应变波进行了测试。理论分析与试验结果表明:含瓦斯煤体爆破裂纹扩展经历了爆炸应力波作用下的快速衰减阶段、爆生气体与瓦斯气体共同作用下的缓慢衰减和近似匀速扩展3个阶段,瓦斯气体的存在有利于爆破裂纹的扩展,可以在裂纹扩展的后期阶段小幅度的增大裂纹的扩展速度。

In order to study the blasting mechanism of coal contained gas further, we have analyzed the mechanism of blasting crack formation and propagation theoretically, and designed the blasting crack propagation experiment. The blasting crack propagation velocity and the blasting strain waves have been measured. The theoretical and experimental results show that the blasting crack propagation has three stages. One is rapid decay stage under blasting stress wave, the other one is slow decay stage and the last one is approximate uniform propagation stage under detonation gas and coal mine gas. The coal mine gas plays a positive role in the blasting crack propagation, and it can increase the crack propagation velocity in a small range in the later stage.