煤在瓦斯一维渗流作用下的初次破坏

作者观察了煤在瓦斯一维渗流作用下的初次破坏,发现破坏煤体呈球冠状;临界破坏瓦斯超压取决于卸载条件,煤型的强度、半径和长度,以及煤型所受的侧压,但与瓦斯吸附特性无关。对实验例进行了数值分析,结果表明煤体的破坏属于拉伸破坏;卸载速率的增高,侧向围压的减小与煤型几何半径的增大将使得煤体在瓦斯渗流作用下更易于破坏。

INCIPIENT FRACTURE OF COAL UNDER ONE DIMENSIONAL GAS SEEPAGE

The fracture of coal under one dimensional gas seepage is investigated. The experiments show that the incipient fracture of coal takes the shape of a spherical crown; the critical gas overpressure is dependent on the unloading condition, the strength, radius, confining pressure, length of the sample, and independent of the characteristics of gas adsorption. Numerical analysis demonstrates that the fracture belongs to tensile mode; the increase of unloading rate, decrease of confining pressure and increase of radius of the sample will cause the coal to fracture more easily under gas seepage.This research will be helpful for understanding the initiation of gas and coal outbursts.