突出煤体空间分布及粒径分布特性试验分析

中国矿业大学 安全工程学院,江苏 徐州 221116

煤与瓦斯突出; 三轴应力; 瓦斯压力; 空间分布; 粒径分布

Experimental study on the spatial distribution characteristics of outburst coal
XING Yue-qiang,CHENG Yuan-ping,TU Qing-yi,WANG Xiao-lei

(School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China)

coal and gas outburst; three axis stress; gas pressure; spatial distribution; particle size distribution

DOI: 10.13800/j.cnki.xakjdxxb.2018.0310文章编号: 1672-9315(2018)03-0411-06

备注

为进一步研究煤与瓦斯突出过程中突出煤体的空间分布与粒径分布特征,利用自主研发的真三轴煤与瓦斯突出模拟试验装置,在相同成型压力3 000 kN基础上,开展瓦斯压力为0.2,0.25,0.3,0.35,0.4,0.5 MPa下的煤与瓦斯突出试验。通过水平加载泵站控制,将垂直应力、构造应力、侧向应力均设置为5.5 MPa.结果证明了煤与瓦斯突出的发生存在一个瓦斯临界值,大于这个临界值,突出发生,本试验中突出临界值位于0.25~0.3 MPa之间。随着瓦斯压力的增加,煤样的突出量逐渐增大,相对突出强度也增大,说明在现场中,瓦斯压力是煤与瓦斯突出强度的重要决定因素。突出煤体呈梭形分布,中间有多条带式间隔,吹扫作用明显。突出煤体主要聚集在远处区域,主要为小粒径煤粉,其中直径小于0.25 mm的煤粉占比均大于20%,而小于0.5 mm的均超过45%,个别甚至高达66.7%.大粒径煤颗粒两头多,中间少。突出试验结果与现场实际突出情况有所不同,尤其是在大粒径煤体分布方面,但是综合试验空间、突出发展时间、煤的自然安息角等多方面因素考虑,可以得到合理的解释。

In order to further study the spatial distribution and particle size distribution of sample in coal and gas outburst,this study,using the independently developed three axis coal and gas outburst simulation test device,on the basis of 3 000 kN molding pressure,carries out the test of coal and gas outburst under the different gas pressures,including 0.2,0.25,0.3,0.35,0.4,0.5 MPa.Vertical stress,tectonic stress and lateral stress are all set to 5.5 MPa by controling horizontal loading pump station.The results illustrate that there is a critical value of gas pressure in the occurrence of coal and gas outburst.It happens only the pressure is higher than the critical value.The outburst critical value is approximately between 0.25~0.3 MPa in this experiment.As the gas pressure increases,the coal samples of outburst increases gradually,as well as the relative protruding strength of the coal,which means that gas pressure is an important determinant factor of coal and gas outburst intensity in the field.The distribution of the outburst coal is shuttle shaped,there are many stripe shaped spacing in the middle and the blowing effect is obvious.The sample of outburst is mainly concentrated in the distant region.It is mainly the small size pulverized coal.The proportion of pulverized coal with diameter less than 0.25 mm is more than 20%,and that less than 0.5mm is over 45%,individual even up to 66.7%.Large size coal particles distribute more in both ends,less in middle part.The result of the outburst test is different from the actual situation in the field,especially in the distribution of large size coal particles.But we can obtain a reasonable explanation by combining the comprehensive factors such as test space,protruding developing time,natural rest angle of coal,etc.