摘要
在松软煤层相邻的岩石进行深孔控制爆破时,相邻煤层也产生裂隙和振动并可提高瓦斯流量。为研究此方法与煤体爆破的差异,利用三维数值模拟结合煤矿现场爆破实验,探讨了不同爆破介质的动应力分布及抽放效果。分析了底板岩石布孔和单煤体爆破布孔的特点;建立了不同条件下的爆破模型;研究了单煤体和煤岩介质中爆破孔与控制孔连心线距离与有效应力的关系。复合介质从岩石变为煤体后,有效应力极值减小57%,相同位置单一煤体只减小27%;瓦斯抽放效果很大程度上与爆破后控制孔轴线方向有效应力分布有关,爆破孔与控制孔间距为2.0 m时,轴线方向平均有效应力与全煤层爆破3.0 m间距时基本相当。通过对重庆渝阳矿进行底板岩石深孔爆破实践,证实了以上研究结论的正确性。
The gas flow increases as cracks and vibrations in coal seam are produced by the deep-hole control blasting in rock adjoining soft coal seam in which drill hole was easily destroyed. In order to study the differences between biasting in rock and that in coal body, dynamic stress distributions and draining effect for different medium blasted were discussed by means of three-dimensional numerical simulation method and blasting test from the coal mine. The characteristics of drilling hole patterns which blasting hole was located in single coal body and in rock media were analyzed. Blasting models on the different condition were constructed by numerical simulation. Relationships between effective stress and distance at linking line between blasting hole and draining hole were studied for single coal seam and coal-rock media. The maximum of effective stress decrease 57% when the stress wave spread from rock to coal seam in the coal-rock media. While it＇ s only 27% in the single coal seam at the same location;gas draining effect was considerably affect by distribution of effective stress along axis of controlling holes. The mean effective stress along axis of the draining hole in coal-rock media, when the distance between blasting hole and controlling hole is 2. 0 m, is appropriately the same as that is 3.0 m in the single coal seam. These research conclusions were validated to be correct by the deep blasting which located in rock nearby coal seam in Yuyang Coal Mine.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2012年第6期972-977,共6页
Journal of China Coal Society
关键词
瓦斯抽放率
岩孔爆破
煤层
动态应力
数值模拟
gas drainage rate
blasting in rock
coal seam
transient stress
numerical simulation
