摘要
煤层深孔预裂爆破近年来在瓦斯抽放中运用日益增多,但目前对其爆破理论研究较少。以矿井现场实际使用的爆破、炸药和煤层参数为基础,利用三维数值模拟方法进行煤层预裂爆破机制研究。建立柱状药包爆破数值计算模型,研究煤体破坏单元的范围和受爆破应力波作用的抽放影响区域。研究结果表明,爆破粉碎范围最大接近40cm,爆破对抽放量影响的作用半径不超过10m,其中以4m内变化最明显。探讨不同距离抽放孔有效应力传播特点,研究中首次考虑因导爆索与乳化炸药传爆速度不同造成的煤层中应力分布差异,澄清了认识上的误区。分析松软煤介质中不同距离抽放孔的位移场变化规律,计算结果与现场爆破前后实测的瓦斯抽放数据相吻合。研究结果对促进预裂爆破技术更好地运用于煤矿瓦斯治理是有益的。
The technique of deep-hole presplitting blasting in coal bed is widely used for gas predrainage recently; but its blasting theory is not clear up to now. Based on the parameters of blasting, explosive and coal bed achieved from the mines, the mechanism of the presplitting blasting in coal body is studied by three-dimensional numerical simulation method. A numerical computational model in coal bed is constructed for cylindrical charge. The damage ranges of elements and zone influenced for the gas drainage by stress waves are investigated in coal body.The results show that the maximum radius of the area crushed by blasting is up to 40 cm, while radius of rate of gas drainage changed by blasting load is less than 10 m. It is also demonstrated that the improvement of draining effect is most obvious within 4 m around the hole. The stress propagation feature is discussed in draining holes with different distances. The differences of stress distribution, which is caused by the different detonation velocities for the primacord and emulsion explosive, are studied for the first time for clarifying some misunderstandings. The displacement field variations of the holes with different distances are analyzed in soft coal strata. Computation results are in good agreement with the gas draining data measured from the mine before and after blastings. This investigation is beneficial for promoting development of the presplitting blasting technique for gas control.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第8期1674-1681,共8页
Chinese Journal of Rock Mechanics and Engineering
关键词
数值分析
预裂爆破
长柱状药包
松软煤层
numerical analysis
presplitting blasting
cylindrical charge： soft coal bed
