坚硬煤层含大直径控制孔爆破增透技术

Blasting anti-reflection technology of large diameter control hole in hard coal seam

为提高煤体瓦斯抽采效果,以沙坪煤矿18204工作面爆破增透为研究对象,采用离散元方法,研究了无控制孔以及控制孔半径分别为60、80及100 mm条件下的速度场、应力场、裂隙场规律。计算结果表明,控制孔的直径越大,应力波的反射程度越大、应力集中区范围越大,控制孔周围裂隙发育频次、连通程度越大,越有利于裂隙沿着“爆孔—控制孔—爆孔”连心线的方向扩展。在此基础上,进行了18204工作面深孔爆破增透现场试验研究,表明采用大直径控制孔及半径100 mm的控制孔平均瓦斯浓度增加96.7%~99.3%,取得了较好的爆破增透效果。研究结果可为爆破增透作业爆破参数设计和科学研究提供参考。

In order to improve the effect of coal gas extraction,taking the blasting and permeability improvement of No.18204 Face in Shaping Coal Mine as the research object,the discrete element method is used to study the velocity field,stress field and fracture field under the conditions of no control hole and control hole radius of 60 mm,80 mm and 100 mm respectively.The results show that the larger the diameter of the control hole,the greater the reflection degree of the stress wave,the greater the range of the stress concentration zone,the greater the frequency of fracture development around the control hole,the greater the degree of connectivity,and the more conducive to the fracture along the'blast hole-control hole-blast hole'.On this basis,the field test of deep hole blasting antireflection in No.18204 Face was carried out.The results show that the average gas concentration of large diameter control hole and control hole with radius of 100 mm increases by 96.7%~99.3%,and good blasting antireflection effect is obtained.The research results can provide reference for blasting parameter design and scientific research of blasting antireflection operation.