突出煤层深孔控制爆破时控制孔的作用

Action of control holes on deep-hole blasting in outburst coal seams

为进行煤层深孔爆破应力传播和有关控制孔作用的研究.以松藻煤电公司实际采用的爆破、炸药和煤层参数为基础.利用三维数值模拟方法,建立煤层长柱状药包爆破数值计算模型。分析了松软煤介质深孔爆破在有控制孔时应力波传播的特点和因爆破作用的抽放影响区域.研究表明:在距爆破孔10 m范围内。有控制孔的孔壁平均有效应力较没有控制孔相同条件下高48%～66%,并随着与爆破孔距离的增加.尽管煤体所受有效应力衰减.但有控制孔的平均有效应力值较无控制孔的比率增大。上述研究结果与现场爆破前后实际取得的瓦斯抽放数据相比基本吻合,证明了爆破前预先设置控制孔的必要性。

In order to explore stress wave propagation and action of control holes for deep-hole blasting in coal seams, based on parameters of blasting, explosive and coal mass got from the Songzao coal and electricity company, a numerical simulation model of linear charge blasting in coal seams was built by means of 3D numerical simulation. The stress propagation feature and effective area of gas drainage by blasting action were analyzed in the soft coal bed with the control holes. The study indicate that the average effective stress in boundary of the control holes which are constructed before blasting is 48%-66% higher than that at the same location without control holes. With the increase of the distance between the blasting hole and control holes, effectives stress decreases in coal seams, but average stress ratio at the same locations with and without control holes increases. Simulated results are in agreement with the gas draining data got from the coal mine before and after blasting. It is necessary that the control hole is pre-arranged before detonation.