定向断裂爆破在综放工作面初采切巷的应用

为解决综放工作面初采期上隅角瓦斯超限问题，采用初采切巷深孔爆破强制放顶的方法充填采空区以缩小工作面有效通风断面，以达到改善初采期间工作面通风状态与提高瓦斯排放效率的目的.但是炮孔间距由于受到初采切巷支护结构的限制往往大大超过预裂爆破经验公式确定的上限，造成预裂效果差的后果.为了选择适合现场使用的增加炮孔间距的最佳爆破方法，应用ANSYS/LS-DYNA软件对不耦合装药、V型刻槽和切缝药包3种爆破方式进行数值模拟，结果显示切缝药包爆破在增加炮孔间距和保护岩壁方面有明显优势，并通过模拟确定了切缝药包的最佳开口宽度.最后，通过在阳泉国阳公司K8205工作面进行超前深孔预裂爆破强制放顶的现场应用，比较爆破前、后和割一刀煤后支柱压力的变化情况，验证了良好的预裂爆破效果. 

Directional Fracture Blasting in Open-off Cut of Fully-Mechanized Caving Mining Face During Primary Mining

In order to solve the gas overrun in the upper corner of fully mechanized caving face during primary mining, a long-hole blasting roof caving method was proposed in the open-off cut to fill the goaf for the effective reduction of ventilation section of working face, so as to improve the ventilation condition and gas emission. Due to the limitation of open-off cut''s bolting structures, the blasthole spacing was generally greater than the pre-splitting blasting spacing determined by the experienced formulas, and this would result in poor consequences in the pre-splitting blasting. In order to select a suitable method to increase the balsthole spacing in the field, several charge methods were simulated with ANSYS/LS-DYNA, including the decoupling charge, V-shaped notch and split-tube charge methods. The results show that, directional fracture blasting with split-tube charge has obvious advantages in increasing blasthole spacing and protection of rock wall, and the optimal width of split-tube can be determined by numerical simulation. Finally, through the application of the long-hole blasting roof caving in the working face K8205 of Guo Yang company, the comparison of coal pillar stress before and after the blasting as well as one-knife cut shows that the method has good effect on the blasting.