摘要
核桃峪煤矿2804工作面机巷遇斜穿性断层,煤机截割全断面硬岩效率低下,阻碍了矿井正常生产。为保证工作面初采期间顺利通过断层,需提前对砂质硬岩进行爆破预裂。基于该工程背景,利用数值模拟软件LS-DYNA建立了不同孔径及不同间距的爆破计算模型,分析了不同孔径对应力波传播规律的影响,研究了不同孔间距的裂缝发育形态。结果表明:孔径在70~100 mm范围内随孔径增大应力峰值相应增大,且应力峰值出现的时间相应滞后,孔径为100 mm时应力峰值相对90 mm时增幅较小,孔径变化对应力峰值的影响减弱,确定最佳深孔爆破孔径为90 mm;通过分析炮孔间裂缝贯通程度及中心测点单元应力值,孔间距从1.2 m增加到1.3 m时应力降幅为2.2%,确定炮孔间距以1.2 m为宜。通过布设预掘爆破工艺巷,采取“五花眼”大装药量分组爆破技术,较好地解决了断层硬岩超前预裂问题。
The mechanical roadway of 2804 working face in Hetaoyu Coal Mine encounters oblique penetrating fault, and the coal machine is inefficient in cutting full-section hard rock, which hinders the normal production of the mine. In order to ensure the smooth passage of the working face during the initial mining, the sandy hard rock should be pre-split by blasting in advance. Based on the project background, the numerical simulation software LS-DYNA was used to establish a blasting calculation model with different pore diameters and different spacing, the influence of different pore diameters on the propagation law of stress waves was analyzed, and the crack development patterns under different hole spacing were studied. The results show that the stress peak value increases with the increase of the pore diameter in the range of 70-100 mm, and the time when the stress peak appears is lagged correspondingly. When the pore diameter is 100 mm, the increase of the stress peak value is relatively small compared with that of 90 mm, and the influence of pore diameter on stress peak value is weakened. It is determined that the best pore diameter for deep hole blasting is 90 mm. Through the analysis on the crack penetration degree between the blast holes and the stress value of the central measuring point unit, when the hole spacing increases from 1.2 m to 1.3 m, the stress decreases by 2.2%. It is appropriate to determine the hole spacing as 1.2 m. The problem of advanced pre-splitting of fault hard rock has been solved by arranging the pre-splitting blasting roadway and adopting the five-hole grouping blasting technology with large charge.
作者
韩晓飞
余睿
郝江海
杨敬轩
HAN Xiaofei;YU Rui;HAO Jianghai;YANG Jingxuan(School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)
出处
《矿业研究与开发》
CAS
北大核心
2023年第3期70-76,共7页
Mining Research and Development
基金
国家自然科学基金资助项目(52074261)。
关键词
斜穿性断层
深孔爆破
硬岩预裂
数值模拟
Oblique penetrating fault
Deep hole blasting
Hard rock pre-splitting
Numerical simulation
