Analysis of empty hole effect in directional fracture controlled blasting
-
摘要: 采用新型数字激光动态焦散线实验系统, 对爆炸荷载作用下空孔周围的动应力场分布及空孔对爆生主裂纹扩展行为的影响进行了研究。研究结果表明, 在空孔周围强应力场的影响下, 2条相向扩展的爆生主裂纹逐渐向空孔处偏转, 并在空孔处贯通; 空孔附近的主应力方向与炮孔连心线夹角基本稳定在约12°, 增大空孔尺寸对空孔附近的主应力方向影响不明显; 爆炸应力波与空孔相互作用, 产生反射拉伸波, 改变了主裂纹尖端的应力场, 降低了主裂纹的扩展速度, 且空孔直径越大, 主裂纹的扩展速度越低; 当爆生主裂纹扩展到空孔附近时, 主裂纹尖端动态应力强度因子再次出现上升的趋势。
-
关键词:
- 爆炸力学 /
- 定向断裂控制爆破 /
- 爆破裂纹数字激光动态焦散线 /
- 空孔 /
- 爆破裂纹
Abstract: A new experimental system of digital laser dynamic caustics was used and the distribution of dynamic stress field around empty holes and the influence of empty holes upon the main cracks expanding under the blasting loading were studied.Experimental results show that two blast-induced main cracks, which were oppositely expanding, deflected gradually to empty hole under the strong stress and penetrated empty hole.The angle between the principal stress direction and the line of two blasting holes center near the empty hole kept about 12°, and the principal stress direction did not change with the size of empty holes increasing; the interaction between explosive stress waves and empty holes produced reflective stretching waves, changed the stress field at the main crack tips, reduced expanding velocity of the main crack.The larger the diameter of empty hole was, the lower the main crack propagation velocity was.When the blast-induced main cracks expanded to empty hole, the dynamic stress intensity factor at crack tips appeared to rise again. -
图 5 新型数字激光动态焦散线实验系统
Figure 5. New-type digital laser dynamic caustics experimental system
图 7 不同空孔直径周围焦散斑
Figure 7. Caustics patterns around of empty holes with different sizes
图 8 空孔周围主应力差值时程曲线
Figure 8. Histories of difference between the two principal stresses around empty holes
图 10 爆生主裂纹扩展速度时程曲线
Figure 10. Propagation velocity histories of the blast-induced cracks
-
[1] 王树仁, 魏有志.岩石爆破中断裂控制的研究[J].中国矿业学院学报, 1985(3): 118-125. http://www.cnki.com.cn/Article/CJFDTotal-ZGKD198503015.htmWang Shu-ren, Wei You-zhi. Fracture control in rock blasting[J]. Journal of China University of Mining & Technology, 1985(3): 118-125. http://www.cnki.com.cn/Article/CJFDTotal-ZGKD198503015.htm [2] 林大能.平巷掏槽爆破空孔尺寸效应及围岩频繁震动损伤累积特性研究[D].长沙: 中南大学, 2006. [3] Mohanty B B. Smooth wall blasting in rock: US4690058[P]. 1987. [4] Mohanty B B. Explosion generated fractures in rock and rock like materials[J]. Engineering Fracture Mechanics, 1990, 35(4/5): 889-898. http://www.sciencedirect.com/science/article/pii/001379449090173E [5] Nakamura Y, Cho S H, Yoneoka M, et al. Model experiments on crack propagation between two charge holes in blasting[J]. Science and Technology of Energetic Materials, 2004, 65(2): 34-39. http://ci.nii.ac.jp/naid/10012343585 [6] Cho S H, Nakamura Y, Mohanty B, et al. Numerical study of fracture plane control in laboratory-scale blasting[J]. Engineering Fracture Mechanics, 2008, 75(13): 3966-3984. doi: 10.1016/j.engfracmech.2008.02.007 [7] 刘优平, 周正义, 黎剑华.井巷掏槽爆破中空孔效应的理论与试验分析[J].金属矿山, 2007, 368(2): 12-14. http://www.cnki.com.cn/Article/CJFDTotal-JSKS200702003.htmLiu You-ping, Zhou Zheng-yi, Li Jian-hua. Theoretical and experimental study on empty hole effect in tunnel cut blasting[J]. Metal Mine, 2007, 368(2): 12-14. http://www.cnki.com.cn/Article/CJFDTotal-JSKS200702003.htm [8] 毕谦, 倪斌, 杨邦成.控制切割爆破中空孔导向机理研究[J].昆明工学院学报, 1992, 17(2): 5-8. http://www.cqvip.com/qk/92599X/199202/821085.htmlBi Qian, Ni Bin, Yang Bang-cheng. A study on orientation control mechanism of loading holes in cutting control blasting[J]. Journal of Kunming Institute of Technology, 1992, 17(2): 5-8. http://www.cqvip.com/qk/92599X/199202/821085.html [9] 文梼, 谭海.岩石爆破中的空孔效应数值计算分析[J].爆破, 2011, 28(3): 58-61.Wen Tao, Tan Mei. The empty hole effect numerical computation analysis during rock blasting[J]. Blasting. 2011, 28(3): 58-61. [10] 姚学锋, 方竞, 熊春阳.爆炸应力波作用下裂纹与孔洞的动态焦散线分析[J].爆炸与冲击, 1998, 18(3): 40-45. http://www.cnki.com.cn/Article/CJFDTotal-BZCJ803.007.htmYao Xue-feng, Fang Jing, Xiong Chun-yang. Dynamic caustics analysis of crack and hole under the explosive stress waves[J]. Explosion and Shock Waves, 1998, 18(3): 40-45. http://www.cnki.com.cn/Article/CJFDTotal-BZCJ803.007.htm [11] 岳中文, 杨仁树, 郭东明, 等.爆炸作用下空孔周围应力场变化的模型实验[J].煤炭学报, 2009, 34(5): 624-628. http://www.cqvip.com/Main/Detail.aspx?id=30427064Yue Zhong-wen, Yang Ren-shu, Guo Dong-ming, et al. Model experimental of stress field around empty hole under blasting loading[J]. Journal of China Coal Society, 2009, 34(5): 624-628. http://www.cqvip.com/Main/Detail.aspx?id=30427064 [12] Arakawa K, Takahashi K. Relationships between fracture parameters and fracture surface roughness of brittle polymers[J]. International Journal of Fracture, 1991, 48(2): 103-114. doi: 10.1007/BF00018393 [13] 杨立云, 杨仁树, 许鹏.新型数字激光动态焦散线实验系统及其应用[J].中国矿业大学学报, 2013, 42(2): 188-194. http://www.cnki.com.cn/Article/CJFDTotal-ZGKD201302004.htmYang Li-yun, Yang Ren-shu, Xu Peng. Caustics method combined with laser and digital high-speed camera and its application[J]. Journal of China University of Mining and Technology, 2013, 42(2): 188-194. http://www.cnki.com.cn/Article/CJFDTotal-ZGKD201302004.htm -
下载:
点击查看大图
图(11)
计量
- 文章访问数: 3121
- HTML全文浏览量: 380
- PDF下载量: 433
- 被引次数: 0