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金属矿山 ›› 2019, Vol. 48 ›› Issue (08): 38-43.

• 采矿工程 • 上一篇    下一篇

冲击加载作用下矿石试件的动态力学特性及块度分布特征

董英健1,郭连军2,贾建军3   

  1. 1. 辽宁科技大学矿业工程学院,辽宁 鞍山 114051;2. 沈阳工业大学土木学院,辽宁 沈阳 110870;3. 鞍钢矿业爆破有限公司,辽宁 鞍山 114046
  • 出版日期:2019-08-15 发布日期:2019-10-10
  • 基金资助:

    基金项目: “十三五”国家重点研发计划项目(编号:2016YFC0801603),国家自然科学基金面上项目(编号:51574123),辽宁省自然科学基金项目(编号:20170540456)。

Dynamic Mechanical Properties and Fragmentation Distribution of Rock Mass under Impact Loads

Dong Yingjian1,Guo Lianjun2,Jia Jianjun3   

  1. 1. School of Mining Engineering,University of Science and Technology Liaoning,Anshan 114051, China;2. School of Civil Engineering,Shenyang University of Technology,Shenyang 110870, China;3. Ansteel Mining Blasting Co., Ltd.,Anshan 114046, China
  • Online:2019-08-15 Published:2019-10-10

摘要: 矿石的动态力学特性影响其破碎效果。利用[?]50 mm霍普金森杆系统改变冲击荷载对矿石A、矿石B试件进行16次动态压缩实验,分析冲击气压对矿石应变率的影响,对抗压强度与应变率之间的关联性做了初步研究;统计破碎后的矿石块度筛分数据,分析块度的分布特征。结果表明:冲击速度在12~16 m/s范围内时每增大1 m/s时,矿石B的动态抗压强度增大8.3 %,矿石A的动态抗压强度总是低于矿石B,且矿石A、矿石B抗压强度随着应变率的增加呈指数型增长;随着耗散能量的增加矿石块度破碎的程度越大,矿石B筛分破碎块度的整体通过率要低于矿石A,表明矿石B内部固有大量微缺陷在吸收能量变形中加速了裂纹的闭合,与矿石A相比,强度增大且破碎程度较为平缓。

关键词: 岩石力学, 霍普金森压杆, 动态力学特性, 块度

Abstract: Fragmentation effect of ore was influenced by dynamic mechanical properties. 16 dynamic compression experiments were conducted on ore A and B by using [?]50 mm Hopkinson bar system to change the impact compressive load. The influence of impact pressure on ore strain rate was analyzed, and the correlation between compressive strength and strain rate was preliminarily studied. The fragmentation degree data of crushed ore were counted and the fragmentation distribution was analyzed. The results show that the dynamic compressive strength of ore B increases by 8.3% when the impact velocity increases by 1 m/s within the range of 12-16 m/s; the dynamic compressive strength of ore A is always lower than that of ore B, and the compressive strength of ore A and ore B increases exponentially with the increase of strain rate; the fragmentation degree of ore increases with the increase of dissipated energy. The larger the size, the lower the overall pass rate of ore B screening fragmentation is than that of ore A, indicating that a large number of inherent micro-defects in ore B accelerate the crack closure in energy absorption deformation. Compared with ore A, ore B shows higher strength and more gentle crushing.

Key words: Rock mechanics, Hopkinson pressure bar, Dynamic mechanical properties, Fragmentation degree