地应力下岩石多孔爆破损伤演化数值模拟  

Numerical Simulation on Damage Evolution of Rock Porous Blasting Under In-Situ Stress

作　　者：庞宁波 杨永康[1] PANG Ningbo;YANG Yongkang(Key Laboratory of In-Situ Modified Mining Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《矿业研究与开发》2023年第10期119-125,共7页Mining Research and Development

基　　金：山西省回国留学人员科研资助项目(HGKY2019038);山西省高等学校教学改革创新项目(J2019055)。

摘　　要：为研究地应力作用下岩石多孔爆破裂纹扩展机理,基于LS-DYNA软件,讨论不同地应力下岩石孔间裂纹扩展与演化过程。结果表明:在各向同性地应力作用下,岩石爆生裂纹的扩展与演化会受到抑制,且抑制作用随地应力水平的提高而增强。裂纹的分布形态呈现各向同性的特征,各向同性地应力仅影响爆生裂纹的发育长度,主裂纹的扩展方向保持不变。在各向异性地应力作用下,爆生裂纹倾向于沿最大主应力方向演化。当岩体开挖方向与最大主应力方向一致时,地应力的抑制作用有利于保护预留岩体不受损伤。减小孔间距、孔内放置水袋和采用高爆速、高爆压的炸药均有利于实现高地应力作用下的孔间裂纹贯穿。水作为耦合介质所占比例从0提高到66%时,压碎区范围扩大了62%,裂纹数量增多;从66%提高到100%时,压碎区范围、裂纹数量无明显变化。其中,后两种方法有利于提高爆破致裂的效果,孔间裂隙发育更完全。To study the crack propagation mechanism of rock porous blasting under in-situ stress,based on LS-DYNA software,the crack propagation and evolution process among rock holes under different in-situ stresses were discussed.The results show that under the action of isotropic in-situ stress,the propagation and evolution of rock burst cracks are inhibited,and the inhibition effect increases with the increase of in-situ stress level.The distribution of cracks shows isotropic characteristics.The isotropic in-situ stress only affects the development length of the blast-induced cracks,but the propagation direction of the main cracks remains unchanged.Under the action of anisotropic in-situ stress,the blast-induced cracks tend to evolve along the direction of the maximum principal stress.When the excavation direction of the rock mass is consistent with the direction of the maximum principal stress,the inhibitory effect of the in-situ stress is beneficial to protect the reserved rock mass from damage.Reducing the hole spacing,placing water bags inside the holes,and using explosives with high detonation velocity and pressure are all beneficial for achieving crack penetration among holes under high in-situ stress.When the proportion of water as the coupling medium increases from O to 66%,the range of the crushing zone expands by 62%and the number of cracks increases.When the proportion increases from 66%to 100%,there is no significant change in the range of crushing zone and the number of cracks.Among them,the latter two methods are beneficial to improve the effect of blasting cracking,and the development of cracks among holes is more complete.

关 键 词：岩石爆破 地应力 裂纹扩展 数值模拟 

分 类 号：TD235.3[矿业工程—矿井建设]