摘要
深孔爆破中,起爆位置决定了爆轰波的传爆方向,进而影响爆炸应力场及岩体裂隙分布。基于Starfield迭加原理,推导链状球药包应力场传播与叠加规律,构建等效柱状药包理论模型,引入链状球药包载荷延时加载方法,开展柱状药包迭加应力场离散元数值仿真,研究各传爆方向下岩体裂隙分布规律的方向效应。结果表明:由于爆炸应力波存在相位延迟,柱状药包的应力波叠加和裂隙分布存在显著的方向效应,应力波沿传爆方向产生较强叠加,叠加应力幅值的增长速度先增大后减小,裂隙分布范围也沿传爆方向逐渐增大;对于不同的传爆方向,底部或上部单侧传爆时,裂隙总体沿传爆方向呈“漏斗状”分布,两端同时向中间传爆时,裂隙在炮孔中心附近最为发育,整体呈“纺锤状”分布,中部起向两端传爆时,裂隙在炮孔两端分布略广,整体分布较为均匀,裂隙分布情况可较好反映各传爆方向下迭加应力场的分布规律;不同传爆方向下等效柱状药包的应力波叠加效果可合理解释岩体中裂隙发育与演化过程,揭示了其方向效应机制。
In deep hole blasting,the initiation position plays a decisive role in determining the propagation direction of the shock wave,subsequently influencing the distribution of the explosive stress field and rock fractures.Leveraging the superposition principle proposed by Starfield,the propagation and superposition rules of the explosive stress field generated by chain-like spherical charges are derived.This forms the basis for constructing an equivalent cylindrical explosive model.By introducing a delayed loading method for the chain-like spherical explosives,numerical simulation of stress fields is carried out through the superposition of cylindrical explosives using the discrete element method.The focus is on investigating the directional effects on the distribution pattern of rock fractures under different propagation directions.The findings indicate that due to the phase delay of explosive stress waves,a significant directional effect is present in the superposition of stress waves from cylindrical explosives and in the distribution of fractures.The superposition of stress waves is stronger along the propagation direction,with the growth rate of superimposed stress amplitudes increasing initially and then diminishing.The range of fracture distribution also gradually expands along the propagation direction.For different propagation directions,when blasting occurs from the bottom or top sides individually,fractures generally exhibit a“funnelshaped”distribution along the propagation direction.When blasting occurs simultaneously from both ends towards the center,fractures are most developed near the center of the borehole,exhibiting an overall“spindle-shaped”distribution.When blasting initiates from the center towards both ends,fractures are slightly broader near the ends of the borehole,indicating a relatively uniform overall distribution.The fracture distribution patterns aptly mirror the distribution laws of superimposed stress fields under different blast propagation directions.The superposition effects of the equivalent cylindrical explosives under different propagation directions provide a rational explanation for the development and evolution of fractures within rock formations,thus revealing the underlying mechanisms of the directional effects.
作者
雷涛
康普林
叶海旺
李宁
王其洲
LEI Tao;KANG Pulin;YE Haiwang;LI Ning;WANG Qizhou(Hubei Key Laboratory of Mineral Resources Processing and Environment,Wuhan University of Technology,Wuhan,Hubei 430070,China;School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan,Hubei 430070,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第2期399-411,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点研发计划项目(2020YFC1909602)
湖北省重点研发计划项目(2021BCA152)。
关键词
爆破工程
岩体爆破
柱状药包
传爆方向
应力波叠加
裂隙分布
blasting engineering
rock blasting
column charge
direction of detonation
stress wave superposition
fracture distribution
