循环冲击荷载下爆堆孔隙分布特征  

Pore distribution characteristics of blasting muck piles under cyclic impact loads

作　　者：崔哲森 徐振洋 范立鹏 王雪松 李政 CUI Zhesen;XU Zhenyang;FAN Lipeng;WANG Xuesong;LI Zheng(School of Mining Engineering,Liaoning University of Science and Technology,Anshan 114051,China;Liaoning Province Metal Mineral Resources Green Mining Engineering Research Center,Anshan 114051,China;Yanqianshan Branch,Ansteel Group Mining Co.,Ltd.,Anshan 114001,China;Hongda Blasting Engineering Group Co.,Ltd.,Guangzhou 510623,China)

机构地区：[1]辽宁科技大学矿业工程学院,辽宁鞍山114051 [2]辽宁省金属矿产资源绿色开采工程研究中心,辽宁鞍山114051 [3]鞍钢集团矿业有限公司眼前山分公司,辽宁鞍山114001 [4]宏大爆破工程集团有限责任公司,广东广州510623

出　　处：《西安科技大学学报》2025年第2期393-403,共11页Journal of Xi’an University of Science and Technology

基　　金：辽宁兴辽英才项目(XLYC2203173);矿山智能爆破与创新技术平台建设项目(LJ232410146045);辽宁科技大学研究生教育改革与科技创新创业项目(LKDYC202329)。

摘　　要：为研究露天矿爆堆块度分布对破碎过程中孔隙分布的影响规律,开展爆堆相似试件的循环冲击试验,结合核磁共振试验,分析冲击前后碎石内部成像结果和分形特征,研究循环冲击荷载下块度分布对孔隙结构的影响规律。结果表明:单一分布试件的峰值应力波动范围基本为0~10 MPa,随着冲击次数增加,峰值应力趋于稳定;复杂分布试件初始峰值应力较高,随着冲击次数增加,整体峰值应力提高4.47~6.68 MPa;冲击后试件的T 2谱产生尖峰,孔隙分布向中孔隙靠拢,内部孔隙按照孔隙压缩、孔隙发育完全和新孔隙产生3个阶段发展,反映了冲击作用下试件的力学响应特性,揭示了孔隙结构在破碎过程中的复杂演变机制;每组试件分形维数均增长1%~4%,极小粒径与大粒径碎石试件的增长率更大,验证了循环冲击作用下块度分布对孔隙结构变化具有明显影响。To study the influence of block size distribution on pore distribution during the crushing process of open-pit mine blasting piles,cyclic impact tests were conducted on similar specimens of blasting piles.Combined with nuclear magnetic resonance tests,the imaging results and fractal characteristics of the crushed stone before and after impact were analyzed,and the influence law of pore structure under cyclic impact load was studied.The results indicate that:the peak stress fluctuation range of the single distribution specimen is basically 0~10 MPa,the peak stress stabilizes as the number of impacts increases.In contrast,specimens with a more complex size distribution exhibit higher initial peak stress,which increases overall by 4.47~6.68 MPa after repeated impacts.Post-impact T 2 spectra reveal new peaks,with pore distribution shifting toward mesopores.The internal pore evolution is developed according to three stages such as pore compression,full development and the formation of new pores.These changes reflect the mechanical response of the specimens under impact and reveal the intricate mechanisms driving pore structure evolution during crushing.The fractal dimensions of all specimen groups increase by 1%~4%,with the most significant growth observed in specimens containing extremely small or large aggregates.This confirms that the size distribution of aggregates plays a critical role in shaping the changes in pore structure under cyclic impact loads.

关 键 词：块度分布 循环冲击 SHPB 核磁共振 孔隙结构 

分 类 号：TD235[矿业工程—矿井建设]