水耦合介质定向断裂爆破裂纹动态扩展机理研究  

Dynamic crack propagation mechanisms of water⁃coupling charge under directional fracture blasting

作　　者：郭东明[1] 李杨[1] 宋耀 王雁冰[1] GUO Dongming;LI Yang;SONG Yao;WANG Yanbing(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;School of Traffic and Transportation Engineering,Dalian Jiaotong University,Dalian,Liaoning 116021,China)

机构地区：[1]中国矿业大学(北京)力学与土木工程学院,北京100083 [2]大连交通大学交通运输工程学院,辽宁大连116021

出　　处：《采矿与安全工程学报》2024年第1期134-141,共8页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2021YFC2902103);国家自然科学基金重点项目(51934001);中央高校基本科研业务费专项资金项目(2023JCCXLJ02);辽宁省教育厅科学研究项目(LJKZ0482)。

摘　　要：为研究水耦合介质在定向断裂爆破过程中对爆生裂纹动态扩展机理的力学影响,基于焦散线理论,采用数字激光动态焦散线试验系统,开展单炮孔切缝有机玻璃(PMMA)试件在3种不耦合系数(1.25,1.67,2)下水耦合及空气耦合定向爆破试验,对比研究水耦合装药下试件爆后分形计盒维数D的分布规律,及爆生裂纹在动态扩展过程中的动态应力强度因子K^(d)_(Ⅰ)与扩展速度v随时间的变化规律。结果表明:相较空气介质,水耦合装药试件爆后的次裂纹数目明显减少,定向致裂效果较好,爆生裂纹在扩展过程中的K^(d)_(Ⅰ)与v值随时间的波动程度明显减弱,该种装药模式下的爆破更易为试件爆生裂纹中后期动态扩展提供稳定、持续的能量;不耦合系数对水耦合装药试件裂纹尖端动态起裂韧度K^(d)_(Ⅰc)值的影响具有正相关性,较低的不耦合系数更易引起水耦合装药试件的动态起裂。For the purpose of studying the mechanical impact on dynamic crack propagation mechanisms of water⁃coupling charge under directional fracture blasting,the caustic theory and digital laser dynamic caustic experimental system were employed.The water⁃coupling and air⁃coupling directional blasting caustic experiments were performed using single⁃borehole PMMA specimens with pre⁃existing cracks un⁃der three different decoupling coefficients(1.25,1.67,2).Key parameter evolutions with time inclu⁃ding the fractal box dimensions D,dynamic stress intensity factors K^(d)_(Ⅰ)and crack propagation velocities v of specimens with water⁃coupling charges were compared and analyzed.The results showed that:com⁃pared with air⁃coupling specimens,specimens with water⁃coupling charged generate less wing cracks and the directional cracking effect were better;K^(d)_(Ⅰ)and v of developing cracks with water⁃coupling charged fluctuate gentler and more stable than those with air⁃coupling charges do,which indicated such charge mode provided steady and consecutive energy to crack propagation during post cracking periods;decou⁃pling coefficients had positive effects on dynamic initiation toughness K^(d)_(Ⅰc),and the crack was more prone to initiating when decoupling coefficient is relatively low.

关 键 词：水耦合爆破 不耦合系数 动态焦散线 裂纹扩展 

分 类 号：TD235[矿业工程—矿井建设]