摘要
对双孔交错起爆方式下孔间爆炸应力波的碰撞机制和破岩效果开展了研究,基于应力波正、斜碰撞理论研究了孔间爆炸应力波的相互作用机制,证明了双孔交错起爆方式下孔间应力波碰撞引起的应力增强效应;借助ANSYS/LS-DYNA有限元程序中岩石的RHT模型和炸药的JWL状态方程,模拟了交错、孔底和孔口起爆方式下孔间应力波的大小和破岩效果;最后,结合现场试验对比分析了不同起爆方式下爆炸应力波的相互作用及含砾石岩体的破碎块度分布特征。结果表明:双孔交错起爆下两应力波首先在孔间正碰撞,碰撞后的压力与应力波稳定传播时的压力比为2.4;当入射角在0°~44°区间时,应力波斜碰撞,压力比由4.1降至2.3;当入射角处于44°~90°区间时,应力波发生马赫反射,压力比由3.5降至1.0。交错、孔底起爆方式下,爆破块度尺寸小于250 mm的比例分别为25.5%和20.9%,爆破块度尺寸大于750 mm的比例分别为9.2%和17.5%。双孔交错起爆引起的应力波碰撞增强效应可有效改善含砾石岩体的钻孔爆破破碎效果。
Different initiation methods directly determine the stress wave propagation and explosion energy transmission law caused by drilling and blasting,thus affecting the effect of rock fragmentations.In this paper,the collision mechanism of stress waves and rock fragmentation characteristics induced by blasting with different initiation methods were studied.Based on the theory of frontal and oblique collision of stress waves,the interaction mechanism of stress waves between holes was studied to prove the stress enhancement effect caused by wave collision under the staggered initiation mode.Using the RHT model for rock and JWL state equation for explosive in the ANSYS/LS-DYNA software,the magnitude of stress waves between holes and the rock fragmentation characteristics were simulated under the staggered,bottom and top initiation modes.Finally,combined with on-site experiments,the interaction of stress waves and the characteristics of fragmentation distribution for blasting of rock mass containing gravel under different initiation modes were compared and analysed.Results show that under the staggered initiation mode,a frontal collision of stress waves happens at the midpoint between two holes,and the pressure after the collision is 2.4 times that of the stable propagation of the stress wave.An oblique collision occurs between 0°and 44°,and the ratio of collision pressure to the stable pressure ranges from 4.1 to 2.3.Mach reflection occurs between 44°and 90°,and the ratio of collision pressure to the stable pressure ranges from 3.5 to 1.The rates of rock fragmentations with a size less than 250 mm under staggered and bottom initiation modes are 25.5%and 20.9%,respectively.The rates of rock fragmentations with a size larger than 750 mm under staggered and bottom initiation modes are 9.2%and 17.5%,respectively.The stress enhancement effect caused by wave collision under the staggered initiation mode can significantly improve the blasting fragmentation of rock mass containing gravel.
作者
范勇
郭一鸣
冷振东
杨广栋
田斌
FAN Yong;GUO Yiming;LENG Zhendong;YANG Guangdong;TIAN Bin(Hubei Key Laboratory of Construction and Management in Hydropower Engineering,China Three Gorges University,Yichang 443002,Hubei,China;College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,Hubei,China;China Gezhouba Group Explosive Co.Ltd.,Chongqing 401121,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2024年第6期90-102,共13页
Explosion and Shock Waves
基金
国家自然科学基金(52379128,51979152)
湖北省自然科学基金杰青项目(2023AFA048)。
关键词
交错起爆
孔底起爆
孔口起爆
应力波碰撞
爆破破岩
staggered initiation
bottom initiation
top initiation
stress wave collision
blasting fragmentation
