Influence of millisecond time, charge length and detonation velocity on blasting vibration
来源期刊：中南大学学报(英文版)2015年第12期
论文作者：CHEN Shi-hai WU Jian ZHANG Zi-hua
文章页码：4787 - 4796
Key words：cylindrical charge; millisecond blasting; blasting vibration; peak particle velocity; displacement
Abstract: The law of blasting vibration caused by blasting in rock is very complex. Traditional numerical methods cannot well characterize all the influencing factors in the blasting process. The effects of millisecond time, charge length and detonation velocity on the blasting vibration are discussed by analyzing the characteristics of vibration wave generated by finite length cylindrical charge. It is found that in multi-hole millisecond blasting, blasting vibration superimpositions will occur several times within a certain distance from the explosion source due to the propagation velocity difference of P-wave and S-wave generated by a short column charge. These superimpositions will locally enlarge the peak velocity of blasting vibration particle. The magnitude and scope of the enlargement are closely related to the millisecond time. Meanwhile, the particle vibration displacement characteristics of rock under long cylindrical charge is analyzed. The results show that blasting vibration effect would no longer increase when the charge length increases to a certain extent. This indicates that the traditional simple calculation method using the maximum charge weight per delay interval to predict the effect of blasting vibration is unreasonable. Besides, the effect of detonation velocity on blasting vibration is only limited in a certain velocity range. When detonation velocity is greater than a certain value, the detonation velocity almost makes no impact on blasting vibration.
CHEN Shi-hai(陈士海)1, 2, 3, WU Jian(吴建)1, ZHANG Zi-hua(张子华)1
(1. College of Civil Engineering, Huaqiao University, Xiamen 361000, China;
2. State Key Laboratory of Disaster Prevention & Mitigation of Explosion & Impact, Nanjing 210007, China;
3. College of Civil Engineering and Architecture, Shandong University of Science and Technology,
Qingdao 266510, China)
Abstract:The law of blasting vibration caused by blasting in rock is very complex. Traditional numerical methods cannot well characterize all the influencing factors in the blasting process. The effects of millisecond time, charge length and detonation velocity on the blasting vibration are discussed by analyzing the characteristics of vibration wave generated by finite length cylindrical charge. It is found that in multi-hole millisecond blasting, blasting vibration superimpositions will occur several times within a certain distance from the explosion source due to the propagation velocity difference of P-wave and S-wave generated by a short column charge. These superimpositions will locally enlarge the peak velocity of blasting vibration particle. The magnitude and scope of the enlargement are closely related to the millisecond time. Meanwhile, the particle vibration displacement characteristics of rock under long cylindrical charge is analyzed. The results show that blasting vibration effect would no longer increase when the charge length increases to a certain extent. This indicates that the traditional simple calculation method using the maximum charge weight per delay interval to predict the effect of blasting vibration is unreasonable. Besides, the effect of detonation velocity on blasting vibration is only limited in a certain velocity range. When detonation velocity is greater than a certain value, the detonation velocity almost makes no impact on blasting vibration.
Key words:cylindrical charge; millisecond blasting; blasting vibration; peak particle velocity; displacement
