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| SHI Xiuzhi1，QIU Xianyang1，ZHOU Jian1，WANG Yang1，NIE Jun1，LI Bihong2 |
| SHI Xiuzhi1，QIU Xianyang1，ZHOU Jian1，WANG Yang1，NIE Jun1，LI Bihong2 |
(1. School of Resources and Safety Engineering，Central South University，Changsha，Hunan 410083，China；
2. National Defense University of Science and Technology，Changsha，Hunan 410073，China) |
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Abstract Short-millisecond blasting with high-precision detonators is an effective way to improve the efficiency of excavation of ultra-large section and high shaft and to reduce the blasting vibrations. The formation process of the blasting crater due to short-millisecond spherical blasting was analyzed. The methods of calculation of the time delay of detonating between the holes of same segmentation and between the holes of adjacent segmentation in shaft excavation by deep-hole blasting were studied. An elastic calculation model was established to analyze the crashing effect of rock and the vibration in shaft excavation by deep-hole blasting under different short delay intervals. The simulated results showed that the optimum time delay of detonating between the holes in the same segmentation was 9–11 ms according to the related parameters such as the peak effective stress，the effective stress time and the peak vibration velocity. The research results of theoretical analysis and numerical simulation have been successful applied in an ultra-large section surge shaft. The bottle neck problems referring to the excavation efficiency and vibration reduction in ultra-large section and high shaft excavation have been solved.
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2016, Vol. 35 
