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| Blast cracking of borehole-crossed bedding under high stress condition |
| YANG Renshu1，2，DING Chenxi1，YANG Liyun1 |
(1. School of Mechanics and Civil Engineering，China University of Mining and Technology(Beijing)，Beijing 100083，China；
2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and
Technology(Beijing)，Beijing 100083，China) |
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Abstract In order to study the dynamic behavior of crack initiation and propagation of borehole-crossed bedding blasting under the high stress condition，the experimental system of digital laser dynamic caustics is used to carry out laboratory model experiments together with the dynamic caustics method. The results show that in the blasting with the borehole cross the bedding，the blasting gas energy is difficult to be efficiently utilized，resulting in the unsatisfactory crushing effect of the rock around borehole. The blasting stress wave plays a dominant role in the initiation and the early period of propagation of crack at the end of bedding，while the static stress has a major effect on the behavior of crack during later propagation. The angle between the bedding direction and the static stress direction has a significant effect on the fracture mode of specimen, the dynamic stress intensity factor and the propagating velocity of the main crack. In addition，with the increasing of the angle, the propagating time and displacement along the bedding direction decrease，but the maximum deflecting angle increases，the propagating path becomes more flexural.
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2018, Vol. 37 
