Tests for blasting induced crack propagation characteristics of short-delay blasting

被引：0
|
作者：
Yang R. [1 ,2 ]
Ding C. [1 ]
Yang G. [1 ]
Yang L. [1 ]
Wang Y. [1 ]
机构：
[1] School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing
[2] State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing
来源：
Ding, Chenxi | 1600年 / Chinese Vibration Engineering Society卷 / 36期
关键词：
Blasting induced main crack; Directional fracture; Dynamic stress intensity factor; Propagation speed; Short-delay blasting;
D O I：
10.13465/j.cnki.jvs.2017.24.015
中图分类号：
学科分类号：
摘要：
Using the model material of PMMA, adopting the new type test system of digital laser dynamic caustics, the blasting induced main crack propagation characteristics of short-delay blasting with time delay of 20 μs and 40 μs were studied. Failure modes and destruction process discrepancies of specimens were compared. Time histories of blasting induced main crack deflection angle, propagation speed, dynamic stress intensity factor and other physical quantities were analyzed. Results showed that vertical off-set value of blasting induced main crack with time delay of 20 μs is obviously larger than that with time delay of 40 μs; time delay value has little effect on the first peak of blasting induced main crack's dynamic intensity factor, but has a remarkable effect on the second peak; furthermore, homodromous and abreast detonation of two or more grooved boreholes makes propagation of blasting induced main crack deviate from grooving direction, and then affects effects of directional fracture, this case should be avoided as much as possible. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.
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页码：97 / 102
页数：5
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