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| Tests for blasting induced crack propagation characteristics of short-delay blasting |
| YANG Renshu1, 2, DING Chenxi1, YANG Guoliang1, YANG Liyun1, WANG Yanbing1 |
1. School of Mechanics and Civil Engineering , China University of Mining and Technology, Beijing 100083, China;
2. State Key Lab for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Beijing 100083，China |
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Abstract 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 20μs and 40μs 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 20μs is obviously larger than that with time delay of 40μs; 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.
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Received: 24 November 2016
Published: 15 December 2017
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[1] 杜云贵,张志呈,李通林. 切槽爆破中V形切槽产生的力学效应研究[J]. 爆炸与冲击, 1991, 11(01): 26-30.
DU Yun-gui, ZHANG Zhi-cheng, LI tong-lin. Studies on the mechanical effects produced by the V-shaped notch borehole blasting [J]. Explosion and Shock Waves, 1991, 11(01): 26-30.
[2] 宗琦. 岩石炮孔预切槽爆破断裂成缝机理研究[J]. 岩土工程学报, 1998, 20(01): 30-33.
ZONG Qi. Investigations into mechanism of crack formation for grooved hole-well blasting[J]. Chinese Journal of Geotechnical Engineering, 1998, 20(01): 30-33.
[3] 李清,王平虎,杨仁树,等. 切槽孔爆破动态力学特征的动焦散线实验[J]. 爆炸与冲击, 2009, 29(04): 413-418.
LI Qing, WANG Ping-hu, YANG Ren-shu, et al. Experimental investigation on dynamic mechanical behaviors of cracks induced by V-notch borehole blasting with dynamic caustics[J]. Explosion and Shock Waves, 2009, 29(04): 413-418.
[4] 杨仁树,高祥涛,陈程,等. 切缝药包爆炸波传播机制实验研究[J]. 煤炭学报, 2014, 39(8): 1434-1440.
YANG Ren-shu, GAO Xiang-tao, CHEN Cheng, et al. Experimental study on blast wave propagation mechanics of split-tube charge holders[J]. Journal of China Coal Society, 2014, 39(8): 1434-1440.
[5] 罗勇,沈兆武. 切缝药包岩石定向断裂爆破的研究[J]. 振动与冲击. 2006, 25(04): 155-158.
LUO Yong, SHEN Zhao-wu. Study on the directional fracture controlled Blasting with slit-charge in rock[J]. Journal of Vibration and Shock, 2006, 25(04): 155-158.
[6] 史秀志, 邱贤阳, 周健,等. 超大断面高天井短微差类球状药包爆破成井技术与工程实例[J]. 岩石力学与工程学报, 2016, 35(8): 1659-1667.
SHI Xiu-zhi, QIU Xian-yang , ZHOU Jian, et al. Technology and case study of ultra-large section and high shaft excavation by short-millisecond spherical blasting[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(8): 1659-1667.
[7] 李铮, 何川, 汪波,等. 城市隧道穿越复合地层的合理微差时间间隔[J]. 爆炸与冲击, 2016, 36(1):93-100.
LI Zheng, HE Chuang, WANG Bo, et al. Optimal microsecond time interval of urban tunnel passing through complex strata [J]. Explosion and Shock Waves, 2016, 36(1):93-100.
[8] 岳中文, 郭洋, 王煦,等. 起爆时差对孔间裂纹扩展影响的动焦散实验研究[J]. 岩石力学与工程学报, 2015, 34(11):2293-2300.
YUE Zhong-wen,GUO Yang,WANG Xu, et al. Dynamic caustics study of influence of delayed initiation on crack propagation between boreholes [J]. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(11):2293-2300.
[9] 苏先基,刘 承. 焦散线实验方法综述[J]. 实验力学, 1987, 2(2): 1-27.
SU Xian-ji, LIU Cheng. Summary of caustics experiment method[J]. Journal of Experimental Mechanics, 1987, 2(2): 1-27.
[10] Papadopoulos G A. Fracture mechanics： the experimental method of caustics and the Det.-criterion of fracture [M]. New York：Springer-Verlag,1992：134–204.
[11] Kutter H K, Fairhurst C. On the fracture process in blasting[J]. International Journal of Rock Mechanics & Mining Science, 1971, 8(3):181-202.
[12] Rossmanith H P, Daehnke A, Nasmillner R E K, et al. Fracture mechanics applications to drilling and blasting[J]. Fatigue & Fracture of Engineering Materials & Structures, 1997, 20(11):1617-1636.
[13] 刘承, 苏先基. 裂纹扩展速度对焦散线的影响和动态应力光学常数的测定[J]. 实验力学, 1988, 3(2): 109-118.
LIU Cheng, SU Xian-ji. On the caustics influenced by the crack propagating speed and determination of the dynamic stress optical constants [J]. Journal of Experimental Mechanics, 1988, 3(2): 109-118.
[14] 杨仁树, 丁晨曦, 杨立云,等. 动态爆生裂纹相互影响的试验研究[J]. 爆破, 2016, 33(2): 1-5.
YANG Ren-shu, DING Chen-xi, YANG Li-yun, et al. Experimental study on interaction effect of dynamic cracks induced by blast [J]. Blasting, 2016, 33(2): 1-5.
[15] 杨立云, 杨仁树,许鹏. 新型数字激光动态焦散线实验系统及其应用[J]. 中国矿业大学学报,2013,42(2)：188-194．
YANG Li-yun, YANG Ren-shu, XU Peng．Caustics method combined with laser & digital high-speed camera and its applications[J]. Journal of China University of Mining & Technology, 2013,42(2):188-194.
[16] 杨仁树，王雁冰，岳中文，等. 定向断裂双孔爆破裂纹扩展的动态行为[J]. 爆炸与冲击, 2013,33(6): 631-637.
YANG Ren-shu, WANG Yan-bing, YUE Zhong-wen, et al. Dynamic behaviors of crack propagation in directional fracture blasting with two holes[J]. Explosion and Shock Waves, 2013,33(6): 631-637.
[17] 李清，张迪，杨阳，等．含单侧预制裂纹梁的冲击动态断裂过程试验研究[J]．振动与冲击，2015，34(4):205-210．
LI Qing， ZHANG Di， YANG Yang， et al． Dynamic fracture tests for a beam containing unilateral pre-existing cracks under impact loads[J]． Journal of Vibration and Shock， 2015，34(4):205-210．
[18] Takahashi K, Arakawa K. Dependence of crack acceleration on the dynamic stress intensity factor in polymers [J]. Experimental Mechanics, 1987, 27(2):195-199.
[19] Lagarde A. Static and dynamic photoelasticity and caustics recent developments [M]. New York: Springer-Verlag, 1987: 407-522.
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