Dynamics characteristics of gas-bearing coal under shock load

被引：0
|
作者：
Kong X. [1 ,2 ]
Wang E. [3 ]
Li S. [1 ,2 ]
Hu S. [4 ]
Ju Y. [3 ]
Li J. [3 ]
机构：
[1] College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an
[2] Key Laboratory of Western Mine Exploitation and Hazard Prevention of the Ministry of Education, Xi'an
[3] School of Safety Engineering, China University of Mining and Technology, Xuzhou
[4] College of Civil and Transportation Engineering, Hohai University, Nanjing
来源：
Wang, Enyuan (weytop@263.net) | 1600年 / China Coal Society卷 / 45期
关键词：
Dynamics characteristics; Gas-bearing coal; Shock load; Strain rate effects;
D O I：
10.13225/j.cnki.jccs.2019.0395
中图分类号：
学科分类号：
摘要：
To study the dynamics characteristics of gas-bearing coal under shock load, the split Hopkinson pressure bar test system of gas-bearing coal (SHPB-GAS) was built. With the consideration of the factors of axial static load, confining pressure, gas pressure and dynamic load impact velocity, the dynamics experiments were carried out. By collecting incident wave, reflected wave and transmission wave signals, the relationships between peak strength, peak strain and various factors were analyzed. The results showed that the dynamic stress-strain curves of gas-bearing coal were of no compaction stage, which showed linear elasticity characteristic at the initial loading stage. With the increase of strain, the stress changes tended to be gentle increase and then rapid increase, which was called "leap" characteristic. This was related with charcoal in coal crystal micro-fracture. After the stress-strain peak, the coal samples didn't have macro rupture, so the stress-strain curves appeared "rebound" phenomenon. The peak strength of gas-bearing coal increased exponentially with effective axial static load, increased linearly with effective confining pressure, and increased first and then decreased with the impact velocity of dynamic load. Peak strain of gas-bearing coal increased linearly with effective axial static load, decreased exponentially with effective confining pressure, and increased with the increase of impact velocity of dynamic load. The strain rate effects of gas-bearing coal were obvious under shock load. At the low level of strain rate, the peak strength and peak strain of gas-bearing coal increased with the increase of strain rate, and when it exceeded the critical strain rate, the peak strength and peak strain of gas-bearing coal would remain stable. This study is useful for improving the dynamics of gas-bearing coal, and provides a theoretical basis for the prevention and control of mine dynamic disasters of gas-bearing coal induced by dynamic load. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.
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页码：1099 / 1107
页数：8
相关论文
共 24 条
  • [1] Liang B., Wang B., Li G., Et al., On the mechanism of the rock-bursts at the roadway sides induced by the dynamic disturbance, Journal of Safety and Environment, 14, 2, pp. 13-18, (2014)
  • [2] Li W., Research on mechanical characteristics and gas migration law of coal influenced by mining, (2014)
  • [3] He J., Dou L., Cai W., Et al., Mechanism of dynamic and static combined load inducing rock burst in thin coal sea, Journal of China Coal Society, 39, 11, pp. 2177-2182, (2014)
  • [4] Dou L., He J., Cao A., Et al., Rock burst prevention methods based on theory of dynamic and static combined load induced in coal mine, Journal of China Coal Society, 40, 7, pp. 1469-1476, (2015)
  • [5] Wang E., Feng J., Zhang Q., Et al., Mechanism of rockburst under stress wave in mining space, Journal of China Coal Society, 45, 1, pp. 100-110, (2020)
  • [6] Xia K., Zhou C., Review of testing methods for dynamic rock mechanical properties, Engineering Blasting, 20, 2, pp. 43-53, (2014)
  • [7] Zhang Q.B., Zhao J., A Review of dynamic experimental techniques and mechanical behaviour of rock materials, Rock Mech Rock Eng, 47, pp. 1411-1478, (2014)
  • [8] Xia K., Wei Y., Dynamic rock tests using split Hopkinson(Kolsky) bar system-A review, Journal of Rock Mechanics and Geotechnical Engineering, 7, pp. 27-59, (2015)
  • [9] Klepacko J.R., Hsu T.R., Bassim M.N., Elastic and pseudoviscous properties of coal under quasi-static and impact loadings, Canadian Geotechnical Journal, 21, 2, pp. 203-212, (1984)
  • [10] Olsson W.A., The compressive strength of tuff as a function of strain rate from 10<sup>-6</sup> to 10<sup>3</sup> sec, International Journal of Rock Mechanics and Mining Science & Geomechanics Abstracts, 28, 1, pp. 115-118, (1991)
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