|
|
|
| EXPERIMENTAL STUDY OF CHARGE INDUCTION OF COAL SAMPLES UNDER UNIAXIAL COMPRESSION |
(1. School of Mechanics and Engineering，Liaoning Technical University，Fuxin，Liaoning 123000，China；
2. School of Science，Liaoning Technical University，Fuxin，Liaoning 123000，China) |
|
|
|
|
Abstract Using the self-developed charge-induced instrument，the experimental system for collecting the charge-induced signal in the process of coal deformation and fracture is set up. The law of charge induction of coal in the same mine during the coal deformation and fracture process is studied under different loading rates in laboratory. The experimental results show that the charge-induced signal is generated during the deformation and fracture process of coal；and the charge-induced signal is the instantaneous pulse. The charge-induced signal strength is the most powerful before the peak stress of coal；and the signal strength is more powerful when coal damages. The charge-induced signals on all surfaces are asynchronous，and their magnitudes are varied. The charge-induced signal strength is more powerful at the larger fracture surface. The greater the loading rate is，the stronger the charge-induced signal strength is. Under sudden loading and unloading，there would generate charge-induced signal with low strength. The main reasons for charge generation in the process of coal deformation and fracture are friction and crack tip charge separation because of micro-rupture. The results suggest that the charge-induced signal is closely related to the deformation and fracture of coal；the status of coal deformation and fracture may be determined by the charge-induced signal. The charge induction method is applicable to studying the exploration of the rock deformation and failure process and predicting catastrophic dynamic phenomena.
|
|
Received: 15 September 2010
|
|
|
|
| Electric field strength of rock under the load[C]// Translated by XU Yufeng. Proceedings of Soviet Union Earthquake Prediction Research. Beijing：Seismological Press，1993：31–34.(in Chinese))
[5] KUKSENKO V S，MAKHMUDOV K F. Mechanically-induced electrical effects in natural dielectrics[J]. Technical Physics Letters，1997，23(2)：126–127.
[6] KUKSENKO V S，MAKHMUDOV K F，PONOMAREV A V. Relaxation of electric fields induced by mechanical loading in natural dielectrics[J]. Physics of the Solid State，1997，39(7)：1 065–1 066.
[7] 郭自强，周大庄，施行觉，等. 岩石破裂中的电子发射[J]. 地球物理学报，1988，31(5)：566–571.(GUO Ziqiang，ZHOU Dazhuang，SHI Xingjue，et al. Electron emission during rock fracture[J]. Acta Geophysica Sinica，1988，31(5)：566–571.(in Chinese))
[8] 郭自强，刘 斌. 岩石破裂电磁辐射的频率特性[J]. 地球物理学报，1995，38(2)：221–226.(GUO Ziqiang，LIU Bin. Frequency properties of electromagnetic emission associated with microscopic cracking in rocks[J]. Acta Geophysica Sinica，1995，38(2)：221–226.
(in Chinese))
[9] 孙正江，王丽华，高 宏. 岩石标本破裂时的电磁辐射和光发射[J]. 地球物理学报，1986，29(5)：491–495.(SUN Zhengjiang，WANG Lihua，GAO Hong. Electromagnetic emission and light radiation during fracture of rock samples[J]. Acta Geophysica Sinica，1986，29(5)：491–495.(in Chinese))
[10] 王丽华，孙正江，陈化然. 岩石样品破裂时带电现象的研究[C]// 八十年代中国地球物理学进展. 北京：学术书刊出版社，1989：204–209.(WANG Lihua，SUN Zhengjiang，CHEN Huaran. A research on electrification during rock fracturing[C]// Geophysics Advance in China in the Eighties. Beijing：Academic Books and Periodicals Press，1989：204–209.(in Chinese))
[11] 朱元清，罗祥麟，郭自强，等. 岩石破裂时电磁辐射的机制研究[J]. 地球物理学报，1991，34(5)：594–601.(ZHU Yuanqing，LUO Xianglin，GUO Ziqiang，et al. A study of mechanism on electromagnetic emission associated with rock fracture[J]. Acta Geophysica Sinica，1991，34(5)：594–601.(in Chinese))
[12] 吴小平，施行觉，郭自强. 花岗岩压缩带电的试验研究[J]. 地球物理学报，1990，33(2)：208–211.(WU Xiaoping，SHI Xingjue，GUO Ziqiang. Study of the electrification of granite samples under compression[J]. Acta Geophysica Sinica，1990，33(2)：208–211.(in Chinese))
[13] 王继军，赵国泽，詹 艳，等. 中国地震电磁现象的岩石试验研究[J]. 大地测量与地球动力学，2005，25(2)：22–28.(WANG Jijun，ZHAO Guoze，ZHAN Yan，et al. Rock experiments for research on seismic electromagnetic phenomena in China[J]. Journal of Geodesy
and Geodynamics，2005，25(2)：22–28.(in Chinese))
[14] 郝锦绮，刘力强，龙海丽，等. 双轴压力下岩样自电位变化试验的新结果[J]. 地球物理学报，2004，47(3)：475–482.(HAO Jinqi，LIU Liqiang，LONG Haili，et al. New result of the experiment on self-potential change of rocks under biaxial compression[J]. Chinese Journal of Geophysics，2004，47(3)：475–482.(in Chinese))
[15] 郝锦绮，钱书清，高金田，等. 岩石破裂过程中的超低频电磁异常[J]. 地震学报，2003，25(1)：102–111.(HAO Jinqi，QIAN Shuqing，GAO Jintian，et al. ULF electric and magnetic anomalies accompanying the cracking of rock sample[J]. Acta Seismologica Sinica，2003，25(1)：102–111.(in Chinese))
[16] 赵扬锋，潘一山. 单轴压缩下花岗岩电磁信号的试验研究[J]. 中国地质灾害与防治学报，2009，20(3)：132–137，141.(ZHAO Yangfeng，PAN Yishan. Study on the charge and magnetic signal of granite samples under uniaxial compression[J]. Chinese Journal of Geological Hazard and Control，2009，20(3)：132–137，141.(in Chinese))
[17] 赵扬锋，潘一山，李国臻，等. 岩石变形破裂过程中电荷感应信号的检测[J]. 防灾减灾工程学报，2010，30(3)：252–256.(ZHAO Yangfeng，PAN Yishan，LI Guozhen，et al. Measuring of the charge- induced signal of rock during the deformation and fracture process[J]. Journal of Disaster Prevention and Mitigation Engineering，2010，30(3)：252–256.(in Chinese))
[18] 何学秋，王恩元，聂百胜，等. 煤岩流变电磁动力学[M]. 北京：科学出版社，2003.(HE Xueqiu，WANG Enyuan，NIE Baisheng，et al. Electromagnetic dynamics of coal or rock rheology[M]. Beijing：Science Press，2003.(in Chinese)) |
|
|
|
2011, Vol. 30 
