An Experimental Study on Acoustic Emission Characteristics of Coal Specimens’ Fracturing Process under Different Stress Paths
Due to investigate the acoustic emission(AE) characters of coal specimens’ deformation and failure process under different stress paths, the general uniaxial compression, triaxial compression and confining pressure reduction experiments were performed by RMT-150B rock mechanics test system. Test results indicate that the AE characters of coal specimens are different under different load path. In experiments of general uniaxial compression, AE events take place in different degrees on every stage, comparing with experiments of uniaxial compression in triaxial cylinder, the values of cumulative AE counts and energy are obviously larger and the values of maximal counts and energy on the peak point are approximately equal; In experiments of general triaxial compression, AE events occur less before yielding and increase obviously after yielding. At stage of post-yielding, AE counts and energy are quite active and enhance rapidly, these are signs of failure portent, AE counts and energy reach maximum at stress peak point; In experiments of confining pressure reduction, with decreasing of confining pressure and friction provided by positive stress, the samples’ inner zones with low strength yield to fail and slide, AE events occur in small amount before yielding, at stage of post-yielding, AE counts and energy are quite active and enhance rapidly, these are also signs of failure portent, AE counts and energy reach maximum at stress peak point; and increase sharply just before failure point. Comparing with general triaxial compression, the maximal values of AE counts and energy are much larger and the failure intensity of coal specimens on such condition is more violent.
coal specimens uniaxial compression triaxial compression confining pressure reduction stress
Cheng-dong SU Bao-bin GAO Hua-min LI
School of Energy Science and Engineering, Henan Polytechnic university, JiaoZuo School of Energy Science and Engineering, Henan Polytechnic university, JiaoZuo School of Civil Engi
国际会议
香港
英文
1-7
2009-05-19（万方平台首次上网日期，不代表论文的发表时间）