AE KAISER EFFECT AND ELECTROMAGNETIC EMISSION IN THE DEFORMATION OF ROCK SAMPLE

摘要

Repeated loading test and simultaneous measurement of acoustic emission (AE) and electromagnetic emission (EME) were conducted on granite samples. In the loading test, the maximum compressive load was increased stepwise until the sample ruptured to examine the Kaiser effect of the granite sample. The results showed that AE appeared at stress levels below the maximum previous stress, and the Kaiser Effect could not be clearly recognized in the granite. However, the EME appeared only when the stress approached and/or exceeded the maximum previous stress. In the present paper, characteristics of the AE and EME activities are experimentally investigated and the physical meaning of the Kaiser effect in granite is discussed, showing a possibility for estimating the current stress level to which granite samples have been subjected.