2007 Volume 56 Issue 9 Pages 803-808
The propagation of microcracks in granite was studied experimentally, focusing on the effects of the temperature and relative humidity on the properties of P-wave propagation. Since it is difficult to observe the propagation of a microcrack directly, P-wave propagation was investigated while controlling the temperature and relative humidity. The results showed that changes in the temperature and relative humidity of the surrounding environment affected the P-wave velocity and amplitude. An increase in the relative humidity affected the P-wave velocity if the temperature was high. On increasing the humidity at high temperature, the P-wave velocity decreased due to subcritical growth of microcracks arising from stress corrosion. We concluded that subcritical growth of microcracks arises from thermal stress and increased humidity.