Properties of P-Wave Propagation in Granite with Changes in Temperature and Humidity
Yoshitaka NARA and Katsuhiko KANEKO
Abstract: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. Key Words:P-wave velocity, Temperature, Humidity, Subcritical crack growth, Stress corrosion, Thermal cracking, Granite