Theoretical study of rock for estimating long-term behavior; FY2012 (Contract research)

Ichikawa, Yasuaki*; Kimoto, Kazushi*; Sato, Toshinori  ; Tanno, Takeo; Hikima, Ryoichi; Sanada, Hiroyuki

Rock mass is a complex material including several classes of discontinuities and inhomogeneous/anisotropic minerals. If observing rock samples, we know that crystalline rock is a complex of minerals, grain boundaries and microcracks. In this study, the series of experiments were managed by a flow-through type changing temperature, pH and applied stress. Attenuation of ultrasonic waves in rock is investigated experimentally using an intact but coarse-grained granite core sample. For ultrasonic measurements, piezoelectric transducers are used in a through-transmission mode. With the estimated response function, phase and amplitude spectra of the transmitted ultrasonic waves are investigated quantitatively to evaluate the attenuation and change in travel time.