Ultrasonic S-wave responses of single rock joints filled with wet bentonite clay

Clay minerals are prevalent in rock discontinuities and have significant effects on mechanical, hydraulic seismic properties of masses. Understanding behaviours across individual clay-rich joints is great importance the fields geology earth sciences. However, wave responses not been well understood until now. This paper reports a laboratory investigation ultrasonic S-wave propagation attenuation single filled with bentonite clays varying degree water saturation. In this study, series acoustic measurements were conducted specimens clay-filled joint using self-developed pulse-transmission test system that equipped transducer pair dominant frequency 250 kHz. Based obtained data, velocity, transmission ratio time-frequency-energy distribution S-waves transmitted through calculated evaluated. The experimental results show saturation clay greatly affects joint. particular, an increase causes nonlinear decrease velocity. addition, as increases, decreases; minimum reached at 71.4% then increases slightly. Additionally, saturation, magnitudes energy firstly decreases. mostly stored range 150 - 300 kHz regardless clay. finding indicates partition rarely changes changing present work could only compensate for lack laboratory-based research but also provides insights into interpretation data from field tests detecting, characterizing monitoring discontinuities.