Propagation of Stress Waves Through Fully Saturated Rock Joint Under Undrained Conditions and Dynamic Response Characteristics of Filling Liquid

This paper describes a liquid application device used in combination with a split Hopkinson pressure bar (SHPB) to perform a series of dynamic tests investigating stress wave propagation through a fully saturated rock joint under undrained conditions. The characteristics of the filling-liquid dynamic response are also analyzed. Granite is used as the experimental material for the rock joint and a dynamic load is applied by the SHPB device to simulate the interaction between a stress wave and the liquid-filled rock joint. In addition, a polymethyl methacrylate (PMMA) sample of the same size as the granite is used for comparative analysis. The initial thickness of the filling liquid is altered by adjusting the sample joint spacing. The transmission coefficient of a stress wave in the liquid-filled rock joint is defined to evaluate the wave attenuation and to analyze the characteristics of the filling liquid’s dynamic response. The experimental results obtained for granite and PMMA demonstrate that the transmission coefficient decreases with increasing liquid filling thickness. As the initial thickness of the filling liquid increases, the peak liquid pressure increases. There is a negative correlation between the peak water pressure value and the transmission coefficient.