[PPS03-P05] Collapse of an inclined wet granular layer induced by impact
Keywords:wet granular, impact, collapse
As the inclination angle approaches the critical one, the granular layer gradually looses its stability. If a small perturbation is applied to the granular layer, granular avalanche might be triggered in the vicinity of critical angle. Although this trend should be identical in both dry and wet granular matter, their detail behaviors could be different.
To investigate the granular avalanche flow triggered by perturbation, we performed simple experiments with dry and wet granular matter. First, the water content dependence of the critical stable angle was measured. As a result, we found that the critical stable angle approaches the asymptotic value by a small amount of water. This tendency is not surprising because it is well-known that the strength of wet granular matter also shows asymptotic value by a small amount of water (S.Herminghaus, Wet granular matter, World Scientific, 2013). Next, a solid projectile is impacted onto a granular layer which is tilted just under the critical stable angle. By the projectile impact, the granular avalanche could be triggered in some experimental conditions. During the impact, vibration of the bottom of granular container was measured using an accelerometer. From the peak amplitude and dominant frequency of the acceleration data, we are going to discuss the physical condition for the avalanche triggering. Details of analysis results will be provided in the presentation.