Effect of erodible bed on dynamics of monodispersed collapse of annular granular columns
摘要
The spreading of a collapsible cylindrical annular granular column on an erodible bed is investigated using discrete element-based numerical simulations. The importance of this study lies in understanding the granular media in applications such as landslides and avalanche flow. Unlike a solid (non-erodible bottom) surface, the erodible bed of grains offers greater resistance to collapsing fronts, leading to earlier and faster arrest of granular media spreading. The initial height-to-column width ratio, termed aspect ratio 𝑎, is used to ascertain the nature of the final deposit profiles. A wider range of aspect ratios was found to characterise deposit profiles, compared with those reported in the literature for a non-erodible bottom. The impact of inter-particle friction and the relative densities of the bed and column on the deposit profile revealed that the ratio of the two densities is more significant. A lower particle density ratio led to greater bed erosion and particulate overflow as a central granular jet. The kinetic energy, normalised with the potential energy of the initial column, is strongly altered by both the inter-particular friction coefficient and the density ratio of the column to bed particles. This study reveals that the inner and outer erodible beds behave differently. A scaling analysis of the deposit profiles suggests self-similarity at higher aspect ratios (