5.2.2 Density control of sand sample

In case of preparing model ground using a spot pouring hopper, which is shown in the upper figure, density of the sand will be controlled by changing a pouring height and the diameter of the pouring holes. The lower figure shows the relationship between diameter of pouring holes D and relative density D_r, for different three velocity of horizontal hopper movement, v. The sand used was Toyoura sand. Variation of the measured relative density is also plotted in this figure. The values of relative density D_r decrease with increasing the diameter of pouring holes D while coefficient of variation v increases.