Size dependence of effective mass in granular columns

An experimental setup is developed to measure accurately and reproducibly the effective mass as well as its fluctuations at the bottom of the granular columns. It is found that the saturated mass Ms obeys a third power function of the diameter of the silos. The data obtained are in agreement with the modified Janssen model proposed by Vanel and Clement [L. Vanel, E. Clement, Eur. Phys. J. B 11 (1999) 525–533].