Dependence of effective screening length in granular columns on bead and silo sizes and their ratio

Apparent mass measurements at the bottom of silo have been carried out. An important parameter in the Janssen model known as the effective screening length has been investigated for different bead and silo diameters as well as of their ratios. It is found that the effective screening length augments with the grain diameter d in addition to the granular column size. It is also revealed that λ exhibits stronger correlation with the bead diameter than that of silo. This phenomenon is attributed to the reduced-shielding of the vertical stresses to the horizontal ones.