The effect of lateral wall deformations on pressures induced by a granular cohesionless material in a shallow bin

This work presents the results of a series of tests designed to determine the validity of the coulomb wedge theory for predicting lateral pressures in a shallow grain storage bin and to determine the relationship between lateral wall pressures and wall deformations. Lateral pressures induced by sorghum grain and measured in a model bin agree very well with pressures given by the Coulomb theory for the active case. Further, lateral pressures are shown to be a function of wall stiffness, only if resulting wall deformations are small compared to the grain size of the contained material. Passive pressures are a function of wall deformation and depth below the grain surface. A relationship is given which offers a possibility of predicting passive pressures resulting from differential movements between the stored material and the structure. The internal friction angle of sorghum grain, determined by the triaxle compression test, is shown to be significantly less than the angle of repose