Statistical Analysis of Silo Wall Pressures

Abstract

Previously published silo wall pressure measurements during plug flow of barley in a large concrete silo are re-analysed under the hypothesis that the wall pressures are gamma-distributed. The fits of the gamma distribution type to the local pressure data from each measuring cell are satisfactory. However, the estimated parameters of the gamma distributions turn out to be significantly inhomogeneous over the silo wall surface. This inhomogeneity is attributed to the geometrical imperfections of the silo wall. Motivated by the engineering importance of the problem a mathematical model for constructing a stochastic gamma-type continuous pressure field is given. The model obeys the necessary equilibrium conditions of the wall pressure field and reflects the spatial correlation properties as estimated from simultaneously measured pressures at different locations along a horizontal perimeter.