On the Storage Pressures and Properties of Alfalfa in a Bottom-Unloading Silo
ABSTRACT Haylage pressures in a bottom unloading monolithic concrete silo were measured for two consecutive years with 15 transducers placed symmetrically around the circumference at five levels. The experimental data were used to estimate the ratio of horizontal to vertical pressure and the coefficient of friction between silage and silo wall. The results indicate that the lower and upper limits for pressure ratio of 0.5 and 0.6 may be taken for alfalfa haylage in concrete silos. Values for friction coefficient of 0.4, 0.5, and 0.6 can be used corresponding to moisture contents of 60%, 50%, and 40% (wet basis) for this material and silo type. The predictions based on the proposed Canadian standard for bottom-unloading silos agree closely with the measured wall pressures at all levels above the unloader. This code also provides a conservative estimate of the overpressures in the unloader region.