Comparison Between Theoretical and Measured Settlements of a Cyclically Loaded Silo

Wheat or corn silos, as well as oil and fuel tanks, are periodically filled and emptied during their lifetime. Cohesive layers, underlying the foundation structure, are thus subjected to loading-unloading cycles that alternatively cause their compression and swelling. Consolidation process has been studied by several authors, which assumed loading-unloading cycles of variable shapes. This paper presents a further simplified theory, valid for scalene triangular shaped cycle of loading and unloading, representing better the actual condition of a cereal silo, quickly loaded at harvest season and slowly emptied during selling time. Theoretical results, obtained by the simplified theory and a F.E.M. analysis, have been compared to the measured settlements of a corn silo located at the Po river delta (Italy).