Analysis of Design Standards and Recommended Practices for Agricultural Storage Bins

The design and analysis of circular and rectangular grain bins are governed by several standards and recommended practices. In the United States, ANSI/ASAE EP433: Loads Exerted by Free-Flowing Grain on Bins, and ACI-313: Design and Construction of Concrete Silos and Stacking Tubes for Storing Granular Materials are predominantly referenced. In Europe, EN 1991-4 Eurocode 1: Actions on structures—Part 4: Silos and Tanks is a mandated code to be used by the European Union Nations. While it appears the general philosophy of the design of grain bins is similar, i.e., determine the resulting loads from grain storage and grain flow within a bin; the design loads calculated by the various codes can be meaningfully different. This presentation will compare and contrast the analytical procedures used to calculate the resultant hoop stress live loads upon steel storage bins; specifically, the differences in the generally recognized equations to determine the horizontal and vertical pressure profiles resulting from the storage and flow of grain, and the effects of temperature changes. The use and limitations of pressure calculations using Janssen’s and the Eurocode formulas will be discussed. Other factors in the design of storage bins are the properties of the stored products. The presentation will discuss the variability in grain properties used in design due to seasonal/weather conditions and long-term effects of genetic modifications. It should be noted that these two stress calculations are not sufficient to adequately design a steel bin. All code and standard specifications must be met.