case study

The Failure of Steel Bins, Hoppers, Bunkers and Silos

Failure in steel structures used for the storage of bulk materials can take various forms:

1. Yielding of the silo walls or other elements

2. Buckling of plate elements - many storage structure walls are imperfection sensitive, in that their failure loads are considerably lower than their predicted buckling loads

3. The interface between yielding and buckling

4. Fracture

5. Corrosion

6. Wear or reduction in wall thickness with time

7. Bad structural detailing

8. Bending in curved walls due to eccentric flow

9. Differential settlement of foundations

10. Changes in the bulk material(s) being stored

11. Modification of wall linings to increase or improve flow

The design of every bin, hopper, bunker or silo must be based on knowledge of the physical and flow properties of the bulk solid(s) being contained. Sadly, many of these structures fail because they appear so simple to design for flow and strength that almost anyone can "have a go".