Silo failures: case histories and lessons learned

Although statistics are not available, hundreds of industrial and farm silos, bins and hoppers experience some degree of failure each year. Sometimes the failure is a complete and dramatic structural collapse. Other times the failure is not as dramatic or as obvious. For example, cracks may form in a concrete wall, or dents in a steel shell, either of which might appear harmless to the casual observer. Nevertheless, these are danger signals which indicate that corrective measures are probably required. The economic cost of a silo failure is never small. The owner faces the immediate costs of lost production and repairs, personnel in the vicinity are exposed to significant danger, and the designer and builder face possible litigation because of their liability exposure. The major causes of silo failures are because of shortcomings in one or more of four categories: design, construction, usage, and maintenance. Each of these is explored in this chapter, with examples and lessons learned.