Citation

Blight GE, Hoogendijk. Bulk Solids Handling 2011; 31(2): 78-82.

Copyright

(Copyright © 2011, Vogel Business Media)

DOI

unavailable

PMID

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Abstract

Several factors that were responsible for the sudden destruction of a silo at a grain depot in South Africa were examined. The detailed analysis showed that the silo failure was not caused by structural weakness, but by a hidden dust explosion. The section of wall leaning between the two silos had been flung violently against the neighboring silo, indenting its walls with impressions of the bolt-heads in the failed portion which, in turn, showed indentations of bolt heads from the neighboring silo. It was discovered that during re-erection of the silos, stiffeners with incorrect thickness had been used in various places, and these were all strengthened appropriately. The inspection also revealed that in the large 18.19 meter diameter silos, plates having different thickness had not been correctly located. The failure was reported to have been caused by the shearing of the joint bolts between the metallic sheets. The roof was dislodged, but landed close to its original position, and the stiffeners were bent radially outwards.