Collapse of a coal loadout structure from fatigue caused by wind-induced vibration

This paper describes the collapse of a large coal loadout structure after one year of operation. The incident occurred on a calm day and without warning. The conclusion of the consultants for the designers and constructors was that there had been a severe overload. The opinion of the writer however, in acting for the owners, was that the failure was due to fatigue. After rebuilding of the structure, it was concluded that fatigue had occurred, being caused by wind-induced vibration, and the structure had to be modified further to provide direct support for the cantilevered portion of the structure that had collapsed. Wind tunnel testing confirmed the fatigue had been induced by vortex shedding and resonance in the structure. In the original design due consideration had not been given to such effects.