Causes of imminent failure damage and repair of steel building purlins

A systemic design of purlins made from Z-sections (cold-formed from sheet metal) and their ties (made from solid bars) had been adopted in the investigated steel building. A periodic survey of the latter's technical condition showed that the purlins were deformed, bent and twisted and the ties were buckled. The condition of the roof deck supporting structure posed an imminent failure hazard. This paper presents the results of investigations of the load-bearing capacity and rigidity of the roof deck supporting structure, the aim of which was to determine the causes of its imminent failure condition.