Collapse of a Car Park Canopy

Abstract

A completed car park canopy collapsed shortly after its completion. The structural system of the car park canopy was a T steel structure of unequal cantilevers connected to the ground at the base with eight 25-mm anchor bolts. The collapse was a progressive one starting with the steel structure located at one end of the roof. An investigation of the causes of collapse was carried out. Before the collapse, the maximum tension acting on an anchor bolt was not more than 10% of the tensile strength of the bolt. This investigation shows that the use of incompatible bolts and nuts such as in the case reported lead to the total loss of the tension capacity of anchor bolts in 3 days.