Failure Due to Deficient Welding

On the afternoon of June 1, 1983, the entire facade of the new wing of a broadcasting headquarters building collapsed during construction. The wall fell suddenly and debris covered the roof setback at the sixth floor, causing damage to the framing at this level. A careful review of the collapsed area indicated that the precast spandrel beam hung from the structural steel overhangs. It was established by analytical computations and by full-scale laboratory testing that the welds are constructed were not adequate to safely support the required loads on the plates. The crucial contribution of weld returns to increased load capacities of the connection was demonstrated by laboratory testing. The tests were conducted both on sections actually retrieved from the collapse area and on equivalent, full-scale assemblies specifically constructed and welded for testing.