Christchurch, New Zealand: CTV Building’s structural inadequacies contributed to failure during earthquake

An editorial at World Architecture News reports that The Department of Building and Housing in New Zealand has issued its report on the collapse of the CTV Building following the catastrophic earthquake last year. The firm responsible for the building’s initial structural design disputes the findings of the report claiming that it is “technically inadequate” and contains “highly questionable” assumptions.

The investigation found the following factors to be instrumental in the destruction of the CTV Building: Intense horizontal ground shaking; Lack of ductility in the columns, making them brittle; Asymmetrical layout of the sheer walls, making the building twist during the earthquake, placing extra strain on the columns. These structural inadequacies also failed to meet the building standards in place when the CTV Building was completed in 1986. Other potential factors mentioned in the report include low concrete strength in some of the critical columns and possible interaction of columns and concrete spandrel panels on the external face of the building making the columns less flexible.