A technical report on the failure of the Canterbury Television building during an earthquake in Christchurch, New Zealand in February 2011 illustrates how important seismic codes are in saving lives. The collapse killed 115 people, including 65 foreign students. The 6.3 magnitude earthquake claimed the lives of a total of 184 people in the country.
The report found the CTV building did not comply with the building code when it was first built in 1986. “Adevastating finding, considering the collapse of this building was responsible for more than 60% of the deaths in the earthquake,” said a Labour Party earthquake recovery spokeswoman.
Three critical factors were found to contribute to the building’s collapse:
- Intense horizontal ground shaking.
- Lack of ductility in the columns, making them brittle.
- Asymmetrical layout of the shear walls, making the building twist during the earthquake, placing extra strain on the columns.
Current building requirements are more stringent now than in the 1980s when the CTV building was constructed. Standards have improved over time as more is understood about how buildings respond in earthquakes. “The findings of the investigation will make a difference to the way the buildings are designed and constructed in the future – both in New Zealand and internationally,” according to a Department of Building and Housing executive.
NOTE: This information is the opinion of the author/blogger and not the official position of IAPMO.