Performance of houses during the Christchurch earthquake of 22 February 2011

The earthquake on 22 February 2011 was very close to Christchurch city, generating very high level ground excitations that caused severe geotechnical effects and widespread structural damage. This paper outlines the wide range of damage to houses resulting from liquefaction, lateral spreading, rockfall, and horizontal and vertical ground accelerations. The response of typical forms of house construction and structural components are discussed, with many different types of damage described. The majority of houses in the Christchurch region are one or two storey light timber frame buildings. This type of construction has performed extremely well for life safety, but thousands of houses have some degree of structural or non-structural damage. The New Zealand Building Code needs to be reviewed in several areas, especially the requirements for foundations and reinforced concrete floors.