Performance of concrete buildings in the 22 February 2011 Christchurch earthquake and implications for Canadian codes

Abstract

At 12:51 pm local time on 22 February 2011, a M 6.2 aftershock of the 4 September 2010, Darfield earthquake shook the city of Christchurch, New Zealand. The aftershock occurred on an unmapped fault less than 10 km from the city centre resulting in significant damage, particularly in the Central Business District (CBD). The earthquake resulted in the collapse of two reinforced concrete office buildings, one parking garage, and numerous unreinforced masonry buildings, including many heritage structures, leading to 185 deaths. Liquefaction was wide spread in the CBD and the eastern suburbs, resulting in foundation movement for housing and office buildings alike. Many buildings in the CBD experienced severe damage, some requiring demolition, necessitating careful controlled access to the CBD in the months following the earthquake. This paper summarizes the recorded earthquake shaking and observed damage to concrete buildings in CBD, with a specific focus on identifying future research and possible changes for seismic design practice and codes in Canada to address the Christchurch observations.