The seismic performance of RC buildings in the 22 February 2011 Christchurch earthquake

The 22 February 2011 Mw 6.2 Christchurch (Lyttelton) earthquake was a particularly severe test for both modern seismically designed and existing non-ductile reinforced concrete (RC) buildings. Some 16.2 % of 833 buildings with RC systems within the Christchurch central business district (CBD) were severely damaged. There were 182 fatalities, 135 of which were the unfortunate consequences of the complete collapse of two medium-rise RC buildings. As with the post-Northridge 1994 earthquake, the design performance of "modern" structures is being scrutinized - with the inevitable question: is "life safety" but irreparable damage still a valid performance target? This brief paper presents a summary of RC building damage from a broad performance-based earthquake engineering perspective. Several preliminary lessons, not all of them surprising, and the issues that have arisen will be discussed using case study buildings, with suggestions for urgently needed research areas.