Damage to concrete structures from the 2010 Darfield (Canterbury, NZ) earthquake

Abstract

The 2010 M7.1 Darfield earthquake was the largest natural disaster to occur in New Zealand since the 1931 Hawke’s Bay earthquake and caused extensive liquefaction and ground spreading, which led to damage to a large number of residential buildings. This damage was particularly significant because of the number of families that had to evacuate their homes, and because of the extensive cost of remediation to these homes. Underground concrete water and wastewater services were significantly damaged, and concerns were raised that water supplies were contaminated, such that bottled water was necessary. Extensive damage occurred to many unreinforced masonry buildings, but damage to concrete buildings was minor, and was attributed to poor seismic detailing. Damage to concrete bridges was primarily associated with spreading of bridge abutments and damage to bridge approaches, and only eight vehicle bridges were closed. Damage to the concrete wharfs at Lyttelton Port was also primarily attributable to ground spreading, and whilst remediation will be expensive, the port was able to remain fully operational. Overall, concrete structures performed very well in the earthquake.