Geotechnical aspects of disaster recovery planning in residential Christchurch and surrounding districts affected by liquefaction

The Canterbury earthquake sequence of 2010-2011 consisted of six main earthquakes and more than 10,000 aftershocks (of which 20 have been greater than magnitude 5.0) directly affecting more than 300,000 people. The earthquakes caused land and building damage to more than 100,000 residential properties across Canterbury. This paper focuses on the issues related to liquefaction in the residential areas. There has been a need for coordination of specialist geotechnical advice into broader Government policy and planning recovery decisions, such as determining which land is suitable for rebuilding on and improving residential construction standards to increase future resilience. From a technical perspective, these earthquakes have provided a valuable opportunity to study the role that specialized engineering knowledge plays in the recovery process. A particular lesson is the importance of systematically capturing technical or factual information in the aftermath of a disaster, thereby planning beyond the short-term response to ensure that the right information is collected to assist the long-term recovery.