Professional engineers have provided a range of inputs into the responses to the Canterbury Earthquake Sequence and the recovery process that has followed. This earthquake sequence has been unique in many respects, including the intensity of shaking produced in the Christchurch CBD by each of the major aftershocks in February, June and December 2011. For engineers, the heavy workload has been continuous from the response to the original 4 September 2010 Darfield earthquake, and will extend for several years to come. There have been many post-earthquake challenges for seismologists and geotechnical and structural engineers, commencing with urban search and rescue responses and rapid building evaluations, and extending through the more detailed assessments and repair specifications during the recovery phase. Engineers are required to interface with owners, regulatory authorities and insurers, and face many challenges in meeting the objectives of these different sectors, which are rarely aligned. Adding to the technical demands has been the requirement for many scientists and engineers to provide input into the Canterbury Earthquakes Royal Commission of Inquiry and other investigations. The Royal Commission was set up to investigate the failure of buildings that led to the loss of 185 lives in the 22 February 2011 aftershock, and has placed close scrutiny on many aspects of engineering activities, particularly those undertaken following the 4 September 2010 earthquake. The prominent public reporting of the Royal Commission hearings has placed additional pressure on many engineers, including those who volunteered their services following the original earthquake into a role for which they had received only limited prior training. Interpreting and communicating ‘safety’ in relation to the re-occupancy (or continued occupancy) of commercial buildings continues to be a challenge in the face of liability concerns. A more comprehensive understanding of the technical and process guidance required by engineers and authorities has resulted from the work undertaken in response to this earthquake sequence. Much of this guidance has now been produced, and will be of considerable benefit for future major earthquake events. This paper reflects on the range of work undertaken by scientists and engineers during the response and recovery stages. The scope and implications of the various official inquiries are summarised, and the potential impacts on engineers involved in the response to and recovery from future major earthquakes are briefly discussed.

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.

In Christchurch, the industrial sectors with storage facilities incurred heavy economic loss due to the collapse of pallet rack systems and loss of contents during the recent the Darfield (2010) and Lyttleton (2011) earthquakes. The failure of such systems could be attributed to various reasons including inadequate design, inappropriate operational conditions, improper installation and lack of maintenance. This paper describes possible sources of damage in pallet racks due to earthquake action, which eventually could trigger the collapse failure mode of the storage system during a severe aftershock. Various racking manufacturers and retail owners were consulted to establish the pre-event condition and loading of the systems and the response of the systems in both ‘publicly accessible’ and ‘industrial’ situations. Investigations by the authors highlighted an apparent lack of consistent national control over the design and construction of racking systems. Progress towards the publication of a revised and extended Design Guide is also described.

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Glazing and window systems in New Zealand have been shown to be susceptible to significant damage as evidenced by the past decade of earthquakes. The seismic performance of glazing and window systems has resulted in considerable financial loss, disruption in business and physical injuries following earthquakes.  In order to investigate the vulnerability of residential windows in typical light timber framed buildings racking testing was conducted on six wall configurations.  Numerous observations of window performance were made during the testing and from these results fragility functions were developed for timber and aluminium framed windows.  These fragility functions suggest that even at low displacement levels damage can occur to windows that can potentially affect weather-tightness and require repairs following an earthquake.  These functions can inform decisions around designing for resiliency in residential structures in New Zealand.