The Kaikōura earthquake had a significant impact on mid-rise buildings, particularly in Wellington’s CBD and the Hutt Valley. Three buildings were identified immediately following the earthquake as having suffered significant damage. These were cordoned off and demolished in the months following.
The Government undertook an investigation into Statistics House on Wellington’s waterfront, after pre-cast floor units partially collapsed on two floors. The investigation found a combination of factors led to the damage, which were not understood by the design standards in place when it was built in 2004. Early in the investigation, concerns with other similar buildings were raised.
Wellington City Council used new recovery powers under the Civil Defence Emergency Management Act, which enabled it to require in-depth engineering assessments of around 80 buildings in the CBD. The Council found no public safety concerns with buildings that were not already unoccupied or being demolished.
The final report to Council showed that around half of those assessed had structural damage and repairs are well underway while the other half had no observed structural damage. The report gave nine recommendations to Council and Government, which are currently being funded and adopted.
While there was no significant impact on unreinforced masonry buildings in Wellington during the November 2016 earthquake due to its distant location, a similar earthquake closer to Wellington could have devastating consequences. In the Canterbury earthquakes the falling debris from these types of buildings claimed 39 lives.
To ensure these unreinforced masonry walls and parapets are strengthened quickly the Government used emergency powers to require building owners to secure masonry walls and parapets within 12 months, by March 2018 and would cover roughly half the cost through a $3 million fund. Around 170 buildings with vulnerable street facing parapets and facades on busy, high traffic areas have been identified across Wellington, the Hutt Valley and upper South Island.
The Government Property Group (GPG), part of the Ministry of Business, Innovation and Employment played a key role in ensuring the safety of and minimising disruption to government staff following the earthquake.
Thousands of government workers were displaced by closed buildings following the earthquake, and GPG led the co-ordination of temporary office space with many agencies who signalled they were willing to help.
The Government was in a good position to offer temporary office accommodation following the earthquake. This was due to the availability of two buildings recently vacated by the Ministry of Health, and a move to more flexible working across government. Already leased by the Crown, the Freyberg Building and 3 The Terrace were both available to accommodate around 1,300 people in 18,000 square metres of space by Monday 21 November. Agile workplaces were also a significant reason the continuity of the state sector was largely unaffected, as people were able to share space more easily and had the option to work remotely.
Regular meetings with Property Managers, information provided on the GPG Shared Workspace; and expert advice have also been led by the GPG. Encouraging government to move towards more agile workplaces will continue to be a key part of the Government National Property Strategy, to allow people to work remotely or as they choose within their usual building.
The Ministry of Business Innovation and Employment (MBIE) continues to work with Councils, engineers and the building industry to share the new knowledge from the November 2016 earthquake. Work includes reviewing regulatory settings to make sure the Building Code system incorporates this knowledge; commissioning expert working groups to look at the Earthquake Actions and Concrete Structures Standards; and working with industry experts to develop guidance to assist with the assessment and remediation of pre-cast floor systems in existing buildings.
This builds on MBIE’s broader work to support better building performance and emergency response procedures to earthquakes. In recent months, MBIE has issued best practice guidance on installing non-structural elements, such as ceilings and ducting in commercial buildings to avoid poor performance of these elements in earthquake events.
Understanding ground conditions and behaviour are crucial to building performance during earthquakes, which is why MBIE has released a suite of geo-technical guidance over recent years and established an online National Geotechnical Database, in partnership with Earthquake Commission (EQC), which allows practitioners to easily access and better understand ground information.