Christchurch buildings are a strength, says international expert
See part two of video below.
Christchurch buildings - a hallmark of NZ earthquake engineering legacy, says international expert
Despite legions of cynical articles and ‘damning’ government reports claiming Christchurch buildings were poorly constructed to face an earthquake, an international expert - who has experienced more quake damage than most – thinks the city stood up remarkably well.
Professor Andre Filiatrault, a structural engineering specialist at two top universities - the State University of New York at Buffalo, and the Institute of Advanced Study in Pavia, Italy - has been visiting Christchurch for the third international SPONSE (International Association for the Seismic Performance of Non-Structural Elements) workshop.
On his first visit back in 20 years, he was surprised to see many landmarks gone, but was highly complimentary of the city’s response, given the circumstances. He remarked, “It was a bit shocking to see the Christchurch CBD with so many buildings gone and many more under restoration. But considering the seismic activity that the city has undergone, it shows the strength of the earthquake engineering profession that exists here in New Zealand – I imagine that a similar earthquake sequence would have caused a tremendous amount more damage in other areas of the world.”
“The built area performed very well. If it hadn’t been for the liquefaction of soil, I think the consequences would have even further reduced,” he continued.
It could be said that Professor Filiatrault has seen it all when it comes to earthquakes. The past president of MCEER (Multidisciplinary Centre for Earthquake Engineering Research – a significant hazard research centre), he has shake-tested a variety of structures on university earthquake simulators – from a wooden, multi-storey house, to heavy, high voltage electrical components. His consulting and assessment work on multi-storey buildings and bridges around the world is extensive. And he helped on the ground within eight days of the fatal Haiti earthquake, leading a team of ten specialists to be the UN’s building safety assessment eyes, inspecting hospitals and orphanages for suitability to house citizens once more.
He commented that the heartbreaking scenes he saw in Haiti could not be compared to Christchurch – largely due to our deeper understanding of earthquake resilience and implementation of codes.
“Haiti is the poorest country in the Northern Hemisphere. It has no earthquake engineering practise of any kind – anyone there could call himself an engineer. This chaos resulted in an extremely poor quality of built environment, so although the 2010 quake was not major, the consequences were devastating (130,000+ casualties compared to Christchurch’s 185). It shows the difference in earthquake engineering education, implementation and practise.”
The 2011 Christchurch earthquake was magnitude 6.3, 5km deep with an epicentre 8km from the CBD. The 2010 Port-au-Prince disaster was magnitude 7.0, 13km deep with an epicentre 25km from the city. On the surface, ground shaking would have felt similar, but the two cities have very different earthquake engineering legacies.
Most of Christchurch’s buildings were constructed or updated in the 1970’s and 1980’s. Although the New Zealand design of these was well-engineered, highly regarded internationally, and withstood a shaking intensity greater than it was designed for, the knowledge and technology we’ve developed 30-40 years on brings potential for even greater improvement.
“Recently we’ve seen earthquakes happening in countries with mature earthquake engineering practise. What we’re seeing in cities like Christchurch is, yes, buildings are performing reasonably well, but the next weakest link that quakes find are the non-structural elements.”
This is the area where SPONSE can offer a contribution. The international association focuses on how things inside buildings - for example, office furniture and interior partition walls - can be designed to minimise quake damage. More than 80 industry practitioners and academic researchers participated in the Christchurch workshop where challenges were identified and ideas began to move forward. Actions in the short-term involve resolving compliance issues, and in the longer-term, collaborative research.