Engineers raise wood's standing
Three engineers have been recognised by the University of Canterbury for their efforts in the rebuild of Christchurch.
Civil and natural resource engineers Professor Andy Buchanan, Professor Stefano Pampanin and Dr Alessandro Palermo have been awarded UC’s Innovation Medal for 2013 for using their academic knowledge to benefit the wider community.
The Innovation Medal is awarded by the University Council for excellence in transforming knowledge or ideas so they are adopted by the wider community in ways that contribute beneficial value.
The trio were chosen as the medal winners following their innovative contribution to the new system of earthquake-resistant buildings using post-tensioned structural timber, referred to as Pres-Lam (pre-stressed laminated timber).
“I was coming to the project from timber structures; Stefano’s interest was in concrete buildings and Alessandro’s interest was in concrete bridges. We combined all three of those areas to come up with a new system for timber buildings,” says Buchanan.
Their innovative design concepts, developed in 2005, were followed by a patent application in 2006 and five years research funded by the Structural Timber Innovation Company Ltd (STIC), before the system was used in the construction of buildings in Nelson, Wellington and Christchurch.
“We are at the point where buildings are under construction in Christchurch using the technology in the rebuild and that is very rewarding,” says Buchanan.
He says industry support has centred on the STIC Research Consortium, jointly funded by industry and government.
“The reason STIC has been so successful is because the timber industry funded the research. Having the funding from industry meant that, from 2008 to 2013, we were able to develop our ideas and this was the key. It took our team to a higher number of staff and scholarships for masters and PhD students,” says Buchannan.
The post-tensioned timber buildings are constructed with laminated veneer lumber (LVL) manufactured by STIC shareholders Carter Holt Harvey or Nelson Pine Industries. LVL is similar to very large sheets of thick plywood, subsequently laminated into large structural beams, columns or walls.
Pampanin says that during an earthquake the structural system “will sway and rock as the ancient Greek temples were doing in earthquakes, like an ‘articulated’ smart body”.
“The post-tensioned tendons are clamping and holding the system together, basically acting as springs. They will re-centre the structure back to its original at-rest position, while the plug-and-play energy dissipaters will absorb the earthquake energy like shock absorbers which are easily replaced after an earthquake,” says Pampanin.
College of Engineering Pro-Vice-Chancellor Professor Jan Evans-Freeman says the award recognises the many years’ work, and creative and innovative thinking, carried out by the three engineers.
“Their contribution includes research, development, promotion and technical support. Their pioneering UC research has lifted engineered timber buildings into serious contention for the Christchurch rebuild after the 2010 and 2011 earthquakes.
“They initiated a step-change in the use of timber as a structural material, allowing direct competition with concrete and steel for many multi-storey buildings.
“They have built on some innovative solutions developed for concrete buildings to invent and develop a whole new system of post-tensioned timber for earthquake-resistant multi-storey timber buildings,” says Evans-Freeman.
Pampanin says one of the highlights of the project has been seeing buildings being built with this technology. The interesting part of the project was not only to develop the theory with computer simulation and experimental validation, but also to disseminate the knowledge and see people’s appetite for the new technology.
“The fact that, internationally, people are getting seriously interested in our technology, especially in Europe, Canada and Japan, is really rewarding.
“It is great to see that both technical and non-technical people are saying that multi-storey timber buildings are just as acceptable as concrete or steel buildings. It is showing that timber is not only ideal for one-storey houses but can be used for multi-storey buildings too.
“Seeing the general public describing with their own words how things work with this technology is very satisfying as an academic,” says Pampanin.
Palermo says that seeing people working with this technology is “fantastic”.
“In terms of an academic environment, it is showing everyone that the University of Canterbury is a leader in the expansion of timber buildings.
“The buildings are the most important thing but, from an academic point of view, if a paper is circulated on these advances and there is no specific reference to UC then it really isn’t credible. And that is something to be proud of,” says Palermo.
The trio says that working together for the past nine years on this research was all possible thanks to a solid professional relationship and friendship.
“If we were just working in a professional capacity it probably would have been more difficult, but because there is a good friendship between us all it has certainly helped in being able to deliver the best possible outcomes,” says Palermo.