Across the globe, wood is making a construction comeback.
With the world’s tallest timber-framed building opening in Norway two months ago, it’s seen as a sustainable way to build.
Back home, engineers in Christchurch are putting wooden structures to the test against earthquakes.
“We know an earthquake’s force is produced mainly by the mass of the building,” the project’s lead researcher Minghao Li says.
“Wood is much lighter than concrete and steel which means much less earthquake force and we know wood is strong”.
They’re investigating core wall structures, which are frames used for elevator shafts and staircases and crucial anchor points for buildings.
“For wind events that’ll happen every day or these earthquakes that can happen, these core walls will prevent the building from falling,” says Justin Brown, an engineer working on the project.
Using an 8.6 metre core-wall test subject at the University of Canterbury, they’re using hydraulic rams to measure how much force a timber structure can take. Mr Brown says the main issue is its flexibility.
“If it moves too far, you might damage the non-structural parts of the building, the cladding, the glass within it”.
But David Carradine from the Building Research Association of New Zealand says timber has other benefits.
“Namely its lower density and its ability to provide then for lower forces and smaller foundations.”
Aiming to test a 10 to 12 storey structure, the engineers are now turning to digital designs.
“With a verified computer model, we can run parametric studies, sensitivity studies to really understand a bigger picture of how these types of structures will behave under different earthquake scenarios,” says Mr Li.
He says the plan now is to design building guidelines around timber core walls for a more stable and sustainable future.
By Jacob Johnson