Brought to you by:

EQC funds building resilience research

New Zealand’s Earthquake Commission (EQC) says it has provided “urgent” funding to University of Auckland researchers who are working to strengthen walls of buildings at higher risk of earthquake damage.

More than 100 multi-storey towers in Wellington’s CBD alone are identified as well below modern building codes.

“EQC decided to fund this research because it will deliver practical guidance on how at-risk walls in older buildings can be strengthened cost-effectively,” Research Manager Natalie Balfour said.

“It will also establish a consistent way of doing these fixes across New Zealand.”

The University of Auckland team has been wrapping danger-spots on at-risk walls in carbon fibre and testing whether this solution can bring the walls up to modern earthquake performance standards.

“We’ve already tested 56 different combinations of concrete, steel and carbon fibre to see when and how they break,” lead researcher Enrique del Rey Castillo said. “This gave us the data we needed to model how to strengthen a particular wall.”

He says the team is now testing these ideas in the lab with 4-metre high walls loaded with the weight of several storeys.

According to him, reinforced concrete buildings from before 1982 are considered a particular problem compared to modern buildings, as their thin and slender walls can be at higher risk of buckling and collapsing in an earthquake.

“Technically it’s called ‘axial failure’,” Dr del Rey Castillo said. “It can still happen in a newer building, as we saw in Christchurch’s Grand Chancellor Hotel, but pre-1982 design methods mean the risk is higher in those older buildings.

“And right now there is no guidance on how they should be strengthened.”