A structural joint designed by University of Canterbury researchers is being used to make buildings safer in earthquakes.
Greg MacRae with a prototype of the sliding joint technology being used in the building behind him. Photo: RNZ / Nicola Grigg
The two-way sliding joint helps dissipate energy from a quake by allowing columns and beams to move, protecting the building from damage.
Hundreds of the joints are being used in The Terrace hospitality and retail precinct being built along the Avon River in the centre of Christchurch.
Aurecon engineering company spokesperson Stephen Hogg said the joints would be used in buildings as a much cheaper alternative to base isolation systems.
"It is classic Kiwi ingenuity. It uses extremely cheap materials, which is basically steel plates and bolts, and it uses friction, which is free," Mr Hogg said.
"This is invented by New Zealanders and it's getting implemented in Wellington and Christchurch on projects at the moment."
Greg MacRae, the lead researcher in the development, said the materials were cheap and the idea simple.
"There are whole lots of other added devices and mechanisms which can be used to make low-damage construction," Dr MacRae said.
"The nice thing about friction is it's very, very cheap. We don't need to put any special device in. We don't need to buy a special bearing. It's just a matter of doing bolts up."
The beams would slide because of elongated holes around the bolts in the joint, he said.