A new dampener – which acts like a car shock absorber – could hold the key to timber buildings that not only withstand major earthquakes but also quickly recentre after major shocks – a game-changer in preventing buildings from remaining titled or misaligned after major shakes.
That is according to Soheil Assadi, PhD candidate from the University of Auckland, who, with the researchers from the Faculty of Engineering and Design, developed the Resilient Slip Friction Joint (RSFJ) – a new joint that not only reduces shaking but restores buildings to original form – who said the quest to improve the seismic performance, especially in the Ring of Fire, has real-world implications for essential infrastructure.
“If there was a school or hospital, it could be used immediately after the earthquake. This solution could not only save lives but also ensure that buildings remain functional, reducing economic losses and recovery time.”
Assadi, who is part of a study co-led by Dr Ashkan Hashemi, tested RSFJ in a “one-of-a-kind, full-scale earthquake test on a two-storey timber building: “This research shows that with innovative design, we can build strong, sustainable and cost-effective timber structures that perform exceptionally well in earthquakes,” said Dr Hashemi. “It’s amazing what you can achieve with a bit of innovation and thinking outside the box.”
Wood Central understands that the full-scale timber structure (which used mass timber supplied by Red Stag – one of the world’s largest and smartest mills) was subject to extreme seismic forces during testing to simulate a major earthquake: “Remarkably, the structure withstood the shaking and showed no signs of damage,” according to a media statement provided by the University of Auckland.
Funded by the Wood Industry Development and Education (WIDE) Trust and the Te Hiranga Rū QuakeCoRE (NZ Centre for Earthquake Resilience), the research team – which includes Professor Pierre Quenneville and PhD candidate Setu Agarwal – said the new solution, now ready for use in real life projects – will provide industry with much-needed confidence when it comes to the seismic performance of timber buildings.
The research comes after Wood Central reported that Simpson Strong-Tie, the world’s largest supplier of connectors, was testing connectors at its purpose-built shake table: “Simpson Strong-Tie uses ground motion recordings from real-life seismic events, with the shake table testing specimens with an inertial weight up to 60,000 lbs,” according to Andrew Dunn. ” It uses some of the largest ground motions recorded to date.”
Mr Dunn – who travelled to Stockton, California, on his way to the International Mass Timber Conference in Portland last year – said the three-storey shape table was the centrepiece of Simpson Strong-Tie’s Tyrell Gilb Research Lab. “The floor is three feet thick and designed to withstand 300,000 pounds in load,” Mr Dunn said, with over 10 million tons of reinforced concrete in the walls and core.
“Why so much concrete? For two reasons,” he said: “one, greater flexibility when testing heavy loads, and second, the actuators need a significant reaction time when testing specimens through earthquake simulation. If the reaction mass of the lab floor was not so large, cyclic tests could transmit vibrations through the rest of the building.”
- To learn more about how clever use of timber can improve the resilience of buildings in earthquake-prone areas, click here for Wood Central’s special feature from last year. To learn more about the role that a new “wall rocking system” – developed by Simpson Strong-Tie – can play in improving building resilience in high seismic areas, click here for more information.
