University of Waikato researchers have been awarded funding to investigate new ways of reducing earthquake damage in a large number of essential buildings, including hospitals.
The Ministry of Business Innovation and Employment has given the project $993,612 over three years from its Endeavour Fund. The work will focus on mitigating the vertical motion in buildings during an earthquake. While several building techniques have already been developed to address horizontal movement, such as lead-rubber base isolators, the few techniques available for managing vertical motion are only theoretical.
The answer may lie in creating foundations that can go from stiff to flexible in the event of an earthquake – an idea inspired by Mimosa pudica, or the touch-me-not plant, which becomes completely floppy and flexible when touched or shaken.
Preliminary modelling indicates the potential of the proposed concept for use as a protection mechanism against vertical ground acceleration in an earthquake. If the new research is successful, this will be combined with existing systems that protect against horizontal motion. The resulting device will be designed for installation in new buildings, and for retrofitting into existing buildings.
Vertical seismic isolation is an identified need in the building industry. Successful outcomes of this research will lead to safer buildings and less damage in the event of earthquakes – offering significant benefits to the building industry, national and local government, and our communities.
Lead researcher Professor Ilanko Sinniah from the School of Engineering is looking forward to proving the concept. The idea came to him in a classic moment of pure inspiration. A keen cultivator of exoctic plants, Professor Ilanko had planted touch-me-not seeds, and promptly forgotten all about them. Shortly after the 2011 Christchurch earthquakes he was on his deck, and spotted what he thought might be a tiny kowhai plant. When he bent down and touched it, and the leaves immediately went into their protective mode: from straight to floppy. It was his forgotten Mimosa pudica. “It occured to me, in that moment, just a few days after to the earthquake, it would be nice if we could come up with a similar mechanism to protect buildings from earthquake shaking, by designing a foundation that could adapt when the need arises. Now we look forward to working towards this goal.”
The inspirational touch-me-not plant in action.
Minister for Research, Science and Innovation, Dr Megan Woods, says we can't predict natural disasters, but we can prepare for them. “As many of our cities lie near major fault lines, research like this is vital for ensuring the resiliency of our infrastructure and keeping our people safe.”
Other members of the research team are Dr Yusuke Mochida (Waikato), Professor Brian Mace (University of Auckland), Dr Kēpa Morgan (Ngāti Mākino Iwi Authority), Ben Holland (OPUS International), Professor Francesco Pellicano and Dr Marco Barbieri (University of Modena and Reggio Emilia, Italy).