RFP Research Project Stories: Cécile L’HermitteNovember 23, 2023
Highlights 2023 – A year in reviewNovember 28, 2023
Cable Ties for Buildings
What if a building could sway back and forth in an earthquake and return to its upright position with no help, and without damaging the connections between the building and its foundation? Greg MacRae of the University of Canterbury has thought of this already. He conceived of a device he calls the “GribNGrab” that’s a bit like a giant cable tie for holding buildings in place.
GribNGrab devices are installed at the base of rocking buildings to tie the frame to the foundation. When an earthquake strikes and ground shaking causes the building to sway, the GripNGrab device on one side of the building allows the structure to uplift while seismic energy is dissipated via friction. When the building sways back in the other direction, a ratchet component operates preventing the GripNGrab from buckling in compression. The building self-centres and the device survives undamaged.
These clever mechanisms are undergoing refinement in a Te Hiranga Rū QuakeCoRE project entitled, “Improving building system performance considering GripNGrab tension-only friction devices in rocking frames.”
University of Canterbury PhD student Kiran Rangwani has been working with Geoff Rodgers to test the GripNGrab device. They found that the ratchet part worked as anticipated but performance of the frictional part was surprisingly unpredictable. Changes to the set-up of nuts and bolts have indicated how improvements may be made. Kiran’s work highlights the importance of proof-of-concept component testing prior to larger-scale experiments.
The GripNGrab device with a rocking steel frame will be one of nine structural configurations to be tested in a full-scale, three-storey building on a massive shake table at a QuakeCoRE Affiliate Organisation in China. This is a crucial part of QuakeCoRE’s Disciplinary Theme 2: “Whole-of-Building seismic performance.” Known as the Robust Building System (ROBUST) project, it aims to demonstrate how economic energy-dissipating technology can ensure buildings are not only safe after earthquakes but also easy to fix, enabling rapid reoccupation.
Our annual Request for Proposals (RfP) supports eighteen-month, Associate Investigator led research projects that complement the Coordinated Research Projects within the Disciplinary Themes (DT) and Inter-disciplinary Projects (IP) of QuakeCoRE's Research Programme.
The RfP includes Proposal Development Grants which enable early career researchers to develop strong contestable external research proposals.
The annual call for RfP Projects and Proposal Development Grants is held in September / October and is announced on the QuakeCoRE website and in our newsletter.
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