Researchers say new bracing could help buildings withstand major seismic events.
University of Sheffield researchers are working with engineers around the world on a new method of strengthening concrete buildings in earthquake zones.
The university’s earthquake engineering research team hopes its post-tensioned metal strapping technique will be used to increase the resilience of buildings in developing countries.
The technology involves wrapping metal straps around each floor of a building and tightening them with calibrated compressed-air tools.
Interest in the technology has surged since the team published an academic paper focusing on recent test results in the Journal of Earthquake Engineering.
Lead researcher professor Kypros Pilakoutas told NCE: “We had unbelievable results from the tests.
“We applied strengthening that was trivial in engineering terms and it changed the building from one that would fail in a minor earthquake to one that we could not break.”
The tests took place on a two-storey building typical of those seen in developing countries and some constructed in Mediterranean countries pre-1980. A specially-designed shaking table was used to simulate the conditions of an earthquake.
“The tests were the validation of the technology. We knew it worked but now it can be seen on [a structure which is] as close as you can come to a real building,” said Pilakoutas.
“We went up to a peak ground acceleration of 0.6g, creating conditions similar to the epicentre of the 2010 Haiti earthquake, which measured 7 on the moment magnitude scale,” he said. “The building did not fail.”
He said he was in discussions with several engineers around the world about the technology, including governments looking to protect embassy buildings abroad. There are also ambitions that governments will see the benefits for areas recovering from earthquakes such as Haiti. The system could even be specified in design codes.
The university team estimates that a typical small dwelling with six concrete columns could be strengthened for about £200 plus the cost of a few days’ labour.
It says the technique is easy to apply, and straps can be replaced if necessary.
It is hoped that developers and property owners will seek the university’s advice on using the system.