System protects historic buildings from earthquakes

UK-based engineers are helping to protect the world’s historic buildings from earthquakes with a new anchoring system.

A team from Bath University and Newport-based company Cintec have developed the device, which dissipates vibrations from earthquakes, as part of the European NIKER project, which was set up to find ways of protecting cultural heritage from seismic activity.

The system also includes a monitoring sensor that collects information about a building’s reaction to an earthquake and which may one day function as a form of early-warning system.

“It gives you far more protection from a major earthquake and probably saves lives”

Cintec managing director, Peter James

Recent events in Japan and New Zealand have highlighted the severe threat earthquakes pose to historic buildings — as well as to human life — while the 2009 quake in L’Aquila in Italy showed how Europe’s cultural monuments are also at risk.

Bath University PhD student Sara Paganoni said the project applied established energy-dissipation principles to historic buildings.

‘It’s a similar idea to what we use at the moment for dissipative systems, for example concrete or steel frames, which are common in Japan and the US,’ she told The Engineer.

‘Because we are dealing with heritage buildings, which are quite sensitive in terms of aesthetics, we have to do something small scale.’

The technology combines a so-called black-box dissipation system with Cintec’s existing anchoring mechanism, which the company has used to reinforce historic buildings all over the world, including Windsor Castle and Egypt’s Red Pyramid.

Cintec’s anchor works as a load carrier at points of intersection between walls or points of known weakness. It comprises a steel bar surrounded by a fabric sock that expands to fill the hole it’s placed in and is held in place by micro concrete.

The system adds a patented device that uses friction between surfaces inside the box to absorb the energy from earthquake vibrations. This allows the structure to safely move by up to 25mm during an earthquake.

The effectiveness of the system varies according to the building specifications and the strength of the earthquake.

‘Anything you do in the way of seismic activity is only mitigation. You can’t say for sure what you can do,’ said Cintec’s managing director, Peter James. ‘The bottom line is it gives you far more protection from a major earthquake and probably saves lives.’

The team will be testing the system at a church in L’Aquila over the next six months. The trial will enable the team to calibrate the monitoring sensor to give information about the connection where each anchor is placed and how the whole building behaves.

‘This will give us a compact monitoring system that doesn’t need designing every time but can be bought as an off-the-shelf system,’ said Pagonini.

‘We hope, depending on the data and analysis, to be able to use this system as an early warning as well.’

Cintec estimates that the system will cost less than £100,000 to develop over the three years of the project, which began at the start of 2010.

The NIKER project has a total budget of €3.5m (£3m), including €2.7m from the European Commission. It involves 18 institutes and commercial partners from across Europe.