Friday, September 10, 1999 Published at 12:06 GMT 13:06 UK
Weird wires to protect basilica
The rubble has been sifted for fragments of the frescoes
Metal wires which can stretch and then snap back like elastic will soon be added to the Basilica of St Francis of Assisi to protect it from future earthquakes.
It will be the first time the technology has been used. Dr Gabriella Castellano, an engineer with FIP Industriale, led the research and told BBC News Online: "We think this approach will be important in the future because it solves problems which cannot be solved using traditional materials."
The idea came out of a European Union project called ISTECH which cost £890,000 and was based at the European Laboratory for Structural Assessment in Italy.
Tests were done on four-metre-high masonry walls built in the laboratory. These showed that, even at double the shaking actually experienced in Assisi, the new flexible wires protected the wall.
"We estimate that structures protected with the new devices can survive an earthquake at least 50% stronger than one which would destroy structures reinforced with the traditional steel bars," said Dr Castellano.
Nickel-titanium alloy will be used in the Basilica. Wires one millimetre wide and up to 70 cm long will be used in bundles of up to 80.
It will take 47 bundles to secure two masonry tympanums in the roof. One of these partly collapsed in 1997 and the falling debris caused great damage.