Metal anti-earthquake

If reinforced with an 'elastic' alloy made of nickel and titanium, the road bridge will be 'jugged' when an earthquake hits. The US scientists confirmed this after experimenting with a nickel-titanium reinforced concrete bridge model ('nitinol' for short).

Illustration. (Reuters)

The 6.9-magnitude Richter earthquake at Northridge in 1994 (killed 57 people, more than 9,000 were injured and the damage spread near Los Angeles) was reproduced at a magnitude of 8 to test the strength of the plant. This 30 m long bridge. Normally with such a strong seismic intensity, all bridges were large and small, even the Northridge overpass was leveled.

However, the bridge built by Nevada University engineers stood still, although the concrete part had a slight peeling but the basic texture was intact. Many sensors are mounted all over the bridge to transmit data to the analytical computer. Initial results showed that nitinol helped minimize damage to the bridge.

According to M.Saiid Saiidi construction professor, nitinol alloy has elastic properties and has 'memory'.'They (alloys) remember their shape before earthquakes happen to maintain the same. During the geological attack, nitinol underwent many deformations but soon returned to its original shape , "he said.

Saiidi's upcoming plan is to test nitinol alloys on some real bridges in California state.