Bridges Over Earthquakes
One part of the country’s flirtation with rebuilding its infrastructure could be a new style of bridge in certain locales. Called a flexible bridge, it is engineered to withstand an 8.0 earthquake.
Engineers at the University of Nevada built and tested a 200 ton model that survived 10 seconds of shaking. Its resilience is attributed to the reinforcement in the concrete – smart nickel titanium or Nitinol. This material has shape memory (perhaps much like that material recovered from the alien ship crash at Roswell more than 50 years ago). Because it remembers the shape it was cast into, after being deformed it springs back to that original shape. These Nitinol bars are used in critical places in the bridge’s structure, like in the columns.
Apparently, the “dumb” steel used in bridges today, stays deformed after earthquake shocks often causing the entire bridge to be rebuilt. The test also suggests that Nitinol might be a great material for the cables of suspension bridges.
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