By Mark Scott
Buffalo, NY – A simulated 7.0 magnitude earthquake was staged at UB's earthquake engineering center Tuesday morning to test the durability of a prefabricated concrete bridge.
Engineers at MCEER (Multidisciplinary Center for Earthquake Engineering Research) say the bridge sustained a few cracks and chips in the test but would have been able to continue handling traffic.
Two powerful earthquake tests were performed on the half-scale bridge, which was erected across the center's twin shake tables.
Hundreds of the pre-fab bridges have been built around the nation. The components are prepared in a shop, then transported to the site, where they are assembled.
It's so fast that it can take just days, not months, to build a bridge, saving states and municipalities precious public dollars.
But federal highway officials were concerned whether they would withstand the the effects of an earthquake.
"The concern is that these bridges are basically concrete boxes held together by steel tendons (cables), which potentially could snap during an earthquake," says Andre Filiatrault, PhD, professor of civil, structural and environmental engineering and director of MCEER.
"You could think of the deck and piers as held together by elastic bands," says Filiatrault. "The elements deform under seismic loading, and then recenter themselves after the earthquake is over."
Filiatrault and Amjad Aref, PhD, also a civil engineering professor at UB, are principal investigators.
"It can take six months or more to construct a bridge in the traditional way," says Aref. "If you could reduce that to just a few days, states and cities could save millions in labor costs."
At the same time, he says, it will give communities that have lost use of their bridges after an extreme event a new tool in rebuilding quickly and economically.
"After a disaster, quick reconstruction is even more critical," Aref says.