Infrastructure protectionRetrofitting old buildings to make them earthquake safe

Published 22 October 2014

Non-ductile reinforced concrete buildings are among the most common structures in the United States. They are also among the most deadly. Structures built prior to the 1950s in California and prior to the 1980s in the central and southeastern United States were typically not designed with proper details to perform adequately during earthquakes. Through a grant provided by the National Science Foundation, researchers are testing retrofits that potentially can make these buildings safer and more secure.

Non-ductile reinforced concrete buildings are among the most common structures in the United States. They are also among the most deadly.

Structures built prior to the 1950s in California and prior to the 1980s in the central and southeastern United States were typically not designed with proper details to perform adequately during earthquakes.

Through a grant provided by the National Science Foundation, researchers at the Georgia Institute of Technology — along with partners at Virginia Tech, Rice University, Howard University, and the University of California, Los Angeles — are testing retrofits that potentially can make these buildings safer and more secure.

“These buildings are considered among the most deadly in the United States,” said Reginald DesRoches, Karen and John Huff Chair and professor in Georgia Tech’s School of Civil and Environmental Engineering. “Their reputation comes from the fact that there are so many of them and they are brittle, which means they will not have a lot of bend before they fail and collapse.”

A Georgia Tech release reports that Georgia Tech and its partners are studying how a full-scale reinforced concrete building reacts during large-scale testing. This testing shakes the structure, allowing researchers to assess different kinds of techniques to make similar buildings more durable so they don’t collapse during an earthquake.

“Our focus right now is trying to understand from a scientific perspective what works and what doesn’t,” DesRoches said. “We built this unique structure, which is split into different bays, that allows us to test three different retrofits as well as one bay without any added support.”

The building
According to DesRoches, it is unusual for researchers to build such a massive structure allowing this type of testing. Originally, the research team tried to locate an existing building they could test, but they then realized there were benefits to building a new structure.

“It is a full-scale building that was constructed from plans of a building that was built in the 1950s in California,” DesRoches said. “We know exactly what is in the columns and how it was designed.”

How the structure is tested
The building was constructed so that it was sliced up into bays, allowing researchers to actually test different portions of the building separately and evaluate different retrofit measures.