Sample design model of the rocking frame seismic engineering system.
September 28, 2010
Jerome F. Hajjar, professor and chair of the Department of Civil and Environmental Engineering, has been named a recipient of a 2010 Popular Mechanics Breakthrough Award, which recognizes the products and innovators that truly moved society forward in 2010.
Hajjar and a colleague from Stanford University will receive the award for developing a new structural system that helps buildings withstand large earthquakes.
Known as the rocking frame seismic engineering system, it employs a design that allows the building frame to rock without shearing, with replaceable steel "fuses" that absorb most of an earthquake’s energy. The system also includes tensile steel cables that pull the building to its plumb, upright position once an earthquake ends.
Hajjar and his colleagues designed the system as a National Science Foundation Network for Earthquake Engineering Simulation research project.
The researchers recognized that during a large earthquake, buildings designed according to current codes can experience significant structural damage and can also shift off their foundations. This kind of damage makes it difficult, and often financially unreasonable, to repair those structures.
"Our goal was to develop a resilient building system that employs self-centering rocking action and replaceable energy-dissipating fuses to provide safe, cost-effective earthquake resistance," said Hajjar.
By dramatically reducing the risk of catastrophic damage and by facilitating quick repairs through replaceable steel fuses, the system minimizes building downtime and the associated disruption following severe earthquakes. The system also improves sustainability by minimizing the environmental impacts of post-disaster reconstruction and by creating more resilient communities.
The research team successfully tested the system on the world’s largest shake table at the Hyogo Earthquake Engineering Research Center Shake Table in Miki, Japan.
"We are working now to determine how best to incorporate the design into the specifications for constructing new buildings," said Hajjar.
Hajjar will be featured in the November 2010 issue of Popular Mechanics.