Buildings that rock during an earthquake and return to plumb would withstand seismic shaking better than structural designs commonly used in vulnerable zones, according to a researcher at Case Western Reserve University in Ohio.

"Those buildings would also be more easily and cheaply repaired and put back to use more quickly", says Michael Pollino, an assistant civil engineering professor.

Pollino developed a computer model that compared rocking steel-braced frames to current earthquake standards in low- to mid-rise buildings.

"Currently, engineers are designing low-rise structures for an earthquake that has a 10% chance of occurring in a 50-year-lifetime. We accept there will be damage but no collapse or loss of life,” Pollino says. "But what about an event that has a 50% chance of occurring? You may still have to tear the building down afterward," he says. "I think this design should do more to make the building usable and repairable afterward."

According to Pollino’s model, there are optimal sizes for two key components of rocking steel-based frames: steel-yielding devices and viscous damping devices.

The steel in steel-yielding devices are able to stretch during a quake, dissipating the seismic energy that would damage the building.

Pollino says the rocking frame would create a better alternative for these buildings and prevent traditional braces from buckling where beams and columns meet.

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