Buildings with rocking steel-braced frames are advantageous in earthquakes

Research at Case Western Reserve University has found that buildings that rock during an earthquake and return to plumb would withstand seismic shaking better than structural designs commonly used today in vulnerable zones of California and elsewhere.

Those buildings would also be more easily and cheaply repaired and could be put back into use faster, said Michael Pollino, an assistant civil engineering professor at Case School of Engineering. The computer model research suggests optimal sizes for damping devices and steel yielding devices that dissipate the energy of a quake.

Pollino’s model compares rocking steel-braced frames to current earthquake standards used 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," Pollino said. "We accept there will be damage, but no collapse or loss of life. But what about an event that has a 50% chance of occurring? You may still have to tear the building down afterward.”

Pollino and other researchers are finding advantages to the design, which has not yet made it into practice. He and colleagues are discussing forming a technical committee of civil engineers that would advance the technology into practice. Pollino is now applying for funding to begin physically testing designs in the university's structures laboratory.