Washington, Aug 26 - Understanding how powerful earthquakes knock down tall buildings in mere seconds can help engineers design damage-proof buildings.

But the nature of collapse is not well understood. It hasn't been well-studied experimentally because testing full-scale buildings on shake tables is a massive, expensive and risky undertaking.

Accordingly, researchers from the University at Buffalo (U-B) and Kyoto University (Japan) teamed up to try a 'hybrid' approach to testing that may provide a safer, far less expensive way to learn about how and why full-scale buildings collapse.

'One of the key issues in earthquake engineering is how much damage structures can sustain before collapsing so people can safely evacuate,' explains principal investigator Gilberto Mosqueda, U-B assistant professor of civil, structural and environmental engineering.

'We don't really know the answer because testing buildings to collapse is so difficult. With this hybrid approach, it appears that we have a safe, economic way to test realistic buildings at large scales to collapse.'

The building in the original full scale test weighed more than 200 tonnes.