University of Alabama research aims to make buildings safer in earthquake-prone cities

By Bryan Davis:

The combination of two proven construction methods could lead to safer wood-frame buildings in earthquake-prone cities.

Two University of Alabama professors, along with a Colorado State University professor, are engaged in research that could combine the light wood frame system (LiFS) and cross-laminated timber (CLT) to form a self-centering structure that could better withstand the force of an earthquake.

Thang Dao (assistant professor of civil, construction and environmental engineering), Sriram Aaleti and John van de Lindt (Colorado State University) are working on National Science Foundation-sponsored research they are hoping will result in a construction method they are calling CLT-LiFS.

Dao said during an interview with the Alabama Center for Real Estate that both methods have unique advantages, and along with a self-centering post-tension system, they could lead to wood-frame buildings in earthquake-prone cities as high as eight to 12 stories.

“One does very well in handling the load, and one does very well in dissipating the energy,” Dao said of CLTand LiFS. “That can improve the height of the structure because it can carry the heavier load.”

The trick is finding the right combination of the two methods, and that is what Dao and his research partners will be doing at UA’s Large Scale Structures Lab.

Dao said too much use of a method like CLT could become too costly, outweighing the benefits of adding stories to a building.

“If you use too much, it costs a lot, because CLT costs a lot more than LiFS,” Dao said. “And CLT is heavy, so if it’s heavy, it creates more force during the earthquake, so LiFS can compensate for that. You have to understand the behavior of the new system and how it works in the seismic zone.”

Dao said the unbonded post-tension tendon could act as a self-centering device for buildings during an earthquake, reducing the threat of residual deformation.

This research becomes more pertinent as population growth and demographic trends push more people to live in apartments in the urban core of major metros around the world.

“In the future, we’re not going to stop at the seismic zone, because CLT does very good in the wind, too,” Dao said. “That could be hurricanes or tornadoes. If you make a safe room out of CLT in a proper way, it will survive.”

alabamanewscenter.com