PORTLAND, Ore. (KOIN) – Mass timber manufactured in Oregon was put to the test of 6.7-magnitude and 7.7-magnitude earthquakes on a shake pad in San Diego Tuesday as researchers work to learn if tall buildings constructed using the material will be resilient to earthquakes.
A 10-story structure built from mass timber produced by the Lyons-based company Freres Engineered Wood was constructed on the shake pad in San Diego as part of the Natural Hazards Engineering Research Infrastructure (NHERI) TallWood project.
The project is headed by Dr. Shiling Pei from the Department of Civil and Environmental Engineering at the Colorado School of Mines. He and a host of other collaborators and researchers from around the country wanted to know how mass timber would fare when jostled by large tremors.
Mass timber is becoming a popular building material and is considered to be a greener and faster alternative to building structures using steel and concrete. It’s made from layers of wood bonded together.
New building codes have been recently updated to allow more mass-timber high-rise buildings to be constructed in the United States. Because of this, many have wondered how the material would withstand an earthquake.
“Mass timber is part of a massive trend in architecture and construction, but the seismic performance of tall buildings made with these new systems is not as well understood as other existing building systems,” Pei said.
The structure Pei and his team tested was a rocking wall lateral system that would be suitable for regions where the risk of an earthquake is high.
The building was designed so that the damage caused by an earthquake would be minimal and could be repaired quickly.
The rocking wall system was made of a solid wood wall panel anchored to the ground using steel cables or rods with large tension forces in them.
“When exposed to lateral forces, the wood wall panels will rock back and forth – which reduces earthquake impacts – and then the steel rods will pull the building back to plumb once the earthquake passes,” Pei explained.
Shake testing on the platform began in late April. On Tuesday, May 9, the building went through two tests: one replicated the 6.7-magnitude Northridge earthquake that occurred in 1994 near Los Angeles and the second replicated the 7.7-magnitude Chi Chi earthquake that occurred in Japan in 1999.
The TallWood project withstood both quakes.
According to a press release from NEHRI TallWood, the structure will undergo tests for a range of earthquake magnitudes on the Richter scale, from magnitude 4 to magnitude 8.
After learning the building made of his company’s wood had withstood the two strong tests Tuesday, Tyler Freres, vice president of sales for Freres Engineer Wood, said, “Seismic resiliency is of utmost importance, not only from a health and safety perspective but also from a societal cost standpoint. If we can design new buildings that are habitable after a significant seismic event we will reduce human casualties from natural disasters and reduce cost for reconstruction. As we have seen from our own local natural disasters, the wildfires, people are displaced for years, not days. This would help minimize suffering significantly for people involved in an earthquake.”
The project is being funded by grants from the National Science Foundation and researchers from Oregon State University and a consortium of other universities have been collaborating on the construction and research.