In his spare time, Shiling Pei watches woodworking videos on YouTube. He wants to be a fan.
Pei has had an affinity for wood for 20 of his 44 years. “It’s a natural material close to art and architecture,” says the associate professor in the civil and environmental engineering department at the Colorado School of Mines.
It’s understandable that Pei has a strong interest in wood. It comes from the People’s Republic of China, where it probably suffered from wood deprivation. Concrete is the preferred material. Except for old buildings, there are few, if any, wooden frames, he says.
Pei is not only an aspiring woodworker. He has been researching wood building systems for years. “I consider myself an experimentalist,” says Pei, also a licensed civil engineer in California.
His latest research on wood in seismic design based on resistant performance is historic. As the principal investigator of the National Science Foundation’s Natural Hazards Engineering Research Infrastructure TallWood project, Pei leads a team that tested a 10-story resilient “rocking wall” frame composed of wood cross-laminated post-tensioned vertically, in the open air. shaking table at the University of California at San Diego. The 112-foot-tall specimen was the tallest full-scale structure ever tested on a shake table, NHERI says.
The tremor simulated the 1994 Northridge earthquake, a magnitude 6.7 tremor in Los Angeles. Then came the 1999 Chichi earthquake in Taiwan, with a magnitude of 7.7.
The specimen was undamaged except for replaceable steel clips, Pei says, and performed exactly as expected, returning to its feathered position after swinging. “We found a cost-effective and practical way to build a tall wooden building that is almost earthquake-proof,” he says.
The unbuilt 12-story frame, designed by LEVER Architecture and KPFF, is the model for the specimen. “Ling had the most difficult position of all,” says Reid Zimmerman, a structural engineer on the NHERI team and technical director of KPFF’s Portland, Ore., office. “He led a large and diverse team,” including six universities, “to design, supply, manufacture and build the world’s tallest shaking table test,” he adds. And Pei leveraged multiple funding sources and numerous vendor donations while building consensus.
Thomas Robinson, founding director of LEVER and NHERI participant, says the rocking wall is “probably the most innovative structure put on a shake table in our lifetime.”
Pei’s research focuses on multi-hazard mitigation through performance-based engineering, numerical modeling of structural dynamic behavior, and large-scale dynamic testing. “There’s something very addictive about testing large structures,” says Pei, who has a Ph.D. in civil engineering from Colorado State University.
Pei first studied bridge engineering as an undergraduate at Southwest Jiaotong University in China. He came to the US in 2003 to study structural engineering.
It was a time when the academy was interested in the seismic performance of wooden structures, following the Northridge earthquake. There were few fatalities, but the number of heavily damaged wooden structures was high, Pei says. “We thought wood could do better,” he adds.
The “sweet spot” for the heavy-duty swing system is three to six stories, Zimmerman says. LEVER, with structural engineer Holmes, is currently designing a three-story office building with a timber tilting wall. If built, it would be the first tilting wooden wall, apart from the example.
Timber tilt-up walls are not up to code, making the system difficult for engineers to use. Pei and Zimmerman hope to change that. They are co-leading an effort to write a proposal for the 2028 update of ASCE/SEI 7, Minimum Design Loads and Associated Criteria for Buildings and Other Structures. For this, Pei must complete the NHERI report by the summer of 2025.
