Testing Mass Timber's Seismic Resiliency

Testing is officially underway at the University of California San Diego (UCSD) on the tallest building ever to be evaluated for seismic resilience. Height is only the start of why this is big news in the building science community, since TallWood, the 10-story building being tested, is constructed from mass timber, contains low-carbon structural building material, and has been outfitted with high-performance components, including windows and doors from Innotech Windows + Doors. The building has also been equipped with DriftReady Stairs, a modular stair system by Construction Specialties that is designed to provide additional resiliency and means of egress in the event of a major seismic event.

[See the article by Stas Zakrzewski and Avery Gray on embodied energy and mass timber here]

The study is part of a a multistage and industry-wide effort to better assess how mass timber buildings respond to major seismic events being pioneered by the Natural Hazards Engineering Research Infrastructure (NHERI). The facility at UCSD was chosen because it is home to the largest outdoor shake table in the world and recent upgrades to the number of axes of shake it can produce now better simulate real-world seismic events. Additionally, the shake table will simulate numerous earthquakes of varying strength, ranging from magnitude 4 to magnitude 8 on the Richter scale, which is slightly stronger than the earthquake that devastated Turkey and Syria in February 2023.

Those involved with the project believe the tests could have major implications for the architectural, engineering, and construction industry, and may potentially lead to changes in building codes in areas with significant seismic activity. These changes could then encourage more investment in global manufacturing capacity for mass timber, thereby accelerating its adoption in large-scale residential and commercial buildings.

The principal investigator on the project Sheling Pei, P.E., Associate Professor in the Department of Civil and Environmental Engineering at the Colorado School of Mines, has been overseeing the testing at the UCSD facility and expressed optimism about the initiative. “This is the first time a building this tall has been tested on a shake table at full scale, and the test will validate mass timber as a seismically resilient building material for tall structures,” Dr. Pei said.

Investigators involved in the tests come from a wide range of institutions, including the Colorado School of Mines; the University of Washington; the University of Nevada, Reno; Colorado State University; Washington State University; and Lehigh University. Industry partners include Simpson Strong-Tie, Sumitomo Forestry, Boise Cascade, the United States Department of Agriculture (USDA), the USDA Forest Products Laboratory, and the U.S. Endowment for Forestry and Communities, among others. The majority of the mass timber that makes up TallWood was donated by Think Wood, its parent organization the SLB, BSLC, WoodWorks, and others. The construction and fabrication of the columns, beams, and the deck for the top four levels of the structure were built by Timberlab, an affiliate company of Swinerton. The building was designed by LEVER Architecture.

Once testing is complete at the facility at UCSD, researchers will then disassemble the top four floors of the structure and send the deconstructed wood to Oregon State University for further analysis. The findings on the construction and testing of TallWood will be published later this year.