Participating in a project to evaluate the performance of a 10-story building composed completely of wood during an earthquake simulation are researchers from the University of Washington. At the University of California, San Diego, the structure will be put to the test on a huge shaking table, with back-to-back shake testing starting at 10:30 a.m. Tuesday, PT. The structure is the tallest timber construction that has ever undergone such testing. Both the magnitude 6.7 Northridge earthquake in California in 1994 and the magnitude 7.7 Chi Chi earthquake in Taiwan in 1999 are intended to be simulated by the experiments. But this time, the scene is in Seattle's Capitol Hill district.

According to Professor Jeffrey Berman of the UW's Civil and Environmental Engineering department, "We chose the location in Capitol Hill and did exactly what you need to do when designing a 10-story mass timber building in the city." 

The researchers collaborated closely with a structural engineering business as well as an architecture firm. The building design was influenced by a site-specific hazard assessment that considered fault lines and soil characteristics.

The National Science Foundation is supporting the Natural Hazards Engineering Research Infrastructure (NHERI) Tall Wood project, which is a partnership between engineering companies and academic researchers.

 Lehigh University, University of Nevada, Reno, Colorado State University, Washington State University, University of California San Diego, Oregon State University, and the Colorado School of Mines are the other institutions that are part of the lead group. The University of Washington is also a member of this group. KPFF Consulting Engineers and LEVER Architecture are a couple of the regional business associates.

The research intends to open the way for mass timber, which is created by bonding layers of wood together, to be used more frequently in taller structures, especially in earthquake-prone areas. For instance, timber is a more sustainable resource than concrete, a popular building material whose manufacture contributes to around 8% of the world's carbon dioxide emissions.

The UW team also created a distinctive swinging wall system for the building, which is also constructed of wood. The lateral stability system stabilizes the building in the case of an earthquake and is often built out of more conventional materials like concrete or steel.

The rocking wall system is specifically created to rock back and forth during a seismic event, as opposed to preventing the building from moving. This makes it possible for the structure to quickly return to its original place with little damage.

An increasing number of earthquakes will be simulated during the month-long testing period. The Seattle Fault, which runs east-west through the center of the city and can withstand earthquakes up to a 7.4 magnitude, and the Cascadia Subduction Zone, which runs along the coast and can withstand earthquakes up to a magnitude 9, are the two main faults in Seattle.

More than 800 sensors were installed throughout the structure. UW researchers plan to use data to refine their computer models, which they hope will be utilized by industry to predict the performance of similar buildings. The researchers also hope their findings will inform building code requirements for timber structures.

Cross-laminated timber and mass plywood panels are the two main types of mass timber that the researchers are examining for performance.

A Seattle architect recommended employing a mass timber-and-steel hybrid construction method to repair the cracked and shuttered West Seattle Bridge when it was out of action a few years ago. There are other high-rise timber structures worldwide, while Portland's plans for one were previously postponed.

Mass timber should be used everywhere, according to Berman. This is serving as a demonstration and validation of this specific system and is targeted at greater seismic zones, mostly along the West Coast, but many of the building's design concepts are universal.