Quake shake on 10-story tower at UCSD simulator will test the mettle of tall wood buildings

Engineers at UC San Diego’s outdoor earthquake simulator are about to finish building a 10-story wooden tower that will undergo fierce shaking to explore how well tall timber structures can handle quakes and other natural disasters.

This is the tallest building ever placed on the Scripps Ranch shake table, which just underwent a $16.3 million upgrade that will enable researchers from around the world to more realistically simulate temblors.

The new project is led by the Colorado School of Mines, which will subject the tower to shaking equivalent to the magnitude 6.7 Northridge earthquake that struck the San Fernando Valley in Los Angeles County in 1994, killing 60 people. The testing will begin in February.

The Northridge earthquake in 1994 caused heavy damage and 60 deaths.

(Associated Press)

The tower is composed mostly of cross-laminated timber along with steel, making it different from traditional tall buildings, which are mostly steel and concrete.

“We’re trying to see if we can construct mass timber buildings that would be resilient in high seismic zones,” said Shiling Pei, a mining school engineer and the project’s co-director.

In this case, resiliency refers to a building’s ability to survive strong shaking without structural damage.

As engineers note, wood has been used in building construction for thousands of years. But they say advances in design are making it possible to efficiently build strong, safe structures eight stories or more that are composed primarily of wood. The concept is being hotly pursued in part because wood is a sustainable material.

Earlier this year, construction was completed on Ascent, a 25-story mixed-use residential tower in Milwaukee that is primarily made of wood. It is the tallest structure of its kind in the world.

Unlike Southern California, Ascent is not in a highly active seismic zone. Engineers won’t know how resilient tall timber buildings truly are until they complete the sort of shaking experiment that will occur at Scripps Ranch.

Pei hopes things go well, saying: “A lot of [tall timber] construction is prefabricated in the factory. Everything is precisely cut. Everything fits. You can assemble it like IKEA furniture.” ◆