UT Engineers Shake Up Earthquake Research in New Zealand

By Emma Ledford in 40 Acres, Research, Special on August 6, 2013 at 9:49 am | 1 Comment

You may have thought nothing could top the “Texas Longhorn” of dinosaurs. But what if we told you that one group of UT engineers gets to work with a 64,000-pound T-Rex?

Yes, you read that correctly. A research team from the Cockrell School is working in Christchurch, New Zealand to help the city rebuild in the aftermath of the Canterbury Earthquakes, six powerful quakes that hit the area between 2010-11. The “T-Rex”—a truck that simulates earthquake waves by shaking and pounding the earth in three different directions—was  the only known operating tri-axial vibroseis truck in the U.S. before it was transported to New Zealand. Its ferocious name is courtesy of team member Ken Stokoe, because the term “tri-axial” reminded Stokoe of the prehistoric beast.

“It’s a big shaking machine, and you want to have a cool name for it,” says Brady Cox, a civil engineering professor at UT. “We didn’t want to name it the Bunny Rabbit or something.”

The team’s research began in mid-June and is focused on preventing and repairing damage from liquefaction, a process by which soil loses strength and stiffness during earthquakes. Because the soils in Christchurch are soft, sandy, and saturated with water, the city is particularly susceptible to this process, Cox explains. Residential structures often have shallow foundations and are not engineered to the same standards as commercial buildings, so they are at high risk of damage from liquefaction.

“The liquefaction [from the Canterbury Earthquakes] was bad enough that the New Zealand government had to prevent 7,500 homeowners from rebuilding their homes,” he says.

By simulating an earthquake, the T-Rex provides the team with data that will inform them on how to improve the ground in existing homes and how to address the critical problem of rebuilding on land that remains at risk of liquefaction in future quakes.

“[The team is] investigating techniques that, if they prove successful, will have a huge impact on residential housing,” Cox says.

The first phase of research was completed in mid-July, and the second phase is tentatively scheduled for September. Information gathered in the project will not only impact the development of Christchurch, but could potentially help set building codes in earthquake-prone areas in the U.S. and abroad.

“A lot of people don’t consider The University of Texas a hotbed for earthquake research,” Cox says. “But the Cockrell School of Engineering is one of the top engineering schools in the country, for sure. The Department of Civil Engineering is one of the top-five programs, always, in the country. Even though we’re in Texas where we don’t have large earthquakes … we feel like we have a good program and we have some unique resources.”

Unique resources, indeed.

The T-Rex at the New Zealand test site. From left: UT graduate student Julia Roberts; the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) IT Manager Robert Kent; T-Rex operator Andrew Valentine; and UT graduate student Sungmoon Hwang. Photo courtesy Cockrell School of Engineering.

Tags: brady cox, canterbury earthquakes, christchurch, Cockrell School of Engineering, liquefaction, New Zealand, research, university of texas