University at Buffalo - The State University of New York

Published: June 30, 2005

By MARY COCHRANE
Contributing Editor

When asked if he experienced any earthquakes while growing up in Los Angeles, Gilberto Mosqueda answers with surprising calm.

Gilberto Mosqueda, assistant professor of civil, structural and environmental engineering, specializes in hybrid simulation, which combines experimental and numerical capabilities to test more efficiently the effects of earthquakes on structures.
PHOTO: NANCY J. PARISI

"Yes, many," says one of the newest faculty member in the School of Engineering and Applied Sciences, who is an earthquake engineer. "The strongest one I felt was the one in 1987, the Whittier Narrows earthquake."

With a magnitude of 5.9, the Whittier earthquake occurred on a previously unknown fault some 12 miles east of downtown LA, killed eight people and caused $358 million in property damage.

Mosqueda also felt tremors from 65 miles away during the Northridge earthquake in January 1994, which had a magnitude of 6.7. He was an undergraduate at the University of California, Irvine, at the time.

The Northridge quake—which until 9/11 was considered the costliest disaster in U.S. history—took just 15 seconds to kill 51 people, injure more than 9,000, shut down 11 major roads, collapse nine bridges and cause $44 billion in damage.

But to Mosqueda, earthquakes were just one feature of California living.

"We would get a lot of small ones that left you wondering whether or not it was an earthquake," he says, smiling. "By the time you realized it was an earthquake and decided to run for cover, it was over."

In fact, Mosqueda makes it sound as if Buffalo winters are harder to bear for him and his wife, also a structural engineer, and their toddler daughter.

"The job is great, but it's a little tough getting used to the weather here," he says.

Despite having experienced earthquakes as a young man, the assistant professor of civil, structural and environmental engineering credits his undergraduate academic advisor, rather than the temblors themselves, as the reason he became an earthquake engineer.

"I knew I wanted to be an engineer and I opted for civil engineering," Mosqueda recalls. "But my advisor was an earthquake engineer. During my meetings with him, I would constantly ask him about how to get more involved in research and after bugging him for a year or so, he finally gave me an opportunity to work on a research project with him."

The project involved experimental testing of a roof isolation system to reduce the damage to buildings during earthquakes. Mosqueda's role on the project was to construct an experimental model of the roof system.

"I viewed the lab work more as a hobby, building models and seeing how much shaking they could take before being damaged," he says. "This experience got me interested in the field of earthquake engineering, and especially in experimental research."

Mosqueda feels he has landed on solid ground at UB, where the program in earthquake engineering "is one of the best in the nation."

"The primary reason I came to UB was because of the earthquake-engineering program. It's one of the best in the nation, and the labs here are among the most innovative in the world," Mosqueda says. "I thought it would be a great opportunity professionally to come to Buffalo and develop as a faculty member."

Mosqueda became interested in hybrid simulation, now his primary area of research, through graduate studies at the University of California, Berkeley. One of his graduate advisors there had helped to develop the hybrid simulation testing method several years earlier.

It also is a subject he is able to study more thoroughly here because UB received two major equipment grants from the National Science Foundation's (NSF) Network for Earthquake Engineering Simulation, or NEES, for researching shake-table experiments and hybrid simulation testing.

"UB was the only school in the country to get two of the 16 grants awarded to upgrade experimental facilities as part of NEES, which total just over $11 million," Mosqueda says. The grants were supplemented with an additional $10 million to build the new earthquake engineering research facility—the NSF's George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) Facility within UB's Department of Civil, Structural and Environmental Engineering—which opened last September.

Hybrid simulation combines experimental and numerical capabilities to test more efficiently the effects of earthquakes on structures. As part of his Ph.D. studies, Mosqueda examined the use of hybrid simulation to test large structural systems with multiple components of the system modeled experimentally in a geographically distributed network of laboratories. In fact, NEES adopted some of Mosqueda's graduate research findings to improve the speed and reliability of the testing approach.

"Hybrid simulation is a new way of combining both the best of numerical simulation and experimental testing to conduct a more realistic simulation of a bridge or other large structural systems during an earthquake," he explains. "We can conduct a numerical simulation and replace those elements which we are not sure how to model with a physical specimen in the laboratory.

"An earthquake might last, say, 30 seconds. When we do a simulation on the shake table, it lasts 30 seconds. But when we used a combined numerical and experimental method with specimens in different laboratories communicating through the Internet, it was taking a number of hours to complete one test. One of these tests was taking about five hours, so NEES researchers took some of the work that I was doing and integrated it with their system, and we got the test down to about a half-hour, which is still not a real-time test, but is substantially faster than what has been done before."

How did they shorten the test? It involved cutting down on the repetition of commands, changing the implementation of algorithms and adding predictors to keep the test moving along more quickly, Mosqueda says.

"I compared these tests to peer numerical simulations; they can have really high accuracy," he says.

The first in his family to go into engineering, Mosqueda is the fourth of six children whose parents were born in Mexico and later migrated to the U.S. Mosqueda's father made the trip alone as a teenager, while his mother came with her family.

Mosqueda always liked the subjects of math and science best, and took part in a mentoring program the summer prior to starting college. There, he met several civil engineers from the Los Angeles area and learned from them about what would become his chosen career.

And he already is applying the same positive attitude to living in Western New York as he does to living through earthquakes.

"The people here are a lot nicer than in California," he notes. "The driving is much better, the traffic is less congested. And we're actually able to afford a house here. The job has been worth the move."