20 Years Later, UCLA Researchers Lead the Charge in Seismic Studies
By UCLA Samueli Newsroom
Los Angeles might have a few faults — including the kind where earthquakes occur — but it also is home to some of the world’s leading earthquake researchers.
Six full-time faculty members in UCLA’s Civil and Environmental Engineering Department, along with dozens of postdoctoral and graduate students, adjunct professors and lecturers, are conducting studies that are helping us to better understand and better prepare for quakes.
UCLA researchers are gauging the vulnerability of Los Angeles structures constructed under the more lax building codes of the past, testing the earthen levees in the Sacramento–San Joaquin Delta that are crucial to California’s water delivery system, studying the sites of major quakes around the world and assessing how earthquakes and other environmental pressures are causing deterioration at L.A.’s iconic Watts Towers — work that could benefit preservation efforts on other landmark structures.
The seeds of many of those efforts were planted in the months following the Northridge earthquake, which was not only the largest natural disaster in the history of the U.S. at the time, but also the best documented earthquake. Scientists and engineers came away invaluable insights about seismic ground failure and the vulnerabilities of buildings, bridges, dams and other structures.
Jonathan P. Stewart, now the chair of UCLA’s civil and environmental engineering department, was a graduate student at UC Berkeley in 1994. After the quake, he led a team of nearly three dozen researchers who compiled a comprehensive report on its impact. The researchers worked from the ground up, and studied data from Santa Clarita to Long Beach.
Stewart, for example, painstakingly visited public utility offices in Simi Valley, Los Angeles and elsewhere to study maps and piece together a detailed picture of the patterns of utility pipelines disrupted by the quake. “There were no Google maps then,” he quipped recently.
Other members of the team compared the ground motion to the motion predicted by scientists in the years before the quake, while others conducted pioneering studies on the impact of ground movement on structures built on hillsides and landfill.
The study was the foundation of Stewart’s career, and he continues to research ground motion, soil-structure interaction and ground failure. He, Professor John Wallace and other UCLA researchers have visited the sites of major quakes in Italy, Greece, Japan, Chile and elsewhere, and they have helped craft industry and government standards for seismically safer structural design.
UCLA’s strength in earthquake studies predates even the Northridge disaster. The late Martin Duke, a UCLA professor who was one of the founders of earthquake engineering, conducted pioneering studies of the 1952 Kern County and 1971 San Fernando earthquakes. Duke identified various processes contributing to ground motion, and was one of the first to study the effects of ground shaking on distributed systems known as lifelines.
Now, 20 years after the Northridge quake, Stewart is committed to deepening and expanding UCLA’s earthquake expertise.
“Our resilience as a community ultimately increased as a result of Northridge and what engineers learned in its aftermath,” he said. “We at UCLA are committed to continue playing a vital role in understanding seismic risk, developing predictive models for the seismic response of infrastructure systems, and producing innovative mitigation measures in order to improve the safety of the public and the integrity of urban infrastructure.”