When the magnitude 7.1 Loma Prieta earthquake jarred the San Francisco Bay area late in the afternoon of Oct. 17, 1989, Ray Clough, seated in the study of his Berkeley home, felt his feet sway beneath him. He also felt confident that many of San Francisco’s tallest buildings would come through it just fine.
His confidence was on solid footing. One of the country’s foremost authorities on earthquake engineering, Clough helped design many of San Francisco’s tallest buildings, including the famous TransAmerica Tower. “Everyone thinks the tall buildings are more vulnerable but it is the small ones built on soft fill that are more likely to be damaged,” says Clough.
A 1942 graduate of the UW civil engineering program, the Seattle native experienced another big shock — albeit a pleasant one — about a year and a half ago — when he was presented with a National Medal of Science by President Clinton on Dec. 19, 1994.
Clough fell into earthquake research pretty much by default. After getting his degree from the UW, he served in the Air Force’s weather service when the Navy said his eyes weren’t good enough for its civil engineering corps. Once that was up, he went to MIT to study structural engineering. Just as he was finishing up at MIT, his thesis supervisor suggested that he go into earthquake engineering, at that time a brand new field. When he arrived at Berkeley for his first teaching job at the University of California, no one there was interested in the effects of earthquakes on structures.
“When they found out I was interested in the dynamics of buildings, I became the earthquake expert just like that,” he says.
Clough, who taught at Berkeley until his retirement in 1987 and who now lives in Sunriver, Ore., became a leader in the field of earthquake engineering. He was part of a National Science Foundation team of engineers sent to Los Angeles in 1971 to find out why so many freeway overpasses buckled and fell as a result of the 6.6 Sylmar quake.
He was very surprised — and critical — to see much of the same type of damage occur nearly a quarter of a century later when the 1994 Northridge quake devastated much of the Los Angeles area. “(The California Department of Transportation) was not interested in earthquake protection,” he says. “After the 1971 quake, they did nothing to protect structures. They built structures to code, but not anything appropriate for earthquakes. It was as if nothing was learned from 1971.”
But things were different in the Bay Area. Clough served as a consultant on the design of many high-rise buildings. His contribution was the development of a mathematical procedure to analyze the stresses on building frames. Once earthquake stresses were determined on a building design using Clough’s analysis, architects and engineers could them modify building materials or design to be able to withstand an earthquake.
“I was quite sure that those buildings we worked on would survive the quake,” says Clough. “To see that they made it was a good feeling.”