Earthquake engineers at the California Institute of Technology recently used large motor-driven weights to shake the Santa Felicia Dam, an earth dam in the Santa Clara Valley. The infinitesimally small, controlled vibrations should help engineers learn more about the dam's response to earthquakes. Such results will then be helpful in developing better methods of testing dams for earthquake resistance and in designing more earthquake-resistant dams.
The Santa Felicia Dam, owned by the United Water Conservation District, was chosen for the experiment because the scientists already have data on how the dam behaved during two California earthquakes: the magnitude 6.5 San Fernando earthquake of 1971 and the magnitude 4.7 earthquake of 1976. ‘This dam is unique in that it was both subjected to strong shaking during these earthquakes and equipped with motion sensors that yielded data on how the dam responded to the shaking,’ Caltech's Ronald F. Scott said.