Vibration tests of full-scale earth dam

Extensive full-scale dynamic tests, including ambient (unique in earth dam research) and forced vibration as well as popper tests were conducted on the Santa Felicia earth dam in Southern California. For the forced vibration tests, the dam was excited into resonance in both the upstream-downstream and longitudinal directions. During the ambient test, the naturally occurring vibrations of the dam were measured. The popper test involved the use of pressure waves originating from a controlled, submerged release of gas. During the tests, three-dimensional measurements of the motions of approximately 25 stations along the crest and seven stations on the downstream slope were recorded and then analyzed in both time and frequency domains. Modes of vibrations and associated natural frequencies as well as damping ratios were determined