El Infiernillo and La Villita earth dams in Mexico have been subjected to a number of earthquakes since their construction, but especially the Mexican earthquake of September 19, 1985. Measurements of strong-motion acceleration, crest displacements, and settlements were obtained during several of these earthquakes. This research program will utilize this information to verify numerical analysis techniques developed as a result of studies in the earthquake response of dams in the United States. In particular, the effects of successive earthquakes in changing the stress conitions, motion response, and performance of the foundation materials, will be examined.
