This project is part of the NSF/USGS initiative within the National Earthquake Hazard Reduction Program (NEHRP) to investigate the effects of the Loma Prieta earthquake of 17 October 1989. Over 100 earth dams were located within a distance of approximately 100 km from the source of this earthquake. The aim of this project is to evaluate in detail two earth dams that were significantly instrumented and in which the instruments were triggered during the earthquake. In addition, and to the extent available, the recordings from other dams, together with other information about these dams, are also being collected and will be made available in a single document that can be utilized by other users. The two dams are the San Justo Dam, 150 ft high, and the San Luis Dam, which is 300 ft high. These dams are respectively about 40 km and 80 km from the zone of energy release. Soil and geologic data are available for both dams. Detailed one- and two-dimensional analyses are being conducted in order to assess the dynamic shear-strain characteristics of the material comprising each dam-foundation system and to examine the adequacy of various available analytical procedures for calculating the response of earth dams during earthquakes. This is the first time that such detailed analyses can be conducted with measured earthquake response records at several locations of an earth dam.
