This is a post Loma Prieta earthquake (Oct. 1989) investigation project in learning from this damaging event. This project is directed toward the evaluation of the performance, including interpretation and analysis of earthquake-response records, of the well-instrumented six earth dams which were shaken by the Loma Prieta, California earthquake (M=7.1) of October 17, 1989. The shaking during the main and after shocks triggered most of the accelerographs on the six dams (one of them is partially damaged) providing the most extensive array of earthquake response measurements yet obtained in the U.S. and abroad. The data obtained will be used to (1) study the effects of sequential earthquakes on the safety of earth dams, (2) correlate dynamic properties (shear modulus and damping) extracted from field performance during earthquakes, via system identification techniques, with existing laboratory-measured properties of the dam materials, (3) verify the adequacy of existing procedures for seismic analysis of earth dams by applying them to observational data and by comparing predicted results with measured responses, (4) disseminate research findings, and (5) document and improve capability to assess the safety of earth dams. The study will provide a comprehensive knowledge base for evaluation of seismic safety of earth dams.
