Advanced analytical procedures to predict earthquake response of arch dams have been developed based on various assumptions that have not been verified experimentally. While these numerical models include the reservoir interaction and the water compressibility effects, they also are sensitive to reservoir geometry and the reservoir bottom reflection coefficient. A cooperative research project with Chinese researchers is proposed under this project to: a) investigate reservoir interaction effects on arch dams, b) conduct field measurements on a large arch dam in China, and c) make quantitative evaluation of analytical procedures by comparing the measured and calculated results. The reflection coefficient of the absorptive reservoir bottom and the actual topography of the reservoir, which are required as input in analytical predictions, are to be determined by field surveys. Measurements will be made to detect water compressibility and spatial variation of ground motion near the dam- foundation contact. This excitation technique is expected to produce larger hydrodynamic pressures and better information regarding the dynamic interaction between the dam and its foundation than has been obtained previously using eccentric-mass shakers. The measured dam response, foundation response, and the hydrodynamic pressures will be compared with analytical predictions using the best current mathematical procedures to validate the accuracy of the analytical techniques. The final product of the research program will be specific testing procedures to measure absorptive coefficient of the reservoir bottom, measured dam-foundation and reservoir response behavior, and the associated analytical predictions which will be useful for design purposes.
