DAM-FOUNDATION ROCK INTERACTION EFFECTS IN EARTHQUAKE RESPONSE OF ARCH DAMS

The dynamic response of Morrow Point Dam to Taft ground motion is pres ented for a wide range of properties of the dam, foundation rock, impo unded water, and reservoir boundary materials. Based on these response results, the effects of dam-foundation rock interaction (considering damping, inertia, and flexibility of the foundation rock) with empty r eservoir are investigated. The significance of dam-foundation rock int eraction effects ignored in standard analyses that consider flexibilit y of the foundation rock but not its inertia or damping-material and r adiation-effects is then identified. Finally, the combined effects of dam-foundation rock interaction, dam-water interaction, and reservoir boundary absorption are studied.