Hydrodynamic and foundation interaction effects in dynamics of intake towers

The dynamic response of Briones dam intake tower to Taft ground motion is presented for various cases: rigid and flexible foundation rock, with and without water. Study of these response results demonstrates that the earthquake response of this tower is increased because of hydrodynamic effects and decreased as a result of tower-foundation-soil interaction. It is also demonstrated that the earthquake response of this tower can be computed to a satisfactory degree of accuracy by considering the contributions of only the first two natural vibration modes. This observation provides a basis for developing a simplified analysis procedure suitable for practical application