Simplified Dynamic Analysis for Gravity Dams

The effect of monolith interaction on the overall dynamic response of concrete gravity dams is investigated. For this purpose, a simplified approach is proposed that is capable of including the effect of the longitudinal direction on the response of the critical monolith. The monoliths are represented by beam elements connected by shear links. The effect of hydrodynamic interaction is considered as added mass to the dam structure. The results of this innovative approach are compared to those of a typical threedimensional analysis and good accuracy is obtained. It is noted that the fundamental frequency of dams with keyed contraction joints increases when monolith interaction is included. The structure tends to be stiffer and, depending on the input ground motion, may have lower response values than those predicted using typical twodimensional analysis. The procedure developed in this study has its limitations but can include the longitudinal effects along the axis of the dam in the response analysis efficiently and fairly accurately.