Seismic Response of Reservoir-Dam Systems

A numerical method is presented to model the transient response of a reservoir when subjected to vertical or horizontal boundary displacements. The procedure assumes the reservoir may be represented by a latticework of line elements and that motion in the continuum may be modeled by solving the one-dimensional transient flow equations in the elements. Thus the two-dimensional behavior is computed by motions in a combination of one-dimensional elements interconnected at nodes. A calibration of the latticework is made to assure accurate predictions of transient response. Comparisions with exact solutions of the two-dimensional hydrodynamic problem are presented for a step function input and for actual earthquake excitations. The temporal variation of hydrodynamic forces are computed on a vertical faced dam in both a confined reservoir and in a semi-infinite reservoir. The interaction between a flexible tapered concrete gravity dam and a confined reservoir is studied. A shear-beam onedimensional model of the dam is analyzed when loaded with the simultaneous hydrodynamic response of the reservoir.