Earthquake-induced hydrodynamic pressures on a 3D rigid dam-reservoir system using DRBEM and a radiation matrix

The dual reciprocity method is applied to determine the hydrodynamic pressure distribution in a three-dimensional dam-reservoir system subjected to earthquake excitation. The reservoir domain is idealized as a finite region of irregular geometry adjacent to the dam followed by an infinite domain of uniform cross-section in the upstream direction. The reservoir hydrodynamic pressure response is governed by the Helmholtz equation subject to free surface, dam-reservoir interface, absorbing bottom/banks and radiation boundary conditions. A three-dimensional (3D) dual reciprocity model is developed to determine the hydrodynamic pressure in the finite reservoir domain. A radiation matrix is developed and introduced to relate the hydrodynamic pressure and its normal derivative on the interface between the finite and infinite domains. The three-dimensional radiation model used is developed by applying a two-dimensional dual reciprocity formulation along the interface of the finite and infinite reservoirs together with a continuum solution in the upstream direction of the infinite domain. The model is compared for the hydrodynamic response of a three-dimensional rectangular reservoir and found to be in excellent agreement with results obtained from a model based on the analytical formulation existing in the literature.