Response of Earth Dams to Rayleigh Waves Using Coupled FE-BE Method

Abstract

The effects of Rayleigh waves on the response of earth dams are examined, with emphasis on the importance of the foundation flexibility and the spatial variability of the ground motion. The study is based on a rigorous hybrid numerical formulation that combines the efficiency and versatility of the finite-element (FE) method and the ability of the boundary element (BE) method to account for the radiation conditions. The two-dimensional (2D) formulation is used here in the frequency domain to investigate the response of infinitely long earth and rockfill dams subjected to Rayleigh waves traveling across the dam width. The study demonstrates the dramatic effect of the flexibility of the foundation rock in reducing the overall response of the dam. It also shows that the spatial variability of the vertical component of the ground motion caused by the Rayleigh waves induces additional rocking motion that contributes significantly to increasing the horizontal response, especially in the upper part of the dam body, while reducing the vertical vibration.