Hydrodynamic pressure on concrete face rockfill dams subjected to earthquakes

Abstract

The hydrodynamic pressure is an important load on concrete face rockfill dams (CFRDs) subjected to earthquakes, the influence of which, however, is not clear as compared with that in concrete dams. In this paper, the coupling effect between the CFRDs and the reservoir water is studied based on two-dimensional finite element simulations by using a verified procedure. It is found that neglecting the solid-fluid coupling effect not only results in an overestimation of the acceleration response within the rockfill materials but also makes an overestimation of the dynamical stresses in the concrete slabs. For a reliable seismic response analysis of the CFRDs, therefore, the hydrodynamic pressure should be taken into account, particularly when the dam is subjected to a simultaneous excitation in both horizontal and vertical directions. Numerical results show, however, that the compressibility of the water can be safely neglected in the seismic response analyses of the CFRDs even when the dam is as high as 300 m, except when the excitation is quite abundant in high frequency contents.