Centrifuge modelling of small earth dams subjected to the combined effects of rainfall and earthquakes

Abstract

In this study, the combined effects of rainfall and earthquakes on earth dams were modelled using a 1/40 scale model embankment, spraying device, and shaking table. Two scenarios were tested: one where the embankment was subjected to seismic motion after rainfall, and another where the embankment was subjected to rainfall after seismic motion. When the rain occurred first, causing the phreatic line to rise, the excess pore-water pressure at the toe of the embankment was higher than if there had been no rainfall, and the seismic stability of the embankment deteriorated. When the shaking occurred first, cracks due to seismic motion promoted subsequent rainfall seepage, increasing the amount of eroded soil in the embankment. Thus, rainfall damage and seismic damage influence and exacerbate each other.