Prediction of the Maximum Wave Elevation in Moraine-Dammed Lakes during Resonant Earthquake Excitation

Large-amplitude water waves can be generated in small lakes, such as moraine-dammed lakes, by resonant earthquake excitation, which may cause the overtopping failure of natural dams and result in destructive floods in downstream areas. This paper experimentally investigated the behavior of seismically induced resonant water waves (SRWWs) with a large-scale shaking table and presented the nonlinear properties of the seismically induced water waves (i.e., second-order resonance and the participation of the second-order mode in the triggered wave motion). Moreover, the effects of several factors (i.e., peak ground acceleration of the seismic wave, resonant order, and water level) on SRWWs were studied. An equation for calculating the maximum wave height of SRWWs was proposed with these experimental data and then verified for a case study of a real earthquake. The proposed equation provides a guideline for estimating whether a moraine dam will be overtopped by SRWWs, and the results of the study broaden the knowledge of the risk assessment of moraine-dammed lakes in earthquake-prone areas. It is expected that the data presented in this study will contribute to the experimental database that can be used to verify numerical models.