Investigation of the hydrodynamic pressure induced by landslide-generated impulse waves on a dam using physical similarity model experiments and numerical simulations

The impact of landslide-generated impulse waves on dams releases substantial hydrodynamic pressures, posing severe threats to dam safety. In this study, physical similarity model experiments and numerical simulations are conducted to investigate the interaction between the impulse wave and dam. Based on the physical experiments, the variation of hydrodynamic pressures with runup heights of impulse waves, the variation at different horizontal directions and water depths is examined. The distributions of maximum hydrodynamic pressures, including positive hydrodynamic pressure (PHDP) and negative hydrodynamic pressure (NHDP), are studied. The influence of the runup height of impulse waves on the dam is analyzed. Using the discrete element method and smoothed particle hydrodynamics method, the influence of dam face inclination on hydrodynamic pressures is explored. The results show that the variation of hydrodynamic pressures is related to the impulse waves running up and the position of the dam surface. Below the positions where maximum hydrodynamic pressures occur, both PHDP and NHDP exhibit characteristics of initially decreasing rapidly, followed by a slower decrease. Furthermore, both PHDP and NHDP on the dam flanks are larger than those near the horizontal center of the dam. The runup height of the impulse wave has a positive influence on the maximum value of the hydrodynamic pressures, while the distribution characteristics remain almost unchanged. Based on the experimental results, empirical formulas for hydrodynamic pressures are established in both vertical and horizontal directions. Additionally, with decreasing dam face inclinations, the runup height of impulse waves, maximum PHDP, and rate of decrease in PHDP with water depth gradually increase. It is recommended to reinforce the dam surface in areas where hydrodynamic pressures are high, especially near the normal water level and on both flanks of the dam. This study contributes to enhancing the understanding of hydrodynamic pressures on dams under complex topographic conditions.