Experimental Study of Landslide Surge Wave Overtopping an Earth Dam

In this study, the experimental investigation on whether the landslide surge waves can influence the dam failure process caused by flood overtopping was presented. The experiments were conducted in a large width flume with length of 50 m, width of 4 m and height of 2 m. The time between the start of the earth dam break and the surge wave reaching the dam site was set to 80 s. During this period, the water depth of the reservoir constantly decreased. The experimental results showed that the surge wave height decreased while the propagation velocity increased slightly as the surge moved to the dam site. Several surge waves could overtop the dam crest and the shear height of the dam crest caused by each surge wave was a function of the surge wave height, which could be described non-dimensionally by Delta z* = 0.946H(s)*(2.113). The surge wave influenced the water level falling velocity and breach width expanding speed from the time of the overlay of the breaking dam. The surge wave could lead to a large instantaneous peak discharge that exceeded the dam failure peak discharge of the experiments with no surge wave.