An Experimental Study on Surge Overtopping Process of Earthen Embankments and Calculation of First Surge Wave Discharge

Abstract

The landslide-induced surge overtopping of embankments not only causes damage to the dam body but also poses a threat to downstream life and property. This paper explored the process of surge overtopping caused by landslides through model experiments, calculated the first surge wave overtopping discharge using empirical formulas, and evaluated the overtopping discharge at Vajont Dam in Italy. The study revealed that the first wave of landslide-induced surge carried higher energy than subsequent waves, and the surge waves action on the downslope of the embankment was non-uniform. The subsequent surge waves will cause localized "rills" on the dam body, and if there were enough subsequent surge waves, these "rills" may connect and ultimately lead to the failure of the embankment. The first surge wave overtopping discharge per unit width obtained in the experiments was 0.274 m²/s. According to geometric similar, the overtopping discharge of the Italian dam was as high as 682,830 m³/s.