Dam-break waves over an erodible embankment: experiments and simulations

ABSTRACT

The impact of a dam-break wave on an erodible embankment with a steep slope is studied in the paper using both experimental and numerical approaches. The laboratory experiments have been specifically designed and performed for a range of the storage water levels and the embankment elevations and slopes. The simulations were carried out using a recently-developed two-phase depth-integrated model, supplemented with a geofailure operator to account for the possible occurrence of geotechnical collapses. A comparison between numerical and experimental results indicates that the two-phase model reproduces the experimental free surface elevation well, with or without the geofailure operator. On the other hand, especially for high embankment slopes, this operator appears to be important for predicting the observed morphological evolution. The results also show that, due to the geotechnical collapses, water and sediment velocities may have opposite signs. While the models based on equal direction of the liquid and the solid motions cannot reproduce this effect, the proposed two-phase approach easily accounts for such a peculiarity of the investigated process.

Keywords:

• Bank failure
• dam-break
• embankments
• erodible bank
• two-phase depth-integrated model

ORCID

Cristiana Di Cristo http://orcid.org/0000-0001-6578-4502

Stefania Evangelista http://orcid.org/0000-0002-3848-6232

Massimo Greco http://orcid.org/0000-0002-3806-9797

Michele Iervolino http://orcid.org/0000-0001-8344-8334

Angelo Leopardi http://orcid.org/0000-0001-6314-0279

Andrea Vacca http://orcid.org/0000-0002-7170-2005