Interactional Erosion Process of Barriers Dams by Over-topping Flood

Rui Ma, Runze Miao, Deyu Zhong, Hongwu Zhang

Thursday 2 july 2015

17:48 - 17:51h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Morphodynamics of estuaries and coastal areas, Poster pitches

Parallel session: Poster pitches: 13A. Sediment - Coast

By laboratory flume tests of barrier dams, this article focuses on the erosion process and mechanism of dam breaking under the alternating action of hydraulic scour and gravitational erosion. The dam overtopping experiments under different conditions within a flume were conducted ,including four influential factors: the dam height, dam slope, storage capacity and dam material, to observe and analyze the dam-break flow, the amount of dam erosion, interactional mechanism of vertical incised scouring process, transverse broadening process and retrogressive erosion process. Four synchronized high-speed cameras were used to record the profiles of the dam body and the transient stages of the water surface. A conclusion is drawn as follows: the dam height, dam slope, storage capacity, and the amount of silver sand are positively related to the maximum peak discharge and are negative to the peak time; the four factors have collaborative influence on the erosion ability, erosion duration and washing range of the flow, and can further influence the erosion processes and erosion rates in three directions; the collapse of slope and ‘scarp’ retrocession can lead to periodic variation of the erosion volume of retrogressive process in the flushing process.