Soil/water interaction during the breaching process of overtopped embankments

摘要

When a flood exceeds the design level of an embankment dam, the dam will be overtopped and breaching can occur. Consequences are major flooding of the area beyond the dam, which can at least cause high economical damage. Residents, local governmental administrations and environmental agencies are highly interested in knowing the precise description of possible breach development and outflow hydrograph Q(t). Many publications and models are available on this topic and model outputs can vary up to ± 50% from the original data. This is due to a limited understanding of the processes involved in the breaching of embankments and the lack of fundamental experimental data. The research presented in this paper has the following aims: First, to generate a reliable data base by carrying out physical experiments (scaled 1:10) and measuring the outflow hydrograph and the erosion of the embankment material per time (erosion curve). Second, to improve the knowledge of the soil/water interactions in partly saturated soils, represented by the water tension in the breach slopes. And third, to provide a 3D elevation picture of a breaching geometry in homogeneous embankments.