|Temple, Darrel - Retired ARS Employee|
Submitted to: The Journal of Dam Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2010
Publication Date: 7/1/2010
Citation: Temple, D.M., Hanson, G.J., Hunt, S.L. 2010. Observations on dam overtopping breach processes and prediction. The Journal of Dam Safety. 8(2):28-33.
Interpretive Summary: Processes resulting in breach failure of earthen embankments subjected to overtopping during flood conditions are complex. Therefore, the computational models used in prediction of this type of failure are simplified representations of the physical processes. Research conducted over approximately the past decade has improved our understanding of the physical processes and allowed improved computational models to be developed. These improved computational procedures are being incorporated into computer software that may be used in predicting embankment performance and breach characteristics. Correct application of the resulting software will result in improved predictions of earth embankment performance and breach, but will require users to develop an understanding of the processes and the parameters used to represent the embankment in the computational procedures (models). The new computational procedures are better representations of the complex physical processes involved, but still contain simplifications.
Technical Abstract: Research conducted over the last decade has led to an improved understanding of the physical processes associated with the response of an earthen embankment to overtopping flows. This research has demonstrated that vegetation and cohesive soil material properties play an important role in the erosion processes and rate of erosion during overtopping. The overall breach process has been observed to involve vegetation failure, surface detachment, headcut development and migration, and breach widening. Computational procedures based on the results of this research are being incorporated into new software tools for use in evaluating the safety of dams and levees subjected to overtopping during extreme flood events. Proper application of these tools and correct interpretation of the computational results requires that the user understand the concepts represented and the extent to which simplification of complex processes is required in development of the computational procedures.