Development and Characterization of Soil Material Parameters for Embankment Breach

Despite the widespread use of earthen dams, the processes by which earthen embankments erode and fail when overtopped during extreme events are only imperfectly understood. Aging of these dams and the associated recent focus on dam rehabilitation has increased the need for new technology and tools for predicting the performance of earthen embankments during overtopping. Windows Dam Analysis Modules (WinDAM B) is a modular software application being developed to address this need for homogeneous earthen embankments. This software is being developed through joint efforts of the Agricultural Research Service, the Natural Resources Conservation Service, and Kansas State University. The computational model being incorporated into this software is the result of research including embankment overtopping tests conducted in the outdoor laboratory. The WinDAM B model is a simplified representation of the observed process of progressive erosion leading to embankment breach to be useful for field application the model has been developed to utilize soil parameters that may be reasonably obtained for the conditions to which the model is applied. This article presents the background for the material parameter input requirements for overtopping erosion and breach analysis including: 1) the detachment rate coefficient and critical stress parameters of the excess stress equation, 2) the total unit weight of soil, 3) the undrained shear strength, and 4) the headcut migration coefficient.