Erodibility in centrifuge models of embankment overtopping

The mechanisms that take place at the instant of dam overtopping, leading to an eventual breaching and failure, depend on many factors – breach dimension, time, soil conditions, reservoir size and inflow, and overflow depth are some of the many variables which contribute to the severity of overtopping failures in embankments. Centrifuge tests can be used effectively for parameter studies in which material properties and behaviour depend on variations in boundary loads and conditions. To examine embankment overtopping, a series of six centrifuge tests were conducted and compared to large-scale, 1G testing conducted by the US Department of Agriculture Agricultural Research Services. An examination of the scaling laws associated with time was performed by comparing the width of headcut at the crest of the embankment between the two sets of data. After establishing a time-scaling factor, an analysis of cumulative volume loss and erodibility was conducted.