The Effects of Soil Erosion Characteristics on Critical Filter Design in Embankment Dams

The commonly accepted criteria available for a critical filter design are considered independent from soil erodibility and make no reference to soil erosion properties. This treatment investigates the interrelationship between core soil erosion resistance and critical filter substantiation. Erosion characteristics, namely, coefficient of soil erosion, critical shear stress, and erosion rate index, for 17 fine clay/silt core soils are determined via the hole erosion test. Also, the no-erosion boundary filter for each core soil is determined through no erosion filter testing. The results suggest that soils with higher erosion resistance permit coarser no-erosion boundary filters, i.e., higher D15b. Moreover, for soils with similar fines content or near d85 values, a lower erosion resistance would necessitate a smaller D15b/d85.