Table 1: Potential for surfacing internal erosion in glacial moraine core embankment dams
Kenny & Lau 1 (1985, 1986)

1. Internally unstable if H/F 9 DB95 regardless of internal stability. Foster & Fell (2001) continuing erosion boundary. Re-grade core soil on the 4.75mm sieve.
3. Sherard and Dunnigan (1989) no erosion boundary (soil group 2 base soils).

Max filter D15 (mm) Unstable core / unstable filter Unstable core and stable filter or stable core and unstable filter Stable core / stable filter
≥ 1.4 2 High2 Increased Neutral
>0.7, <1.4 Increased Neutral Reduced
≤0.7 3 Neutral Reduced Low