80 EMBANKMENT DAM ENGINEERING
Fig. 2.11 Idealized flownet for foundation seepage (Worked example
2.1 should also be referred to)
Fig. 2.12 Flownet for internal seepage in embankment core (Worked
example 2.2 should also be referred to)
2.6.2 Core and cut-off efficiency
The effectiveness of a core or cut-off may be empirically defined in terms
of two criteria (Telling, Menzies and Simons, 1978):
- head efficiency,
EHh/H (2.18)
wherehis the head loss across the core or cut-off and His the overall
differential head, as shown in Figs 2.9(b) and 2.11;
