Geotechnical Engineering

DHARM

SEEPAGE AND FLOW NETS 171

H

Dam

Impervious blanket Filter

Impervious

Fig. 6.7 Concrete dam with impervious blanket on the upstream side

and filter on the downstream side

Top flow line

Impervious

Top flow line

Impervious

Pervious blanket

Top flow line

Impervious

Chimney

drain Drain pipe

Top flow line

Impervious

Rock toe

(d) Homogeneous dam with rock toe on the downstream side

(c) Homogeneous dam with chimney drain

(b) Homogeneous dam with underdrain on pervious blanket

(a) Homogeneous dam without internal drain

Fig. 6.8 Top flow line for typical cases of homogeneous earth dams on impervious

foundation with different internal drainage arrangements