CIVIL ENGINEERING FORMULAS

358 CHAPTER TWELVE

CaseII. When I< 2U,

(12.213)

Figure 12.33 gives 10 formulas for seepage through the embankment of an
earth dam with an impervious foundation.

Slope Protection. The slopes of earth embankments must be protected against
erosion by wave action, rainwash, frost, and wind action. Protection cannot

Q

hk

2 U

I

 (^1) 
1  3

2

L

20.0

10.0

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.33-m-flat slopes

0.25-m-medium slopes

0.10-m-steep slopes

m

ht

d

ht

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

10 ° 20 ° 30 ° 40 ° 50 ° 60 ° 80 ° 100 °

Q = 0.90khtL

Q = 0.80khtL

Q = 0.70khtL

Q = 0.60khtL

Q = 0.50khtL

Q = 0.40khtL

Q = 0.30khtL

Q = 0.20khtL

Q = 0.10khtL

Q = 0.05khtL

d

α

α

FIGURE 12.33 Seepage through embankment on impervious foundation. (Davis—Handbook

of Hydraulics, McGraw-Hill.)