Geotechnical Engineering

DHARM

532 GEOTECHNICAL ENGINEERING

H=

4.5 m

Wall

AC 1 C 2 C C 3 C 4 C 5 C 6 (D)

B y= 70°

f= 32°

K

y-line

1

1 ¢

t

2 F

3

2 ¢ F¢

3 ¢

4 ¢

4

Repture plane

t^5 ¢

5

Culmann curve

6(6 )¢

t-t : tangent parallel to -linef

Fig. 13.68 Culmann’s method (Ex. 13.23)

Example 13.24: A retaining wall with its face inclined at 75° with horizontal is 10 m high and
retains soil inclined at a uniform surcharge angle of 10°. If the angle of internal friction of the
soil is 36°, wall friction angle 18°, unit weight of soil 15 kN/m^3 , and a line load of intensity 90
kN per metre run of the wall acts at a horizontal distance of 5 m from the crest, determine the
active thrust on the wall by Culmann’s method.

K

t¢

t¢

8 ¢

7 ¢

6 ¢

6

7

8

5 ¢

5

4

3

4 ¢

3 ¢

2

1 f= 36°

y= 57°

5m

A b10°

C 1 C^2

C 3

90 kN/m

C 4

C¢ C^5 C^6

C 7

C 8

Ground line

f-line

Modified

culmann line

Rupture line

Culmann line

without line load

F¢

10.35 m

10 m

Wall

a= 75°

B

Fig. 13.69 Culmann’s method for line load on backfill (Ex. 13.24)