Civil Engineering Reference
In-Depth Information
23,500 tan 30°
750
__________________
FS
23,000 cos 30°
0.72
Factor of safety for overturning:
Overturning moment
(
P
AE
cos
) (
1
3
H
)
(
P
AE
sin
) (7)
(23,000 cos 30°) (
1
3
) (20)
(23,000 sin 30°) (7)
52,300 ft
lb/ft
Moment of weights
55,500 ft
lb/ft
55,500
______
FS
52,300
1.06
Location of
N:
x
55,500
52,300
______________
23,500
0.14 ft
For the middle third of the retaining wall foundation,
x
2.33 to 4.67 ft. Therefore,
N
is
not within the middle third of the retaining wall foundation.
10.7
Static analysis:
P
Q
P
2
QHk
A
200 (20) (0.333)
1330 lb/ft at 10 ft
P
H
P
A
P
2
7330
1330
8660 lb/ft
N
33,600 lb/ft
Factor of safety for sliding:
FS
N
tan
P
p
___________
Eq. (10.11)
P
H
33,600 tan 23°
740
__________________
8660
1.73
Factor of safety for overturning:
20
___
Overturning moment
7330
3
1330 (10)
62,200
Moment of weight
235,000
235,000
_______
FS
62,200
3.78
