Civil Engineering Reference
In-Depth Information
Take moments about the toe of the wall:
4
__
Nx
P
H
3
W
(moment arms)
3
P
v
4
3
__
__
86.1
x
40.1
3
35.3
2
32.9 (2.8)
17.9 (3)
x
145
____
86.1
1.69 m
Maximum and minimum bearing pressures:
q
N
(
B
6
e
)
q
N
(
B
6
e
)
__________
__________
Eqs. (8.7
a
) and (8.7
b
)
B
2
B
2
Eccentricity
e
1.5
1.69
0.19 m
q
86.1 [3
6 (0.19)]
_________________
39.6 kPa
3
2
86.1 [3
6 (0.19)]
_________________
q
17.8 kPa
3
2
Factor of safety for sliding:
N
tan
P
p
___________
FS
Eq. (10.11)
P
H
where
N
W
P
v
86.1 kN/m
FS
86.1 tan 38°
4.07
_________________
40.1
1.78
Factor of safety for overturning:
Overturning moment
P
H
1
3
H
3
P
v
40.1 (
1
3
) (4)
17.9 (3)
0.23
Therefore
FS
Earthquake analysis:
To find
P
AE
:
a
max
____
g
0.20
