Civil Engineering Reference
In-Depth Information
Safety Factor against Sliding (also discussed at length in Section 13.10)
Assuming soil above the footing toe has eroded and thus the passive pressure is due only to soil of a
depth equal to footing thickness,
C
p
wh
2
2
(3.0)(110)(1)
2
2
H
p
165 lb
Safety factor against sliding
(0.5)(10,228)
165
2637
2.00
1.50
OK
Distance of Resultant from Toe
Distance
36,484
10,548
10,228
2.54
2.33
Inside middle third
Soil Pressure under Heel and Toe
A
(1)(7.0)
7.0 ft
2
1
12
(1)(7)
3
28.58 ft
4
I
R
v
A
R
v
ec
(10,228)(3.50
2.54)(3.50)
28.58
10,228
7.0
f
toe
I
1461
1202
2663 psf
R
v
A
R
v
ec
I
f
heel
1461
1202
259 psf
13.8
EFFECT OF SURCHARGE
Should there be earth or other loads on the surface of the backfill, as shown in Figure 13.10,
the horizontal pressure applied to the wall will be increased. If the surcharge is uniform over
Figure 13.10
