Civil Engineering Reference
In-Depth Information
earth pressure resultant force
P
A
is inclined at an angle equal to
. Additional important
details concerning the active earth pressure follow.
1.
Sufficient movement:
There must be sufficient movement of the retaining wall in
order to develop the active earth pressure of the backfill. For dense granular soil, the
amount of wall translation to reach the active earth pressure state is usually very small (i.e.,
to reach active state, wall translation
height of wall).
2.
Triangular distribution:
As shown in Figs. 10.2 and 10.3, the active earth pressure
is a triangular distribution, and thus the active earth pressure resultant force
P
A
is located at
a distance equal to
1
0.0005
H,
where
H
3
H
above the base of the wall.
3.
Surcharge pressure:
If there is a uniform surcharge pressure
Q
acting upon the entire
ground surface behind the wall, then an additional horizontal pressure is exerted upon the retain-
ing wall equal to the product of
k
A
and
Q.
Thus the resultant force
P
2
, in kilonewtons per linear
FIGURE 10.2a
Gravity and semigravity retaining walls. (
Reproduced from NAVFAC DM-7.2, 1982.
)
FIGURE 10.2b
Cantilever and counterfort retaining walls. (
Reproduced from NAVFAC DM-7.2, 1982.
)
