Civil Engineering Reference
In-Depth Information
Total
resistance,
Q
Total
resistance,
Q
Point
resistance,
Q
p
Frictional
resistance,
Q
s
Point
resistance,
Q
p
Frictional
resistance,
Q
s
Q
=
Q
p
+
Q
s
Q
=
Q
p
+
Q
s
Movement of pile top in clay soil
Movement of pile top in sand soil
FIGURE 4.7
Typical load-movement characteristics of an axial loaded pile.
Sand
Clay
Pile displacement (
y
)
FIGURE 4.8
Example of a typical p-y curve for a 36-inch pile.
In sand, as presented in
Figure 4.7
, the ultimate capacity seems to increase
and reach a constant value. The point resistance in sand continues to increase
gradually. This is probably why a pile in sand does not usually reach a plunging
failure during a load test. The difference between pile behavior in sand and that
in clay is attributed to the different point and frictional resistances as a function
of pile movement.
The relation between the lateral resistance and displacement for a 36-inch-
diameter pile in clay and sand is shown in
Figure 4.8
.
Search WWH ::
Custom Search