709
Technical Committee 103 /
Comité technique 103
(a) for H/L= 0.5
0
1
2
3
4
5
6
7
8
9
10
-6
-4
-2
0
2
4
Pile Depth (m)
BendingMoment (kN. m)
X= 8 m
X = 2 m
X= 4 m
(b) for H/L = 0.4
Figure 3 Bending moment distribution along pile shaft (d = 600 mm,
E
wall
I
wall
= 6.10 x10
4
kN.m
2
)
2.2
Effect of wall-stiffness
Variation of pile head lateral deflection and maximum bending
moment with wall stiffness are shown in Figures 4 and 5;
respectively. From these figures, it is apparent that wall stiffness
has an insignificant effect on both pile head deflection and
maximum bending moment for H/L < 0.30. Specifically, the
percent decrease in pile head deflection ranged from 1.7% to
5.2% with increase in wall stiffness; while the percent decrease
in maximum bending moment ranged from 1.5% to 7.8% with
increase in wall stiffness. For H/L greater than 0.3, the wall
stiffness seem to have a more markable effect with percent
decrease in pile head deflection ranging from 12.5% to 20% and
percent decrease in maximum bending moment ranging
between 25% and 62% with increase in wall stiffness. It should
be noted that Figure 4 show reversal in bending moment sign
(from negative to positive) indicating reversal in the location of
maximum moment due to excessive deflection underwent by the
pile as H/L approaches 0.5.
0
1
2
3
4
5
6
7
8
0
5
10
15
20
Pile head lateral deflection (mm)
Wall Stiffness (EI x 10
4
, KN.m
2
)
H/L = 0.1
H/L = 0.2
H/L = 0.3
H/L = 0.4
H/L = 0.5
Figure 4. Effect of wall stiffness on pile head lateral deflection (d=600
mm)
-10
-5
0
5
10
15
20
0
5
10
15
20
Max. BendingMoment (kN.m)
Wall Stiffness (EIx10
4
,KN.m
2
)
H/L = 0.1
H/L = 0.2
H/L = 0.3
H/L = 0.4
H/L = 0.5
Figure 5. Effect of wall stiffness on maximum the bending moment (d=
600 mm)
2.3
Effect of excavation depth and pile distance from the wall
The effect of excavation depth (expressed as H/L) and distance
of pile from wall (X) on the lateral deformation and maximum
bending moment of pile due to excavation induced movements
are illustrated in a combined plot shown in Figure 6. With
respect to the pile lateral deflection, it is observed that H/L has a
significant effect on lateral deflection. The maximum increase
in pile head lateral deflection ranged between 6% and 11.3% as
H/L increases to 0.5. It can be further inferred from Figure 6
that the pile head deflection is highly sensitive to X for H/L >
0.30. In particular, the percentage decrease in pile head lateral
deformation was observed to range between 14% and 60% with
increase in X for H/L > 0.30.
On the other hand, it is apparent from figure 6 that H/L has a
small effect on the maximum bending moment in the pile with
