Civil Engineering Reference
In-Depth Information
or
R
R
215
1 7
72
1 4
b k
;
s k
;
R
=
+
=
+
=
178
kN
c d
;
.
.
γ
γ
b
s
The design compressive resistance of the ground is thus determined:
R
=
min(
287 287 169 178
,
,
,
)
=
169
kN
c d
;
Example 10.5:
Maintained load tests (to EN1997-1:2004)
A structure is to be supported by a series of 9 bored piles, arranged symmetrically
beneath a pile cap. Each pile has diameter of 600 mm. The pile cap will carry a vertical
representative permanent load, P
G
of 10 MN (includes self-weight) and a vertical repre-
sentative transient load, P
Q
of 2800 kN applied with no eccentricity.
Results from two maintained load tests carried out on test piles are shown in Fig
10.9
.
Check compliance of the bearing resistance limit state by determining the over design
factor for:
a) Design Approach 1
b) Design Approach 2
Use the partial and correlation factors from EN1997-1:2004.
Solution:
From Table
10.2A:
ξ
=
1 30
.
;
ξ
=
1 20
.
1
2
The measured resistance R
c, m
is taken as the pile load recorded at a settlement equal
to 10% of the pile diameter (
=
60 mm).
R
=
2750
kN Test
(
1
),
R
=
2900
kN Test
(
2
)
c m
,
c m
;
Pile Load (MN)
0
0.5
1
1.5
2
2.5
3
3.5
4
0
20
Test 2
40
Test 1
60
80
100
Fig. 10.9
Maintained load test results.
