2806
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
5 CONCLUSIONS
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Modulus Reduction, G/G
0
Mobilized Strength, q/q
max
= 1/FS
The upward and downward pile segments of an O-cell load test
can be conveniently represented by a versatile elastic continuum
solution. Results from seismic piezocone testing (SCPTu)
provide the necessary input data to evaluate axial side and base
resistances of the deep foundations, as well as the small-strain
stiffness (G
max
) needed for deformation analyses. Modulus
reduction is dependent upon mobilized capacity (P/P
ult
= 1/FS)
using a simple algorithm. A case study involving a two-level O-
cell arrangement for a large bored pile situated in the calcareous
Cooper marl formation of South Carolina was presented to
illustrate the application.
Algorithm: G/G
0
= 1 ‐ (q/q
max
)
g
Resonant Column,
Torsional Shear,
and Triaxial Data
g = 0.2 0.3 0.4 0.5 = exponent
ACKNOWLEDGMENTS
The writers thank Billy Camp of S&ME and the SCDOT for
providing access to the load test results.
REFERENCES
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Figure 5. Modulus reduction algorithm for monotonic static loading
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0
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0
10
20
30
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O-Cell Load, Q (MN)
Meas. Stage 1
Meas. Stage 2
Meas. Stage 3
Shaft diameter
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L = 16.3 m
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L = 14.0 m
1 m
1
2
3
Upper
O-Cell
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Casing
10 m
20 m
30 m
40 m
0 m
Depth
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s
profile, the
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nonlinear load-displacement-capacity behavior.
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are quite similar to those shown herein.
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