describes the results of axial loading tests on a group of
five driven piles in medium dense sand at a site located in San
The piles were tubular steel pipes with Young’s modulus of 160GPa,
external diameter 273mm, wall thickness 9.3mm, driven to a depth
of 9.15m through a 300mm diameter hole predrilled to a depth
of 1.4m. The piles
were arranged in the configuration shown in the inset to the
graph to the right, and connected by a rigid cap with a clearance
of 0.6m from the ground level.
The soil profile consists of medium dense sand, overlain by 1.4m of sandy
gravel and underlain by bedrock at a depth of 14.3m below ground
level. The water table is 2.4m deep.
A non-linear soil model has been adopted within Repute. The assumed soil
parameters are based on a subsoil idealisation with two layers resting
on a rigid base, as shown on the diagram to the left. Considering that
the predrilled hole disconnects the piles from the top 1.4m of gravelly
soil, the ground level (GL*) used within Repute is taken at 1.4m below
the actual ground level (GL). Thus, the embedded length of piles will
be taken as 7.75m, and the free-standing length as 2m (i.e. 1.4 + 0.6m).
Results from Repute
The results from Repute are given
in the graph below.
Comparison with benchmark
The computed and measured
load-settlement curves are reported in the graph below and show a good agreement.
Further details on this comparison may be found in .
 Briaud, J. L.,
Tucker, L. M. & Ng, E. (1989). Axially loaded 5 pile group and
single pile in sand. Proc. 12th Int. Conf. Soil Mech. Fdn Engng,
Janeiro 2, 1121-1124.
 Basile, F. (2003). Analysis and design
of pile groups. In Numerical Analysis and Modelling in Geomechanics,
E & FN Spon (eds J. W. Bull), Chapter 10, in press.
project for this example