الملخص الإنجليزي
The objective of this experimental and numerical analysis research was to study the
response of reinforced concrete bored piles in layered soils with a soft clay layer under
axial and lateral loads. The first part of the study consisted of analysis of the full-scale
pile load tests. This is followed by development of a numerical model and was validated
using the results of the full-scale pile load tests. The full-scale pile load tests location was
at Duqm Integrated Power and Water Plant Project at Duqm City – Sultanate of Oman.
The site for the full scale consists of 3.0 m of sand overlying 4.50 m of soft clay that
extends to the bedrock. The groundwater table was about 1.4 m below the ground surface.
The full-scale tests were performed independently on two identical piles, one pile was
tested for axial loading and the other for lateral loading. The piles were reinforced
concrete bored piles with a 600 mm diameter and 16.0 m length. The test load for the
axially loaded pile axial was 2750 kN whereas it was 100 kN for the laterally loaded pile.
Two types of numerical models were developed in this research, one was axisymmetric
two-dimension model for the axially loaded pile. The second one was a threedimensional model for the laterally loaded pile and for the combined loading. The fullscale testes results showed the load-settlement curve for axially loaded pile, and the loadlateral deformation curve for the laterally loaded pile. The numerical model showed
perfect agreement with the results of the axial load test results and good agreement with
the results of the lateral load test.
The results show that the thickness of the soft clay significantly increases the settlement
of the axially loaded piles. On the other, the effect of the soft clay layer on the
deformations of the laterally loaded piles depends on the location of the soft clay layer
below the ground surface. The lateral deformations increase significantly with the
thickness of the soft clay layer, if the layer is within less than 3.0 m or 4 to 5 times the
diameter of the pile below the ground surface. However, the soft clay has no effect on
the pile lateral deformation of the pile if the clay is below 3 m (5 D) under the ground
surface. Moreover, choosing the wrong soil model could lead to wrong results even when
using the same soil parameters. It was found that the use of Modified Mohr-Coulomb
model for all layers was the most suitable model. Furthermore, the groundwater table
location affects the lateral deformation, while it had minimal effect on the pile settlement.
Additionally, combined loading leads to an increase of both the pile settlement and lateral
deformation. Finally, Increasing the slenderness ratio will increase both the pile
settlement and lateral deformation. The lateral load increased the pile settlement by 14%
while the axial load increased the pile lateral deformation by 9%
