A Parametric Study on the Interaction factors of Pile-Raft System
Keywords:
Interaction factors, Settlement, and finite element software.Abstract
Traditionally, the interaction factors including pile-soil-raft and pile-soil-pile in pile-raft system are
often ignored to simplify the analysis that leads to unsafe and inadequate designs. In addition, the pile-raft
system involves interaction with soil which makes it complex to analyze. The interaction depends on many
geometrical and strength factors: including, modulus of elasticity of soil (E), Poisson's ratio (ν),
spacing/diameter (s/d) ratio, length of piles, geometry of raft etc. To investigate the effect of these parameters
in the design of pile raft system, we proposed interaction charts for pile-raft system. A series of 3D finite
element analysis were performed and effect of parameters was studied. It has been found that there is a
possible interaction between pile, soil, and raft that has effect on the design of pile-raft system. From the
developed charts, the results clearly highlighted that the pile-soil-pile interaction decreases with increasing
s/d ratio, and soils with high modulus of elasticity are more sensitive to variation of interaction factors
between the piles of a pile-raft system. Furthermore, increasing the length of pile enhances the interaction
between pile and soil while increase s/d decreases the interaction factor. It is concluded from the parametric
study that the designers should consider the effect of interaction factors in the design of the pile-raft system.
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