At the last decades, the design of piled raft foundation has been evolved in order to provide sufficient
bearing capacity and reduction in settlement. While, minimum number of piles should be used for economical
design. For this purpose, the concept of settlement reducer piles was presented. This system depend on using a few
number of pile for reducing the settlement of raft to an allowable value. When these piles are structurally connected
to the raft, a high axial stress develop in the pile heads. Therefore, the load-carrying capacity of these settlement
reducing piles may be governed by their structural capacity mere than by their geotechnical capacity. In order to
conquer problem of high stresses at connected point between piles and raft, unconnected piled raft foundation is a
new developed system. Where the piles and raft are separated by granular cushion. The granular cushion is used as
load redistribution between piles and soil in between. This system is a hybrid of shallow and deep foundation. In this
system pile isn't acting as a structural element, but as a soil reinforcement. In this study, finite element software
(plaxis 3D) was employed to investigate the effect of cushion properties (thickness and material properties) and raft
thickness on the distribution of load through piles lengths, raft settlement, and the portion of load carried by piles.
The results showed that, the maximum settlement of raft increases as cushion thickness increases or raft thickness
increases. While, it decreases as cushion density increase. Moreover, carried loads by piles decrease as cushion
thickness increases but, it decrease as cushion density increases. Raft thickness almost hasn’t significant effect on
redistribution of carried loads by piles.