Author : AL-Qaissy, Mahmoud
Engineering and Technology Journal,
2013, Volume 31, Issue 20, Pages 288-408
Piled raft foundations are a geotechnical composite construction consisting of three elements: piles, raft and soil. In the design of piled rafts, the load is assumed to be shared between the piles and the raft. Therefore, this may improve the ultimate load capacity and reduce settlements in a very economic way as compared with the traditional foundation concepts. Due to the development of structures that use piled rafts as a foundation system, an extensive experimental study was performed by two different scale models with the same L/Dp (Embedment length to pile diameter ratio) and L/Br (Embedded length to raft width ratio Br) to achieve the scale effect and plane stress condition for the large scale model and plane strain condition for the small scale model. The load carrying capacity of the piles and raft have been studied and presented as load-settlement illustrations. From a comparison between the two models of the experimental work, it is found that the effect of scale cause an increase in carrying load of piled raft with increasing the number of piles. It was found that the percentage of the load carried by raft to the total applied load of the experimental model in the case of four piles with raft is ranged between 60.6 - 64.8 %.