Load Sharing mechanism of Piled-Raft-Foundations

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In practice, deep foundations are made of a set of piles connected together with a concrete raft. The role of the raft is to transfer the column load to the piles uniformly. It does not however share the building load with the piles. While engineers often design raft foundation alone to carry the entire building load. Accordingly the design of pile foundations is regarded as highly conservative, in fact uneconomical. The concept of Piled-Raft-Foundation has been increasingly receiving recognition around the world. While engineers recognize the contribution of the raft to the foundation loads, research in this field has been lagging to estimate the raft share. This is due to the fact that interaction among the piles/soil/raft is complex in nature and field testing is difficult at best. In the literature, several reports can be found dealing with the load-settlement relationship of piled-raft foundations. Nevertheless, these reports are based on limited modeling, and failed to recognize the effect of some vital governing parameters and the three-dimensional stressdeformation mechanism, which take place within the piled-raft foundation. In this proposal; experimental and numerical investigations on piles-raft foundation will be performed. A three-dimensional numerical model will be developed to simulate the case of piled-raft foundation and laboratory tests will be conducted on prototype experimental set-up. After validating the numerical model with the experimental results and the data available in the literature, the model will be used examine the parameters, believed to govern the performance of this foundation. The results of this study will have significant economic impact on the construction of piled-raft foundations for high-rise buildings without compromising on the safety. It is expecting that the design theories, guidelines and recommendations developed will be incorporated in the Canadian Foundation Engineering manual and American Society of Civil Engineers manual of practice. It is equally important to take note that this project will provide training to the Highly Qualified Personnel and scientists.