SETTLEMENT BEHAVIOUR OF PILED-RAFT FOUNDATION WITH NON-UNIFORM PILES IN SAND by Opinder Singh Ghuman
In civil engineering, foundation system is one of the most important aspect of the structure. Structures
are said to be safe and efficient which are having proper design of foundation system. Foundation system design also lead to the overall economy of the project. In foundations, piles and rafts are used individually in many respects. By combining the two systems, necessary values for design, required safety and more economical solutions are find by the foundation engineers. The piled raft foundation systemis a composite foundation systemwhich involves piles,raft and soil to transmit loads of superstructure to the ground. In the design of piled rafts, the load sharing between the piles and raft is taken. The PRF is an effective way of minimizing both total and differential settlements, improving the bearing capacity of a shallow foundation, and effectively reducing the internal stress levels and bending moments within a pile.By utilizing these type of foundations that share the contributions of both raft and piles in tall and heavy buildings, or otherwise when extraordinary loadings such as earthquake, wind and wave loads exist or more. When the condition of soft and loose subsoil is seen, piled raft foundations seem to be a quite reasonable implementation. In the present study, Plaxis 3d software is used for finding behaviour of piled raft foundation by varying pile parameters such as length and diameter. The material used is sand and concrete piles. To check the settlement behaviour of pile raft foundation on sand, different types of loads are appliedon the raft. It is observed from the software observations that the bearing capacity of the piled raft foundation is increased by using the piles of greater length and diameter installed at the periphery under the centre point load, piles of greater length and diameter installed under the eccentric point loading condition.