Study on Mechanism of Load Transfer in Pile Raft Foundation

The growth of urban infrastructure has forced the introduction of tall buildings under any subsoil condition. Many a times, pile foundation becomes an absolute choice causing increased cost of construction. In such situations, pile raft foundation can be a convenient alternative, wherein the raft also contributes toward a part of the load transfer, and hence number of piles required can be reduced. This results in reducing the total foundation cost leading toward sustainable solution. Many tall towers across the globe have been built on pile raft foundations, and they are performing successfully. The present paper focuses on assessing the load transfer mechanism of pile raft foundation. For this purpose, PLAXIS-3D software is used. Pile raft foundation system is idealized as a continuum. The soil is modeled using Mohr–Coulomb criteria, and structural components of the foundation system are modeled as rigid, elastic, and concrete structures. The objective of the present paper is to identify the mechanism of load transfer and hence to arrive at the total load carrying capacity of the system. Here, an attempt is made to explain how the load is transferred to the soil from pile raft foundation system, and an attempt is also made to identify the conditions under which pile raft foundation becomes more appropriate.