Sustainable Foundation System for Alluvial Region

Abstract

A structure resting on soil having low bearing capacity and where differential settlement due to erratic nature of soil is expected, raft foundation is recommended to cope-up with mixed or poor ground condition and simultaneously to transfer heavy loads to ground while controlling the differential settlement. The essential task in the analysis of a raft foundation is the determination of the distribution of contact pressure underneath the raft which is a complex function of the rigidity of the superstructure, raft itself and supporting soil. The IS: 2950 (Part I)-1981 recommends the analysis based on the assumption of linear distribution of contact pressure. In this paper, an attempt has been made to design a raft foundation based on its geotechnical analysis. An extensive survey of research works devoted to study the geotechnical parameters affecting the behavior of raft foundation is carried out with detailed experiments raft foundations are increasingly being recognized as an economical and effective foundation system for high rise build-ings. This paper sets out some principles of design for such foundations, including design for the geotechnical ultimate limit state, the structural ultimate limit state, and the serviceability limit state. Attention will be focused on the improvement in the foundation performance due to the raft being in contact with, and embedded within, the soil.