Pile Raft Foundations for Tall Buildings

Abstract

Piled raft foundations are increasingly being recognised as an economical and effective foundation system for tall buildings. 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. The advantages of using a piled raft will then be described with respect to two cases: a small pile group subjected to lateral loading, and then the design of the Incheon Tower in South Korea. Attention will be focused on the improvement in the foundation performance due to the raft being in contact with, and embedded within, the soil.