Load-sharing mechanism of non-displacement piled-raft foundation in sand

Abstract

Piled-raft foundations are recognised for sharing the total load by both the piles and the raft. The economic benefits of this system lead to its popularity in practice; however, research in this field has continued to lag behind owing to the difficulties associated with modelling and availability of field data. This is due to the fact that the load-sharing mechanism of the piled-raft foundation is a complex soil–structure interaction problem, which is governed by the pile/raft/geometry/soil condition and by their by-product parameters. This paper presents the results of an experimental investigation on a prototype model of a piled-raft foundation in sand. The effects of the governing parameters on the load-sharing mechanism are examined. The results of this investigation show that pile spacing and settlement govern the load-sharing mechanism between the piles and the raft. A widely accepted analytical model in the literature was modified in this study to take into account the effect of settlements and pile spacing on the load-sharing mechanism in a piled-raft system. The theory developed is validated by the current experimental results and those available in the literature. The design procedure is presented as a guide in the design of the piled-raft foundation in sand.