Bearing characteristics of model piled raft foundations supported by sheet piles

Recently, with the development of new piling methods, steel sheet piles can be penetrated into various types of ground with high quality and precision. Although pipe piles are used for piled raft foundations, sheet piles could become an alternative. Thus, the aim of this research study is to demonstrate the possibility of using sheet piles for piled raft foundations. In this study, a series of model tests was carried out first to investigate the load transfer behaviours of model piled raft foundations supported by three types of piles in an air-dried sand ground. Two of them were composed of sheet piles, called plate piles and box piles, respectively, and the other was composed of conventional pipe piles for comparison. Both vertical and horizontal load tests were carried out, and the load sharing between the raft and piles was carefully investigated. As the plate pile foundation (PPF) exhibited outstanding behaviours, numerical analyses were carried out using finite-element methods to investigate the foundation-soil interaction in PPFs. According to test and calculated results, a piled raft foundation supported by sheet piles would be a promising alternative to a conventional pipe pile foundation, especially in highly seismic areas.