Abstract: Based on three aspects: (1) the great deal of data in field experimental study of piled raft or piled box foundations for 17 buildings at home and abroad; (2) calculated results using four methods: simple pratical method, semi-theoretical and semi-empirical method, FEM integrated with statistic method and theoretical method; (3) mechanism analysis taking the piled raft foundation with 20d 20d as a model, this paper synthetically demonstrates the resonableness for loading between pile and raft or box. Especially, the calculated results are satisfactory in agreement with the data obtained from 8 piled raft or box foundations for buildings. Finally, the available suggestions have also been proposed in detail for reference of drawing up a new item in foundation code.

Key words: field experiment, load-sharing between pile and raft, mechanism analysis