Improvement of design method for pile raft foundation and its economical significance

The advantage of a new method for pile raft foundation design——Sparse Outside Dense Inside(SODI) and its tremendous economic value are systematically discussed in this paper.With this new method,almost all of the internal secondary forces of super structure can be eliminated,the internal force of raft cut down to the minimum,numbers of piles reduced,and length or diameter of piles decreased.In this way,cost of foundation is lowered and funds for construction is saved.