Experiments in Expandable Tip Piling

Significant economic savings can be realized if pile design loads can be increased to those of which the pile itself is capable of sustaining as a structural column. In friction pile conditions or uplift conditions a system is described whereby pile capacities are increased by expanding the pile cross section by extruding steel plates from the pile body after the pile is driven. Results of a laboratory model test and reduced scale prototype test are given and compared with a theoretical preliminary design procedure. A design example illustrates potential economy. An examination of the scheme's adaptability to various pile sections already in commercial use throughout the world emphasizes the versatility of the system.