The multi-column pile foundation which has been employed at the Ohnaruto-Bridge in the Honsyuu-Shikoku Bridge, was the first real structure in Ja pan that made use of the center column pile with 7 meters in diameter . By using of the case-study of the Ohnaruto-Bridge in this thesis, in order to establish the method of design, the model experiment on a large scale and it's theoretical study were excuted and this property has been proved.
