PURPOSE: In a process for driving a pile while softening earth by discharge of pressurized water at the bottom face of the pile, to facilitate the work by removably connecting a pliable feed water hose to the bottom end of the pile and driving the pile.

CONSTITUTION: A pliable feed water hose 1 is attached to a pile 2 and is connected to the bottom end of the pile 2 in such a manner that the hose 1 can be removed by the operation on the ground. While pressurized water is fed through the hose 1 and discharged at the bottom end of the pile 2 to soften the earth, the pile 2 together with the hose 1 is driven into the ground by a suitable means. After completion of the driving, water supply is stopped and the bottom end of the hose 1 is removed from the bottom end of the pile 2 by the operation on the ground, and only the hose 1 is recovered onto the ground.