PURPOSE: To make driving work of a steel pipe pile efficient by estimating a drive stopping penetration amount of a friction pile, and establishing a drive stopping control method applicable to any of both bearing pile and friction pile.

CONSTITUTION: A penetration amount per one strike in a drive stopping point for a test pile is shown on the axis of abscissa, penetration resistance force against it is shown on the axis of ordinate, and the relation between the penetration amount and penetration resistance force in each striking time is linked with broken lines to draw a curved A to derive an estimated curve A in the case of drive stopping. After that, when time elapses from pile-drive stopping, the ground is recovered, bearing force is recovered, so that restriking measurement is made for one point B0 corresponding to A0 point to estimate recovery force, and B0 is derived. The same method is repeated to each point to remeasure, and a curve B is derived. According to the constitution, bearing force R1 necessary for a design can be derived.