PURPOSE: To increase bearing capacity of a pile by method in which a pile driven, and cement-based hardener is injected through an injection tube connected with a cloth cylinder near the foot of the pile through the hollow of the pile to form an expanded foot protection sphere.

CONSTITUTION: A cloth cylinder 6 is covered on the foot portion of a pile 2 and clamped with a band 7. An injection tube 3 through which a cement hardener is injected into the cylinder 6 is provided in the hollow of the pile 2, and its lower end 4 is fixed to the pile 2. The pile 2 is settled to a given depth, and soil cement mortar 8 is injected through the tube 3 into the cylinder 6 to form a soil cement spherical footing 9.