Pile-forming method of immersed tube pile

The invention relates to a construction method for building pile foundation engineering, in particular to a pile forming method of an immersed tube pile, which is the preferred construction method of a multi-stage base large-bearing-capacity pile. The pile forming method of the immersed tube pile of the invention comprises the following process steps: a. the immersed tube with a metal pile head is sunk to a hard soil layer for designing elevation; b. the metal pile head is drawn out; c. a lower base space is formed, and fine earth is thoroughly taken out; d. flowing concrete is put into from an opening of the immersed tube to design an elevation L; e. the immersed tube is pulled upward to a set height H; f. an earth bucket is put into from an opening of a self-immersed tube, an upper base space is formed mechanically, and the earth bucket is lifted out; g. flowing concrete is used for casting the upper base; h. a precast pile body with dowels are put into and anchored with the base; and i. the immersed tube is pulled out, and concrete slurry is injected into the gap. The construction method can greatly enhance the precision, the quality, and the safety performance for the enlargement of the base.