METHOD OF BUILDING SYNTHESIZED PILE

PURPOSE:To form a synthesized pile, which has uniform quality and high support force, by means of a small amount of an improving agent, by a method wherein a powdered granular improving agent is injected in a soft ground, and an existing pile is driven in an improved pillar body formed by agitating and mixing the improving agent and earth. CONSTITUTION:As a hollow agitating shaft 3 is rotated, a soft ground A is excavated down to a given depth by means of agitating blades 12 and 13. With the agitating blade 3 rotated, a powdered granular ground improving agent is conveyed through the agitating shaft 3, and as the improving agent is injected to agitate and mix the improving agent with original position earth B, the agitating shaft 3 is pulled off to form an improved pillar body C. Before the pillar body C is cured, an existing pile D is driven in the pillar body C to form a synthesized pile.