| 摘要 |
PURPOSE:To easily construct a pile having high strength quickly by a method in which an expanded portion is formed through rod, many projected blades are formed on the periphery of the rod, and nozzles through which a ground improving agent is jetted are provided to form an in-place pile. CONSTITUTION:A guide rod 24 is driven into the ground, and while applying vertically and horizontally rotational vibrations to the expanded portion 25 of the rod, the expanded portion 25 is penetrated into the ground. By using the blades 26 being irregularly vibrated with greater amplitudes toward the tip portion, soil and cement milk are well mixed together to form an in-place pile 32. After the formation of the pile 32, when the expanded portion 25 is pulled up, the application and vibration and the supply of cement milk are continued, and the penetrating actions of the expanded portion 25 are repeated plural times. The construction speed of the pile can thus be increased, the mixing of soil and ground improving agent can be improved, and sufficient strength can be given to the pile. |
