| 摘要 |
PURPOSE:To construct a large-diameter pile whose strong outer layer is covered with the periphery of an existing pile by a method in which a pile is driven into poured cement milk or mortar without being mixed with soil and ground water while preventing the degradation of the ground by an excavating casing. CONSTITUTION:An excavating casing 1 is penetrated into the ground, an air- ventilating valve attached to the rotary output portion 11a of a deiver is closed to air-tightly seal up the upper end of the casing 1, and excavation is made while sending cement mortar into the casing under pressure. Then, the rotary output portion 11a is removed, an extending casing is connected with the upper end of the casing 1, and cement mortar is injected into the casing under pressure, during which excavation is progressed to a support layer 13. While slightly pulling up the casing 1, a pile 18 is inserted into the casing, a C ring which is clamping split pieces 3 is removed to expand the split pieces 3, and the pile 18 is erected on the support layer 13. The upper end opening of the pile 18 is covered with a cover 17, the rotary output portion 11a is connected, cement mortar is poured into the aperture between the casing 1 and the pile 18, and the casing is drawn out. |
