| 摘要 |
PURPOSE:To exactly form a friction cut part by a method in which iron bars and a thin inner tube are erected in a casing set underground and then concrete is placed into the inner tube to construct the upper part of a pile. CONSTITUTION:After or while excavating a shaft A in the ground, a casing 1 is erected in the ground, and an iron bar cage 2 is inserted into the casing 1. Then, a inner tube 4 with a thin wall of a corrugated pipe, etc., whose tip part is wound with a strap packing 3 of an expanded synthetic resin, e.g., urethane form, is erected on the inside of the casing 1 and on the outside of the iron bar cage 2. Then, ready-mixed concrete 5 is placed into the shaft A until it reaches the bottom of the casing 1 and then the casing 1 is slightly pulled up in such a way as to prevent the extension of the concrete 5 to the outside of the inner tube 4. |
