| 摘要 |
The apparatus includes two tools for forming holes in the subsoil without excavating it, which tools being coaxially mounted on a drill column. To the end of the drill column there is attached a hollow tool which is concealed when a skirt is in a lower position and exposed when the skirt is in an upper position. A soil displacing body is mounted on the drill column and above the tool. The soil displacing body is a hollow structure and has an upper opening wherethrough its inner space communicates with a concrete feeding tube and a lower opening closable by the skirt in its upper position. To construct a tubular pile the apparatus is driven into the subsoil whereby a design hole is formed, then the apparatus is withdrawn from the hole with a simultaneous filling of the hole with a concrete mix through the concrete feeding tube, the soil displacing body, and the lower opening provided therein. A ballasting material is concurrently fed through the drill column, out of the hollow tool, and into the space defined by the skirt, which, as the apparatus is being withdrawn, assumes a lower position to conceal the hollow tool and define a hollow in the concrete that has been laid in the tube. |
