GB256150A - Improvements in the construction of concrete piles - Google Patents

Abstract

256,150. Wolfsholz, A. March 16, 1926. Piles.-Concrete piles are made by forming a bore-hole having at intervals lateral extensions made by means of an earth-removing device, and filling in concrete under pressure. The extensions may be made by means of jets of fluid. Reinforcements may be provided in the extensions connected to the main reinforcements of the pile. The bore-hole is made by driving a tube 1, Fig. 1, and introducing a cutting-device comprising cutters 2 and levers 3. The tube 1 is raised slightly, and the cutters 2 are forced apart by the levers 3 while the whole device is rotated, producing an enlargement of the hole. The cutters being withdrawn and the loose soil removed, the tube 1 is driven deeper and a second enlarge. ment made, followed if desired by further enlargements. A single bladed cutting-device may be used, or a device consisting of a cone 8, Fig. 3, formed with grooves on its surface in which are mounted a number of chisels 9. A ram 10' slides on the rod supporting the cone 8 and drives the chisels downwardly and outwardly, so forming the enlargement. In forming the enlargements by jetting, a pipe provided with lateral openings is lowered and supplied with water under pressure. When complete, the bore-hole is filled with concrete under pressure. Reinforcing members may be introduced into the central hole, but preferably articulated members 15, 16, Fig. 6, adapted to enter the enlargements are used. These members are introduced into the tube 1, and pressure put upon the rods 15. When the tube is withdrawn, the rods 16 are forced outwardly into the enlargements. A central clamp 19 is preferably provided, and. the joints 17, 23 are such as to allow limited movement only. Piles of varying diameter such as shown in Fig. 7 may be made by driving one tube 24 and a second tube 25 of lesser diameter driven to a greater depth, both bore holes being formed with enlargements 26, 27. Two systems of reinforcing members are used.