GB1114935A - Improvements in or relating to piling - Google Patents

Abstract

1,114,935. Forming piles. B. GREEN 7 July, 1966 [7 July, 1965], No. 28751/65. Heading E1H. A precast concrete shell is inserted into a driven driving tube by supporting a first shell section 5 (Fig. 1), around a mandrel section 2 on a supporting unit 4 on the mandrel section, lowering the mandrel section with the shell section into the driving tube 1 until supported by a first cross pin 6 on the upper end of the driving tube, telescoping the nose of a second mandrel section 11 (Fig. 2) into the first and pinning them together above the cross pin, locating a further shell section 15 around the second mandrel section, supporting the mandrel sections from a second cross pin 10 in the second mandrel section above the second shell section, removing the first cross pin 6 and lowering the second shell section 15 on to the first 5 to be supported thereby lowering the two mandrel sections 11, 3 and supported shell sections 15, 5 until supported on the upper end of the driving tube by the second cross pin 10, repeating the cycle of operations to add mandrel and shell sections until the lower end of the first mandrel section 3 reaches a pile shoe 2 at the bottom of the driving tube, and the shell is of the required length, releasing the supporting unit 4 from the first mandrel section and then withdrawing the mandrel sections and the driving tube. The unit 4 may comprise a disc of concrete (Fig. 6, not shown) having a ring in its surface for engaging a hook pivotally mounted in the first mandrel section and spring loaded to disengage when the unit contacts the shoe 2. Concrete may be poured into the shell before or after withdrawing the driving tube, the upper part of the concrete being reinforced by reinforcements.