GB289495A - Improvements relating to the construction of concrete piles - Google Patents

Abstract

289,495. British Steel Piling Co., Ltd., and Hiley, A. Oct. 29, 1926. Piles.-In the construction of concrete piles according to the method described in Specification 197,430. a pilot pile is driven by means of a tube until a firm stratum is reached and plastic concrete is poured into the tube and deposited and tamped in the hole on top of the pilot pile by vibratory movements imparted to the tube by upward and downward strokes of the hammer. The pilot pile may be precast, but is preferably constructed in the ground by the same method and then, after setting, driven to the described depth by the empty tube. The pilot pile A,Fig. 4, is constructed in situ by vertical vibratory movements imparted to a tube filled with plastic concrete, as described in Specification 197,430. The top of the pilot pile is located at a short distance below the surface of the ground, reinforcing members being carried above the top to bond with the main pile. When the concrete is set, a steel band C is placed in position and filled with plastic concrete, and a steel driving rim D placed in position within the band C. A two-part mould E, Fig. 7, preferably of tapering form, is placed resting on the rim D and filled with concrete. Metal rods E<2> are inserted through holes in the mould E and remain in the head of the pile. When the concrete is set the mould is removed, and blocks of wood E<3> are secured to the head of the pile by means of the rods E<2>. The driving tube B fits loosely over the blocks E<3> and bears on the rim D. The pilot pile is driven by means of the tube B until a firm stratum is reached. Concrete is poured into the tube B, and the latter withdrawn while being given vertical vibratory movements to consolidate the concrete to form the main pile F, Fig. 3. A metal shoe A' is provided at the bottom of the pilot pile A. When a pre-cast pilot pile is used it is provided with the band C, the driving rim D and the blocks E<3> as before. The pile F and the pilot pile A may be driven deeper if required, and a third pile section constructed as before described above the pile F. In soft ground, the pilot pile may be deposited inside a casing surrounding the tube B which can be withdrawn freely within it.