IE33702B1 - Self-locking pile joint - Google Patents

Abstract

1294134 Composite pile LONDON MIDLAND & SCOTTISH CONTRACTORS Ltd 2 Feb 1970 [4 Feb 1969 22 May 1969] 6059/69 and 26064/69 Heading F2G A composite pile comprises two precast prestressed concrete piles 10, 11 joined by a bifurcated spigot 13 cast in one pile engaging a socket in the other pile. The socket is formed by a tube 2 embedded into the second pile and widened at the lower end, a wedge 17 being placed on an end closure 16 and serving to splay the ends of the spigot as the piles 10, 11 are brought together. Jointing material 12 (e.g. bituminously impregnated asbestos) is located between the piles 10, 11. The bifurcation in the spigot 13 may be a single axially extending diametral saw cut. Alternatively two diametral saw cuts at right-angles are used (Figs. 2 and 3 not shown), the ends of the cuts terminating in diametral holes to reduce the possibility of splitting the spigot when wedged apart. A metal plate 15 may back-up the spigot 13 or alternatively the surface of the spigot may be roughened to key with the concrete. The wedge may be installed on the closure plate 16 prior to making the joint, or may be loosely engaged in the bifurcation of spigot 13. The spigot may be hollow and need not be circular, and more than one spigot and socket may interconnect the piles 10, 11. A suitable material for the spigot, socket tube and closure is mild steel. [GB1294134A]