SCREW PILE Russian patent published in 2007 - IPC E02D5/56 

FIELD: construction, particularly to fixedly install different machines and mechanisms on ground surface, to drive ground-surface, underground and underwater tunnels, as well as underground passes and to construct load-bearing foundations.

SUBSTANCE: screw pile comprises metal pipe with metal helical threading formed on outer pipe surface. The helical threading extends for the full pipe length and made as helical blade with width equal to 0.5-15 pipe diameters. Threading in lower pile part occupying not less than 1/8 of pile length is of conical shape. Pile driving member is arranged in upper pipe part and facilitates pile driving. The pile driving member may be formed as metal head with hook fastening means formed in upper part thereof. Bolt is installed in lower part of pile driving member. Pipe interior is covered with corrosion-resistant material. Frost-resistant polymer coating of 1-30 mm thickness is applied on outer pile surface. Lower part of metal pipe may be sealed and tapers downwards. The frost-resistant polymer is polypropylene. Windows may be formed in upper metal pipe part. The pipe is closed from the top thereof and provided with helical ridge formed so that ridge turns are in register with that of helical threading formed on outer pipe surface. Upper pipe part may also have inner helical ridge welded to the head and having turns aligned with that of outer threading. The corrosion-resistant material is frost-resistant polymer.

EFFECT: increased structural load-bearing capacity, reliability and life time, improved pile installation ability and possibility to install the pile in densely built-up areas.

6 cl, 5 dwg