WORKING MEMBER FOR DEVICE OF SCREW BORED PILES Russian patent published in 2010 - IPC E02D5/56 

FIELD: construction.

SUBSTANCE: working member for device of screw bored piles consists of casing pipe, shoe with screw blade and a tip and is sunken in the soil by being screwed by applied torque moment and axial vertical force. Working member differs by the fact that a cone-shaped tip has sharpness angle of 90°, inclination angle of screw line of the blade is chosen as per the given formulas for ensuring rational values of force impacts from the submerging mechanism, there is tight demountable joint of casing pipes, shoe has the radius which is more than that of casing pipe, which is chosen from the given equation, owing to which soil pressure is relieved to casing pipe due to recovery of elastic soil deformation after introduction of the shoe. When the working member is submerged, the soil is expanded with a shoe to sides, thus being compacted. When design reference mark is reached, reinforcement cage is installed in casing pipe, and pile is concreted with simultaneous removal of the working member by unscrewing and rotating it in opposite direction; at that, the tip remains in the soil. By means of the above, soil is compacted once again, and cavities left with the shoe are filled with concrete.

EFFECT: considerable decrease of power consumption required for well erection process.

1 cl, 3 dwg