BORED PILE AND METHOD FOR PILE ERECTION IN KARST OR SOFT GROUND Russian patent published in 2006 - IPC E02D5/56 

FIELD: building, particularly pile foundation construction.

SUBSTANCE: pile is made as elongated body of revolution provided with tip in lower part thereof and with helix auger mounted on outer surface and extending for the full length of the body. The helix auger has constant cross-section, predetermined pitch and helix angle. Upper end of the body has tie members, which cooperate with torque transmission device to transmit torque to the pile and to apply axial load thereto. The auger is created as solid pipe wound about outer body surface or as solid pipe sections with inner diameters of 0.5-1.5 inches connected one to another. The solid pipe or pipe sections are perforated in lower part facing the tip to inject fixer under pressure through the perforations. Method for pile erection involves immersing pile provided with tip and helical auger in ground up to design level reaching by pile rotation along with bringing cut ground to day surface; supplying cement mix to pile foot area, wherein the cement mix is fed through perforation made in lower part of hollow helix auger winding facing the tip to fill karst cavities or ground hole surface consolidation over the full pile length.

EFFECT: increased strength of consolidated ground at hole surface.

2 cl, 1 dwg