Method and apparatus for producing a support element in the ground

A method for producing a columnar support element in the ground, comprising the steps of:

• providing a cylindrical core tube having a longitudinal axis, a hollow interior space and an outlet opening, the core tube having an inclined wedge surface extending into the hollow interior space of the core tube and a cutting edge extending perpendicularly to the axis at a lower end of the wedge surface;
• sinking a hole through non-load bearing soil at least down to load bearing soil by rotating the core tube in a first direction and axially moving the cylindrical core tube so that the cutting edge cuts through non-load bearing soil;
• simultaneously displacing said non-load bearing soil radially outward into an area surrounding said hole by said inclined wedge surface;
• feeding support material into the hollow interior space of said cylindrical core tube;
• supporting an upwardly leading profiled support element through the outlet opening on the load bearing soil;
• retracting the cylindrical core tube from the hole so that the support material pours through said hollow interior space and through said outlet opening into said hole;
• and
• tamping said support material into said hole during axial movement of the cylindrical core tube out of said hole by means of said cutting edge.

A device for producing a columnar support element in the ground by producing a hole and filling it with support material, comprising:

• a circular cylindrical core tube having a tub core axis, a core tube jacket and a lower end face;
• an inclined wedge surface having a lower edge, the wedge surface being arranged on a chamfer at a free end of the core tube, the wedge surface extending inward into a jacket circle formed by the core tube so that the wedge surface occupies a portion of the cross-sectional area of the jacket circle, the lower edge of the wedge surface and the lower end face of the circular cylindrical core tube defining an outlet opening of the core tube, the wedge surface having, in axial projection, a radially directed free leading edge, the free leading edge extending from the core tube axis to the core tube jacket;
• a funnel-shaped enlargement formed by the wedge surface and merging into said core tube jacket;
• a cutting edge extending perpendicularly to the core tube axis and being arranged on the lower edge of the wedge surface, the cutting edge extending radially from a point on the core tube axis to the maximum outer circumference of the device.