Filling tube for producing a column of filling material in the ground as well as device and method related thereto

Filling tube for producing a column of filling material in the ground with a tube body, at the lower end of which pivotably linked closing flaps are arranged, which,

• on introduction of the filling tube into the ground, assume a closed position, in which the tube body is closed in the downward direction and the closing flaps form a penetrating tip, and,
• on withdrawal of the filling tube from the ground, assume an open position, wherein the tube body is open in the downward direction and filling material can be fed from the tube body into the ground in order to form the column of filling material,
• wherein
• the closing flaps have at least one support element, which is arranged in a central region at a lower end of the tube body,
• in the closed position the closing flaps rest against the support element,
• the support element is designed as a central shaft, which is vertically arranged and fixed via cross-braces on the tube body,
• the support element has at least one upper vertical end, which is tapered, and a curved lower end,
• the closing flaps are curved shell-shaped closing flaps,
• the curved shell-shaped closing flaps comprise a curvature in an axial view direction along the longitudinal filling tube axis,
• the curved shell-shaped closing flaps provide for an oval shape in a cross sectional view along the longitudinal axis of the filling tube in a closed position, and
• the support element is tapered in an upward direction.