| 摘要 |
PURPOSE:To improve the passage of sand by eliminating friction between sand and hollow tube by providing a means to form a fluid film to relieve the friction encountered when discharging sand in the lower part of the hollow tube of a sand pile former having a sand discharging and compacting part. CONSTITUTION:A hollow tube 1 is penetrated into soft ground by means of a penetrator 2, sand is charged into the tube 1 from a hopper 3, and the sand is discharged and compacted by vertically moving a sand discharging and compacting part 7 by driver 5. A fluid, e.g., water or compressed air, supplied by a fluid supply tube 11 is directed into a fluid chamber 9 provided to the outer tube 4 of the hollow tube and jetted toward the peripheral side of the sand 12 from many jet nozzles 10 to form a fluid film between the sand 12 and the outer tube 4. The friction between the sand to be discharged and the outer tube can thus be removed, and the passage of the sand can be improved. |
