| 摘要 |
PURPOSE:To effectively perform dredging work without being affected by tidal wave by a method in which a suction head is hung down from a device set on the surface of water, and soil and sand at the bottom under water are sucked up through the suction head. CONSTITUTION:A hanging device 2, e.g., crane, etc., is set on a structure 1 projected from the bottom to the surface of water, and the tip of the hanging device 2 is provided with a suction head by a rope, etc. Soil and sand 5 at the bottom under water are sucked up by the suction head 3 and delivered through a feed pipe 6 to a sand-flashing area 7 by means of a sand pump. On the other hand, a water jetting device 8 is set near the bottom to be dredged under water, and soil and sand 5a located far from the suction head 3 are delivered to the place near the suction head 3 by jetting water slantly downwards by the water jetting device 8. |
