| 摘要 |
PROBLEM TO BE SOLVED: To provide a water bottom excavation system which enables replacement of excavation teeth without pulling up a riser pipe onto water and which can excavate a wide range of a water bottom, and a water bottom excavation method.SOLUTION: An excavation mechanism 5 comprises a drill pipe 6 and excavation teeth 7 that are installed at an end thereof. The excavation teeth 7 are contracted to a size small enough to be housed inside an inner peripheral surface of a riser pipe 4, and inserted from an upstream-side end of the riser pipe 4. The excavation teeth 7 are protruded from a water bottom-side end of the riser pipe 4, and expanded to the state of being at least partially extended to the outside with respect to an outer peripheral surface of the riser pipe 4. Subsequently, the water bottom 2 is excavated by the excavation teeth 7.SELECTED DRAWING: Figure 4 |
