| 摘要 |
PROBLEM TO BE SOLVED: To remove noises caused by air leakage from an airlock device in the construction of a caisson and release operators from unpleasant noises and make possible works in an urban area adjacent to folk dwellings or works at night. SOLUTION: The sound absorbent structure is provided with a pair of hatch members 4, 4 opening/closing the upper hatch opening 3 of the airlock device A and a pair of half bodies 5, 5 forming a pressure reducing chamber 7. The pressure-reducing chamber 7 reducing the air in the airlock device A is constituted by making them adjacent at the upward and lowerward sides by a pair of half bodies forming the pressure-reducing chamber in the state that the hatch members 4, 4 are closed. Further, a wire insertion holes 12 are formed in the connection part 10 of the hatch members 4, 4 and the connection parts 11 of the pair of half bodies 5, 5 forming the respective pressure-reducing chamber provided at the hatch members 4, 4, and the air in the airlock device A can be reduced in the pressure.
|
