| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a noise reduction mechanism capable of reducing noise in tunnel work. Ž<P>SOLUTION: A rectangular-shaped and a roll-screen shaped sound absorbing screen 3 formed with a sound absorbing material at a cross section of a tunnel 1 is hanged by a hanging member 5 from a tunnel ceiling 4. A gap 7 is formed between the tunnel ceiling 4 and the sound absorbing screen 3. A winding mechanism 6 is arranged at the lower edge part 5a of the hanging member 5. The sound absorbing screen 3 is spread and hung at the time of blasting work and the sound absorbing screen 3 is wound up by the winding mechanism 6 at work other than the blasting work. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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