PROBLEM TO BE SOLVED: To provide a tunnel blasting sound reduction device by which a blasting sound reduction effect can be surely obtained without degrading workability in a tunnel and without needing a power or the like separately.;SOLUTION: In designing a tunnel blasting sound reduction device, a target frequency of the blasting sound to be reduced by a sound absorbing body of the tunnel blasting sound reduction device is selected. Then, a dimension of the sound absorbing body is set. Moreover, rigidity of each face of the sound absorbing body is set. Furthermore, sound energy loss due to friction of an opening of the sound absorbing body, resonance of air inside the sound absorbing body, and effect of displacement of a wall surface of the sound absorbing body are expressed by applying an equivalent electric circuit theory, and an acoustic absorption coefficient of the sound absorbing body is estimated on the basis of the equivalent electric circuit theory. Then, when the acoustic absorption coefficient becomes a desired acoustic absorption coefficient or more with respect to the target frequency of the blasting sound, the sound absorbing body is formed by using the set rigidity as rigidity of the faces of the sound absorbing body.;COPYRIGHT: (C)2014,JPO&INPIT
展开▼
