| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for multiplying the lifetime of a product by improving the factor of stagnant water and remaining moisture and removing causes of corrosion, because the sound absorbing plate of a current sound insulation wall is structurally formed so as to allow rainwater to be stagnant and corrosion of metal is progressed in the sound absorbing plate under the induction of electric corrosion or the influence of salt water which is a freezing prevention material for a winter season road.SOLUTION: A state in which water is stagnant inside the seam folded crown joint portion P of the base of a front sound absorbing plate 1A is removed by opening drain windows 5 having a predetermined size of length at equal intervals in the outside lowermost point portion of the crest of the seam folded crown joint portion P of the base of a front sound absorbing plate 1A of a sound insulation wall. Thereby, induction of rust, etc., corrosion, deterioration, and the like are suppressed as much as possible. |
