Study on noise barrier shape for reducing Shinkansen noise using scale model experiment

Since Shinkansen viaducts are aging, a large-scale renovation project has been planned. In this project, aged noise barriers of various shapes are scheduled to be removed and replaced. After replacing the noise barriers, further noise reduction is required. Therefore, it is desirable to verify the relationship between shapes of noise barriers and noise reduction effects. Against this background, the scale model experiments were conducted in anechoic chamber, focusing on the heights, the edge shapes of noise barrier and the differences in the area where sound absorbing materials were applied to the noise barrier. In these experiments, noise levels outside a viaduct were evaluated when the conditions of the noise barrier were changed. As one of the results, it is shown that applying sound absorbing material as large an area as possible is effective in reducing noise, regardless of the differences of edge shapes. Based on the experiments, it is thought that noise barriers with simple shape for easy maintenance can be realized by effective use of sound absorbing materials for replacing the aged noise barriers.