Acoustic characteristics of tunnel-shaped noise barriers

This paper investigated acoustic modelling methods of tunnel-shaped noise barriers (soundproof tunnel). Sound fields characteristics of inside- and outside- soundproof tunnel are estimated using acoustic ray-tracing models. Several road configurations were employed according to bending degree and number of traffic lanes. Soundproof tunnel profile was modelled based on the existing wall-shaped noise barriers. As results, parametric evaluation of sound pressure level distribution inside and outside of the target road was made in accordance with length, height, sectional shape and materials of soundproof tunnel profiles. In addition, effective noise reduction methods are discussed based on the experimental results.