Prediction and Mitigation of Noise from Shinkansen Tunnel Portals

Abstract

Noise levels measured at points near Shinkansen tunnel portals include both the ordinary wayside noise and that radiating from tunnel portals, making them generally higher than elsewhere. To effectively reduce the noise levels at such locations, therefore, it is necessary to understand the contributions of both noise components. This paper describes a model used to predict the noise from a road traffic tunnel portal and applies it to Shinkansen noise. It has been confirmed that the model would be valid for predicting Shinkansen noise, if some modifications were made. Furthermore, higher sound barriers near a tunnel portal and the installation of sound-absorbing materials on tunnel inner walls are proposed as countermeasures and their effects are estimated on the basis of the modified prediction model.