高速鉄道の車両床下騒音を用いた沿線騒音予測に関する検討

抄録

In order to reduce the wayside noise of a high-speed railway, it is important to understand the contribution of each noise source to the total noise level at each observation point. The noise generated from the lower part of cars, which mainly consists of aerodynamic noise and rolling noise, is one of dominant noise sources. Rolling noise varies with the surface roughness of wheel and rail and track conditions and so on. This paper attempts to quantitatively estimate the contribution of lower part noise to wayside noise by using the sound pressure measured close to bogies under the floor of a high-speed train (referred as under-floor noise). First, the relationship between under-floor noise and noise close to rail on the ground (referred as rail side noise) is evaluated. Secondly, by using both the above relationship and under-floor noise when a train runs on prediction section of wayside noise, the acoustic power level of lower part noise that is applied to an existing wayside noise prediction method is identified. As a result, the estimated level of wayside noise was approximately consistent with the measured result.