Abstract
For the mitigation of noise accompanied by passages of the ultra-high-speed trains running at 500 km/h, a hood of a concrete segment frame structure was developed and installed on the Yamanashi test line. Through the on-site measurements, it was found that the effect of structure-borne noise generated by vibrations of the hood in the event of the train passages was not negligible and therefore its reduction was considered to be essential. In this paper the effect was carefully investigated by analyzing the measured data and by simulating with mathematical models, and a hood structure with a greater noise mitigation performance was proposed. A hood with the new structure was produced accordingly whose effectiveness was then demonstrated through laboratory tests and on-site measurements under the passages of the ultrahigh-speed trains. Also a method to estimate the noise level taking into account the structure-borne noise is also worked out and proposed. The estimation with the proposed method showed a fair agreement with the field measurement data, and therefore, the method is expected to serve as a useful tool to provide reasonable noise level estimation for a hood section in the future.
