Determination of ambient environmental noise levels for optimizing viaduct enclosure noise barrier by urban high-rise buildings and predicting maglev noise

摘要

Road viaducts passing high-rise buildings in a city are occasionally unavoidable. Enclosure is generally the preferred treatment for such noisy elevated roads. In order to optimize the acoustic design and cost-efficiency of such enclosures, it is necessary to evaluate the contribution of ambient noise from sources other than the researched viaduct. Typically, for Environmental Impact Assessment (EIA), ambient noise levels are determined by site measurements. However, in the situation of noise planning for noise sensitive receivers located in high-rise buildings, it may be difficult, expensive and even erroneous to carry out noise measurements on all floors. Alternatively, ambient environmental noise levels can be determined by prediction, referring for instance to the methods given in ISO 1996 and ANSI S12.9. Such predictions are carried for an existing road considering also the noise due to boats on a nearby river in China. The results from predictions compare well with measured data and are applied to the EIA study for a viaduct to be built nearby high-rise residential buildings. The method was also used for a magnetic levitation train line.