Abstract: By using software Cadna / A the distribution patterns of sound field in vertical plane of  traffic noise for elevated complex road in different road conditions are analyzed. Owing to changing of the distribution pattern of sound field in vertical plane by viaduct it is in need to analyze the effects of viaduct in different road conditions. A large amount of noise barriers had been built on viaduct in China with not definite value of noise reduction. In this paper the noise reductions of barriers in different road conditions were calculated and analyzed. The results help to make right decision for building viaduct noise barriers effectively according to different road conditions.

Key words: acoustics , elevated complex road , traffic noise , vertical sound field , viaduct noise barriers , noise reduction effect

摘要： 采用Cadna/A 软件研究高架复合路在不同路况条件下交通噪声垂直面声场的分布规律和建设高架路声屏障的降噪规律。高架桥使高架复合道路垂直面声场发生较大变化，由此需要研究高架桥对不同路况交通噪声垂直面声场分布的影响规律。国内在高架路上建设大量声屏障，但在很多情况下，这种声屏障的降噪效果并不理想。为了研究产生这种现象的原因，计算并分析不同路况下建设高架路声屏障的降噪效果，提出可以根据不同路况来决定是否应建造声屏障，以避免建造无效声屏障造成的浪费。

关键词: 声学, 高架复合道路, 交通噪声, 垂直面声场, 高架路声屏障, 降噪效果