Numerical and experimental research on road traffic noise propagation for various type of road structure and development of environmental noise prediction method

虽然道路交通是我们社会不可缺少的工业基础，但它也带来了严重的问题，如噪音或空气污染，它威胁着我们的生命。特别是在交通量巨大的东京及其郊区，这一问题更为严重，城市设计对噪声环境的准确预测方法提出了更高的要求。为了解决这一噪声问题，本研究通过数值分析和缩尺模型试验相结合的方法，对城市道路结构特殊部位的噪声传播机理进行了分析，取得了以下成果：[1]各种类型声屏障和路堤的声衰减效果研究近年来，在噪声问题严重的地区发展并采用了各种类型的声屏障。然而，噪声预测方法还没有得到充分的检验，其设计程序也没有建立到足够的…本研究对这类声屏障和路堤进行了数值分析和试验验证，获得了有效应用于噪声预测模型的基本定量数据和知识。[2]基于波动理论的数值方法的适用性基于波动理论的数值分析技术对于几何复杂地区的噪声环境预测是必不可少的。在这项研究中，定量地考察了二维数值分析对三维真实环境的适用性。[3]半地下道路环境噪声预测的声源模型为建立半地下道路噪声预测方法，提出了声源模型的新概念，并通过二维数值分析和三维模型实验验证了其适用性。此外，为了掌握半地下道路的噪声辐射特性，进行了现场测量。较少

Though the road traffic is indispensable to our society because it supports the industrial basis, it also causes the serious problems such as the noise or air pollution and it threats our life. Especially, in Tokyo and its suburban areas which have enormous traffic volume, the problem is more serious and precise prediction method of noise environment is strongly required for the urban design. In order to deal with such a noise problem, noise propagation mechanism in the special parts of road structures which is peculiar to urban areas have been analyzed by both of numerical analysis and scale model experiments in this research and the following outcomes have been obtained.[1] Study on sound attenuation effect of various type of noise barriers and embankmentRecently, various types of noise barriers have been developed and adopted on the areas where noise problem is serious. However, the noise prediction method has not been fully examined and its design procedure is not established enoug … More h. In this study, numerical analysis and experimental examination on such types of noise barriers and embankments were performed and the basic quantitative data and knowledge which are effectively applied for making the noise prediction model have been obtained.[2] Applicability of numerical method based on wave theoryNumerical analysis technique based on the wave theory is indispensable for predicting noise environments in the area with geometrical complex. In this research, the applicability of the 2-D numerical analysis to 3-D real environment are quantitatively examined. On the insertion loss of the noise barriers, quantitative difference between 2-D numerical analysis and 3-D experimental values for various sound source conditions have been clarified.[3] Sound source modeling for environmental noise prediction around semi-underground roadsIn order to establish noise prediction method for semi-underground roads, the new concept for sound source model have been proposed in this research and its applicability has been examined by 2-D numerical analysis and 3-D scale model experiments. Furthermore, in order to grasp the noise radiation characteristics from semi-under ground road, an in-situ measurement has been conducted. Less