Acoustic Research On Special Sound Barriers For Unilateral High-Rise Buildings Along High-Speed Railways In Urban Area

Noise pollution has become a global problem. It is listed as one of the world’s three major sources of pollution, together with air pollution and water pollution. In the21st century, with the rapid development of China’s economic construction, transportation industry including railway, highway, etc. has entered a new stage. Today, a growing number of high-speed railways are inevitably have their routes chosen through cities in plan, which brings traffic noise and its serious interference to the residents along the railway route on both sides. Urban noise prevention and governing for high-speed rail segment are required to be stricter as the execution has become increasingly difficult.Construction of sound barriers is one of the important measures for the prevention of railway noise. In this thesis, the noise prevention methods adopted to a unilateral high-rise sensitive building in urban area in a new railway projects of Beijing Railway consulting firm are studied. Along the newly-constructed railway there is a sound environment prevention target just20m from the centerline of the outer side of the railway track, and the target is a high-rise building. As demolition can not be implemented, in order to achieve the requirements of the environment noise control, sensitive point here requires the use of special form of sound barriers to minimize the impact of rail noise. We found the shortcomings exposed in actual operations on this basis of a full range of research and site visits, as well as the mature experience gotten from existing high-speed rail projects of sound barrier along the railway. By review relevant documentation, they propose the design and improve plan of special sound barriers.According to the [2010] No.44letter from the ministry of railways."Guiding Opinions for Environmental Impact Evaluation of Strong Values and Governance Principles of Noise Vibration Source for Railway Construction Project (Revised)", model prediction method is used to predict equivalent sound level of railway noise. Ensure and input necessary parameters and datum, analyze the impact of each correction term related to formula on the railway noise attenuation and predict the equivalent sound level of railway noise before building a special sound barrier. Establish different forms of two-dimensional model of noise barrier to calculate sound attenuation of different forms of sound barrier under various shadowing conditions. By comparing the amount of sound attenuation, the noise reduction effect of different types of sound barriers can be gotten. In this way, the sound barrier forms in the boundary noise limits for railway boundaries can be ultimately determined. The adopted sound barrier structures—whole sealed structure and semi-enclosed structure made of sound absorbing materials—meet the requirement of cost saving and the reduction of conflicts between railway construction and overall urban planning, land use arrangement and environment protection planning by applying existing equipment and bridge beams type, so as to solve the problem of noise reduction on unilateral high-rise noise sensitive points of high-speed railway as well as to provide better choice for the set up of high-speed railway sound barrier in the future.