A Study On The Applicability Of Expressways' Noise Barriers

The construction of expressway leads to the fast development of regional economy yet causes noise pollution to the sensitive spots of citizens, school, and hospitals, etc. along the road. Noise barriers, occupying less space and lowering more noises, are much adopted. However, most of them are unreasonably designed. Abroad, comprehensive noise barriers design and lectotype regulations have been established, while in China, research on noise barriers is on the first step, to say nothing of the research on its applicability. So, it is necessary to have such research. This thesis, based on the research achievements abroad and at home and the experience of expressway environmental protection, has a close classification of noise barriers according to their forms, materials, structure and locations, through much investigation. It also has the samples to draw structural graphic of noise barriers, thus to provide valuable and practical date base. The thesis, based on the designing experience of noise barriers, provides the experts' evaluation criterion and methods and develops noise barriers evaluation system, thus makes their designing more normalized and scientific. , It also deduces the theory of noise barriers' diffraction loss, based on the formula of sound wave pressure and the theory of diffraction, getting the programmed formula of finite sound barriers and making it be compared with conventional calculation. Though there is only fine distinction between them, formula calculation is simpler and more exact, and it is turns out to be feasible through the experience of noise barriers along one side of He-Xu (Hefei to Xuzhou) Expressway. Last, the thesis has a project as sample, according to the work above, thus has significance to the noise barriers design of expressways in China.The thesis shows the acoustic design formula of noise barriers, thus sets up comprehensive evaluation system. It makes the geometrical figure and location of noise barriers through acoustic design, and chooses appropriate materials and structure of noise barriers through the evaluation system, so to make the expressway with such design more rational and applicable.