Optimization Research On Road Noise Barriers

With the rapidly development of road traffic, the pollution of traffic noise has become more and more severe, that have been disturbed the residents along the road. Noise barrier is one of the economical and effective engineering measures in preventing traffic noise pollution. So the optimization of noise barriers as to promote the performance, to improve the acoustical environment, has important practical significance in terms of advancing the coordinated and balanced program of development between road traffic and environment.Based on the investigation of current pollution situation, production causes, frequency spectrum, distribution and propagation characteristics of road traffic noise, this dissertation analyze the theory of noise barriers. In view of the shortcomings of calculation methods in'design and measure standard of acoustic barrier, No. HJ/T 90-2004', and in connection with problems of application for the road noise barriers in our country, insertion loss of noise barriers for Discrete-linear sound sources has been researched in this dissertation, and build the calculation model, which can be applied to acoustic barriers designing under the Discrete-linear sound sources (200veh/h—800veh/h) condition by using of ?Ld correction curve. Researching on sound-absorption noise barriers, this dissertation introduces a calculate method about the noise decreasing by absorbing, and established a new method which can choose the good sound-absorption material. This method has more application value in engineering comparing with evaluation method in'The gradation of sound absorption property for absorbent products'(GB/T16731-1997). Analyze Doppler Effect and its influences on the effectiveness of reducing the road noise barriers,and put forward optimization measures about enlarging the shielding angle in the front-end and the effective height which was decreased gradually from the front-end to the back-end.This work provided some bases and references to optimize the designing of noise barriers, choosing sound-absorption material, and scientifically delimitating the front-end and the back-end installation position and optimizing shape of noise barriers.