| With the rapid development of urban road traffic in our country, the increasing of traffic noise problem, makes the traffic noise become the focus of environmental pollution. Cut off the spread of road traffic noise by sound barriers, improve the acoustic environment, reducing the noise of the road on both sides of the sound area is a very effective method in a lot of noise reduction measures. However, sound barriers in today, just consider the problem of transmission, refraction and diffraction without consider the relationship of traffic noise and sound barriers, while not research noise reduction effect of different structure and materials of noise barrier on different frequency noise, makes noise reduction ability of the noise barrier is greatly reduced. The structure research of urban traffic noise barriers based on acoustic frequency, can more effective enhance the effect of sound barriers, improve the utilization rate of limited resources, it is important for urban noise reduction.First, study on the related theory of urban road traffic noise and acoustic barrier, analysis the situation of frequency and noise in Harbin, data analysis showed that urban road traffic noise mainly concentrated in low and middle frequency band. According to the characteristics of traffic noise frequency, set model simulation by acoustic software LMS Virtual. Lab acoustics on the different top types of noise barrier. Through analysis the action of the vibration displacement amplitude and distribution of traffic noise on different top type sound barriers, the location and the size of sound waves on sound barriers when the different top type sound barriers subjected to medium and low frequency noise, to determine the set of absorption materials and sound absorbing structure on sound barriers, get a more effective noise reduction ability. Analysis the influence of sound barriers structure on noise reduction. According to the lack of sound barriers exist today, improve noise barrier structure, design impedance composite structure sound barriers, realize the goals to reduce acoustic reflection sound energy and damping noise barrier, reduction energy and exhumation of acoustic wave in noise barrier, reduce traffic noise induced and exposure on drivers. Reduce the possibility of a cause fatigue driving. The subject of research provide certain technical support for the urban road traffic noise barrier structure optimization and the management of traffic noise, to create conditions for creating a favorable city sound environment. |
