Analysis Of Urban Express Road Sound Field Characteristics And Noise Barrier Noise Reduction Effect

With the rapid development of society and economy,developed transportation brings convenience to people's lives.At the same time,it also brings serious noise pollution to the residents around the main line of traffic.As an effective and economical noise reduction method,the sound barrier has many advantages such as easy installation and transportation,easy repair and maintenance,long service life and compatibility with the local environment,and is widely used in highway noise reduction.This article starts with analyzing the principle of noise reduction in sound barriers,and expounds the acoustic characteristics of sound barriers.Field monitoring was conducted on the noise barriers of an expressway in Lanzhou,and a noise reduction above was established to calculate the actual insertion loss.Through the field test and analysis of the sound field distribution after the sound barrier is inserted,the noise field distribution characteristics of urban noise barriers are revealed,which provides a scientific basis for the convergence method and acoustic design of road sound barriers.The absorption coefficients in air are calculated and their variations with environmental factors are analyzed,which is based on molecular kinetics,vibrational relaxation processes,Navier-Stokes equations,Laplacian and the propagation theory of acoustic waves.The environmental factors include mainly air pressure,temperature and humidity.A detailed analysis of the environmental effects of air pressure on the absorption of sound is presented.On the other hand,we also measured sound intensity of car horns signal.And then we calculated the corresponding absorption coefficient.The results obtained are in good agreement with the theoretical value.A model was established to optimize the acoustical design of the existing sound barriers,and the finite element software was used to simulate the noise reduction features and optimization effects of the sound barrier.It provides a reference for the setting of noise barriers for road traffic noise control in Lanzhou City.