The Research Of Noise Barrier Simulation And Optimization Design On The Expressway

With the rapidly development of expressway, the pollution of traffic noise has disturbedpeople’s life, work and study. As a kind of economic and effective noise reduction method,the noise barrier has become the main measures of noise reduction. The noise barrierparameters, includes the height, length and position of noise barrier which determines thenoise reduction effect and the cost of construction. The parameters of noise barrier wereoptimized in this paper, for the purpose not only improve the noise reduction effect, but alsoreduce the construction cost of noise barrier.The application of noise simulation software Cadna/A on the expressway wasresearched and discussed, the result showed that the predicted values and measured valueshad deviation, but the change rule was the same, so it can be considered that the Cadna/Aapplied to expressway.The noise reduction effect of upright type, T type and introversive noise barrier weresimulated by using Cadna/A, the result showed that T type noise barrier was suitable for thelocation that noise sensitive points are lower, and introversive was suitable for the locationthat the noise sensitive points are higher.In this research, one vertical type of noise barrier was chose as subjects. The realisticsimulation circumstance was constructed based on the distribution features of noise sensitivepoints near the Chang Xiang expressway. Then the prediction model of noise reductioneffects of noise barrier was built by Cadna/A software, utilizing this model, the parameters ofthis type of noise barrier were optimized, and the result of optimization design was used toguide the setting of the noise barrier. The research results revealed that this type of noisebarrier not only decrease the noise value of sensitive points to reach the environmentalstandards, but also minimize the construction price when the right side noise barrier was440meters in length and3.6meters in height, and the left side was400meters in length and4.4meters in height.Through measuring the noise level, all the sensitive spots can reach the standard aftersetting the noise barrier. But the predicted values and measured values had deviation at thesame time, and the measured values were lower than predicted values. The differences maybelie in factors such as software parameters, the background noise and the leak of noise barrier.