Review article
DIFFICULTIES IN ACOUSTIC CALCULATIONS AND NOISE PROTECTION PROJECTS FOR ROAD TRAFFIC
Robert Vukić
Abstract
SUMMARY: Unlike the typical field measurements, the chief method for determining the level of noise and its propagation, as well as the protection measures for future planned roads is by simulation employing the acoustic calculation. A whole range of factors affects the precision of the acoustic calculation resulting in the unreliability of the results on which rest the two basic aspects of the noise protection projects realized for road traffic: the extent of the investment and the effectiveness of the protection for the population living near the road. There are also certain provisions in the valid regulations on noise protection that contribute to the imprecision in acoustic calculations. The paper indicates the imprecision of certain parameters in the development of the acoustic calculation of the noise in road traffic which affect the accuracy of the results. Acoustic calculation is a complex and demanding procedure conducted, as a rule, in a time squeeze, regularly after all other segments in the project have been completed and with a frequently encountered lack of the investor's understanding of the importance of noise protection and with the perception that such a calculation is an unnecessary impediment. Input parameters in the acoustic calculation are separately treated, and so are their effects on the results of the calculation. The acoustic calculation may be carried out ''manually'', with a set of calculation procedures or with the help of an integral computer program. The input parameters, such as the daily number of vehicles, the percentage of freight vehicles, road characteristics such as the slope, type of paving, etc., significantly affect the results of the acoustic calculation. The ground configuration and natural and artificial obstacles also greatly affect the propagation of noise. The paper shows the need for control measurements as a method of accounting for imprecision of parameters used in the acoustic calculation and in the noise protection project aimed at an efficient level of protection.
Keywords
road traffic; noise protection; acoustic calculation; input parameters; imprecision; results
Hrčak ID:
18171
URI
Publication date:
20.12.2007.
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