Method for evaluating noise reduction effect of railway totally-enclosed sound barrier

Abstract

The invention discloses a method for evaluating the noise reduction effect of a railway totally-enclosed sound barrier, and belongs to the technical field of environmental protection. The method comprises the following steps: (1) determining reverberant sound in the totally-enclosed sound barrier; (2) determining a total sound field in the totally-enclosed sound barrier; and (3) calculating the noise of the full-closed sound barrier section. According to the method for evaluating the noise reduction effect of the railway totally-enclosed sound barrier, direct sound inside the totally-enclosed sound barrier when a train passes is calculated on the basis of directional characteristics of a high-speed pneumatic dipole and a wheel track noise approximate dipole, internal noise characteristics of the totally-enclosed sound barrier are obtained, finally on the basis of a sound insulation theory and a limited long sound source radiation model, a simplified calculation model of the noise reduction effect of the closed sound barrier is constructed, rapid calculation of the noise reduction effect of the closed sound barrier is achieved, and support is provided for optimization design, popularization and application of the closed sound barrier of the high-speed railway.

Description

technical field [0001] The invention relates to a noise reduction effect evaluation method of a fully enclosed railway sound barrier, which belongs to the technical field of environmental protection. Background technique [0002] Noise barrier is the most commonly used noise control measure in the railway industry. The most basic starting point of sound barrier control technology is to block the transmission path from the sound source to the sound receiver, so as to reduce the impact of railway noise. [0003] However, the vertical sound barriers used in large numbers only have a certain noise reduction effect on the sound shadow area. For areas with greater noise impact, urban rail transit has adopted a large number of fully enclosed sound barriers, semi-enclosed sound barriers, etc. to further reduce the noise of the noise. Barrier types, the railway industry is also gradually studying the feasibility of fully enclosed and semi-enclosed sound barriers. The semi-enclosed sou...

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Problems solved by technology

[0003] However, the vertical sound barriers used in large numbers only have a certain noise reduction effect on the sound shadow area. For areas with greater noise impact, urban rail transit has adopted a large number of fully enclosed sound barriers, semi-enclosed sound barriers, etc. to further reduce the noise of the noise. Barrier types, the railway industry is also gradually studying the feasibility of fully enclosed and semi-enclosed sound barriers. The semi-enclosed sound barrier was first applied on the Shanghai-Hangzhou Passenger Dedicated Line in my country, and the fully-enclosed sound barrier was used on the Shenmao Railway, passing through the Bird Paradise section. but run at a lower speed

[0004] There is diffraction attenuation at the top of the vertical sound barrier, and its noise reduction effect is based on the theory of sound diffraction, and there is a clear calculation method; however, the fully enclosed sound barrier blocks the sound transmission between the sound source and the sound receiving point, and traditional prediction cannot be used method to calculate

[0005] When a train passes through a fully enclosed sound barrier, the sound barrier is affected by direct sound and reverberation sound at the same time. The length of the sound barrier is generally much larger than its width and height. It has the characteristics of a long space and cannot form a diffuse sound field. The traditional Sabine formula is difficult Directly used for reverberation sound calculation

The calculation method of long spatial reverberation time based on the geometric reflection boundary has been widely used in the calculation of noise propagation and sound field in tunnels such as subways and highways. The propagation in the length direction of the sound barrier, and the fully enclosed sound barrier generally has a certain degree of sound absorption, and cannot be completely regarded as a geometric reflection boundary

It is difficult to accurately define the railway noise source and its directional characteristics by using the general-purpose acoustic calculation software on the market, and it is directly used in the calculation of the noise reduction effect of the fully enclosed railway sound barrier, which may cause large errors

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