摘要
为探明绿化带对公路交通噪声吸收消减的频谱特性,在西安市子午大道两处绿化带设置监测点,对交通噪声在不同倍频程中心频率下的衰减特征进行了测试研究。结果表明,在低频范围内,噪声能量的衰减量随倍频程中心频率增加呈逐渐上升趋势。在250 Hz中心频率处,绿化带A和B产生的A声级声衰减量可达17 dB和13.3dB。在中频段,由于植被支干的阻隔效应,交通噪声在4 kHz处出现最大衰减。在8-16 kHz的高频区域,两处绿化带所引起的噪声衰减量也均在10 dB以上,表明通过设置绿化带可有效控制公路交通噪声对两侧敏感点的影响。
Approximately 40% of European citizens are supposed to be exposed to the road traffic noise grades above 55 A-weighted decibels （dB（A） ） during the day. This ratio is regarded as a threshold of serious annoyance by the World Health Organization. On the other hand, the noise barriers are an effective way for reducing the noise exposure of human settlement if they were living by the roadside. Considering the noise pollution and its relation to the human health, the present paper made octave frequencies noise measurements on two different road traffic sites with the vegetation belts and control sites （without the vegetation belt） in Xi＇ an, Shaanxi, China. To make the noise measurements, AWA6228 sound level measuring meters with the facility of integration, spectrum analysis and data logging in real time conditions is adopted. The equipment is put on the tripod stands at a height of 1.2 m above the ground surface and placed on either side （front and rear） of the vegetation belts and managed to test and measure the traffic noise attenuation at different octave fre- quencies on Ziwu Street. The results of our study indicate that the at- tenuation of the traffic noise may increase gradually with the octave frequency falling. At 500 Hz of the road noise, the attenuations of the traffic noise account for 17 dB and 13.3 dB for the green belts A and B, respectively. This might be attributed to the interaction between the sound waves and the ground surface. The maximum attenuation that we can find characteristically may account for d. 0 kHz, which is probably as a result of geometrical scattering of the sound by the stems and branches of the trees and flowers. And, simultaneously, it can be found that comparatively high attenuation may occur at a high frequency range between 8 and 16 kHz. Since human ear is most sen- sible for the middle sound frequency range, the results we have gained in our study indicate that the greening belts could be used as effective barriers for the traffic noise attenuation and c
出处
《安全与环境学报》
CAS
CSCD
北大核心
2014年第5期211-213,共3页
Journal of Safety and Environment
基金
中央高校基本科研业务费创新团队项目(2013G3292017)
关键词
环境工程学
交通噪声
频谱特性
降噪
environmental engineering
traffic noise
frequency
attenuation
