草坪降低噪声规律的初步研究

Preli Minary Studies on the Regularity of Noise Reduction by Sod

对关中地区2种常见草坪（高羊茅和白三叶草）降低交通噪声进行了研究，结果表明，单-草种的草坪也有很好的降低交通噪声的效果；连续等效声级（￡叼值）随着穿越草坪距离的增加，降噪梯度增大，距声源4～8m，梯度开始增大，8～12m时，梯度达到最大值，随着距离的进一步增加，降噪梯度减小；高羊茅的总体降噪效果明显好于白三叶草，适于在城市交通高噪路段种植；同一测点，不同高度时，近地面处高频交通噪声减弱效果明显；同一频率，距地面0．3m时减噪幅度最大。

Two kinds of sod grass ,i. e. ,tall fescue and white clover,usually applied in Guanzhong area,were used to study the regularity of the traffic noise reduction. The results showed that sod with only one grass species could greatly reduce traffic noise. As the distance of the noise passing through the sod increased ,or the value of equivalent sound level Leq increased,the amplitude of sound reduction decreased. The amplitude of noise reduction began to decrease as the distance from noise soure was 4 to 8 m,and the amplitude reached its maximum at 8 to 12 m. The amplitude of noise reduction began to decrease beyond 12 m. The overall effect if noise reduction of tall fescue was 3 times better than white clover sod,indicating that it could plant in the urban area with high traffic noise. In the same measuring point,the reduction effect to the noise with high frequency was significant near by the surface. Within the same noise frequency,the amplitude of noise reduction reached is maximum 0.3 m above the ground.