Facade effects on the traffic noise from the expressway

✍ Scribed by Chye H. Chew; Kah B. Lim

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 652 KB
• Volume: 41
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(94)90084-1

✦ Synopsis

A BS TRA CT

A prediction equation Jor the propagation of traffic noise has been derived semi-empirically. The accuracy attained with the prediction equation is within +2 dB(A) compared with measured field data. The common experience of having a higher Lio as one goes up a building is explained by the ground effect. Buildings on one side of the expressway increase the Lio by 2.5 dB(A) at 1 m jJ'om the Jacade, while buildings on both sides could increase the Lio by more than 10 dB(A). The presence of buildings on both sides of the expressway negates the reduction of traffic noise by the ground effect. The facade effect is significant only when one is near the buildings. At distances of more than 20 m from the buildings, the facade effect is negligible. The so-called cannon effect, where Lio increases with the height of the buildings for buildings on both sides of the expressway, is significant only when the buildings are close together, say less than 20 m apart. The cannon effect is due to the contribution of the diffuse energy component to L~o.