高速公路上盖对交通噪声传播的影响机制与效应评估OA

With the continuous expansion of urban expressways into high-density built-up areas,traffic noise has become a major concern affecting the urban acoustic environment and spatial quality.As a multifunctional form of urban infrastructure integrating transportation,greenery,and public space,the freeway lid has potential advantages in traffic noise control.However,the quantitative relationship between its structural scale and noise reduction performance remains insufficiently studied.Taking a residential area above an expressway in Guangzhou as a case for study,this paper combines on-site noise measurements with calibrated SoundPLAN acoustic simulations to comparatively examine the traffic noise propagation features under multiple scenarios,including the existing freeway lid,no-lid condition,at-grade roadway,and configurations with shortened and extended lids.The results indicate that the existing freeway lid can form a stable acoustic shadow zone outside the tunnel,achieving a maximum noise reduction exceeding 15 dB(A)at certain locations compared with open-road conditions.Shortening the lid by 20 m leads to a noticeable increase in regional noise levels,whereas extending the lid further enhances noise attenuation,with the most significant improvement observed within an extension length of approximately 50 m,beyond which the marginal noise reduction effect gradually diminishes.These findings provide quantitative evidence for optimizing the acoustic design of urban freeway lids.