既有桥梁伸缩缝降噪方案研究

Research on Noise Reduction Schemes for Existing Bridge Expansion Joints

摘要:

桥梁伸缩缝噪声已经成为城市噪声污染的突出问题，需采取切实有效的措施降低噪声对周边居民的影响。基于重庆某既有桥梁伸缩缝降噪工程，阐述了伸缩缝噪声的产生是由于伸缩结构内的竖向振动激励和缝内空腔声模态激励的共同耦合作用，以及车辆跳车引起的结构振动。车型、车速、缝宽和错台高度均与噪声强度存在相关性。对增设声屏障、维修现有伸缩缝和更换无缝式伸缩缝3种方案的降噪原理和特点进行了分析，结合工程实际情况对方案进行了比选，最终确定采用聚氨酯无缝式伸缩缝作为降噪方案。

Abstract:

Noise from bridge expansion joints has become a prominent problem in urban noise pollution. It is necessary to take the effective measures to reduce the impact of such noise on surrounding residents. Based on the noise reduction project of the expansion joint of an existing bridge in Chongqing, it is expounded that the generation of noise from the expansion joint is due to the combined coupling effect of the vertical vibration excitation within the expansion structure and the cavity acoustic mode excitation within the joint, as well as the structural vibration caused by vehicle jumping. The vehicle type, vehicle speed, joint width and misalignment height are all correlated with the noise intensity. The noise reduction principles and characteristics of three schemes, namely adding sound barriers, repairing existing expansion joints and replacing seamless expansion joints, are analyzed. Combined with the practical engineering situation, the schemes are compared and selected. It is finally determined to adopt the seamless polyurethane expansion joints as the noise reduction solution.